Biodiversity loss has been recognized as a threat to global stability for decades. The decline in overall diversity of species on our planet, either through extinction or a fall in abundance, can culminate in ecosystem collapse.

But in this excerpt from "Despite it All" (Granta, 2026), author and journalist Fred Pearce looks at the remarkable resilience of nature. If we can put aside our notions of what should and shouldn't be in a given environment and leave nature to adapt and thrive, we may begin to see the gains needed to support a healthy biosphere.

"Despite it All" has been shortlisted for the 2026 Royal Society Trivedi Science Book Prize.

If we are serious about rewilding, then we need to accept that it will take its own course.

Often invasive species are just the first stage of an ecological resurgence. They are the first movers, and their infestations are short-lived. In time, diversity usually returns — even if it's not always the same diversity as was there before. We should recognize that. We need to be as adaptable as nature itself, and jettison our more romantic notions about biodiversity and pristine environments.

So do many oldschool ecologists, says Chris Thomas, an ecologist at the University of York. They too often simply ignore any bits of nature that do not meet their expectations of what "should" be present. "The establishment of successful species in new locations is commonly interpreted as further evidence that the Earth's system is departing from a more desirable state," he told me.

So when biodiversity assessments are conducted, "alien" species lurking in the undergrowth are simply not counted. As outsiders, they are deemed not to belong to the ecosystem they inhabit. Thomas says that, in Britain, official records show biodiversity in decline, even though, if we add all losses and all gains together, "it is unequivocally true that the total number of species in Britain is increasing."

Most of the gains — the weeds, pests and alien species — are kept off the biodiversity books. This amounts to an ecological catch-22. Biodiversity can only ever decrease, as new species are seen as inimical to the local environment, and each year millions of pounds, dollars and euros are being spent to eliminate them.

Of course, it sometimes makes practical sense to eradicate invaders. I don't say we shouldn't try to keep out pests that cause short-term ecological mayhem and economic damage. But if we choose to get rid of new species, we can't then hold up our hands in horror at declining biodiversity. And besides, ecologically as much as socially, migrants can stir things up to good effect. They interact with other species — eating or being eaten, pollinating, and rotting after death to nurture new organisms.

We should embrace novel ecosystems that contain both what we regard as native species and the feral, opportunistic interlopers that find their new environment congenial. In his book about weeds, British naturalist Richard Mabey celebrated what he called these "outlaw plants" and showed how they have had a hand in shaping not only our landscape but our civilization, becoming crops, medicines and sources of beauty and creative inspiration.

It is easy to be nostalgic about past ecosystems as a golden age. But what we imagine to be the perfect ecological state — a supposedly natural order of things that often gets called "the balance of nature" — was mostly itself a passing phase. Nature is always moving on. And more often than we realize, humans have had a hand in what we now like to regard as natural.

Environmental scientist Erle Ellis, who runs the Anthroecology Lab of the University of Maryland, argues persuasively that most of the planet has been heavily influenced by human activity for thousands of years, including places such as the Amazon that we often think of as untouched. We have, in effect, long lived on a "used planet," and humans and nature have not historically been at odds. The most biodiverse places are often those where people have lived the longest. By constantly tending the land, past civilizations created ever-changing mosaics of habitats where more species thrived than in places with less human interference.

So, we should be careful not to let our reverence for the pristine blind us to the environmental potential of today's wastelands, backwoods, abandoned fields, scrublands and no-go areas. In a Good Anthropocene we are likely to need more of them.

There is a final reason for believing that nature is equipped for recovery from almost anything we can throw at it. The apparent chaos of the Anthropocene is turbocharging evolution itself. Every perturbation of our environment creates an opportunity for existing species to adapt or for new ones to evolve, says Chris Thomas.

I first met Thomas in 2004, when he had just published an influential paper warning that climate change could wipe out a quarter of the world's species this century. He called it "terrifying." It was headline news. Two decades later, he has not changed that forecast, but he has added an important rider. Despite the coming extinction holocaust, he told me, "the Anthropocene could raise biological diversity."

His research is showing that evolution in the twenty-first century is speeding up to fill the gaps left by the extinctions — delivering new and better-adapted species. "The seeds of recovery are already visible," he told me. "Genes are jumping around. New species are beginning to emerge." Rob Dunn, an ecologist at North Carolina State University, agrees. In his book "A Natural History of the Future," he says that this evolutionary spurt is happening fastest in urban landscapes, where species are adapting to city life with almost as much alacrity as newly arrived humans.

This urban ecological renaissance resembles the story of the finches on the Galápagos archipelago, which Charles Darwin observed to have evolved different beaks to match the food on the different islands. In modern cities, house mice have evolved to produce saliva with a chemical make-up better able to digest the carbohydrates available in urban food; cockroaches and bedbugs have developed resistance to pesticides and even learned to avoid sugar-impregnated bait; London's pigeons have learned to commute on the Underground. We have clothes moths and carpet beetles.

Such natural innovations may not always be cuddly, but they do show that nature is on the prowl in the Anthropocene. So where is biodiversity headed? It is undeniable that most species of plants and animals are currently in numerical decline in a human-centric world.

This global disturbance is favouring some generalists — so-called superspecies — that can occupy a wide range of habitats, displacing local, rare and specialist species. Locally, however, biodiversity has sometimes increased substantially, especially in the rich kaleidoscopes of gardens, parks, toxic brownfield sites, roadside verges and so on that humanity has helped create.

Such places may become crucibles for a biodiversity rebound. Understanding this reality should change how we do conservation. We should not abandon nature to its fate. Some of our favourite species will pass into history unless we act to save them, and I'd vote for action any day. But it does mean embracing rather than rejecting the processes of change. Change in the Anthropocene is good. We should be grateful that nature is finding a way.

This is an extract from Despite it All by Fred Pearce, published by Granta.

The Socotra Archipelago is a cluster of four islands and two rocky islets belonging to Yemen. It is nicknamed the "Galápagos of the Indian Ocean" due to its staggering biodiversity, which includes hundreds of species that aren't found anywhere else in the world.

Located about 250 miles (400 kilometers) south of the Arabian Peninsula and 140 miles (220 km) east of the Horn of Africa, the Socotra Archipelago is home to around 60,000 people. As of 2023, visitors could reach it only via a weekly flight from Abu Dhabi, United Arab Emirates, that had to be booked through WhatsApp and was often canceled without reason.

The archipelago has one main island, Socotra, which makes up 95% of the landmass, along with three smaller islands and two islets. The main island hosts snow-white sand dunes, a central mountain range, and limestone plateaus peppered with drought-resistant cucumber trees (Dendrosicyos socotranus) and umbrella-shaped dragon's blood trees (Dracaena cinnabari) that do not exist elsewhere on Earth. The dragon's blood tree gets its name from its crimson resin, which is used for natural medicine and as a pigment.

Socotra was recognized as a UNESCO World Heritage Site in 2008, thanks to its unique plants and animals, which have evolved in isolation for at least 15 million years. Socotra is a leftover fragment from when Arabia and Africa pulled apart around 30 million years ago. The split opened the Red Sea and the Gulf of Aden, which connects the Red Sea and the Arabian Sea.

More than one-third of Socotra's plants, 90% of its reptiles and 95% of its land snail species are found exclusively in the archipelago, according to UNESCO. The marine life in Socotra is also incredibly diverse; it includes sea turtles, whale sharks (Rhincodon typus) and more than 250 species of reef-building corals.

The archipelago is tricky to get to, and pirates sometimes hijack vessels in the surrounding seas. Due to Yemen's ongoing civil war, many governments, including the U.S., advise against all travel to the country, including Socotra, citing threats of terrorism, unrest, crime, health risks, kidnapping and landmines.

Discover more incredible places, where we highlight the fantastic history and science behind some of the most dramatic landscapes on Earth.

Two marsupial species that were thought to have gone extinct at least 6,000 years ago have been found on the island of New Guinea.

The discovery was far from swift, with the first clues of the marsupials emerging in 1999 and requiring ample photographic evidence to confirm. But 27 years later, scientists are now sure that the ring-tailed glider (Tous ayamaruensis) and the pygmy long-fingered possum (Dactylonax kambuayai) are alive in the remote rainforests of the Vogelkop Peninsula in Papuan Indonesia.

"The Vogelkop is an ancient piece of the Australian continent that has become incorporated into the island of New Guinea," Tim Flannery, a professor at the Melbourne Sustainable Society Institute and a distinguished visiting fellow at the Australian Museum who led the research, said in a statement. "Its forests may shelter yet more hidden relics of a past Australia."

Marsupials are mammals with a characteristic pouch to hold newborns until they are fully developed. The pygmy long-fingered possum and the ring-tailed glider were previously known to scientists only from fossils in Australia dating to the last ice age and the first phase of the early Holocene epoch, which is the current period of geological time.

The pygmy long-fingered possum is a striped marsupial with one digit on each hand that is twice as long as the next-longest finger. The ring-tailed glider is a relative of Australia's three greater glider (Petauroides) species, which are named after their ability to soar through forest canopies using furry membranes that extend from their elbows to their ankles. The ring-tailed glider is smaller than its Australian cousins and has unfurred ears, as well as a tail adapted for grasping and wrapping around objects such as branches.

The pygmy long-fingered possum and the ring-tailed glider are what researchers call "Lazarus taxa," meaning they are animals that vanish from the fossil record and seem to go extinct for an extended period before reemerging as living species. Their recent discovery was possible thanks to Indigenous communities in Papuan Indonesia that helped Flannery and his colleagues track down the animals. Specifically, the researchers collaborated with local elders from the Tambrauw and Maybrat clans.

"The discovery of one Lazarus taxon, even if thought to have become extinct recently, is an exceptional discovery," Flannery said. "But the discovery of two species, thought to have been extinct for thousands of years, is remarkable."

Some local Indigenous groups consider the ring-tailed glider to be sacred and deserving of the highest protection, which might help explain why the species has remained hidden, New Scientist reported.

Ring-tailed gliders form lifelong pair bonds and raise only one young per year. Like greater gliders, they nest in tree hollows, which makes them extremely vulnerable to logging.

The pygmy long-fingered possum also faces threats from logging. Its ears may be adapted to detect low-frequency sounds, including noise from wood-boring beetle larvae, which the possums dig out from rotting wood with their fingers to eat, Flannery told New Scientist.

Much remains unknown about the specific range and ecological needs of each species. The exact locations where they were found is being kept secret to prevent wildlife traders from targeting them. What is known so far about the marsupials was published March 6 in two peer-reviewed studies in the journal Records of the Australian Museum.

"The findings underscore the critical importance of preserving these unique bioregions and the value of collaborative research in uncovering and protecting hidden biodiversity," Flannery said in the statement.

Bird populations are in free fall across North America. And in some hotspots their decline is accelerating, a new study reveals.

Wild bird numbers declined at an accelerating rate in California, the Midwest and the Mid-Atlantic between 1987 and 2021. Across these hotspots, losses were associated with high-intensity agriculture, according to the study.

Although the study, published Feb. 26 in the journal Science, shows a correlation between declining bird populations and intense agriculture, it doesn't definitively prove that agriculture is driving the increased decline or identify which agricultural activities might be responsible.

However, signs of intense agricultural activity consistently proved to be the best predictor of increased bird decline, which mirrors similar research conducted in Europe. The researchers also found that declines were stronger in warming areas, suggesting that rising temperatures due to climate change were driving some bird disappearances.

Birds perform important roles in the ecosystem, including spreading plant seeds and keeping insect populations under control. For decades, scientists have been concerned that bird populations are falling due to human activities, both in North America and globally — a plight shared by many other animals. What's special about the new research is that it reveals how the decline in North America has accelerated since the late 1980s.

"We are not talking about the decline but the acceleration of the decline," study lead author François Leroy, a postdoctoral researcher in macroecology at The Ohio State University, told Live Science. "We see that this decline is getting faster and faster with the intensification of human activities."

Leroy and his colleagues mapped bird decline by studying data from the North American Breeding Bird Survey, which is an annual surveying effort by professional biologists and skilled amateurs to monitor bird populations across North America. As a part of the survey, participants walk along specific routes and record the birds they find.

The researchers focused on specific routes with enough data to measure the rate of decline over 35 years. These routes were primarily in the U.S. and included 261 bird species. Across all of the species surveyed, the overall abundance of birds fell by at least 15%, with significant drops documented in about half (122) of the species and accelerating declines reported in about a quarter (63) of the species. Common birds ‪—‬ like red-winged blackbirds (Agelaius phoeniceus), house finches (Haemorhous mexicanus) and American crows (Corvus brachyrhynchos) ‪—‬ were among the native species found to have suffered an accelerated decline.

The study focused on the rate of decline in specific routes, so it's unclear how many individual birds were lost across the entire continent during the study period. However, previous research has found that billions of birds have disappeared in recent decades.

A 2019 study published in the journal Science estimated that the North American bird population decreased by 2.9 billion individual birds between 1970 and 2017. That estimate equated to a drop of 29%, which is almost double the 15% decline documented in the new study. However, the 2019 study also covered an earlier and longer time period when there may have been more severe losses.

People only started surveying North American birds in the second half of the 20th century, but we've been killing them directly and indirectly for much longer than that. For example, commercial hunting by humans forced passenger pigeons (Ectopistes migratorius), a species estimated to have once had a population of 3 billion to 5 billion, to extinction in 1914.

What caused the "birdemic"?

The new study demonstrated that birds were incurring losses not just at the species level but across whole families of species and across different habitats. To better understand the worrying trend, the researchers compared the bird data to potential contributing factors, such as temperature change, rainfall and land-cover changes.

The acceleration of bird decline coincided with large areas of croplands and high usage of fertilizers and pesticides, which are signs of intense agriculture. This tracks with research in Europe that has found that agricultural intensification has negatively impacted bird diversity.

Intense agriculture can destroy, change and break up traditional bird habitat. The amount of land used for farming in the U.S. hasn't changed that much since the 1980s. Agriculture has become more consolidated in that time, with a decline in midsize farms and a shift to larger farming operations, but there's slightly less land being used for farming overall. Thus, the bird losses can't be blamed solely on the amount of farmland. However, they could be the result of changes in farming practices.

Leroy said that from the new study, it's not really possible to say which specific practice in agriculture is the worst for bird losses. However, he noted that from previously published studies, it seems like pesticide use is one of the main suspects.

A 2023 study published in the journal PNAS found that the use of pesticides and fertilizers was the key to agricultural intensification being the main pressure behind most bird population drops, particularly in birds that feed on invertebrates. Most disappearing bird species depend on insects for food, and insects are in steep decline as they are killed through the use of pesticides. Birds also consume pesticides directly.

Leroy said he would like to see what farmers think about the correlation between agricultural intensification and bird losses. He and his co-authors also noted in the study that agriculture warms landscapes by reducing the amount of vegetation and altering its properties, which may then amplify warming impacts on birds.

While the findings were mostly bad news for birds, there were some bright spots. For example, the researchers found some local increases in forest bird populations, which likely benefited from the reforesting of old farmland. There was also a small pocket of land just north of the U.S.-Canada border where the overall abundance of birds increased — the only region in which this occurred. However, Leroy said he had "no clue" why this was the case.

"It doesn't mean that Canada is doing better because if you look at other regions in Canada, there were also some significant declines," he added.

China's Yangtze River is showing signs of recovery following the introduction of a 10-year ban on commercial fishing in 2021. The number of large fish has increased, and there has been recovery among endangered animals, including the Yangtze sturgeon (Sinosturia dabryanus) and the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis), new research finds.

"These results show that strong political decisions are required to restore biodiversity," Sébastien Brosse, an ecologist at the University of Toulouse in France and co-author of the new study, told Live Science via email. "This is an encouraging message because biodiversity loss is often seen as irreversible." The Yangtze is the longest and largest river in China. About 30% of the country's population lives within its drainage basin, and the 11 provinces and municipalities that make up the Yangtze River Economic Belt generate about 47% of China's total gross domestic product.

But rapid urban development since the 1950s, dam building, decades of overfishing, pollution and habitat degradation had all led to a decline in water quality and a biodiversity crisis. The Yangtze River dolphin (Lipotes vexillifer) and the Chinese paddlefish (Psephurus gladius) went extinct, and 135 fish species found in historical surveys disappeared.

This decline continued despite the establishment of a network of protected areas and an investment of more than $300 billion in water-quality management and improvement. In response, China took drastic measures: The country instituted a 10-year fishing ban across the entire Yangtze basin in 2021, used river police to enforce strict penalties, and continued broad environmental management.

To assess the effects of the fishing ban, Yushun Chen, a hydrobiologist at the Chinese Academy of Sciences in Wuhan, China, and his colleagues used data from between 2018 and 2023 to evaluate the health of fish communities in the Yangtze before and after the ban went into effect.

They found that overall, the total mass of fish collected in samples more than doubled between those dates, and there was a 13% boost in the number of species in the samples.

The overall number of fish stayed about the same, but larger-bodied species that are higher up in the food web, including the economically valuable black Amur bream (Megalobrama terminalis) and the white Amur bream (Parabramis pekinensis), grew, and they contributed a larger amount of the biomass. However, the total mass of smaller species sampled decreased by 18%.

The team's findings, published on Thursday (Feb. 12) in the journal Science, also included positive signs for migratory and endangered species. For example, populations of slender tongue sole (Cynoglossus gracilis) increased after the ban, and its freshwater migration extended farther upstream. Endangered fish species — such as the Yangtze sturgeon, Chinese sucker (Myxocyprinus asiaticus) and tube fish (Ochetobius elongatus) — also showed signs of recovery.

Another notable positive was the boost in numbers of the only freshwater mammal remaining in the Yangtze River, the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis), whose population rose by a third from 445 in 2017 to 595 in 2022. This gain may have resulted from a greater availability of bigger fish to eat; fewer deaths related to vessel strikes or fishing bycatch; and a reduction in other stressors, such as underwater noise from vessel propellers, the researchers suggested.

"In an era of unprecedented biodiversity losses and declines, especially in freshwater systems, this study offers a glimpse of hope regarding the future of biodiversity," said Lise Comte, a conservation ecologist at California-based Conservation Science Partners who wasn't involved in the research.

"It demonstrates that bold protection and restoration strategies can be efficient in slowing down and even reverting human impacts on ecological communities," she told Live Science via email.

Chen and his colleagues are still monitoring Yangtze River biodiversity, and they said the recovery is continuing. But they warned that the progress could easily be reversed if commercial fishing were to restart and that lasting biodiversity recovery will depend on sustained management that addresses all human pressures on river systems.

They also suggested that similar conservation measures might be useful on rivers such as the Mekong and the Amazon.

However, the Yangtze fishing ban had huge human and financial costs, as it involved the recall of 111,000 fishing boats, the resettlement of 231,000 fishers, and an investment of more than $2.74 billion in the Yangtze River Economic Belt.

"The promising findings demonstrate the resilience of these systems but are also a case study of an approach that I hope we don't have to emulate elsewhere," co-author Steven Cooke, a professor of biology at Carleton University in Ottawa, Canada, told Live Science via email. "Closing all fisheries in a river basin has significant socio-economic consequences. Fishers, and those in related industries, often move on, forever changing those communities. Managing fisheries in ways that do not require such a 'nuclear' option is always preferred."

A better approach would involve the ongoing assessment of fish populations; science-based fisheries management; and the study of watersheds as integrated systems that connect people, water and fish, he added.

The Coral Triangle is a tropical marine region between the Pacific and Indian oceans where 76% of Earth's coral species are found. It encompasses 2.3 million square miles (6 million square kilometers) of ocean around the Philippines, Indonesia and Papua New Guinea, and stretches south to Timor-Leste and as far east as the Solomon Islands.

Biodiversity in the Coral Triangle is much higher than in other regions with coral reefs, such as the Caribbean Sea and the southwest Pacific Ocean. Around 605 reef-building coral species inhabit the Coral Triangle — 10 times the number in the Caribbean Sea, according to an article from the U.K.'s Natural History Museum (NHM).

These corals provide a home for six of the world's seven sea turtle species and 37% of the world's coral reef fish species, as well as marine mammals like dolphins, dugongs, blue whales and sperm whales, according to the NHM article. This incredible array of species has earned the Coral Triangle the nickname the "Amazon of the sea."

"This part of the world contains the highest diversity of marine species," Nadia Santodomingo, a coral expert and marine biologist at the NHM, said in the article. "Scientists have been trying to understand why it's so diverse for a very long time." In fact, British naturalist and explorer Alfred Russel Wallace was working there when Charles Darwin was alive, trying to solve the same problem, she added.

Wallace traveled through the Malay Archipelago between mainland Southeast Asia and Australia, collecting specimens and developing theories regarding the region's staggering biodiversity. He came up with what scientists call the "Wallace Line" — a gigantic biological boundary that separates the Oriental and Australian faunal regions — and proposed the theory of evolution by natural selection around the same time as Darwin.

Scientists today have more tools at their disposal to understand the region, with evidence suggesting that murkier conditions in the Coral Triangle compared with other shallow tropical waters may provide a haven for different species. The Coral Triangle has been a biodiversity hotspot for at least the past 20 million years, and this is partly thanks to a huge variety of habitat types and optimal conditions for larvae that ride on ocean currents, according to the nongovernmental organization Blue Corner Marine Research.

Research also suggests that the Coral Triangle has a plethora of species simply because diversity built up over time. Unlike temperate and polar marine regions that have undergone glaciations, tropical regions like the Coral Triangle have remained relatively stable. And what sets this region apart from other tropical seas is its unique, platform-like geology and location at the intersection between two oceans, researchers say.

Like other coral reef regions, the Coral Triangle is vulnerable to overfishing, pollution from coastal development, and ocean acidification linked to climate change — although scientists think its murky conditions may shield it somewhat.

"Corals living under continuous sediment stress seem to be more resilient, as the mud may block light, which in turn alleviates bleaching stress induced by high temperatures," Kenneth Johnson, a paleobiologist and principal researcher at the NHM, said in the article.

Nevertheless, it's important to protect this patch of ocean, Johnson said. "Nobody really thinks about these reefs," he said, "but they might be the ones we really want to protect."

Discover more incredible places, where we highlight the fantastic history and science behind some of the most dramatic landscapes on Earth.

A deep-sea expedition off the coast of Argentina has captured stunning footage of more than 40 never-before-seen species.

One unexpected star of the show is a plump sea creature that has been dubbed the "big-butt starfish" for its uncanny resemblance to Patrick Star from "SpongeBob SquarePants."

During the remotely operated vehicle (ROV) SuBastian's dives in Argentina's Mar del Plata submarine canyon, which have been running since July 23, scientists aboard its accompanying research vessel provide a high-definition livestream, with real-time commentary on rarely seen deep-sea life. The dives have revealed carnivorous sponges, translucent fish, vividly colored rays and corals that have never been documented in the South Atlantic, a biodiversity hotspot that remains largely unexplored.

The sea star, which has become a viral hit on social media, belongs to the genus Hippasteria, which is known for its thick central disc and short, stubby arms. During the livestream, viewers interacting via chat affectionately nicknamed it "estrella culona" — Spanish for "big-butt star."

Argentine scientists involved with the expedition have offered a few hypotheses for the creature's attention-grabbing anatomy. The starfish may simply be well fed; they are voracious carnivores. Or, its rounded appearance could be the result of gravity, as it was filmed on a vertical surface with its central disc hanging downward, creating the illusion of glutes.

Starfish don't have rear ends like humans or other bilaterally symmetrical animals do. Instead, they exhibit radial symmetry, with a mouth located on the underside of the central disc. That lower, or "oral," surface lies pressed against the seafloor, where feeding occurs. The anus is located in the center of the upper, or "aboral," surface, which is what a diver would see first when approaching the animal.

Related: 'A disembodied head walking about the sea floor on its lips': Scientists finally work out what a starfish is

"Although starfish do have a complete digestive system and an anus, it's not in the location people are pointing to on social media," Mariela Romanelli, a biologist and curator of the invertebrate collection at Argentina's National Museum of Natural Sciences, told local news site Infobae in Spanish. "Still, the resemblance to Patrick Star's butt is pretty hilarious."

The big-butt starfish isn't the only creature from the expedition, led by scientists from the National Scientific and Technical Research Council and the Schmidt Ocean Institute, that has charmed the public. Another deep-sea creature captured on camera was a violet sea cucumber, belonging to the genus Benthodytes, whose plump body and purple hue earned it its name "Batatita"" ("Little Sweet Potato"). The specimen was collected by the ROV and is alive and well at the surface, expedition scientists said.

So far, the expedition has documented at least 25 species of fish, both bony and cartilaginous; carnivorous sponges that have never been recorded in the South Atlantic; and crustaceans and other invertebrates that are specially adapted to the pitch-black depths.

The livestream, broadcast for the first time from nearly 13,100 feet (4,000 meters) below sea level, continues through Aug. 10 and can be viewed on the Schmidt Ocean Institute's official YouTube channel.

About 66 million years ago — perhaps on a downright unlucky day in May — an asteroid smashed into our planet.

The fallout was immediate and severe. Evidence shows that about 70% of species went extinct in a geological instant, and not just those famous dinosaurs that once stalked the land. Masters of the Mesozoic oceans were also wiped out, from mosasaurs — a group of aquatic reptiles topping the food chain — to exquisitely shelled squid relatives known as ammonites.

Even groups that weathered the catastrophe, such as mammals, fishes and flowering plants, suffered severe population declines and species loss. Invertebrate life in the oceans didn't fare much better.

But bubbling away on the seafloor was a stolid group of animals that has left a fantastic fossil record and continues to thrive today: bivalves — clams, cockles, mussels, oysters and more.

What happened to these creatures during the extinction event and how they rebounded tells an important story, both about the past and the future of biodiversity.

Surprising discoveries on the seafloor

Marine bivalves lost around three-quarters of their species during this mass extinction, which marked the end of the Cretaceous Period. My colleagues and I — each of us paleobiologists studying biodiversity — expected that losing so many species would have severely cut down the variety of roles that bivalves play within their environments, what we call their "modes of life."

But, as we explain in a study published in the journal Sciences Advances, that wasn't the case. In assessing the fossils of thousands of bivalve species, we found that at least one species from nearly all their modes of life, no matter how rare or specialized, squeaked through the extinction event.

Statistically, that shouldn't have happened. Kill 70% of bivalve species, even at random, and some modes of life should disappear.

Related: The 5 mass extinction events that shaped the history of Earth — and the 6th that's happening now

Most bivalves happily burrow into the sand and mud, feeding on phytoplankton they strain from the water. But others have adopted chemosymbionts and photosymbionts — bacteria and algae that produce nutrients for the bivalves from chemicals or sunlight in exchange for housing. A few have even become carnivorous. Some groups, including the oysters, can lay down a tough cement that hardens underwater, and mussels hold onto rocks by spinning silken threads.

We thought surely these more specialized modes of life would have been snuffed out by the effects of the asteroid's impact, including dust and debris likely blocking sunlight and disrupting a huge part of the bivalves' food chain: photosynthetic algae and bacteria. Instead, most persisted, although biodiversity was forever scrambled as a new ecological landscape emerged. Species that were once dominant struggled, while evolutionary newcomers rose in their place.

The reasons some species survived and others didn't leave many questions to explore. Those that filtered phytoplankton from the water column suffered some of the highest species losses, but so did species that fed on organic scraps and didn't rely as much on the Sun's energy. Narrow geographic distributions and different metabolisms may have contributed to these extinction patterns.

Biodiversity bounces back

Life rebounded from each of the Big Five mass extinctions throughout Earth's history, eventually punching through past diversity highs. The rich fossil record and spectacular ecological diversity of bivalves gives us a terrific opportunity to study these rebounds to understand how ecosystems and global biodiversity rebuild in the wake of extinctions.

The extinction caused by the asteroid strike knocked down some thriving modes of life and opened the door for others to dominate the new landscape.

While many people lament the loss of the dinosaurs, we malacologists miss the rudists.

These bizarrely shaped bivalves resembled giant ice cream cones, sometimes reaching more than 3 feet (1 meter) in size, and they dominated the shallow, tropical Mesozoic seas as massive aggregations of contorted individuals, similar to today's coral reefs. At least a few harbored photosymbiotic algae, which provided them with nutrients and spurred their growth, much like modern corals.

Today, giant clams (Tridacna) and their relatives fill parts of these unique photosymbiotic lifestyles once occupied by the rudists, but they lack the rudists' astonishing species diversity.

Mass extinctions clearly upend the status quo. Now, our ocean floors are dominated by clams burrowed into sand and mud, the quahogs, cockles and their relatives — a scene far different from that of the seafloor 66 million years ago.

New winners in a scrambled ecosystem

Ecological traits alone didn't fully predict extinction patterns, nor do they entirely explain the rebound. We also see that simply surviving a mass extinction didn't necessarily provide a leg up as species diversified within their old and sometimes new modes of life — and few of those new modes dominate the ecological landscape today.

Like the rudists, trigoniid bivalves had lots of different species prior to the extinction event. These highly ornamented clams built parts of their shells with a super strong biomaterial called nacre — think iridescent pearls — and had fractally interlocking hinges holding their two valves together.

But despite surviving the extinction, which should have placed them in a prime position to accumulate species again, their diversification sputtered. Other types of bivalves that made a living in the same way proliferated instead, relegating this once mighty and global group to a handful of species now found only off the coast of Australia.

Lessons for today's oceans

These unexpected patterns of extinction and survival may offer lessons for the future.

The fossil record shows us that biodiversity has definite breaking points, usually during a perfect storm of climatic and environmental upheaval. It's not just that species are lost, but the ecological landscape is overturned.

Many scientists believe the current biodiversity crisis may cascade into a sixth mass extinction, this one driven by human activities that are changing ecosystems and the global climate. Corals, whose reefs are home to nearly a quarter of known marine species, have faced mass bleaching events as warming ocean water puts their future at risk. Acidification as the oceans absorb more carbon dioxide can also weaken the shells of organisms crucial to the ocean food web.

Findings like ours suggest that, in the future, the rebound from extinction events will likely result in very different mixes of species and their modes of life in the oceans. And the result may not align with human needs if species providing the bulk of ecosystem services are driven genetically or functionally extinct.

The global oceans and their inhabitants are complex, and, as our team's latest research shows, it is difficult to predict the trajectory of biodiversity as it rebounds — even when extinction pressures are reduced.

Billions of people depend on the ocean for food. As the history recorded by the world's bivalves shows, the upending of the pecking order — the number of species in each mode of life — won't necessarily settle into an arrangement that can feed as many people the next time around.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

More than half of all known animal species on Earth are insects — critters with a hard external skeleton, three pairs of jointed legs, antennae and a body divided into three segments (the head, thorax and abdomen). There are about 1.4 billion insects for every human on the planet, and their combined weight is 70 times that of all people. Insects are found on every continent and in almost every habitat type, including hot deserts, salty coastal waters and frigid mountain streams. While 97% of insects live on land, some thrive in fresh water and seawater.

5 fast facts about insects

• More than 1 million insect species have been described so far, but scientists estimate there could be up to 30 million we haven't discovered yet.
• Insects are the only invertebrates (creatures without a backbone) to have wings. Most insects have two pairs of wings, but some — including fleas, ants and lice — have no wings.
• Parasites can transform insects into real-life zombies. Infected insects do what the parasite wants, which can be to go up to a predator to be eaten or jump into a pool of water where the insect will drown.
• Many insects are cannibals. For example, female praying mantises may attack and eat males during or after they mate.
• Bees and moths pollinate plants, which helps give us food. But harmful pesticides are leading to large declines in these insects' numbers.

Everything you need to know about insects

Insect pictures

Discover more about insects

• These insects keep evolving to look like sticks. Why?
• How do insects know which flowers have pollen?
• Why are insects attracted to artificial lights?

Further reading

• "Rise of the Zombie Bugs: The Surprising Science of Parasitic Mind-Control"
• "The Jewel Box: How Moths Illuminate Nature's Hidden Rules"
• Discover fun facts about insects at the Smithsonian Institution and learn more from the Australian Museum about how scientists categorize insects.

Cerro El Cono is a 1,310-foot-tall (400 meters), pyramid-like formation in the Amazon rainforest. It rises steeply from the relatively flat jungle landscape of eastern Peru, making it visible from as far west as the Andes — 250 miles (400 kilometers) away — on a clear day.

The formation, whose name translates to "cone hill," is located in a mountainous region on the border between Peru and Brazil known as the Sierra del Divisor. The mountains are visible in the background of most photographs of Cerro El Cono, but the formation is isolated from the other peaks and has an unusual pyramidal shape, making it stand out from the rest of the mountain range.

The origins of the strange peak have remained mysterious due to its remote location. While some sources suggest that the cone could be an extinct volcano, others say it might simply be an unusual rock formation.

Related: Mount Roraima: The 'lost world' isolated for millions of years that Indigenous people call the 'house of the gods'

Indigenous people have another explanation for the bizarre mountain: According to the Peruvian newspaper La República, Cerro El Cono is a spiritual entity for local tribes and groups, some of which revere the peak as an "Andean Apu" — a sacred mountain god or spirit. In the mythologies of Peru, Bolivia and Ecuador, Apus emerged from Earth to guide and protect the people living close by.

A fourth explanation — one for which there is no evidence — is that Cerro El Cono sits on the ruins of a pyramid built by ancient Indigenous tribes, according to La República.

Cerro El Cono stands adjacent to the Ucayali River, which is a major tributary of the Amazon River. The surrounding jungle is a biodiversity hotspot and home to several vulnerable species, including giant armadillos (Priodontes maximus), jaguars (Panthera onca) and various types of monkeys, according to The Guardian. The peak itself is forested and forms part of a large area that has been considered a biodiversity conservation priority since the 1990s.

Concern that this ecosystem may become degraded by infrastructure, illegal logging and gold mining prompted the creation of the Sierra del Divisor National Park in 2015. But recent surveys indicate that the protected park, which is 1.5 times the size of Yellowstone National Park, has not removed threats from illegal deforestation and wildlife poaching.

Discover more incredible places, where we highlight the fantastic history and science behind some of the most dramatic landscapes on Earth.

Parasite, zombie, leech — these words are often used to describe people in unkind ways. Many of us recoil when ticks, tapeworms, fleas, head lice or bed bugs are even mentioned. Coming across such unwelcome guests — in our hair, on our skin or in our beds — can be a real nightmare.

Some parasites cause horrific deformities and diseases, maiming and killing millions of people and wildlife. Others may help boost immunity or provide the basis of food chains.

Parasites are often demonised and misunderstood. But the more we study these oddities and wonders of evolution, the more we appreciate their vital roles in ecosystems and our complex relationships with them. They're essential to life on Earth.

As an ecologist with a focus on wildlife and conservation, I wrote this article to share some of my fascination for parasites and the importance of their extraordinary lives.

Related: 32 scary parasitic diseases

What is a parasite?

Parasites rely on living organisms for food, to grow and to reproduce.

They can either live on the outside (ectoparasites) or inside (endoparasites) of their hosts. Far from being invited dinner guests, parasites typically turn up of their own accord and feed at the host's expense, consuming part or all of them.

Parasites can live within their host (or hosts) for short or extended periods — in some cases many years — going largely unnoticed. For instance, one man lived with a tapeworm in his brain for more than four years until the headaches and strange smells become too much to bear. In other cases, parasites can kill their host.

Perhaps the most gruesome type of parasite, parasitoids, kill their hosts in order to reproduce. The disturbing chest-bursting scene from the 1979 movie Alien is a truly visceral sci-fi example of a parasitoid.

In real life, examples include spider wasps that first immobilise their spider prey, lay an egg on them, and bury them. Then when the egg hatches, the wasp larvae devour the incapacitated spider. That is, of course, if another animal such as a "bin chicken (Sacred Ibis)" or insect doesn't intervene.

Parasites are typically much smaller than their hosts. Many are furnished with equipment for latching on and remaining attached, including hooks, suckers and "teeth".

Endoparasites such as tapeworms are often flat, allowing them to live within the tight spaces inside other organisms. The flatworm Diplozoon paradoxum that lives in gills of some fish must conjoin with another to reach adulthood and reproduce. Once fused, they form a permanent, lifelong bond and mate with each other over many years.

As much as 40% of all animal species may be parasites, and this mode of life might have evolved more than 200 times in the animal kingdom. But parasitism is not solely confined to animals. Many plants, fungi, protists, bacteria and viruses are parasites too.

Parasite powers

The leech scene in the iconic 1986 movie Stand By Me comes back to me every time I walk through a damp forest. The idea of providing a blood meal for another species sparks fear in many people. But leeches may also come to our aid, either by helping to reduce pooling of blood or reestablishing blood flow to areas post-surgery. Their anaesthetic saliva also has anti-inflammatory and anticoagulant properties, which are advantageous for medical procedures.

As the blood of leeches contains DNA from their past meals, conservation scientists can use them to search for rare and cryptic wildlife.

One of the world's most widespread parasites is Toxoplasma gondii. Some estimates suggest as many as one in three people are affected. This parasite's main host is cats, large and small species. House cats are frequently infected, spreading this parasite through their faeces.

While many infected people appear to have no symptoms, serious effects can include organ damage, complications with pregnancy or abortion, erratic risk-taking behaviour, mental conditions, and more traffic accidents than unaffected people.

There are potential "benefits" too. Research suggests Toxoplasma infection, which can increase confidence and risk-taking, may even be linked with increased entrepreneurial and business-related activities. Indeed, this same study found that nations with higher rates of toxoplasmosis had a lower proportion of individuals concerned about failure related to new business ventures.

Toxoplasma gondii manipulates its host to increase transmission and continue its life cycle. Infected rodents may become unwitting participants in a game of cat-and-mouse-and-parasite in which they lose their fear of cats and instead become attracted to them.

Rather than manipulating host behaviour, as in the case of fungi that turn ants into zombies, some parasites cause body malformations. This makes hosts more likely to become prey for subsequent hosts and hence to continue the parasite's life cycle. One of the most striking examples is a trematode (flatworms often known as flukes) that causes missing legs, extra legs or deformed legs in frogs and other amphibians. Extra legs, in some cases several, serve no function and simply impede movement, making it harder to escape predators.

Parasites are fundamental to ecosystems and require conservation

Parasites are a big part of life on Earth. A study on the Californian coast found the sheer mass of parasites exceeded that of top predators. In particular, the biomass of trematodes was greater than that of birds, fish, burrowing shrimps and polychaetes (marine worms).

Evidence suggests ecosystems rich in parasites are healthier than those with fewer parasites. But there is increasing concern for the survival of these species amid a growing extinction crisis. So a global plan for parasite conservation was proposed in 2020, with priorities including increased data collection and genetic analysis, making conservation assessments, and raising public awareness.

Sadly, parasites can inflict great pain, meat allergies, suffering, and a heavy death toll. Malaria, schistosomiasis (sometimes referred to as snail fever, bilharzia, and Katayama fever), and sleeping sickness are just a few examples.

But they also shape our world in profound ways, have crucial ecological roles, and paradoxically, may in some cases help keep us healthier. Though it may be confronting to admit, we need parasites as much as they need us.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

Almost one-third of species around the world would be at risk of extinction by the end of the century if we continue to churn out greenhouse gases, according to a new study.

The study found that if global temperatures rise to 2.7 degrees Fahrenheit (1.5 degrees Celsius) above the pre-industrial average temperature, exceeding the target of the Paris Agreement, extinctions would rapidly accelerate — especially for amphibians; species in mountain, island and freshwater ecosystems; and species in South America, Australia and New Zealand. Earth has already warmed about 1.8 F (1 C) since the Industrial Revolution.

Climate change causes shifts in temperatures and precipitation patterns, altering habitats and species interactions. For instance, warmer temperatures have caused monarch butterfly migration to mismatch with the blooming of plants they pollinate. Many animal and plant species are shifting their ranges to higher latitudes or elevations to follow more favorable temperatures.

While some species might adapt or migrate in response to changing environmental conditions, some can't survive the drastic environmental changes, resulting in population declines and sometimes extinction. Global assessments have predicted rising extinction risks for over a million species, but scientists have not clearly understood how exactly this growing risk is linked to climate change.

The new study, published Thursday (Dec. 5) in the journal Science, analyzed over 30 years of biodiversity and climate change research, encompassing over 450 studies of most known species. If greenhouse gas emissions are managed in accordance with the Paris Agreement, nearly 1 in 50 species worldwide — an estimated 180,000 species — will be at risk of extinction by 2100. When the climate model's temperature is increased to a 4.9 F (2.7 C) rise, which is predicted under current international emissions commitments, 1 in 20 species around the world would be at risk of extinction.

Related: How many animals have ever existed on Earth?

Hypothetical warming beyond this point makes the number of species at risk rise sharply: 14.9% of species were at risk of extinction under a 7.7 F (4.3 C) warming scenario, which assumes high greenhouse gas emissions. And 29.7% of all species would be at risk of extinction under a 9.7 F (5.4 C) warming scenario, a high estimate, but one that is possible given current emissions trends.

The increase in the number of species at risk increases steeply beyond the 1.5 C warming target, study author Mark Urban, a biologist at the University of Connecticut told Live Science.

"If we keep global warming to below 1.5 C, in accordance with the Paris Agreement, then the [extinction] risk from today to 1.5 C is not a large increase," Urban said. But at a 2.7 C rise, the trajectory accelerates. Species in South America, Australia and New Zealand face the greatest threats. Amphibians are the most threatened because amphibians' life cycles depend heavily on weather, and are highly sensitive to shifting rainfall patterns and drought, Urban said. Mountain, island and freshwater ecosystems have the most at-risk species, likely because these isolated environments are surrounded by inhospitable habitats for their species, making it difficult or impossible for them to migrate and seek more favorable climates, he added.

Limiting greenhouse gas emissions can slow warming and halt these growing extinction risks, but understanding which species and ecosystems are most affected by climate change can also help target conservation efforts where they're needed most.

Urban hopes the results have an impact on policymakers. "The main message for policymakers is that this relationship is much more certain," Urban said. "There's no longer the excuse to do nothing because these impacts are uncertain."

Researchers in Australia are building a "living seed bank" to protect the continent’s last-remaining fragments of rainforest from climate change. One goal is to avoid the extinction of ancient trees, whose ancestral roots trace back to Gondwana, the supercontinent that existed before Earth's continents separated hundreds millions of years ago.

Historically, Australia's lush Big Scrub Rainforest flourished across 185,000 acres (75,000 hectares) of eastern Australia. But over the centuries, human encroachment and wildfires have shrunk it to just 1% of that original expanse. Now, rising temperatures and drought threaten the remaining fragments. 

These smaller patches contain fewer trees and dwindling diversity, which leaves species vulnerable to changing weather, warming, and disease.

That's a worry particularly for Gondwana-descended species like Red Carabeen (Karrabina benthamiana) and Yellow Carabeen (Sloanea woollsii) from lineages over 50 million years old, a time when Australia was still attached to Antarctica before Gondwana had fully broken apart. 

These canopy trees can grow to 115 and 164 feet (35 and 50 meters) tall respectively, and are "the main frame-builders of the forest," said Robert Kooyman, a plant biologist at Macquarie University, Australia who is involved with the research. 

Related: Mystery of 'living fossil' tree frozen in time for 66 million years finally solved

In the new project, called Science Saving Rainforests, which is run by the Australian non-profit Big Scrub Rainforest Conservancy, scientists have selected 60 plant species, including several of those Gondwana-era trees. 

For each species, they've gathered DNA from leaf samples taken from dozens of plants across their geographic range, to build up the genome of each one. The geographic spread is important, Kooyman said: "What we get out of that is a measure of how much diversity a species has within its genome, and how much of that diversity is structured relative to climate variation." 

This will reveal the genetics of rainforest plants that are able to thrive in warmer, drier environments that more closely resemble future climate conditions.

Using the genome, the researchers can then identify and collect populations of each plant species that will collectively contain as much of the diversity it reveals as possible — including populations that are better -equipped to withstand climate stress.

Those plant candidates are currently being propagated, and will be raised in a 37 acre (15 ha) research plantation in New South Wales, dubbed the "living seed bank." In about five years, the raised trees will be ready for planting in the remaining forest fragments.

The hope is to transform those patches into landscapes with diversity resembling a larger, intact rainforest. And for species facing climate threats, the plantation offers a resource from which they can select and "move material that enhances their capacity to deal with it," Kooyman said. For trees from ancient lineages, like the Gondwana-descended Carabeens, this could be an essential toolkit for survival. 

"I admire the positive attitude and trust in plant genetic science of the people involved," Sebastian Pfautsch, a researcher who has studied how trees respond to climate stress and is not involved with the research, told Live Science. However, he is cautious about its overall goal.

Pfautsch's own research has revealed — through controlled experiments on eucalyptus species — that the capacity of trees to adapt to higher temperatures may be limited. Pfautsch, who is a professor of urban planning and management at Western Sydney University, also expressed concern about the project's reliance on public donations to keep afloat: "Continued state and federal government funding is critical to secure the growth of the trees," he said.

Kooyman, however, remains optimistic, and believes that the project could provide a blueprint for future genetic work — not just in rainforests, but other threatened ecosystems worldwide. "It's a starting point to demonstrate what's possible," he said. 

Scientists are using artificial intelligence (AI) to identify new animal species. But can we trust the results?

For now, scientists are using AI just to flag potentially new species; highly specialized biologists still need to formally describe those species and decide where they fit on the evolutionary tree. AI is also only as good as the data we train it on, and at the moment, there are massive gaps in our understanding of Earth's wildlife.

But AI is helping researchers understand complex ecosystems as it makes sense of large data sets gleaned via smartphones, camera traps and automated monitoring systems.  

"We're accelerating the pace of research to be able to get at some bigger questions, and that's exciting," Christine Picard, a biology professor at Indiana University, told Live Science. 

Related: GPT-4 has passed the Turing test, researchers claim

In a 2023 study published in the journal Methods in Ecology and Evolution, Picard and colleagues trained an AI model to classify more than 1,000 insect species. Live Science spoke with Picard and lead author Sarkhan Badirli, who completed the study as part of his doctorate in computer science at Purdue University in Indiana. 

The model learned to recognize species from images and DNA data, Badirli said. During training, the researchers withheld the identities of some known species, so they were unknown to the model. 

"It couldn't say which species it was, but our model could say which genus it most probably belonged to," Badirli told Live Science. 

The model correctly identified 96.66% of the known species and assigned species with withheld identities to the correct genus with an accuracy of 81.39%. However, the success rate was considerably lower when the model didn't have DNA data and relied on images alone — 39.11% accuracy for described species and 35.88% for unknown species. 

The researchers blamed that in part on the low resolution of the images, which came from a public database. They noted that the model's accuracy would improve with experience and higher-resolution images. 

"Some of those photos were actually quite bad, so I can't believe the model did as well as it did with that data," Picard said. 

Making sense of biodiversity

Most of Earth's Biodiversity — the variety of animal and plant life — lives in the tropics, which are among the poorest and least-studied regions. As a result, much of the world's wildlife remains undiscovered. Insects have more species than any other animal group, but most of them have yet to be identified. AI may help fill this massive knowledge gap. 

"It allows us to be able to dive into this unknown space of insect species diversity," Picard said. 

Some scientists are also using AI to monitor entire ecosystems. These tools combine AI with automated cameras to see not just which species live in a given ecosystem but also what they're up to.

Live Science spoke with Jenna Lawson, a biodiversity scientist at the UK Centre for Ecology and Hydrology, who helps run a network of AMI (automated monitoring of insects) systems. Each AMI system has a light and whiteboard to attract moths, as well as a motion-activated camera to photograph them, she explained. The systems also record audio to identify animal calls and ultrasonic acoustics to identify bats. Powered by solar panels, these systems constantly collect data, and with 32 systems deployed, they produce an awful lot of it — too much for humans to interpret.  

"We have this amazing hardware, and we can put it out to collect all of this data, but then without the AI, we have no chance of analyzing it," Lawson said. 

Katriona Goldmann, a research data scientist at The Alan Turing Institute, is working with Lawson to train models to identify animals recorded by the AMI systems. Similar to Badirli's 2023 study, Goldmann is using images from public databases. Her models will then alert the researchers to animals that don't appear on those databases.

"They'll be able to flag images and say, 'This looks like something I've not seen before,'" Goldmann told Live Science. 

The AMI systems also allow researchers to monitor changes in biodiversity over time, including increases and decreases. Researchers have estimated that globally, due to human activity, species are going extinct between 100 and 1,000 times faster than they usually would, so monitoring wildlife is vital to conservation efforts.  

Lawson's systems will measure how wildlife responds to environmental changes, including temperature fluctuations, and specific human activities, such as agriculture.  

"The birth of technology in biodiversity research has been fascinating because it's allowed us to record at a scale that wasn't previously possible," Lawson said. 

One irony inherent in these AI systems is that AI algorithms are incredibly energy intensive, so they may have an outsize impact on the environment, according to the London School of Economics and Political Science. 

So Goldmann is training her models on supercomputers but then compressing them to fit on small computers that can be attached to the units to save energy, which will also be solar-powered.  

The tidy classification of organisms into different species forms the foundation of modern biology. 

Yet the criteria used to differentiate a species is surprisingly fluid. In all, scientists have adopted at least 16 species definitions, and potentially as many as 32, to describe the roughly 2 million known species that exist today.

The upshot? 

That number is constantly changing as species are adjusted or reclassified on the basis of new evidence. Single species are often broken apart into multiple, and seemingly different species sometimes turn out to be the same.

From the African elephant to the orca, even seemingly popular and well-established animals have come under scrutiny. Here are six times when scientists seemed to get classifications wrong.

Manta ray

For hundreds of years, the manta ray was universally regarded as a single species, Manta birostris. Then, in 2009, University of Queensland graduate student Andrea Marshall published a paper differentiating the manta ray into two distinct species — the giant, or oceanic, manta ray (Mobula birostris) and the reef manta ray (Mobula alfredi) — based on consistent differences in their appearance. At the time, Marshall hinted at the possibility of a third species, and in 2020, researchers published genetic evidence backing her claim. While this new species has not yet been formally described, it is known colloquially as the Caribbean manta ray.

Florida panther

Deep in the Florida Everglades, lucky visitors might glimpse a flash of the state's largest and most endangered cat — the Florida panther. It's smaller than a typical cougar and has a kinked tail attributed to inbreeding among members of a shrinking population. 

And the big cat has courted controversy since its discovery in 1896. Throughout the 19th and 20th centuries, scientists vacillated between classifying the Florida panther as just another North American cougar (Puma concolor couguar) and giving it its own unique subspecies identification (P. c. coryi). In 2017, as part of a global effort to standardize the taxonomy of the world's felines, the Cat Classification Task Force went with the former, choosing to recognize all cougar populations in North America as P. c. couguar.

Reef fish

Coral reefs are among the most biodiverse habitats in the world. Every square inch is occupied, and every scrap of food is eaten. Given this intense competition for space and resources, species are driven to diversify in order to find new niches to exploit. This phenomenon, called adaptive radiation, can produce thousands of new species, many of which look extremely different from one another. But in other cases, species can appear so similar that the only way scientists can tell them apart is by looking at their DNA — a form of hidden biodiversity known as cryptic diversity. In a study published in February, scientists found that the DNA of a single species of tiny, sponge-dwelling fish called a goby held seven distinct genetic lineages that may represent new species, said senior/co author Jordan Casey, a molecular ecologist at the University of Texas at Austin's Marine Science Institute.

African elephant

The African elephant was once thought to be a single species. But in 2021, it was divided into the African savanna (or bush) elephant (Loxodonta africana) and the African forest elephant (Loxodonta cyclotis). 

And while scientists have previously argued that parsing species into ever-more groups can make it challenging for conservationists to direct resources, the African elephant is one example of how new data can actually make it easier. The International Union for Conservation of Nature (IUCN) — an organization that oversees the listing of threatened and endangered species — had previously listed the single species of African elephant as vulnerable, but splitting the group caused the African forest elephant to be reclassified as critically endangered, paving the way for new protections. 

Following population declines of over 86% in the past 30 years, some populations have now stabilized due to strict anti-poaching policies.

Orca

The orca, or killer whale, is a well-known example of speciation occurring in real time. While all of the estimated 50,000 orcas living today are currently lumped into a single species, Orcinus orca, there are at least 10 distinct ecotypes, each with their own distinct appearance, behavior and habitat. Resident killer whales, for example, tend to have smaller home ranges and specialize in eating fish, while transient orcas travel vast distances and feed on seals and other whales. These populations are currently diverging such that they struggle to communicate with one another or reproduce, prompting some scientists to push for a reclassification that would split the orcas into multiple species.

Giraffe

When famed Swedish biologist Carl Linnaeus first described the gangly, bizarre-looking giraffe in 1758, he did so without ever actually having seen the animal. Yet, for hundreds of years, his classification of the giraffe as a single species (Giraffa camelopardalis) persisted. It wasn't until 2016, once scientists had access to cutting-edge genetics tools, that they realized the roughly 120,000 giraffes alive today may actually represent four different species. Their suggestion was contentious at the time and remains so today. The IUCN, for example, continues to list the giraffe as a single species with nine subspecies.

In 2016, scientists published a paper with a bold claim: that the giraffe, first described as a species by Swedish biologist Carl Linnaeus in 1758, might actually have been four species all along. Unlike Linneaus, the researchers had access to modern genetic tools, which revealed that giraffes fall into distinct clusters based on differences in their DNA, some of which are "larger than the differences between brown bears and polar bears," the authors said at the time.

The news sent ripples through the giraffe conservation community, which suddenly needed to protect four species instead of one. But from the start, there was disagreement about this new classification, and even today, the International Union for Conservation of Nature — an organization that oversees the listing of threatened and endangered species — lists the giraffe as a single species, Giraffa camelopardalis, with nine subspecies.

The dustup and others like it highlight the "species problem," a fundamental uncertainty over how we parse organisms, and it continues to rile biologists the world over.

Arguments often hinge on decades-old definitions. In 1942, biologist Ernst Mayr coined what is perhaps the most enduring one: the biological species concept, which labels two organisms as different species if they cannot reproduce and create fertile offspring. Researchers have since established definitions on the basis of shared ancestry (the phylogenetic species concept), physical features (the morphological species concept), or shared ecology (the ecological species concept), wherein species diverge as they take over different niches in their environment. In all, there are at least 16 species definitions, and potentially as many as 32, circulating among scientists today.

No definition seems to be without exception, however. There are species in which individuals look very different from one another, as well as "cryptic species" that appear identical but are genetically distinct. Hybridization is also common, leading to animals like the liger (a lion-tiger hybrid) and the beefalo (a cross between domestic cattle and the American bison). Evidence even suggests that humans once bred with two other ancient hominins that are usually considered separate species, the Neanderthals and the Denisovans, suggesting they might not have been so different from us after all.

Related: 'More Neanderthal than human': How your health may depend on DNA from our long-lost ancestors

"Some of the rules that we set don't work, and it gets quite messy sometimes," Jordan Casey, a marine molecular ecologist at the University of Texas at Austin Marine Science Institute, told Live Science. "Humans inherently want to put order on things, and even I have to make a lot of decisions about whether I'm just seeing diversity between individuals or trying to bend things needlessly into different species."

But pinning down the definition of a species isn't just an academic exercise — many of the world's conservation policies are structured around species as the de facto unit of conservation. Ultimately, it poses more existential questions as well. If there are four species of giraffe, after all, does it really matter if one goes extinct?

To answer these questions, groups are now coming together to establish guidelines for how species should be named and ordered across the tree of life and how to handle disputes when they arise. Indeed, coming up with a working list of agreed-upon rules is crucial, even if it's not perfect, biologists say.

"It gets quite messy"

The concept of a species is an ancient one. In 343 B.C., for instance, Aristotle wrote "History of Animals," in which he described differences between individual animals as well as between groups.

But it wasn't until the mid-1700s that the concept of taxonomy — the formal classification of living things — truly took off and was turned into an official discipline by Linnaeus. Taxonomy blossomed for a time as scientists across the globe began naming new species, but as the field and related ones advanced, conflicts inevitably emerged.

Scientists have officially described around 2 million species, and others are constantly being added or reclassified based on new evidence. Even for large, seemingly well-studied animals, adjustments are fairly common, and iconic animals like the giraffe, African elephant and orca have come under review.

The problem is that scientists can't agree on a universal definition that can classify organisms as diverse and dissimilar as mammals, birds, fish, plants and bacteria. Still others argue whether such an exercise is even useful, noting that scientists have carried on in the absence of consensus for centuries and will still need to do so as the world's creatures are lost at a staggering rate.

"We're losing things before we even have a name on them, and so we absolutely need to keep pushing in order to advance our conservation goals," Terry Gosliner, an evolutionary biologist and taxonomist at the California Academy of Sciences who has discovered thousands of species over his decades-long career, told Live Science. "But in some cases, we also need to set aside the question of what a species is in order to move forward in meaningful ways."

Today's scientists are tackling the species problem in different ways. Some are attempting to reconcile existing definitions with modern methods, such as by rebranding Mayr's biological species concept as the genetic species concept, which still suggests an inability to reproduce but links the mechanism specifically to genetic incompatibility.

Others continue to develop new ideas. Jeannette Whitton, an evolutionary biologist at the University of British Columbia, codeveloped the retrospective reproductive community concept. Rather than adopting a strict definition, this concept encourages scientists to embrace uncertainty and acknowledge that speciation is a continuous process — that organisms we observe today were shaped by past forces.

Taking this holistic view, which incorporates facets of several existing definitions, means that scientists can still make predictions or explain natural phenomena even in the absence of a clear definition. Whitton told Live Science it took her and a colleague seven years to settle on the final language, in part because of how challenging it was to reconcile their own conflicting ideas.

Still others have argued for setting the species problem aside, noting that the question itself might be a distraction. Yuichi Amitani, a senior associate professor of biology at the University of Aizu in Japan, noted in 2022 that scientists' fears that a lack of consensus would lead to communication breakdowns and make it impossible to compare research have not come to pass.

"There are many concepts in science that lack a unified meaning, and we still manage just fine in that space of uncertainty," he told Live Science, adding that there seems to be something about the idea of a species "that excites such a strong emotional reaction."

Confronting "taxonomy anarchy"

In many ways, conservation is where those emotions boil over, with fierce debates playing out in the scientific literature. In 2017, Leslie Christidis, a taxonomist at Southern Cross University in Australia, argued in a paper that biology's ongoing explosion of newly described species — what he dubbed "taxonomy anarchy" — was making it challenging for conservationists to direct resources or rally support.

Christidis told Live Science that this idea was indeed contentious, prompting more than 180 scientists to cosign a public rebuke. But Christidis insists he never meant to suggest that taxonomy has no place in conservation. Instead, he said, he was advocating for a unified framework for naming new species and managing disputes.

Indeed, as scientists develop more sophisticated tools that combine taxonomy with genomics, tagging studies, modeling and even machine learning, it's clear that the optimal solution likely isn't a one-size-fits-all definition.

It's not even true that probing for new species inevitably leads to more species. When Thomas Near, an evolutionary biologist at Yale University, investigates the evolutionary histories of fish, he often finds that separate species, including several popular sport fish, are in fact the same.

"We have to let the science lead us where it will, and that's not always necessarily to more species," Near told Live Science.

Working groups are now attempting to establish new guidelines. The Catalogue of Life, for example, is developing rules for naming within each kingdom of life, while other groups are carving out even smaller pieces of the puzzle. The World Register of Marine Species is tracking marine species, while the Cat Specialist Group is reassessing the taxonomy of the world's felids.

Christidis is leading an effort to merge three existing lists of bird species and hopes to release a report later this year. After a controversial 2016 paper doubled the number of bird species based on a new definition, the field was clearly due for a reckoning, he said. Fortunately, the group's efforts are revealing that "it is often possible to reach consensus — if not universal agreement — once all of the evidence has been presented," he said. From there, it's easier to make judgments on which species are most in need of protection.

"As scientists, we all want to protect our biodiversity," Christidis said, "and I think starting from that shared ground has helped tremendously."

 The planet's last surviving mammoth population was killed by a random and sudden mystery event, a new study has revealed.

The population, isolated from the rest of the world for 6,000 years on Wrangel Island in what is now extreme northern Russia, was previously believed to have been slowly wiped out by genetic inbreeding.

But a new study has found that the population — which grew from at most eight individuals to 300 before its demise 4,000 years ago — did not go extinct for genetic reasons. This leaves an even bigger mystery as to what actually happened. The researchers published their findings June 27 in the journal Cell.

"We can now confidently reject the idea that the population was simply too small and that they were doomed to go extinct for genetic reasons," study senior author Love Dalén, an evolutionary geneticist at the Centre for Palaeogenetics in Stockholm, said in a statement. "This means it was probably just some random event that killed them off, and if that random event hadn't happened, then we would still have mammoths today."

From about 300,000 to 10,000 years ago, woolly mammoths roamed the frigid plains of Europe, Asia and North America. As the ice across these northern regions melted, the Arctic tundra that the giant pachyderms relied on for food disappeared. This caused the mammoths' range to shrink until they eventually disappeared.

But sometime during this timeframe, a small group of mammoths crossed the ice on the northwest coast of Siberia and began to inhabit Wrangel Island, becoming cut off from the population on the mainland once the ice bridge disappeared around 10,000 years ago. Secluded on the frozen island, the mammoths there survived for an additional 6,000 years.

Related: 'Archaeological sensation': Winemaker discovers hundreds of mammoth bones while renovating his cellar

Because Wrangel Island's mammoths originated from at most eight individuals, scientists previously believed that harmful mutations due to inbreeding could have caused the animals' demise.

To look into the consequences of the Wrangel Island bottleneck, the researchers in the new study used DNA extracted from bones and tusks to analyze the genomes of 21 mammoths — 14 from the island and seven from the mainland population before the bottleneck occurred.

They found that the island's woolly mammoths did show signs of inbreeding and low genetic diversity, but their mutations were only moderately harmful, and the most dangerous ones were slowly being purged from their genome.

"If an individual has an extremely harmful mutation, it's basically not viable, so those mutations gradually disappeared from the population over time," study first author Marianne Dehasque, an evolutionary geneticist at the Centre for Palaeogenetics, said in the statement. "But on the other hand, we see that the mammoths were accumulating mildly harmful mutations almost up until they went extinct."

With inbreeding ruled out, the real cause of these woolly mammoths' demise is still unknown, the researchers said.

"What happened at the end is a bit of a mystery still — we don't know why they went extinct after having been more or less fine for 6,000 years, but we think it was something sudden," Dalén said. "I would say there is still hope to figure out why they went extinct, but no promises."

To investigate further, the researchers will look for clues in unearthed mammoth fossils from the population's final 300 years on the island. In the meantime, the scientists say their findings are useful for understanding the ongoing diversity crisis, as the mammoth's grim fate is mirrored by many present-day populations.

"It's important for present-day conservation programs to keep in mind that it's not enough to get the population up to a decent size again," Dehasque said. "You also have to actively and genetically monitor it because these genomic effects can last for over 6,000 years."

Scientists have found the first evidence of insects crossing an entire ocean — after finding butterflies that made a 2,600-mile (4,200 kilometers) journey across the Atlantic.

Gerard Talavera, an evolutionary biologist at the Botanical Institute of Barcelona, made the discovery in French Guiana in 2013, when he spotted a flock of painted lady butterflies (Vanessa cardui) sitting on the sand, their wings tattered and shot through with holes.

This discovery puzzled scientists, as the tiny species can be found around the world, but not in South America. Now, after a decade of investigation, the researchers have pieced together an answer for how the butterflies got there: They embarked on the first transoceanic flight recorded in an insect. 

The researchers published their findings Tuesday (June 25) in the journal Nature Communications.

"We tend to see butterflies as a symbol of the fragility of beauty, but science shows us that they can perform incredible feats," study co-author Roger Vila, a researcher at the Institute of Evolutionary Biology in Barcelona, said in a statement. "There is still much to discover about their capabilities."

Insect migrations aren't uncommon, but they're difficult to track. Scientists usually rely on records from amateur insect watchers and radar coverage to study insect movements, but these are limited and not always reliable.

Related: 'Russian doll' set of stomach-bursting parasites released inside butterfly on remote Finnish island

To work out how the painted lady butterflies got to French Guiana, the researchers pulled together multiple strands of evidence. They sequenced the butterflies' genomes, which revealed that they were closely related to populations in Europe and Africa. The team also analyzed pollen DNA on the insects' 2-inch-long (5 centimeters) bodies and identified two plant species only found in tropical Africa. In addition, they studied isotopes of hydrogen and strontium on the butterflies' wings, finding that they were unique to western Europe. 

Taken together, this evidence ruled out a North American origin for the insects and suggested that their lives began in Africa or Europe.

"The painted lady butterflies reached South America from West Africa, flying at least 4,200 km over the Atlantic. But their journey could have been even longer, starting in Europe and passing through three continents, implying a migration of 7,000 km [4,350 miles] or more," study co-author Clément Bataille, a professor of earth and environment science at the University of Ottawa in Canada, said in the statement. "This is an extraordinary feat for such a small insect." 

Painted lady butterflies are already known to migrate up to 9,000 miles (14,500 km) between Europe and Africa, including crossing the unforgiving expanse of the Sahara. 

But this trip is made with nightly stops to rest and refuel. To reach French Guiana from West Africa, the butterflies would have to fly for up to eight days without rest.

To resolve this part of the mystery, the scientists analyzed wind currents that rise from the Sahara and blow dust from Africa to the Americas. They found that by gliding upon these aerial highways, the butterflies could complete their remarkable journey.

"The butterflies could only have completed this flight using a strategy alternating between minimal effort to avoid falling into the sea, facilitated by ascending winds, and active flight, which requires more energy consumption," study co-author Eric Toro-Delgado, a doctoral student at the Institute of Evolutionary Biology, said in the statement. "We estimate that without wind, the butterflies could have flown a maximum of 780 km [485 miles] before exhausting all their fat and thus their energy."

The finding highlights insects' abilities to traverse huge distances in ways scientists previously haven't considered.

"This discovery opens new perspectives on the capabilities of insects to disperse over long distances, even across seas and oceans. It is possible that we are underestimating the frequency and impact of these movements on our ecosystems," study lead-author Talavera said in the statement. "Throughout history, migratory phenomena have been important in defining the distributions of species that we observe today."

Paleontologists have named a newly unearthed dinosaur after the Norse god Loki due to a striking similarity between its horns and the deity's regal headpiece, as it was depicted in recent superhero films and television shows.

Scientists described the new dino, Lokiceratops rangiformis, in a study published Thursday (June 20) in the journal PeerJ. The researchers identified the species based on the partial remains of a skull unearthed in 2019 at the Judith River Formation in Montana's Badlands, around 2 miles (3.2 kilometers) from the U.S.-Canada border. 

The species belongs to the clade Ceratopsia — a group of herbivorous horned dinosaurs, including Triceratops, that is renowned for its members' large bony head plates, or frills, and long, pointed horns.

However, L. rangiformis, which was likely around 22 feet (6.7 meters) long and weighed 5.5 tons (5 metric tons), "pushes the envelope on bizarre ceratopsian headgear" to extremes never seen before, study co-lead author Joseph Sertich, a paleontologist at Colorado State University, said in a statement.

L. rangiformis had a massive frill that was adorned with a pair of flattened, curvy horns at the top, in addition to the standard lance-like horns protruding from above its eyes. The frill horns are the largest ever seen in any ceratopsian. The unique headgear inspired the scientists to name the dinosaur's genus Lokiceratops in honor of the Norse trickster god Loki, who is often depicted wearing a helmet with similarly ornate horns — especially in modern comic-book portrayals by Marvel. 

The newfound species also had a third pair of asymmetrical horns at the top of its frill, which earned it the species name rangiformis, meaning "looks like caribou" in Latin, because caribous (Rangifer tarandus) also have antlers that are longer on one side of their head than the other. 

The dinosaur's skull also notably lacks a nose horn, a feature most other ceratopsians possess, including Triceratops.

Related: What was the typical life span of a dinosaur?

L. rangiformis lived around 78 million years ago during the Cretaceous period, about 12 million years before Triceratops emerged. Back then, what is now North America was a large island continent, known as Laramidia. The newly identified species likely dwelled in swamps and floodplains along this ancient land's east coast. 

Researchers had previously assumed that only a couple of horned dinosaur species were likely to co-exist on Laramidia at any one time, because later species in this group likely dominated the competition for resources.

But L. rangiformis is now the fourth ceratopsian — and fifth horned dinosaur — that has been found dating from the same period in Laramidia's history, hinting that there was more diversity among this group than expected, researchers wrote. Two of these other dinosaurs were also unearthed from the Judith River formation, suggesting they co-existed in relative harmony.

However, "the skull of Lokiceratops is dramatically different from the other four animals it lived alongside," study co-lead author Mark Loewen, a paleontologist at the University of Utah, said in the statement. The high levels of ceratopsian biodiversity, which led to increased competition for resources at the time, likely resulted in sexual selection that favored these giant horns, he added.

In addition to providing protection from predators, scientists believe the frills and horns of ceratopsians were primarily used to attract potential mates, similar to the elaborate colored feathers of birds. The size of L. rangiformis' horns was likely a marker of how successful each individual was. In this case, bigger really was better.

Within a human lifetime, concentrations of CO2 in Earth's atmosphere could reach levels associated with 19 "mass extinctions" that have taken place in the last 534 million years, new research suggests.

By 2100, atmospheric carbon dioxide levels could rise to 800 parts per million by volume (ppmv) — almost double the concentration of roughly 421 ppmv recorded this year — if we fail to curb emissions from burning fossil fuels and converting land for agriculture.

That would be edging close to the average CO2 concentrations (870 ppmv) associated with huge crashes in marine biodiversity over the last 534 million years, according to a study published June 22 in the journal Earth's Future. These extinction events are preserved in the fossil record, allowing scientists to plot how biodiversity and atmospheric CO2 evolved throughout Earth's history.

"The relationship between carbon dioxide in the past and extinction in the past gives us a kind of yardstick that we can apply to the present," study author William Jackson Davis, a biologist and president of the non-profit Environmental Studies Institute in Santa Cruz, California, told Live Science.

Related: Hidden 36 million-year-long cycles may fuel biodiversity on Earth, ancient rocks reveal

Atmospheric CO2 contributes to biodiversity loss via ocean acidification, Davis said. The oceans soak up atmospheric carbon dioxide, which turns the water more acidic, reducing the availability of calcium carbonate ions needed for organisms to build their skeletons and shells. When these effects are strong enough to affect the entire food chain, they can lead to mass extinctions. 

CO2 and extinction move in tandem

In the new study, Davis found that CO2 concentrations oscillate with marine biodiversity in the fossil record. 

"When carbon dioxide goes up, extinction goes up, and when carbon dioxide goes down, extinction goes down," he said. Davis then used this relationship to estimate biodiversity loss under current atmospheric conditions.

"The current concentration of CO2 in the atmosphere is 421 ppmv," he said. "When we plug that into the relationship between biodiversity and concentration of CO2 in the past, that corresponds to a biodiversity loss of 6.39%."

This estimate comes close to the percentage of biodiversity lost in the smallest "mass" extinction event considered in the study — called "extinction event #10" — which doomed 6.4% of species 132.5 million years ago. This means "humans have already caused extinction-grade biodiversity losses," Davis said.

Scientists generally define mass extinctions as three quarters of species dying out over short geological time periods — in under 2.8 million years. Under this definition, five mass extinction events have shaped Earth's history, with a sixth likely underway. 

But another 45 peaks in biodiversity loss that can also be considered mass extinctions, Davis said. For the study, a mass extinction was defined as "any peak in biodiversity loss that is flanked by lesser values." By this definition, there have been 50 mass extinctions in the last 534 million years, ranging from 6.4% to 96% of marine species going extinct.

The results suggest ocean acidification resulting from elevated CO2 concentrations is "the immediate kill mechanism" of most mass extinctions, according to the study.

"The link between CO2 in the atmosphere, global temperature, and biodiversity loss is well established," Mike Benton, a professor of vertebrate paleontology at the University of Bristol in the U.K., told Live Science in an email. 

Atmospheric CO2 concentrations are currently rising by more than 2 ppmv every year, which may trigger a 10% loss in biodiversity over the next few decades, Davis said.

The massive slabs of slowly-moving rock just under Earth's surface — known as tectonic plates — may drive bursts of marine biodiversity every 36 million years, a new study finds. 

As tectonic plates slide over the mantle, Earth's inner rocky layer above the core, they cause sea levels to rise and fall. In turn, fluctuating sea levels around continents and shallow inland seas provide new habitats for ocean life to thrive, the researchers found. 

"Warm, shallow water environments are the primary cradles of marine biodiversity," study co-author Dietmar Müller, a geophysics professor at the University of Sydney, told Live Science.

This cyclical flooding and drying up of continents goes back at least 250 million years, the researchers wrote in the study, published Monday (July 10) in the journal PNAS.

The slow ballet of tectonic plates explains the creation of these prolific habitats. In areas called mid-ocean ridges, where movement in the Earth's mantle pushes plates away from each other, hot magma and water rises to form new oceanic crust — a process known as seafloor spreading. In other areas, these tectonic plates collide, with one sliding beneath the other through a process called subduction, pulling ocean water into the Earth's mantle, a process that lowers sea levels. The pace of these events can change the elevations of the ocean floor and, consequently, sea-level rise, according to Müller. 

"When there's a lot of new seafloor created and destroyed, that's when you get sea-level highs," he said. "And when the system slows down … you get sea-level lows." 

Related: Hunks of oceanic crust are wedged inside Earth's mantle

When sea levels rise and coastlines are flooded, this can create pockets of shallow seas, which may eventually give rise to new species that are uniquely suited to these newly formed habitats, the researchers found. During the study, the researchers compared plate tectonic movements and sea-level changes with marine fossil records dating back 250 million years ago, which they largely pulled from the Paleobiology Database, a public resource that combines data for fossils collected across geological history. 

Their analysis revealed that tectonic changes that drove shallower sea levels in and around continents every 36 million years correlated with highly biodiverse periods in the fossil record roughly 6 million to 8 million years later. Essentially, when sea level rise peaked, it led to a peak in marine biodiversity.

"There's essentially periods where mid-ocean ridges go faster and subduction goes faster, and they're followed by periods when the system slows down," Müller said. "Why exactly this process is cyclic like that is actually a question that we haven't fully answered yet."

The new research provides growing evidence that global sea level change fueled by Earth's geological processes have largely influenced the biodiversity of marine life over history, the study's authors say. 

The study highlights how tapping into massive amounts of data within the Paleontology Database can be a "game changer in its own right," Gareth Roberts, a senior lecturer in Earth Sciences at Imperial College London, told Live Science. He added that the study is "another foundation stone to understanding how marine fossil diversities changed through time."

According to the cycle, the Earth is currently at a sea-level low and marine biodiversity low, if we were factoring in only tectonic-driven changes, Müller said. However, shifting tectonic plates aren't the only thing that can change sea levels and, as a result, the ocean's biodiversity. Human-caused climate change is heating up ocean temperatures and melting ice sheets, contributing to a global rise in sea levels, research shows. This means sea-level rise and coastal flooding could happen much faster than previously observed in the 36 million-year cycle, according to Müller.

"What we're talking about is not an alternative mechanism to explain global warming," he said, adding that the rate of sea-level rise documented in their study is relatively slow. "[The rates] at which we are changing the climate and the surface environments now are faster than ever in the geological record."

A cursory flip through any high school biology textbook will inevitably surface a mention of the Cambrian explosion, a period about 540 million to 520 million years ago during which many animal groups first sprang into life and diversified. The event is frequently described as rapid and prolific, evoking a chaotic moment in early evolutionary history. 

But was there really a dramatic burst of biodiversity on Earth during this time? 

Thomas Servais, a paleontologist and research director at the French National Center for Scientific Research (CNRS), and colleagues published a 2023 paper in Palaeogeography, Palaeoclimatology, Palaeoecology arguing that the Cambrian explosion didn't happen in the way it's popularly portrayed. It wasn't truly an explosion, he told Live Science, but rather a gradual increase in biodiversity that took place throughout the early Paleozoic era (541 million to 251.9 million years ago). The appearance of an "explosion," he said, is really an artifact of the biases scientists have when studying the past. 

The process of locating, excavating and cataloging fossils is costly and laborious, so researchers often add their specimens to large databases to make it easier to compare finds. Two of these databases, the Paleobiology database and the Geobiodiversity database, collectively contain roughly 2 million entries and have been used to investigate global patterns in biodiversity, including trends that appear during the Cambrian.

The authors assert that these resources aren't truly global, however. The Paleobiology database is largely made up of fossils found in Europe and North America, while the Geobiodiversity database mostly includes fossils from China. These regions host some of the most famous Cambrian deposits in the world — including Canada's Burgess Shale and the Chengjiang fossil bed in China's Yunnan province — that pull the majority of the funding. But at best, they can give "a regional assessment of patterns in diversity, and then only for those species that preserve well enough to persist in the fossil record," Servais said.

The databases also include specimens from another period, called the Great Ordovician biodiversification event (GOBE), thought to have taken place roughly 40 million to 50 million years after the Cambrian explosion. The period between the two events is relatively understudied and seems to lack the same pattern of flourishing biodiversity. But this too, Servais said, is the result of bias on the part of scientists. Were they to put the same effort into studying this period, the existence of two individual events would likely melt away, he said.

Related: Why do Cambrian creatures look so weird?

Karma Nanglu, a paleontologist at Harvard University who studies Cambrian and Ordovician fossils, told Live Science he understands why Servais and his colleagues would like to tamp down on the use of terms like "explosion" and "event," and said it's well-accepted in the field that biodiversity estimates may be influenced by sampling bias. "But to my mind, I still do think there is actually quite good evidence that there was a Cambrian explosion, as we would typically call it," he said.

Regardless of whether the databases are biased toward certain groups or areas, there is a general trend of increasing complexity that is visible in the animals themselves.

"It's not just that two species are equivalent to each other in terms of what they contribute to diversity, it's that species A and species B are drastically different from each other in terms of the way their bodies are organized, how they develop, what their ecological role might be, how they live," Nanglu said. "And to that point, I think there's direct evidence that you can read straight from the rocks.

The causes for this biodiversification aren't fully known, but scientists have a few ideas. During the Precambrian, the supercontinent Rodinia broke apart into pieces, including Gondwana (modern-day Antarctica, South America, Africa, Australia, India and New Zealand) and Laurentia (most of North America). During this time, oxygen levels in the ocean increased, and there was a greater proportion of warm, shallow, tropical coastline — the perfect conditions for new species to evolve and later be fossilized in. A similar hypothesis has been studied for the breakups of the supercontinents Pannotia and Pangaea much later, and researchers have identified a link between the fracturing and animal diversity in the Phanerozoic eon (541 million years ago to the present). 

As climate change transforms our world, the impacts will be felt unequally, with some animals struggling to survive and others finding ways to overcome the resulting challenges.

This phenomenon is increasingly described as the "winners and losers under climate change," said Giovanni Strona, an ecologist and former associate professor at the University of Helsinki, now a researcher at the European Commission. Strona led a 2022 study, published in the journal Science Advances, that found that under an intermediate emissions scenario, we stand to lose, on average across the globe, almost 20% of vertebrate biodiversity by the century's end. Under a worst-case warming scenario, that loss rises to almost 30%.

So which animals are the "winners," and how well will they really fare under increasing temperatures, drought and habitat loss?

Related: When did scientists first warn humanity about climate change?

Everything is connected

There's no doubt about the threats to Earth's biodiversity from climate change and habitat destruction. In 2022, the World Wildlife Fund (WWF) released the Living Planet Report, which described a 69% decline in the relative abundance of monitored species since 1970. Meanwhile, 1 million species now face extinction across our planet because of these twin threats, according to the report. There's now mounting evidence that Earth is experiencing its sixth mass extinction.

Climate change contributes to these extinction risks in complex and interconnected ways, some of which are still-unknown. It will affect populations directly by inducing extreme weather events, like storms; by driving up temperatures or reducing rainfall beyond the thresholds a species needs to survive; and by shrinking key habitats on which animals depend. 

As Strona's research showed, climate change can also have indirect effects that ripple through an ecosystem. He and his team built several model Earths incorporating over 15,000 food webs to represent the connections of many thousand terrestrial vertebrate species. Then, they simulated various climate and land-use change scenarios in these ecosystems. 

Their simulations showed that when climate change directly caused the loss of one species, it resulted in a cascading loss of several species that depend on that one species for food, pollination or other ecosystem services. This domino-like effect, known as "co-extinction," will drive the bulk of terrestrial vertebrate species diversity declines under projected climate change, the research predicts. Because the study didn't model the impact of climate change on communities of insects or plants, these findings are likely also optimistic, Strona said.

The huge complexity of animal relationships within natural ecosystems, plus the uncertainty over how extreme climate change will get, makes it difficult to drill down into such data and pinpoint which animals will do better than others as our world warms. However, Strona's research did pick up on a general trend: "What we found is that larger species and species at high trophic [food chain] levels will be more adversely affected," he told Live Science.

So animals with lower positions in the food chain, such as insects or rodents, may fare better in a warming world.

Related: What would happen to Earth if humans went extinct?

Adaptable animals

Larger species tend to reproduce more slowly, and that's another clue researchers have connected to climate vulnerability.

Another recent study, published in the journal Global Change Biology, looked at 461 animal species across six continents and analyzed the disruptive effects of historical land-use and temperature changes on their populations. "What we found in our study is that species that breed really fast are really good at exploiting new habitats — taking energy and transforming it into offspring," study lead author Gonzalo Albaladejo Robles, a conservation biologist at University College London, told Live Science. 

Faster breeding may benefit species in a changing climate because they're more adaptable to changing habitats; fast breeding cycles give these species an "opportunity to survive these peaks in environmental disruption," such as extreme weather or habitat loss, Albaladejo Robles explained. Meanwhile, slower-breeding animals showed the opposite trend in the study, and their populations declined when temperature and habitat changed.

Size is a factor that may also work against species. For instance, bigger animals might struggle more under climate change because they typically need larger stretches of uninterrupted habitat, as well as more food, which is easily threatened by habitat loss and the landscape and resource impacts of climate change, Albaladejo Robles said. 

"If you're an elephant, it's more likely that you're going to be sensitive to severe droughts, and also deforestation, than other smaller species that need less resources," Albaladejo Robles said. "Generally speaking, small species are going to be more likely to survive human-change interactions, like climate change and land use change." 

Species with more niche diets, such as pandas and koalas, may be at increased risk under environmental change, too. By contrast, the broad diets of generalist feeders, such as crows and raccoons, give them a wide range of foods to fall back on if one food source disappears. 

The ability to migrate and adapt to different habitats could also insure animals against an uncertain future. For instance, many creatures that can survive only at frozen latitudes or in coral reefs, which will dwindle under continued warming, face greater risks. Research has also unearthed evidence that animals such as parrots, bats and shrews are "shape-shifting" over generations, developing bigger beaks, wings and tails to help them cool down more effectively in warmer climates, and possibly making them more adaptable.

All this suggests that animals that are more resilient to habitat disruption and temperature changes are most likely to thrive in a warmer world. For clues to which species that future might include, just look to the unfussy, generalist, fast-breeding species that occupy the most disrupted habitats on our planet: cities. Those include cockroaches, mice, rats, crows, pigeons, some raptors, monkeys and raccoons. 

Related: Could climate change make humans go extinct?

And that's assuming we don't end up with catastrophic levels of heat that stretch beyond the thermal limits of those species. If that scenario were to unfold, we'd be looking at a world populated by extremophiles like tardigrades, also known as water bears. These tiny creatures can go into a state of hibernation that almost completely shuts down their metabolism, enabling some tardigrade species to weather extreme cold of minus 320 degrees Fahrenheit (minus 196 degrees Celsius), and heat of up to 300 degrees Fahrenheit (150 degrees Celsius).

And yet, even their seemingly indestructible bodies have limits, according to some of Strona's previous research. This study, published in the journal Scientific Reports, simulated how tardigrades would fare under extreme cold and warming based on their temperature-tolerance levels alone. The research confirmed that the tardigrades could withstand incredible extremes. But when the researchers factored in the other species interactions that make up the ecosystems on which they depend, tardigrade populations plummeted under projected extreme warming that would decimate these other animals.

"Tardigrades are super resistant by themselves, but they need the other species to survive," Strona said.

That is the flaw in the idea of "survivor species," he said, because it misses the need for whole ecosystems and their web of complex species interactions to sustain life on Earth, as the Science Advances research showed.

Instead of resting our hopes on some resilient species to survive under climate change, we need to protect whole ecosystems. That means slowing warming by curtailing fossil fuel consumption, limiting habitat destruction and reducing other human impacts on wildlife, experts say. 

Projections can help by shining a spotlight on the most vulnerable animals that need our immediate attention. Even better, paired with the likes of recent research that identifies projected habitat refuges for climate-threatened animals, we can proactively protect whole ecosystems that keep species interconnected. 

There may be short-term "winners" under projected climate change. "But what matters, I think, is the net balance," Strona said. "My perception is that there will be much more losers than winners" — and ultimately, those losers could include us, he said.

Deserts are not easy places to call home. Broiling in the day, frigid at night, and lacking ample water, these landscapes test their inhabitants. The creatures that call deserts home have adaptations to help them survive and thrive in these harsh conditions. Many of these creatures never need to drink and have skin or scales that enable them to hoard what little water they require; some have evolved to move and be active solely at night to avoid the punishing sun. Here are 15 of the strangest animals found in deserts around the world.

Fennec fox

Desert animals don't get much cuter than fennec foxes (Vulpes zerda). These teeny canids are smaller than domestic cats, measuring 14 to 16 inches (35.6 to 40.6 centimeters) long, not including their tails, but they sport enormous ears that can grow to be 4 to 6 inches (10.2 to 15.2 cm) long. These ears help the foxes shed heat and listen for prey under the sand. When the foxes catch the sound of rodents, insects or other small animals they predate, they use all four paws to dig out their quarry in a shower of sand, according to the Smithsonian National Zoo.

Fennec foxes are well-adapted for life in African and Arabian deserts. Their pale fur camouflages them against the sand; it also grows on the bottoms of their feet to give them traction while running in the sand and protects their feet from the hot desert surface. When air temperatures rise, the foxes can pant up to 690 times per minute to cool down. Fennec foxes also dig elaborate burrows to escape the sun in the hottest part of the day.

Screaming hairy armadillo

Perhaps less cute than fennec foxes — but no less well-adapted to their desert environment — are screaming hairy armadillos (Chaetophractus vellerosus). These armadillos really do scream; when threatened, they make a terrible cry that sounds similar to the wails of a newborn human baby. Research published in 2019 suggests that these screams are designed to startle predators, or to attract other predators to the scene, perhaps distracting an attacker and enabling the armadillo to get away. 

Screaming hairy armadillos are small, weighing only 1.9 pounds (0.86 kilograms). They live in the Monte desert of Argentina, Bolivia and Paraguay, preferring spots with loose, sandy soil where they can dig burrows, according to the Smithsonian National Zoo. The armadillos rarely need to drink. Their kidneys are highly efficient, and they get most of the water they need from the plants they eat. It's a waste not, want not environment in the desert, so screaming hairy armadillos are opportunistic eaters — they also consume insects and small animals such as lizards and rodents.

Hairy desert scorpion

Among the many scorpion species that call deserts home, the hairy desert scorpion (Hadrurus arizonensis) is a standout. These sorpions can measure between 4 and 7 inches (10.2 to 17.8 cm) long, according to Utah's Hogle Zoo, making them North America's largest scorpions. Though they are a drab olive-green color, hairy desert scorpions fluoresce under ultraviolet (UV) light. No one knows exactly why scorpions fluoresce, but the best way to find these shy nocturnal predators is to take a UV light into the desert on a summer night, when they tend to be most active. 

Hairy desert scorpions are found in North America's Sonoran and Mojave deserts, as well as in Nevada and Utah. When looking to mate, male and female hairy desert scorpions lock pincers in a mating dance that looks more like a wrestling match. In fact, if the male does not flee quickly after depositing his sperm, he might find himself becoming his mate's next meal. 

Females gestate their young for six to 12 months, live-birthing up to 35 babies that piggyback on their mother's carapace until they're large enough to hunt on their own. Fortunately for humans, desert hairy scorpions would rather flee than sting, and their venom is relatively weak. For most people, the sting is similar to a bee's sting.

Harris's hawk

Harris's hawks (Parabuteo unicinctus) are oddities in the falcon world. These impressive red-winged raptors sometimes hunt in packs, working together to pursue their prey around bushes, thickets and the saguaro cactuses of Arizona's Sonoran desert. The birds eat lizards, other birds and small desert mammals such as kangaroo rats and ground squirrels. When they catch large prey, they'll share the meat with their fellow hunters, according to the conservation nonprofit Audubon.

These birds also often work in groups to raise their young. Two males may mate with a single female, and the trio work together peacefully to raise any ensuing hatchlings. Hawk siblings help each other, too; an older brood from earlier in the season may stick around to bring food to younger broods.

Desert ironclad beetle

The desert ironclad beetle (Asbolus verrucosus) is a tank of an insect. Its powder-blue color comes from a waxy coating that helps the beetle retain moisture in the dry Sonoran desert. The bumps on the beetle's shell give it an armored appearance that is even tougher than it looks. The ironclad beetle subfamily is known for its ultra-strong exoskeleton — it’s so strong, these beetles can shrug off being stepped on by a human, according to the University of Wisconsin, Milwaukee. 

Desert ironclad beetles are also known as "death-feigning beetles" for their defensive behavior in the face of threats. When alarmed, the beetles roll over and play dead, according to the Cincinnati Zoo and Botanical Garden. They eat plants and decaying organic matter, and — like many desert denizens — rarely, if ever, need to drink.

Sand cat

A softer, fuzzier desert denizen is the desert sand cat (Felis margarita). It is the only cat species that makes its home in true desert environments. Desert sand cats are found in the Sahara desert, the Arabian Peninsula, Turkmenistan, Kazakhstan and Uzbekistan. Though they look remarkably similar to fluffy domestic kitties, sand cats are elusive and rarely seen by people. They're secretive and difficult to track, according to the International Society for Endangered Cats (ISEC) Canada. Researchers who tried to observe these animals in the wild found that the cats' fur-lined paws left no tracks, and their light-colored coats made them challenging to spot. What's more, the cats crouched low and closed their eyes against searchlights at night, hiding their reflective retinas. 

Sand cats are stealthy hunters and are able to kill snakes as well as desert rodents and lizards. Their mating call sounds like a dog's bark.

Desert long-eared bat

Once dubbed "the hardest bat in the world," the desert long-eared bat (Otonycteris hemprichii) is found in North Africa and the Middle East. What earned this bat species that nickname? Well, its main diet is scorpions. 

Desert long-eared bats hunt scorpions by falling onto them out of the sky and wrestling the venomous arachnids into submission. The bats are unbothered by the multiple scorpion stings they often receive in the process, according to research from Ben-Gurion University of the Negev in Israel. Ben-Gurion University researchers also found that desert long-eared bats can switch the settings on their sonar, using one type of echolocation to seek out ground-dwelling prey like scorpions and another type to hunt down flying insects.

Pink cockatoo

Colorful birds are often found in lush, tropical rainforests and are scarce in arid regions — except if that region happens to be in Australia’s interior. One of the continent's most beloved bird species is the pink cockatoo (Lophochroa leadbeateri), which ekes out an existence in the semi-arid and arid Australian Outback. 

Identifiable by its showy orange-and-yellow crest and its blush-shaded body, the pink cockatoo is divided into two subspecies: one found in western-central Australia and other in the east, according to the Australian Museum. These pretty birds live off seeds and insects. They mate for life, according to the Australian Foundation for National Parks and Wildlife (FNPW), and they can be found prancing on tree branches, bobbing their heads up and down to attract mates.

These iconic Australian birds have a variety of names and nicknames, according to FNPW. They're also known as Major Mitchell’s cockatoos (after the early English explorer who wrote about them for a global audience), as well as Leadbeater’s cockatoos, desert cockatoos, cocklerinas, chockalotts and — adorably — wee jugglers.

Sidewinder

Perhaps nothing screams "desert" like the image of a sidewinder rattlesnake undulating over a sand dune, leaving behind bizarre curved tracks. Sidewinders (Crotalus cerastes) can slither at speeds of up to 18 mph (29 km/h) using their strange sideways crawl — even across loose sand, according to the Smithsonian Channel.

Sidewinders are ambush hunters. They bury themselves in sand, leaving only their eyes peeking upward. When a lizard happens by, they snap forward and spring the trap. These snakes strike in the blink of an eye, injecting venom that ]attacks both the blood and the nervous system of unwary prey. 

Sidewinders are found in the southwestern United States and northwestern Mexico. They can be recognized by the protruding horn-like structures shading their eyes, which may keep sand from obscuring their vision.

Desert pupfish

Fish in the desert? Desert pupfish (Cyprinodon macularis) are small, silvery fish that can survive remarkably well in parched conditions. Pupfish have evolved to thrive in water that flows through arid regions. They're found in California's Salton Sea and its tributaries, and in waterways along the lower Colorado River in Mexico. 

These fish require a high degree of resiliency to survive in a desert's meager or brackish water sources. Special adaptations enable pupfish to survive despite  conditions that would be deadly for most fish, according to the California Department of Fish and Wildlife. Pupfish can live in water ranging from fresh to 70 parts-per-thousand salt (most of the ocean is between 34 and 26 parts-per-thousand salt). They can live in water as cold as 40 degrees Fahrenheit (4.4 degrees Celsius) and as hot as 108 degrees F (42.2 C). They can even live in water as poorly oxygenated as 0.1 parts-per-million (ppm) oxygen (most warm-water fish require 5 ppm oxygen in their water to survive, according to Florida's Center for Aquatic and Invasive Plants). 

Despite their toughness, desert pupfish are endangered in California, threatened by the introduction of non-native species and habitat loss.

Thorny devil

No list of weird desert animals would be complete without a nod to lizard-kind. And no nod to lizard-kind would be complete without mentioning the thorny devil (Moloch horridus), the sole species in the genus Moloch, named for an ancient, sacrifice-demanding god worshipped by the Caanites and mentioned in the Hebrew Bible. Thorny devils are only found in Australia. They grow to be just over 8 inches (21 cm) long from nose to tail and are covered with sharp spines that serve as a defense against predators. 

Thorny devils also have two heads — really. One is a false head, a protuberance that sits on top of the devil's neck. When threatened, a thorny devil will lower its real head, presenting the false head as a decoy. Thorny devils also have a distinctive jerky walk that may confuse predators, according to Bush Heritage Australia.

As intimidating as thorny devils may look, they're really only a danger to ants, which they lap up by the thousands with their sticky tongues, according to Bush Heritage Australia. These desert denizens "drink" through their skin, collecting dew and moisture from sand with tiny channels between their scales. These straw-like channels, which direct the precious drops to the lizards’ mouths, are just one example of the creative hydration mechanisms that keep animals alive in the driest places on Earth.

Saharan silver ant

Saharan silver ants (Cataglyphis bombycina) get their name from their silky, silvery coats. Yes, these ants have hair. 

Unlike most desert animals, Saharan silver ants forage in the middle of the day, when the Sahara can reach temperatures of up to 158 degrees Fahrenheit (70 degrees Celsius). This strategy helps them avoid predators but requires them to cool themselves very efficiently. A 2015 study in the journal Science found that the ants' silver hairs are shaped to help them reflect and radiate both sunlight and heat across the electromagnetic spectrum, keeping the insects cool.

Elf owl

Adorable elf owls (Micrathene whitneyi) are only the size of a sparrow, making them the world's smallest raptors, according to The Cornell Lab. Found in the southwestern United States and Mexico, these owls make their nests in old woodpecker holes in large saguaro cactuses or in trees. They avoid the desert heat during the day and instead use their incredible eyesight and hearing to hunt at night, pouncing on prey such as scorpions, insects and centipedes, according to the Arizona-Sonora Desert Museum.

Tarantula hawk

Tarantula hawks aren't birds: They're a group of predatory wasps that prey on — you guessed it — tarantulas. These wasps are found around the world, but several species that dwell in the United States live in the desert southwest. Pepsis thisbe, for example, is a species of tarantula hawk that lives at the Grand Canyon. Wasps of this species have bright-orange wings and can grow up to 2 inches (5 cm) long, according to the National Park Service.

What really makes these wasps unique, though, is their habit of using tarantulas as living food for their larvae. Mother tarantula hawks paralyze tarantulas with their venom, carry them back to their nests and seal them in, laying their eggs in the spiders' abdomens. As the larvae grow, they feed on the paralyzed tarantulas, saving the vital organs for last.

Greater bilby

Looking a bit like a cross between a shrew and a bunny, greater bilbies (Macrotis lagotis) are found in deserts and grasslands in Australia. These cute creatures are about the size of a housecat. They spend their days in tunnels that they dig out of the dry Australian soil, and they spend their nights foraging for food such as termites, tubers and grubs. Like many desert animals, bilbies get all the moisture they need from their food, according to Bush Heritage Australia.

Originally published April 12, 2022 and updated Jan. 27, 2023.

The Devils Hole pupfish is small, blue and incredibly endangered. It also may be the most inbred creature on Earth. 

All 263 wild Devils Hole pupfish (Cyprinodon diabolis) live in one location: a 10-foot by 20-foot (3 by 6 meters) cavern in the middle of Devils Hole in Nevada, a detached part of Death Valley National Park, one of the hottest places in the world. Their cavern oasis, located just 50 or so feet (15 meters) below the desert floor, is at least 500 feet (152 m) deep (scientists have yet to find the bottom) and stays at a balmy 92 degrees Fahrenheit (33 degrees Celsius) year-round. The species has lived there, isolated from all other pupfish, for at least 1,000 years, and possibly as long as 20,000 years, according to the National Park Foundation. 

That isolation has led to some very dramatic genetic consequences, scientists reported Nov. 2 in the journal Proceedings of the Royal Society B. They found that Devils Hole pupfish genomes are 58% identical, on average — "the equivalent of five to six generations of full sibling matings," said Christopher Martin, an evolutionary biologist at the University of California, Berkeley and senior author of the new study. That's enough to make the infamously inbred Habsburg dynasty look wildly diverse.

Related: 'Hell fish' likely killed by dinosaur-ending asteroid is preserved in stunning detail

For the new study, the researchers sequenced the genomes of eight Devils Hole pupfish, as well as one preserved specimen from the 1980s. They found that the fish were missing some seemingly important genes. For example, they lacked a gene normally involved in producing sperm — one that causes infertility if knocked out in other species. "It's kind of surprising that they're even able to reproduce at all," Martin told Live Science.

The fish had also lost a gene that helps other types of pupfish survive in low-oxygen environments — a surprise, given that the warm, stagnant pool they call home is very deoxygenated. At the moment, it's unclear to what degree the absence of these genes is harming the pupfish's overall health. 

"The genome is a complex place," Martin said. He and his team plan to study the fishes' genetics in greater detail to determine what, exactly, each of their genes is doing and how they're compensating for genomic losses.

The intense inbreeding observed in the fish is likely due to their geographic isolation, coupled with multiple population bottlenecks in recent years. In the past two decades alone, the population nearly crashed twice — dipping to 38 individuals in 2006 and as low as 35 in 2013, according to the U.S. Fish and Wildlife Service.

This unique fish was one of the first species to be officially added to the Endangered Species Preservation Act in 1967, which was later folded into the Endangered Species Act of 1973. Since then, thanks to considerable conservation efforts — including the construction of a 100,000-gallon (379,000 liters) replica of Devils Hole that houses a separate captive-bred pupfish population — the species has survived, though it has not always thrived.

"They're still in a precarious situation," Martin said. "But the good news is that human interventions and accidents haven't really made the population worse than it was … I don't think they're doomed."

A Chinese pet-cloning company has announced the birth of the world's first cloned Arctic wolf (Canis lupus arctos), which was carried to term by an unlikely surrogate mother — a beagle.  

The cloned female wolf pup, named Maya, and her beagle mother were unveiled to the world in a brief video at a press conference held Sept. 19 by the Sinogene Biotechnology Company in Beijing, according to Chinese news site Global Times. The video was released 100 days after Maya was born: on June 10 in a laboratory in Beijing, according to Sinogene representatives. 

Normally, Sinogene specializes in cloning dead pets, such as cats, dogs and horses, for private clients. But the company now wants to use its expertise to help clone endangered species for conservation purposes, Global Times reported.  

Maya was cloned using DNA collected from a fully grown Arctic wolf, also named Maya, that died in captivity at Harbin Polarland, a wildlife park in northeast China. The original Maya, who was born in Canada before being shipped to China in 2006, died due to old age in early 2021, according to Global Times.  

Related: Why haven't we cloned a human yet? 

The cloning of Maya was successfully completed "after two years of painstaking efforts," Mi Jidong, general manager of Sinogene, said at the company's press conference, according to Global Times.    

Sinogene researchers originally created 137 Arctic wolf embryos by fusing skin cells from the original Maya with immature egg cells from dogs, using a process known as somatic cell nuclear transfer (SCNT). Of those embryos, 85 were successfully transplanted into seven beagle surrogates. From those transplanted embryos, just one fully developed during pregnancy, according to Global Times.

The researchers used beagle surrogates because there were not enough female wolves in captivity for the scientists' experiments. Luckily, dogs share enough DNA with wolves for the hybrid pregnancy to gestate successfully.

Maya now lives with her surrogate mother at a Sinogene lab in Xuzhou, eastern China, but the wolf pup will eventually be transferred to Harbin Polarland to live with other Arctic wolves. However, the park's keepers believe she will have to be slowly introduced to the rest of the pack because of her isolated upbringing, according to Global Times. 

Sinogene also revealed that a second Arctic wolf clone, created using DNA from an unknown male, was due to be born Thursday Sept. 22. However, there have been no confirmed reports so far of the pup's birth.

The company also announced a new partnership with the Beijing Wildlife Park to clone more captive species in the future, although no specific projects have yet been announced, according to Global Times. 

In 2019, Sinogene was also involved with a project that produced six identical German shepherd clones, which were then inducted into the Beijing police force, according to CBS News. 

Cloning endangered animals 

Despite reports from Global Times and other media outlets, Arctic wolves, which are a subspecies of gray wolves (Canis lupus) are not an endangered species. Instead, they are listed as least concern by the International Union for Conservation of Nature, though climate change is likely to severely disrupt their food supply in the wild in coming decades, according to WWF.

But endangered species have been cloned by scientists before.  

In 2020, scientists from U.S.-based non-profit conservation organization Revive & Restore successfully cloned an endangered black-footed ferret (Mustela nigripes). That same year, the company also successfully cloned an endangered Przewalski’s horse (Equus przewalskii), and their technicians are now attempting to revive the extinct passenger pigeon (Ectopistes migratorius) using cloning technology.

"Cloning is a drastically underutilized tool," Ben Novak, lead scientist at Revive & Restore, told Live Science in an email. "In the future, it could be a literal lifeline for species that become rarer or worse, go extinct."

The main benefit of cloning endangered species is that it maintains the amount of genetic diversity within a species, Novak said. If the clones can reproduce with other non-cloned individuals, this gives threatened species a fighting chance to adapt to the selection pressures that are driving them towards extinction, he added.  

Another benefit of cloning is that it can be used in conjunction with existing captive-breeding programs, especially when surrogate mothers from other species are used, Novak said. Rather than taking animals from the wild to create a back-up population in captivity, scientists can take genetic samples from wild animals and create clones in the lab using more readily available surrogates, as they did with Maya and her beagle mother. These genetic backups can then be introduced into the wild to replenish struggling populations, Novak said.   

"For mammals, it appears that two species must share a common ancestor less than 5 million years ago" for the surrogate pregnancy to be successful, Novak said. This opens up the possibility of reviving extinct species by using closely related living surrogate species, he added.

Related: Is it possible to clone a dinosaur?

However, there are also some major limitations to cloning. 

One of the main issues is that not all animals can be successfully cloned yet. To date, only mammals, fish, amphibians and a single insect species have been cloned using SCNT, Novak said. For birds, reptiles and egg-laying mammals, like platypuses and echidnas, SCNT does not work because the eggs do not properly develop, he added.

Cloning also has a very low success rate compared with artificial insemination or in-vitro fertilization, Novak said. As with Maya the wolf pup, researchers often have to create hundreds of embryos and successfully implant them in multiple surrogates for just one animal to be born, which can make cloning an expensive process.

Due to these high costs, the emergence of private entities like Sinogene and Revive & Restore will likely play a key role in the future of conservation cloning. Historically, most cloning research has been done by universities that are underfunded, Novak said. Therefore, "the partnership of for-profit companies with conservation programs is key to turning cloning from a seldom-researched technique into a valuable conservation tool."

For cloning advocates, the birth of Maya is another step in the right direction for this area of research.

"It's great to see more wildlife cloning work being done," Novak said. "I hope all these recent achievements in cloning show the world that cloning is ready to use as a beneficial tool for wildlife conservation."

Originally published on Live Science.

This article is republished from The Conversation(opens in new tab) under a Creative Commons license. Read the original article(opens in new tab).

Amazon, Borneo, Congo, Daintree. We know the names of many of the world’s largest or most famous rainforests. And many of us know about the world’s largest span of forests, the boreal forests stretching from Russia to Canada.

But how many of us could name an underwater forest? Hidden underwater are huge kelp and seaweed forests, stretching much further than we previously realised. Few are even named. But their lush canopies are home to huge numbers of marine species.

Off the coastline of southern Africa lies the Great African Seaforest, while Australia boasts the Great Southern Reef around its southern reaches. There are many more vast but unnamed underwater forests all over the world.

Our new research has discovered just how extensive and productive they are. The world’s ocean forests, we found, cover an area twice the size of India.

These seaweed forests face threats from marine heatwaves and climate change. But they may also hold part of the answer, with their ability to grow quickly and sequester carbon.

What are ocean forests?

Underwater forests are formed by seaweeds, which are types of algae. Like other plants, seaweeds grow by capturing the Sun’s energy and carbon dioxide through photosynthesis. The largest species grow tens of metres high, forming forest canopies that sway in a never-ending dance as swells move through. To swim through one is to see dappled light and shadow and a sense of constant movement.

Just like trees on land, these seaweeds offer habitat, food and shelter to a wide variety of marine organisms. Large species such as sea-bamboo and giant kelp have gas-filled structures that work like little balloons and help them create vast floating canopies. Other species relies on strong stems to stay upright and support their photosynthetic blades. Others again, like golden kelp on Australia’s Great Southern Reef, drape over seafloor.

How extensive are these forests and how fast do they grow?

Seaweeds have long been known to be among the fastest growing plants on the planet. But to date, it’s been very challenging to estimate how large an area their forests cover.

On land, you can now easily measure forests by satellite. Underwater, it’s much more complicated. Most satellites cannot take measurements at the depths where underwater forests are found.

To overcome this challenge, we relied on millions of underwater records from scientific literature, online repositories, local herbaria and citizen science initiatives.

With this information, we modelled the global distribution of ocean forests, finding they cover between 6 million and 7.2 million square kilometres. That’s larger than the Amazon.

Next, we assessed how productive these ocean forests are – that is, how much they grow. Once again, there were no unified global records. We had to go through hundreds of individual experimental studies from across the globe where seaweed growth rates had been measured by scuba divers.

We found ocean forests are even more productive than many intensely farmed crops such as wheat, rice and corn. Productivity was highest in temperate regions, which are usually bathed in cool, nutrient-rich water. Every year, on average, ocean forests in these regions produce 2 to 11 times more biomass per area than these crops.

What do our findings mean for the challenges we face?

These findings are encouraging. We could harness this immense productivity to help meet the world’s future food security. Seaweed farms can supplement food production on land and boost sustainable development.

These fast growth rates also mean seaweeds are hungry for carbon dioxide. As they grow, they pull large quantities of carbon from seawater and the atmosphere. Globally, ocean forests may take up as much carbon as the Amazon.

Read more: A marine heatwave has wiped out a swathe of WA's undersea kelp forest

This suggests they could play a role in mitigating climate change. However, not all that carbon may end up sequestered, as this requires seaweed carbon to be locked away from the atmosphere for relatively long periods of time. First estimates suggest that a sizeable proportion of seaweed could be sequestered in sediments or the deep sea. But exactly how much seaweed carbon ends up sequestered naturally is an area of intense research.

Hard times for ocean forests

Almost all of the extra heat trapped by the 2,400 gigatonnes of greenhouse gases we have emitted so far has gone into our oceans.

This means ocean forests are facing very difficult conditions. Large expanses of ocean forests have recently disappeared off Western Australia, eastern Canada and California, resulting in the loss of habitat and carbon sequestration potential.

Conversely, as sea ice melts and water temperatures warm, some Arctic regions are expected to see expansion of their ocean forests.

These overlooked forests play an crucial, largely unseen role off our coasts. The majority of the world’s underwater forests are unrecognised, unexplored and uncharted.

Without substantial efforts to improve our knowledge, it will not be possible to ensure their protection and conservation – let alone harness the full potential of the many opportunities they provide.

Read more: Can selective breeding of 'super kelp' save our cold water reefs from hotter seas?

Originally published on The Conversation.

The rim rock crowned snake (Tantilla oolitica) is the rarest snake in North America, and scientists hadn't glimpsed one in the wild in more than four years. But when one of the elusive snakes recently turned up in a state park in Florida, the sighting wasn't a happy one — the snake was a corpse in a gruesome wildlife death scene.

A visitor to the John Pennekamp Coral Reef State Park on Key Largo found the dead snake on Feb. 28; it had choked on a giant centipede that was still lodged partway down its gullet. (The centipede, which had been swallowed headfirst, was also deceased.)

While this grisly tableau suggests that the snake perished while choking on the monstrous meal — the centipede was about one-third the size of its predator — it's also possible that the snake succumbed to a lethal dose of the centipede's venom, researchers suggested in a new study, published online Sunday (Sept. 4) in the journal The Scientific Naturalist.

Rim rock crowned snakes are nonvenomous and have black heads and pinkish-tan bodies that measure 6 to 11 inches (15 to 28 centimeters) long, and they are found only in the Florida Keys and along the state's southeastern Atlantic coast, according to the University of Florida's Department of Wildlife Ecology and Conservation. The snakes have been on the state's list of threatened species since 1975; the last living specimen was spotted in 2015, while the last recorded sighting was a dead individual that had been killed by a cat in 2018, said lead study author Kevin Enge, an associate research scientist with the Florida Fish and Wildlife Conservation Commission.

Related: Snake photos: Pythons swallow crocodiles and other animals … whole

"Rim rock crowned snakes have never been easy to find on Key Largo or elsewhere," as these small, burrowing snakes spend most of their time hiding under leaf litter or in soil pockets, and are typically only seen after heavy rains force them to the surface, Enge explained. 

"For snake lovers who keep a species life list, this is the Holy Grail in Florida — but most snake hunters have never seen one despite weeks of searching," he told Live Science in an email. 

When the park visitor found the dead snake, which measured about 8 inches (21 cm) long, the reptile's mouth was gaping wide and the back end of a 3-inch-long (7.3 cm) juvenile Caribbean giant centipede (Scolopendra alternans) was hanging out, protruding about 1 inch (2.3 cm). Park rangers then contacted scientists with the Florida Museum of Natural History (FLMNH) in Gainesville, who brought the snake and centipede to the museum's herpetology collection. There, researchers preserved and analyzed the pair, hoping that the specimens united in death would reveal clues about the snake's habits and biology. 

"Extremely rare"

"As a snake biologist in Florida, this finding was extremely exciting," said study co-author Coleman Sheehy, a researcher and collection manager at the FLMNH. "We have 15 preserved Tantilla oolitica specimens at the Florida Museum, which is half of all the known specimens of this species known anywhere. We also have the holotype and paratype specimens, which are the specimens on which the original species description is based. However, we do not have any specimens like this that died while eating prey, and I don't think anyone else does either."  

Related: Do snakes have ears?

This find was extremely rare, "even for common species of snakes," Sheehy told Live Science in an email. "In our entire collection, I think we may have two other snake specimens of other species that died while eating prey." 

To learn more about what, exactly, killed the snake, the scientists used enhanced computed tomography, or CT scans, to peer inside the animal and visualize its last meal, without physically damaging the specimen. It was unknown how long the snake had been lying on the path after it died, but the soft tissue was still intact and in good condition, revealing an unexpected wealth of detail. 

"The trachea was so well preserved that we could actually see what parts along its length contained air and what part[s] were occluded," Sheehy said. Their scans revealed that the snake's trachea was compressed and may have been obstructed, possibly leading to asphyxiation, the scientists reported. Snakes frequently swallow large prey and can vomit it back up if necessary, but in this case, it's likely that "the orientation of the numerous legs of the centipede made it difficult to regurgitate quickly," Enge said. 

Another possible cause of death may have been a venomous sting from the oversize front legs of the dying centipede during its journey down the snake's throat. When the study authors examined the scans, they detected a wound that was barely visible externally but showed more damage internally. While this injury on its own wouldn't have been life-threatening, it may have delivered enough venom to be fatal.

However, it's also possible that the snake was wounded prior to swallowing the centipede and the venom did not prevent it from subduing its meal, the scientists noted. If this scenario is correct, it would suggest that the species has some resistance to centipede toxins — an adaptation that scientists have suspected but have not confirmed.

"This fluke finding of a freshly dead, intact specimen on the surface provided a rare opportunity to do some detective work using state-of-the-art science," Enge said. "We were able to get a good idea of what killed this rare snake, which probably could not have been ascertained by dissection."

Originally published on Live Science.

Can an extinct species be brought back to life? Scientists are taking a "giant leap" in that direction by using gene-editing to resurrect the Tasmanian tiger, a carnivorous marsupial from Australia and the continent's only marsupial apex predator. It died out nearly a century ago, driven to extinction by human hunters and by the introduction of nonnative species to their grassland, wetland and forest habitats.

Researchers with the project, a collaboration between the University of Melbourne and the genetic engineering company Colossal Biosciences in Dallas, suggest that this so-called de-extinction could reinstall Tasmanian tigers (Thylacinus cynocephalus) to the wild within a decade, and could help restore balance to beleaguered Australian ecosystems where the animals once roamed, university representatives said in a statement.

However, such efforts also raise questions about prioritizing high-tech solutions for resurrecting charismatic animals that humans have already exterminated, while hundreds of species teeter on the brink of extinction today, The Guardian noted.

Related: Stunning colorized footage provides a glimpse of the last known Tasmanian tiger

Scientists in the Thylacine Integrated Genomic Restoration Research (TIGRR) Lab at the University of Melbourne have already sequenced the thylacine genome from preserved thylacine DNA and pinpointed which living marsupials are most genetically similar to thylacines, according to the statement. Colossal's CRISPR gene editing technology will enable the group to take cells from a closely related living marsupial species, the fat-tailed dunnart (Sminthopsis crassicaudata), create a template genome, and then edit it to produce a thylacine genome and grow viable thylacine embryos. 

"With this partnership, I now believe that in ten years' time we could have our first living baby thylacine since they were hunted to extinction close to a century ago," team member Andrew Pask, a professor of epigenetics at the University of Melbourne and leader of the TIGRR Lab, said in the statement. "We can now take the giant leaps to conserve Australia's threatened marsupials and take on the grand challenge of de-extincting animals we had lost."

Tasmanian tigers, or thylacines, appeared in Australia about 4 million years ago and were once widespread across the continent, according to the Australian Museum in Sydney. Despite their name, they didn't look much like tigers; in fact, they were sometimes referred to as "long dogs with stripes" because of their doglike heads and distinctively-marked rumps, according to the University of Melbourne. Thylacines had short ears and legs, and long, rigid tails, and they were about the size of an American coyote, standing approximately 24 inches (60 centimeters) tall and weighing 37 to 44 pounds (17 to 20 kilograms), scientists reported in 2020 in the journal Proceedings of the Royal Society B: Biological Sciences.

Thylacines vanished from most of the Australian mainland about 2,000 years ago, and an estimated population of about 5,000 were in Tasmania around the time of European colonization in the 1800s, according to the National Museum of Australia (NMA) in Canberra. But by the 1920s, thousands of Tasmanian tigers had been slaughtered by human hunters who mistakenly saw the marsupials as a threat to livestock. The last Tasmanian tiger seen in the wild was killed in 1930, and the last specimen in captivity — an individual nicknamed "Benjamin" — died in the Hobart Zoo in 1936, NMA says.

According to researchers with the de-extinction project, resurrecting Tasmanian tigers would be a conservation success story; not only for restoring a species lost to human activity, but also for building a lifeline for vulnerable and threatened species across Australia, "developing gestational and genetic rescue technologies for future marsupial conservation efforts," Colossal CEO and co-founder Ben Lamm said in a statement.

"With our planet's biodiversity at risk, we will continue to contribute scientific resources to preserving the species and ecosystems necessary to sustain life," Lamm said.

Originally published on Live Science.

It's one of the oldest questions tackled by naturalists: Why do tropical regions have so much biodiversity compared with other areas of the globe? 

"The nearer we approach the tropics, the greater the increase in the variety of structure, grace of form, and mixture of colors, as also in perpetual youth and vigor of organic life," German naturalist Alexander von Humboldt wrote in 1807. In tropical regions, there are more species of plants, animals and fungi in any given area, and that concentration declines as you move farther from the equator. 

This phenomenon is known as the latitudinal diversity gradient. But what causes it?

According to Andrew Dobson, a professor of disease ecology and conservation at Princeton University, there are three main hypotheses to explain why tropical areas are so biodiverse, and multiple explanations may play a role.

Related: What is the most genetically diverse species?

The first hypothesis relies on energy. There is more sunlight in the tropics and, when combined with rainfall and soil nutrients, this leads to more plant growth. "Half the year is in darkness as you go into the Arctic Circle or the Antarctic Circle," Dobson said. "There's no energy coming in to sustain life." The abundance of plants, therefore, means more animals can survive and reproduce.

From an evolutionary perspective, the abundance of plant growth leads to a greater diversity of animals. "If you can explain plant diversity, then you have more things to eat the plants and either be specialists or generalists, and then more things to eat the herbivores and either be specialists or generalists," Dobson said. This level of interaction across the food web — with plants and fungi, herbivorous animals, and predators — leads to a "higher rate of speciation," the point at which a new species appears to be distinct from its evolutionary ancestors.

The second hypothesis is that the tropics are much older environments that haven't been interrupted by big freezes, so species have had a longer time to evolve. Most of today's biodiversity has been developing over the past 200 million years, but it has been affected by multiple ice ages. The expansions and contractions of the polar ice sheets "completely remove life from the northernmost [and southernmost] areas," Dobson said. "Life goes on in the tropics, continuing to evolve and diversify," whereas life at the poles has to recolonize. 

Meanwhile, diverse tropical life can't just spread to Earth's colder regions. As more species accumulate in tropical environments, they adapt to tropical climates and then struggle to adapt while attempting to expand to colder climes, Dobson said.

The third hypothesis has to do with diversity limits. This theory posits that different environments have a "carrying capacity for species richness, which means that more species can exist in the tropics than in the temperate zones," said David Storch, a professor of ecology at Charles University in Prague. Environments with more resources support a greater diversity of animals, some of which are in competition. But an increase in the production of plant matter does not also cause a rise in the number of species. "It's not only about the productivity and the amount of resources, but also about the fluctuation of resources in the environment," Storch said. 

However, although the tropics have a high rate of speciation (creation of new species), these balmy regions also have a high rate of species extinction. High rates of speciation can lead to smaller populations of species, in which many species are interacting or in competition in a small area, leaving them at a higher risk of extinction. This hypothesis is supported by the second, which suggests that the tropics, as well as being a "cradle" for the emergence of new species, is also a "museum" where the lineages of many older species remain. 

Of course, not every species that has emerged over the last 200 million years remains there, but the equilibrium between the rates of speciation and the extinction gives rise to the idea that the tropics have a high carrying capacity for species richness, according to Storch.

Related: How long do most species last before going extinct?

But the latitudinal diversity gradient is not universal. There are some examples that buck the trend. Some animals, such as penguins, rely on the abundance of food in cold Antarctic waters. Some "species originated far away from the equator [and] they didn't have enough time to spread into the tropics," so they became specially adapted to colder climates, Storch said. In other words, diversity in certain plant and animal groups can still emerge on the frigid poles.

Equally, there is a greater diversity of certain species in temperate or colder climates compared with the Earth's poles. Conifer trees, for example, "are confined to the colder regions due to competition from broadleaf [trees]. Some groups are outcompeted, basically pushed out of the tropics by their competitors," Storch said. Being forced to adapt to temperate or colder climates causes a different kind of biodiversity in the creation of subspecies. While the tropics are host to a greater variety of distinct, different species, many studies now report a high diversification of subspecies at higher latitudes, according to Storch.

One group that reverses the hypothesis of the latitudinal diversity gradient is parasitic worms; diversity in parasites increases as you move away from the equator. The high number of species in the tropics means their relative abundance is reduced because they are all competing, so the population density of the species, and the species ranges (the amount of geographical distance they cover) are much smaller than they are in the temperate zone or in the Arctic. 

The bigger the host population, "the more parasites they can support and more parasite species they can support," Dobson said. "If you have lower diversity but bigger population of those host organisms, then they can support a bigger diversity of parasites. Having larger species with larger range sizes allows more parasites to colonize those species in the temperate and subtropical zones." Therefore, an area with lower overall biodiversity, actually acts as a "speciation pump" according to Dobson, generating more kinds of parasitic worms than anywhere else in the world.

Originally published on Live Science.

The present extinction rate of life on Earth doesn't qualify as a mass extinction event yet — but current trends show that it eventually will, a new study finds. The number of species that are currently hurtling toward extinction has led many ecologists to argue that we are undergoing a sixth mass extinction — but we are only witnessing the beginning and it will likely get much worse. 

According to a new study, however, the percentage of extinctions caused by global temperature increases from climate change will not reach the same level as a major mass extinction event, at least not in the near future.

There have been five major mass extinctions throughout Earth's 4.5 billion-year history, and scientists look to those cataclysms of the distant past to understand how climate change is now affecting global diversity in ways that may be irreversible. 

During a mass extinction, a high percentage of global biodiversity is extinguished faster than it can be replaced, and this happens over a relatively short period of time by geologic standards — less than 2.8 million years, according to the Natural History Museum in London. Species may go extinct for a number of reasons, so to understand what a "normal" extinction rate looks like, ecologists measure what is known as the "background rate"' of extinction, said the study's sole author Kunio Kaiho, a professor emeritus at the Department of Earth Science at Tohoku University in Japan. 

According to Kaiho, "5-10% species extinctions in 1 million years corresponds to the background rate." A higher rate, such as "more than 10% species extinction in a short time (e.g., hundreds of years) is a significant event," Kaiho told Live Science in an email.  

Related: 'Lost extinction,' uncovered for the first time, claimed more than 60% of Africa's primates

However, estimating the background rate of extinction for past epochs can be "really tricky," because fossil records tend to overrepresent larger, more abundant species, said David Storch, a professor in the Department of Ecology at Charles University in Prague who was not involved in the new study. That being said, "the current rate of extinction is about two orders of magnitude higher than the normal rate of extinction," Storch told Live Science. 

Major mass extinctions result in "more than 60% species loss," Kaiho said. However, "minor mass extinction [events] occurred more frequently." In the new study, published July 22 in the journal Biogeosciences, Kaiho argues that changes in climate cause higher extinction rates, but that the present rate cannot yet be considered a mass extinction event by this strict definition. 

The previous five major mass extinction events were the Ordovician-Silurian extinction (about 440 million years ago), the Late Devonian extinction (about 365 million years ago), the Permian-Triassic extinction (about 253 million years ago), the Triassic-Jurassic extinction (about 201 million years ago) and the Cretaceous-Paleogene extinction (about 66 million years ago). These events have also been associated with drastic changes in Earth's climate, such as changes in surface temperature (both warming and cooling), acid rain, ozone depletion, reduced sunlight, desertification, soil erosion and a reduction of oxygen in the ocean, Kaiho reported. But according to Storch, changes in atmospheric and oceanic chemistry played bigger roles in these extinctions than global warming or cooling did. (These changes are linked, as global warming can increase the oceans' acidity as well as the atmosphere's composition, but volcanic activity also played a large role.)

"The climate change detected during these last mass extinctions may not be the [sole] cause of the extinctions, but [the rate of extinction] may be the consequence of the other global changes which happened at that time," Storch said.

Because prior mass extinctions were triggered by volcanic eruptions and, in the case of the Cretaceous event, an asteroid impact, the resultant changes in climate were rapid and drastic. In the study, Kaiho argues that the speed of environmental change is more important than the magnitude of change alone in causing massive extinction rates, because "during slow climate changes, animals can migrate to survive."

In order to meet the definition of a major mass extinction event, scientists would need to observe the extinction of 60% of species and 35% of genera (the plural of genus). However, just because this magnitude of extinctions has not been observed yet, does not mean it is not currently underway. The sixth extinction differs from its predecessors because it is driven by human-made climate change. Kaiho's paper argues that because the pace of such climate change is gradual, rather than abrupt and drastic, we are unlikely to see extinction rates in the near future that meet the definition of a major mass extinction event, but they may well qualify for a minor mass extinction.

Related: What could drive humans to extinction?

"An increase in average global temperatures of 9 degrees Celsius [16.2 degrees Fahrenheit] is essential for major mass extinctions coinciding with global warming," and such an increase would not happen "at least till 2500 under the worst scenario," Kaiho said. Because the rate of species extinction changes in parallel with global surface temperatures, we will not see an abrupt and massive loss of species, but rather a slow and steady rate of species extinction in the near future, which will not culminate in the loss of 60% of earth's species, Kaiho wrote in the study.

These findings come with an important caveat from many ecologists: the present rate of extinction is only an estimate and may be an inaccurate one. According to a January 2022 study published in the journal Biological Reviews, the number of species extinctions recorded is highly biased toward mammals and birds and overlooks many invertebrates, therefore significantly underestimating the true rate of species extinction. For now, according to David Storch, other human-driven actions such as habitat transformation through deforestation and pollution, as well as overhunting and the introduction of non-native species, play a much bigger role in driving the present rate of species extinction than rising average global temperatures.

Originally published on Live Science.

Tiny, monkeylike creatures called tarsiers sing duets together in the style of opera singers — but those who fail to hit the high notes may also flop at attracting mates, scientists recently suggested. 

With their large, pointed ears and expressive eyes, nocturnal tarsiers carry a striking resemblance to the diminutive Jedi master Yoda from "Star Wars" films. But while Yoda never demonstrated any operatic ability, tarsiers are energetic singers who may exert themselves vocally as a form of sexual selection or to signal to each other that it's time for all members of a troop to gather together to sleep, according to a new study.  

To learn more about these vocal performances, scientists eavesdropped on tarsiers in Tangkoko National Park in Sulawesi, Indonesia in July and August 2018, and captured 50 recordings of 14 pairs of Gursky’s spectral tarsiers (Tarsius spectrumgurskyae) singing their morning duets. Researchers from Sam Ratulangi University in Sulawesi and Cornell University in Ithaca, New York, used machine learning to distinguish and classify notes and musical phrases in the tarsiers' songs. Their findings, published Aug. 2 in the journal Frontiers in Ecology and Evolution, suggest that these performances are so taxing that not all tarsiers can hit the fast and high notes and duet proficiently. 

Related: See 15 crazy animal eyes — rectangular pupils to wild colors

Measuring just 3.5 to 6 inches (9 to 15 centimeters) tall and weighing no more than 7 ounces (200 grams), Gursky’s spectral tarsiers live only on Sulawesi, an Indonesian island east of Borneo. They were described as a separate species from other tarsiers in 2017 and are classified as vulnerable by the International Union for the Conservation of Nature's (IUCN) Red List of Threatened Species. About 13 species of tarsiers inhabit islands in Southeast Asia.

The researchers captured the tarsiers' duets using a handheld digital recorder and autonomous recording devices that were installed in the tarsiers' jungle habitats. "Tarsiers are one of the easier duetting primates to record and study, at least in Tangkoko National Park, as they have small home ranges and seem to duet most mornings," said senior study author Dena Clink, a researcher at Cornell’s K. Lisa Yang Center for Conservation Bioacoustics. "They are not afraid of humans, so we were able to get high-quality recordings relatively easily." 

When the scientists analyzed the intricate duets, which were performed between male and female tarsiers, they found that the performances resembled coloratura — a singing style that produces many notes very rapidly and that’s used by opera singers during arias to showcase their control and virtuosity. 

"The duets exhibit acoustic trade-offs in note rate and note bandwidth — the range of frequencies within a note," said Isabel Comella, lead study author and a researcher at the K. Lisa Yang Center. The tarsiers that sing more slowly do so with the widest range of frequencies within a note, while the tarsiers that repeat notes more quickly only appear capable of a narrower range of frequencies within a note, Comella told Live Science in an email. Only a minority manage both simultaneously. The authors hypothesize that rapidly singing notes containing a broad range of frequencies during a duet may be more physiologically and neurologically taxing for the singer, with only physically fit individuals able to do so. 

Exactly why tarsiers duet in such a complex and physically taxing way is unknown, largely because the animals are rarely studied. Other primates are known to sing duets, including a type of lemur called the indri (Indri indri), titi monkeys in the Callicebus genus, and northern gray gibbons (Hylobates funereus), according to the authors. Prior studies into primate duets suggest that this behavior may be used for finding or guarding a mate, defending territory or strengthening social bonds, though further research is required to determine exactly why tarsiers are performing these duets, the study authors reported.

However, one possibility for the Sulawesi tarsiers is that their duetting could be linked to organization of their social groups. Tarsiers often forage alone at night for insects, and then reunite in the morning to sleep, and they may sing together at night "as a way to bring all group members to the same sleep tree," a function that is not seen in other duetting primates, Comella said. 

It could be a unique behavior to the tarsiers in Sulawesi, according to the authors. Tarsiers in the Philippines and Borneo are more solitary and don’t engage in duets as regularly. 

Though Gursky’s spectral tarsiers sing their duets in the range of human hearing, the primates also vocalize in the ultrasonic range, which researchers are currently investigating. “We hope that with the advent of low-cost autonomous recording units and even smartphones we can start to learn more about the vocal behavior of tarsiers across Sulawesi," Clink said.

Originally published on Live Science. 

New footage showing a giant, peculiar-looking tentacled sea creature floating languidly in the depths of the Pacific Ocean has left researchers questioning if what they’re seeing is a new species.

A team of scientists spotted the strange animal while on board the E/V Nautilus, a research vessel used by the Ocean Exploration Trust — a nonprofit organization conducting deep-sea research. In a recently released video, the expedition researchers oohed and aahed as images of the bizarre creature came into focus. "My mind is blown right now," one of the scientists on board can be heard saying off-camera, as the boat’s remotely operated vehicle (ROV) scanned the ocean floor and inched closer to the strange sight. "I’m not on the edge of my seat or nothing," another scientist quipped.   

Moments later, the scientists spied another of the oddball creatures nearby, though they were unable to record video of the second individual.

With tentacles extending 16 inches (40 centimeters) from a nearly 7-foot-long (2 meters) stalk, and a single feeding polyp with barbed tentacles cupping the polyp like spiky petals, the creature resembled a very strange, free-swimming flower that was roughly the size of the ROV. It was spotted July 7 at 9,823 feet (2,994 m) below the surface near a previously unexplored seamount north of Johnston Atoll, an unincorporated U.S. territory and a National Wildlife Refuge in the Pacific Ocean west of Hawaii.

Researchers initially suspected that they had crossed paths with Solumbellula monocephalus, also known as a Solumbellula sea pen, which is part of the Cnidaria phylum that includes jellyfish, hydras and coral. However, the only known sightings of sea pens prior to this have occurred in the Atlantic and Indian oceans, so it's possible that the scientists may have stumbled upon a new species.

Related: 10 weird creatures found in the deep sea in 2021

Steve Auscavitch, the expedition’s lead researcher and a deep-sea biologist and post-doctoral scholar at Boston University, described the sighting as "fascinating."

"From time to time, we come across something that we never expected to see, and those are often the most powerful observations," he told Live Science.

He added, "We were nearing the end of our cruise and were at the bottom of the seafloor when we observed the two [sea pens]. The one we captured on video was massive, possibly the same size or larger than Hercules, our ROV. When I saw this amazing sea pen on video, I knew exactly what it could be."

But just to be sure, Auscavitch sought input from biologists on shore, who helped confirm his suspicions that it was a sea pen, a coral relative. Based on the animal’s impressive size, Auscavitch surmised that it was rather old, however he can’t give a specific age. (Sea pens reach maturity at five or six years of age, and can live for more than a decade.) 

"Prior to this, Solumbellula monocephalus had never been seen in the central Pacific and never collected," he said.

Interestingly, his team’s discovery came several months after scientists in Spain named two new genera of sea pens: Pseudumbellula. and Solumbellula , the latter of which would include the new species. Those findings were published in February in the journal Invertebrate Systematics.

However, Auscavitch said that more research needs to be done to determine if this is the first Pacific Solumbellula monocephalus or potentially a new species in the ocean basin.  

"Findings like this are rare, and we never expected to see something like this," he said. "The most exciting part of this research is that we come across these things from time to time, and it really does expand our horizon about where animals can live and exist in the deep sea."

Originally published on Live Science.

Is the summer heat getting you down? Cool off with a virtual dip into icy Arctic waters and watch as tens of thousands of beluga whales frolic in the frigid sea. Starting Friday (July 15), the research vessel Delphi will broadcast a beluga whale livestream, direct from the Churchill River estuary where the river flows into Hudson Bay in northeastern Canada. 

The livestream, produced in a partnership between Arctic conservation nonprofit Polar Bears International and explore.org, is in celebration of Arctic Sea Ice Day on July 15. The goal is to raise public interest in sea ice and increase awareness of its importance to the Arctic ecosystem.

"It is to the ocean what soil is to the forest," Alysa McCall, the director of conservation outreach and staff scientist at Polar Bears International, told Live Science.

Viewing belugas 

The "beluga cams" go live each year as a group of approximately 55,000 beluga whales migrate to the shallow waters of Hudson Bay. The bay is locked in by ice in the winter, according to Stephen Petersen, director of conservation and research at Canada's Assiniboine Park Conservancy, which forces the belugas (Delphinapterus leucas) to head north into more open seas. But in the summer, the whales return. The whales may find that the sheltered waters of the bay offer protection from killer whales, Petersen told Live Science, while the estuaries provide hungry belugas with ample food. It’s also possible that the warm, low-salt waters from the Churchill River estuary may be beneficial for young calves that haven't developed a full covering of blubber, or for adult whales as they undergo an annual molt and shed their skin. 

Two cameras aboard Polar Bears International's beluga boat Delphi (short for Delphinapterus, part of beluga's scientific name) provide different views of this thriving whale population: one from the deck and one from below the water’s surface, which also captures audio of the whale's chittering calls. The whales can make a variety of noises, ranging from clicking sounds to squawks and airy snorts. 

Related: Lone beluga whale spotted 1,500 miles from home, and nobody knows why

Beluga whales are found throughout the Arctic and sub-Arctic. Some populations are endangered, but the one that migrates into Hudson Bay each year is a healthy size, Petersen said. One of the goals of the beluga cams is to maintain that population's health.

"We want to build up monitoring so if threats appear or if that population changes we can see that before we get to a critical spot," Petersen said. 

As part of that effort, Petersen runs the Beluga Bits citizen science project. Beluga cam viewers can collect screenshots of the whales they see as the Delphi livestreams the migration during July and August. Then, throughout the year, anyone can get involved with the project by helping to identify individual whales in the images at zooniverse.org. These classifications help scientists answer questions like whether the same whales return to the same places each year. 

Saving sea ice 

Polar Bears International will hold a live launch event for the beluga cams at 10:45 a.m. Eastern Standard Time (EST) on July 15. The organization will also be celebrating Arctic Sea Ice Day with a live event at 1:00 p.m. EST that will focus on why the ice is important. 

"Sea ice is a critical habitat for Arctic species," McCall told Live Science. Walrus and seals use sea ice as a refuge to haul out on, seals give birth on sea ice, beluga whales use sea ice for protection from orcas. Every species in the Arctic, in the ocean, is supported by Arctic sea ice, because within Arctic sea ice grows algae which is like the plants of the north." 

This algae forms the base of the food chain, McCall said, feeding fish that then feed belugas and other sea mammals. 

However, Arctic sea ice cover overall is shrinking rapidly due to the warming climate, with recent years marking record lows in summer ice extent and experiencing thinning of old, multi-year ice. Near Churchill, Manitoba on the Hudson Bay, the ice historically broke up around July 15, McCall said. These days, the breakup typically occurs three to four weeks earlier than that.  

But sea ice's sensitivity to climate change means that it can also potentially recover quickly if the climate cools, McCall said, which offers hope for a future chilly enough to keep polar bears, beluga whales and other Arctic denizens thriving. 

"When we get our carbon emissions at a more sustainable level and we start moving to greener energy more broadly, we know that sea ice will bounce back," she said. "Actions you take now to reduce carbon emissions and switch to solar energy, wind energy and get these big corporations on board with being more sustainable, that absolutely positively impacts the ice which positively impacts all the animals that rely on it."

Originally published on Live Science 

A bizarre-looking translucent, gelatinous fish with an unusual suction cup on its belly made a surprise appearance for a group of scientists who were studying the deep sea near Alaska. 

The odd animal is a blotched snailfish (Crystallichthys cyclospilus), a seafloor-dwelling creature that lives exclusively in the North Pacific and can survive more than 2,723 feet (830 meters) below the ocean surface. Researchers from the National Oceanic and Atmospheric Administration (NOAA) stumbled upon this squishy weirdo while trawling off the coast of the Aleutian Islands in Alaska as part of a routine survey of the deep sea ecosystem there. On June 19, NOAA scientist and expedition crew member Sarah Friedman shared a photo of the blotched snailfish on Twitter.

The fish's body is "very gelatinous" and felt like "holding a lump of Jell-O," Friedman told Live Science in an email. "This is thought to be an adaptation to maintain neutral buoyancy and efficiently swim while coping with the crushing pressure of the deep sea," she added.

The team was excited to show off the peculiar specimen online so that more people could see the fish for themselves. "They live in relatively remote locations and at deeper depths, so the average person will never encounter this species," Friedman said. But although such fish are uncommon, the researchers did find "four or five" different blotched snailfish specimens during the trip, she added.

Related: Translucent jellyfish, with fish trapped inside it, washes up on UK beach 

Blotched snailfish have bodies that are almost entirely see-through — apart from their eyes, stomachs and dark spots on their skin. This adaptation helps them to stay hidden from predators. "Many animals that live at deeper oceanic depths are translucent," Friedman said. It enables them to "blend in with the dark background in a habitat with limited light availability and few structures to hide behind."

Like several other species of snailfish, blotched snailfish have modified fins on their bellies that form a suction cup. "This allows them to easily attach to rocks and corals on the ocean floor and avoid expending the energy to constantly swim around, particularly in strong currents," Friedman said.

Overall, little is known about what these snailfish get up to in the deep ocean. "Snailfish are an incredibly enigmatic and diverse group of fishes, with species that inhabit a wide range of environments, from tidepools to the deepest trenches of the ocean," Friedman said. "But not much is known about the ecology of deeper snailfish species," although scientists do know that they prey on small invertebrates that crawl along the seafloor, she added. (There are more than 400 species of snailfish globally.)

The team also found a number of other interesting marine specimens during the trip, including a giant sea spider (which isn't actually a true spider); an anglerfish with massive pointed teeth and a luminous barb for luring prey; and a barreleye fish, which can swivel its eyes to peer through the top of its translucent head.

However, the main goal of these trawls is not to find rare species. Rather, the surveys are carried out to assess the overall health of the ecosystem, particularly regarding the populations of commercially targeted species. "This research is essential to sustainably manage fish and crab species that support commercial, recreational and subsistence fisheries and Alaska coastal communities," Friedman said.

Originally published on Live Science.

A secret population of polar bears in Greenland has been discovered in a seemingly impossible habitat — one that, for most of the year, lacks the floating platforms of sea ice the beasts use to hunt. The unusual group, which scientists previously thought was part of another nearby population, has been hiding in plain sight for hundreds of years.

The bears live on the steep slopes around fjords — long and narrow coastal inlets, where glaciers meet the ocean — and hunt on a patchwork of glacial ice that breaks up in these inlets. The new discovery suggests that some polar bears, at least, may be able to adapt to sea ice disappearing as climate change worsens, the study suggests.

Still, that's no silver bullet for the species at large.

"Glacier ice may help small numbers of polar bears survive for longer periods under climate warming, but it is not available for the vast majority of polar bears," lead researcher Kristin Laidre, a wildlife scientist at Polar Science Center at the University of Washington, told Live Science in an email. That's because this type of glacier ice is only found near a small fraction of other polar bear populations.

Related: Why aren't there polar bears in Antarctica?

Until recently, scientists had identified 19 known subpopulations of polar bears (Ursus maritimus) living in the Arctic Circle. One of those populations spans a 1,988-mile (3,200 kilometers) stretch of the eastern coast of Greenland. But when researchers took a detailed look at this group to monitor their numbers, they realized the bears actually comprised two completely separate populations. 

Researchers analyzed 36 years' worth of tracking data from bears tagged with GPS collars and found that bears from southeast Greenland did not pass above a latitude of 64 degrees north, and bears from the northeast did not pass the same line in the other direction. Genetic sampling from individual bears confirmed that the southeastern bears were distinct from their northeastern neighbors. 

"We present the first evidence for a genetically distinct and functionally isolated group of polar bears in southeast Greenland, which meet [the] criteria for recognition as the world’s 20th polar bear subpopulation," the researchers wrote in their new study, which was published June 16 in the journal Science.

The new southeastern population contains around 300 individuals, although determining an exact number is tricky, the researchers said. The newfound group is the most genetically diverse out of all 20 populations in the Arctic, and genetic comparisons suggest that they have been isolated from the northeastern population for around 200 years, the researchers said.

Polar bears are listed as vulnerable to extinction, according to the International Union for Conservation of Nature (IUCN) Red List, and there are around 36,000 individuals left in the wild. But some studies have suggested that the species could vanish by the end of the century due to the effects of climate change.

Despite being the world's largest land predator, polar bears are actually listed as marine mammals because they rely on a predominantly aquatic diet, consisting mainly of seals. But in order to hunt for food, the snow-white bears rely on sea ice as a platform to stalk their prey from above. Unfortunately, rising temperatures caused by climate change are reducing the amount of sea ice available, shrinking their natural habitat.  

Sea-ice extent waxes and wanes in the Arctic. The temporary ice sheets form on the ocean's surface during autumn and then melt away in spring. Polar bears normally survive for between 100 and 180 days without food as the sea ice disappears over the summer. But warming temperatures in the Arctic mean that sea ice is melting sooner and freezing later, pushing polar bears to the brink of starvation.

The fjords that are home to the southeastern polar bears lie at the southern edge of the Arctic Circle and, as a result, the region is sea ice-free for more than 250 days a year. These sea ice conditions mimic those predicted for the rest of the Arctic by the end of the 21st century, based on previous studies, which should make the fjords unlivable for polar bears, the researchers said. But the southeastern bears seem to be managing surprisingly well without the sea ice.  

The researchers think that the bears are taking advantage of glacial mélange, or the bits of ice that break off the fjords' glaciers and into the sea. The bears likely use these freshwater ice patches in the same way they use sea ice to hunt, which allows them to feed themselves during the long spells when sea ice is absent from the region. "This suggests that marine-terminating glaciers may serve as previously unrecognized climate refugia," the researchers wrote.

The southeastern population also lives nowhere near any human populations, and the area is believed to be too hard to reach for most hunters, which adds an extra layer of security for the bears. However, the steep slopes of the fjords can also be quite tricky for the polar bears to traverse, which may limit their movements. The birth rate among the new population is also very low compared with other populations, which researchers suspect is because potential mates struggle to reach one another.

In the new study, the researchers used genetic data to identify two individuals that could be immigrants from the northeastern population. These immigrant bears appear to have adapted very well to hunting on glacial mélange, which suggests that other populations might be able to follow suit as sea ice conditions deteriorate in other areas. The researchers identified other similar locations where glacial conditions could support polar bears in northern Greenland and Svalbard. However, moving to these locations may not be possible for a majority of bears. 

Although the study does provide a glimmer of hope for some polar bears, the researchers insist that this does not make climate change any less of a threat to the Arctic predators. "Loss of Arctic sea ice is still the primary threat to all polar bears," Laidre said. "This study does not change that." Sea ice will continue to decline across the Arctic, which will decrease the survival odds for most polar bears, she added.

Originally published on Live Science.

Scientists have discovered the world's biggest clone in Australia: A massive network of seagrass meadows that covers more than 77 square miles (200 square kilometers). The network of meadows is actually one single plant that has been continually cloning itself for almost 4,500 years. 

Researchers found the enormous clone while studying the genetic diversity of seagrasses in Shark Bay, a protected body of shallow water in Western Australia. They learned that almost all the region's meadows of Poseidon’s ribbon weed (Posidonia australis) are genetically identical. Further analysis revealed that unlike the other seagrasses in the area, which reproduce sexually, P. australis is actually cloning itself through an underground network of branching roots.

The P. australis clone stretches for around 112 miles (180 km) from end to end — albeit with a few patches — "making it the largest known example of a clone in any environment on Earth," the researchers wrote in the study, which was published online May 31 in the journal Proceedings of the Royal Society B. It dwarfs the previous record-holder: a clone of the seagrass Posidonia oceanica in the western Mediterranean, which spans around 9 miles (15 km).

"It is a single plant" that has been able to grow uninterrupted, senior researcher Elizabeth Sinclair, an evolutionary biologist at the University of Western Australia, told Live Science. If it remains undisturbed, the gigantic clone could continue to expand indefinitely, Sinclair added, making it practically immortal.

Related: 24,000-year-old 'zombies' revived and cloned from Arctic permafrost 

Clonal expansion 

The researchers found that the P. australis clone was expanding through a process known as "horizontal rhizome extension," in which a plant creates a genetically identical offshoot via an underground stem, or rhizome, which then develops its own roots and stem. When viewed from the surface — in this case, the sandy seafloor — the seagrass clumps look like separate specimens, but on a genetic level they are the same plant.

This is the same process that birthed Pando, a forest of quaking aspen trees (Populus tremuloides) in Utah that is actually just one massive, interconnected tree. 

While the P. australis meadows do not form a single unbroken meadow, they can still be considered to be one plant, Sinclair said. "Seagrass plants can fragment over time if there is damage or disturbance, but the fragments are still genetically identical," she added. It is possible that the P. australis meadows were once fully connected and may have been fragmented by grazing marine animals or extreme heat waves, the researchers wrote in the study. 

Based on the size and age of the P. australis meadows, researchers suspect that the clone is growing at a rate of around 6 to 14 inches (15 to 35 centimeters) per year. This may not sound like much, but it's a fairly quick rate when compared with the growth of other clonal seagrass meadows, the study authors reported. 

Theoretically, the clone could continue to grow indefinitely, Sinclair said, "as long as it's not disturbed and the environment doesn't change too quickly." The near-pristine conditions in Shark Bay, which was designated in 1991 as a World Heritage Area by the United Nations Educational, Scientific and Cultural Organization (UNESCO), mean that P. australis has remained relatively undisturbed throughout its entire life, she added. 

Genome duplication 

The researchers suspect that another part of the P. australis success story can be attributed to an unusual genetic superpower among plants that enables them to make an additional copy of their genome, which doubles the amount of DNA they can utilize to adapt to extreme changes in environmental conditions. 

Most organisms on Earth are diploids, which means their DNA contains a single pair of chromosomes. However, this is not the case for every organism. Some organisms, such as males of certain species of bees, have DNA that consists of single unpaired chromosomes, and these organisms are known as monoploids. Some organisms, known as polyploids, have two or more pairs of chromosomes.

Diploid plants can rapidly evolve into polyploids by doubling the number of chromosomes they have — a process known as whole-genome duplication, or polyploidy. The researchers suspect this is what happened to P. australis. 

There are two ways that a diploid plant can become a polyploid. It can happen when two separate but closely related species reproduce. Rather than combining parental DNA like a standard hybrid does, polyploid offspring get an entire copy of each parent's DNA. This is known as allopolyploidy. Polyploids can also emerge when two individuals from separate populations of the same species reproduce, and the offspring gets both complete sets of DNA. This is known as autopolyploidy. In both cases, the process is completely random and offspring becomes a brand new species because it is unable to reproduce with other individuals from its parents' species. 

In the case of P. australis, the researchers determined that the self-cloning seagrass likely emerged via autopolyploidy from a diploid ancestor that has likely since gone extinct. 

Polyploid plants are sometimes regarded as "evolutionary dead ends" because many are sterile, meaning they cannot reproduce sexually, Sinclair said. This limits the plants' ability to mutate, which is a key part of the theory of evolution. However, becoming a polyploid may can act as a last chance for plants that are facing extinction due to extreme environmental changes. 

"Combining two different genomes has essentially doubled the genetic diversity in the plant, likely increasing its ability to tolerate a wider range of environmental conditions," Sinclair said.

Changing conditions 

Until around 8,500 years ago, Shark Bay was actually above sea level and part of continental Australia. But rising sea levels caused by the end of the Last Glacial Period, the most recent ice age that ended around 12,000 years ago, submerged that part of the continent. The newly created marine habitat was inundated with new species, such as seagrasses. 

However, Shark Bay would have been a very unstable environment at the time because of its shallow water. Today, the average depth of Shark Bay is around 30 feet (9 meters) across the entire 8,880 square mile (23,000 square km) area, but it would have been even shallower around 4,500 years ago when P. australis emerged. Shallow oceans are more vulnerable to extreme shifts in temperature and salinity because there is less water to distribute and circulate heat and minerals. Their ecosystems are also more prone to disturbance and damage from tropical storms than deep-sea environments are.

In the study, the researchers suggested that if P. australis became polyploid before some type of extreme environmental upheaval during this more turbulent period, that gave P. australis an advantage over its diploid predecessors, which were unable to survive whatever change occurred.

Shark Bay continues to experience extreme conditions today to some degree. Annual temperatures can range between 63 and 86 degrees Fahrenheit (17 and 30 degrees Celsius), and the water is very salty. The bay's shallowness also means it is at risk from increasingly powerful heat waves caused by climate change, and is potentially susceptible to damage from cyclones. However, the environment is more stable than it was when P. australis first emerged. 

P. australis has likely continued to thrive in the area for millennia thanks to its resilience to environmental changes; other local seagrass species that continue to reproduce sexually, which is energetically expensive and requires lots of available space for new plants to grow, may be less resilient, Sinclair said. Without having to compete for space or divert energy to reproduction, P. australis has been free to clone itself at a steady pace and dominate the local ecosystem, she added.

Originally published on Live Science.

A pair of newfound species of glass frog — amphibians with transparent underbellies that put all their internal organs on display — have been discovered in Ecuador. But the naming of one of the species has triggered controversy. 

One of the new species has been, Hyalinobatrachium nouns, is lime-green on top and clear as window glass underneath; it's named after the Nouns decentralized autonomous organization (DAO), a group that buys and sells non-fungible tokens (NFTs) with cryptocurrency. The Nouns DAO won the right to name the frog species after donating (in traditional cash) to the environmental nonprofit Rainforest Trust. But because cryptocurrency is carbon-intensive, some conservationists are unhappy with the association.

"When charities get involved in crypto projects, they legitimize them — they legitimize a whole ecosystem that has a very high environmental impact," Peter Howson, a researcher from Northumbria University in the United Kingdom who studies environmental technologies, told Popular Science.

The little frogs at the center of the controversy were discovered in 2019. They're boggle-eyed and almost cartoonishly cute, with an eye-catching pattern on their backs of lime green with light yellow spots. The two new species look nearly identical and are very similar in appearance to other Hyalinobatrachium glass frogs. In fact, researchers led by Juan Manuel Guayasamin, a biologist at Universidad San Francisco de Quito in Ecuador, had to use genetic sequencing to discover that the frogs were unique species. 

H. nouns and the other newly described frog, now known as H. mashpi, live in the Ecuadorian Andes. They were quite genetically distinct despite being found only 11.7 miles (18.9 kilometers) apart, the researchers reported March 18 in the journal PeerJ. The species were separated by the Intag-Guayllabamba river valley. Numerous river valleys cut through the Ecuadorian Andes, the researchers wrote, which have led to a great deal of amphibian diversity in the region as populations get cut off from one another and diverge into different evolutionary paths. Of the 1,120 amphibian species reported in the Andes, about 70% are endemic, or found nowhere else on Earth, the researchers wrote. 

Glass frogs are known for their doting parenting style, which is unusual for amphibians. Females will stay on their eggs as the males fertilize them, protecting the brood. In some species, the fathers then take over, staying with the eggs as they develop, according to a 2017 study published in the Journal of Evolutionary Biology.

The Noun DAO is a group of people who pool together their crypto assets, voting on what to spend them on. Noun NFTs are mostly bought with the cryptocurrency Ethereum. One of the members of the Noun DAO is also on the board of the Rainforest Trust, Popular Science reported.

The controversy arises from the fact that cryptocurrencies get their value through a process called "proof of work," in which computers compete against one another to solve mathematical puzzles. This is extremely carbon-intensive, as it involves large amounts of computing power. James Deutsch, the CEO of Rainforest Trust, said the organization's leadership did not want to be seen as promoting cryptocurrencies and is worried about cryptocurrencies' impacts. 

"I am impressed that this group of very energetic, creative and wealthy people have taken the NFT art concept and used it specifically for charitable purposes," Deutsch told Popular Science. "But having said all that, it still wouldn't justify buying into something that was inherently destructive."

Originally published on Live Science

The Cambodian government recently asked people to stop picking a rare carnivorous plant that, when viewed from a certain angle, looks a lot like human male genitalia.

The Cambodian Ministry of Environment shared images on Facebook of three women snatching up pitcher plants and posing with them, and ministry officials requested that members of the public leave the rare plants alone, Cambodian news website the Khmer Times reported.

"What they are doing is wrong and please don’t do it again in the future!" The Ministry of Environment wrote on May 11 in the Facebook post. "Thank you for loving natural resources, but don’t harvest so it goes to waste!" 

Some news websites have reported that this plant is Nepenthes holdenii, but it's actually a closely related species called Nepenthes bokorensis, Jeremy Holden, a freelance wildlife photographer who first discovered N. Holdenii, and François Mey, a botanical illustrator who described both species, separately told Live Science.  

Related: Here's how plants became meat eaters

N. holdenii and N. bokorensis are similar in appearance and both only occur on nearby mountain ranges, which may explain the confusion. However, N. holdenii is the rarer of the two species and only a few researchers know where to find it.   

"My plant [N. holdenii] grows at a few secret locations in the Cardamom Mountains," of southwestern Cambodia, Holden said. "Bokorensis occurs on the far more accessible Phnom Bokor, which has undergone extensive development in recent years."

The Ministry of Environment's Facebook post and photos were responding to a video filmed on May 11 that showed the women picking the plants, according to Newsflare, a website that buys and licenses videos. This isn't the first time the government has issued a warning against harming the phallic and photogenic plants; senior officials at the ministry asked tourists not to pick N. bokorensis and N. holdenii in a statement in July 2021, because the activity could drive the plants to extinction.    

Nepenthes plants survive in low-nutrient soil by supplementing their diet with live insects, using their nectar and a sweet scent to attract prey. "When you smell a bokorensis pitcher, it smells sweet — just like a candy," Mey said.

Insects feed on nectar around the mouth of the plants' modified leaves that, when mature, resemble pitchers. When insects fall inside the pitchers, they drown in digestive fluids and the hungry plants absorb their nutrients. A pitcher plant's phallic resemblance is most pronounced when Nepenthes' leaves are still developing and the pitcher is closed. 

The natural habitats of carnivorous pitcher plants in Cambodia have declined due to agricultural expansion on private lands and the growth of the tourism industry into protected areas, according to a 2021 study in the Cambodian Journal of Natural History. 

Mey noted that while the phallic appearance of the plants is "fun," picking them could jeopardize their survival. 

"If people are interested, even in a funny way, to pose, to make selfies with the plants, it's fine," he said. "Just do not pick the pitchers because it weakens the plant, because the plant needs these pitchers to feed."

Originally published on Live Science.

Most people think of fishing as a relaxing way to pass an afternoon. But for YouTuber and conservationist Payton Moore, a recent fishing excursion was instead an intrepid monster hunt.

Last week, the Texan set sail down a Houston bayou in search of a truly gargantuan alligator gar (Atractosteus spatula) stretching over 8 feet (2.5 meters) long and tipping the scales at an estimated 300 pounds (136 kilograms). He found what he was looking for —and he even managed to catch the gigantic fish. "It felt like somebody's car had just started up and was rolling out of the driveway, and I’m hanging on to the end of it," Moore told the Houston Chronicle in an interview.

After hauling the fish ashore and measuring it, he released the gar back into the wild. Then he uploaded a video of the catch to his channel, WILD LIFE on May 7.

Related: Amazon 'river monster' turns up dead in Florida

"This was an excellent specimen," Nate Smith, a research biologist at the Texas Parks and Wildlife Department who researches alligator gar, told Live Science. "It’s hard to say what the exact weight was without more precise measurements or an official scale, but it's obviously a big fish." 

Officially, the largest alligator gar ever caught in Texas weighed in at 302 pounds (137 kg), according to Texas Parks and Wildlife. It was captured in 1953 on a trotline — a heavy line with shorter baited lines attached along its length at regular intervals. Moore's catch may have outweighed the previous champ, but since he did not seek official certification, his fish isn't record-eligible.

Gars belong to an ancient lineage of fish that were once widespread across the globe. Fossil remains of extinct gar dating back to the Cretaceous period (145 million to 66 million years ago) have been unearthed in Europe, Africa and south Asia, according to the Florida Museum. Only seven species are still around today.

Alligator gar, the largest of the extant gar species, are among the biggest freshwater fish in North America, according to National Geographic. They live exclusively in the lower Mississippi River Valley, where they chow down on smaller fish, blue crabs, waterfowl and the occasional turtle. While a fully-grown alligator gar may look intimidating, they pose no threat to humans. However, like other gar, their eggs are toxic to people and should not be eaten.

Historically, gar have been targeted by culling efforts by various state and federal agencies to make more room for game fish. But recent years have seen an increase in conservation efforts from organizations like the Texas Parks and Wildlife Department. Though there are few prohibitions on gar fishing (aside from a one-fish-per-day limit on alligator gar), Smith recommended that anglers interested in catching gar take a catch-and-release approach.

"One cool thing about alligator gar is that they can actually breathe air," Smith said. "For that reason, it's OK to have the fish out of the water for a few minutes for measurements or photos, just be sure to keep them cool and wet, especially in the hot sun."

Moore hopes that by sharing his video of the gargantuan gar he will help spark an appreciation for nature in all who see the massive fish. "They're so rare now, unfortunately," he said in his video. "It's an honor to share a wild space like this with an incredible wild animal like that."

Originally published on Live Science.

Fishers in Cambodia recently received a massive surprise when they reeled in a gigantic 400-pound stingray. The hefty ray was dragged up from the murky depths of the Mekong River after it swallowed a fish that had already been snagged on the fishers' line. 

The monstrous ray, which has been identified as a giant freshwater stingray (Urogymnus polylepis), was accidentally caught by locals on May 5 in the Stung Treng province in northeastern Cambodia. The fishers immediately alerted team members from the Wonders of the Mekong project — a conservation group run by the University of Nevada, Reno (UNR), in collaboration with local fishing authorities — who helped remove the fishing line and measure the ray before safely releasing it back into the river.

The massive specimen weighed a hefty 397 pounds (180 kilograms) and measured 6 feet (1.9 meters) wide and 13 feet (4 m) in length including its whip-like tail, which terminated in a 6 inch (15 centimeter) venomous, serrated barb, UNR representatives said in a statement.

Giant freshwater stingrays are the world's largest stingray species and "are contenders for the title of world's largest freshwater fish," Zeb Hogan, a UNR fish biologist and director of the Wonders of the Mekong project, told Live Science. 

Related: 7-foot 'monster' sturgeon found in Detroit River could be over 100 years old 

Little is known about these remarkably large fish because "catches are almost never reported," Hogan said, "which also makes it difficult to determine true abundance or population trends." 

However, past reports suggest that individuals can grow even bigger than this behemoth. "The size of this stingray was surprising," Hogan said. "But what's more surprising is that it's dwarfed by accounts of [individuals] twice the size reported by fishermen in the same area." 

The current record-holder for the largest fish in the Mekong River — which flows through China, Myanmar, Laos, Thailand, Cambodia and Vietnam — is a 646-pound (293 kg) Mekong giant catfish (Pangasianodon gigas) that was caught in Thailand in 2005, Hogan said. Giant freshwater stingrays can likely grow larger than this, he added. In 2009, a giant freshwater stingray caught in Thailand was estimated to weigh between 550 and 770 pounds (249 and 349 kg) but was never officially weighed. 

The largest freshwater fish in the world are beluga sturgeon (Huso huso); these enormous fish, which are found in Russia, can reach a maximum length of more than 26 feet (8 m) and weigh up to 2.2 tons (2 metric tons).

The Mekong River is also home to a number of other large aquatic species, including Irrawaddy dolphins, giant softshell turtles, Mekong giant catfish, giant barbs (a type of carp), giant goonch catfish and giant sheatfish (another type of catfish), according to the statement. "This remote and relatively pristine stretch of the Cambodian Mekong River appears to be the last place on Earth where all of these iconic giant freshwater species live alongside one another," Hogan said.

These giant species are able to grow to extreme sizes because the Mekong River has a wide variety of different habitat types including deep pools, braided channels, sand bars and islands that "provide refuge and space for the species to grow," Hogan said. Historically, the Mekong River is one of the "most productive rivers in the world" and would have provided an abundance of food for larger animals, he added.

However, the health of the Mekong River has seriously declined in recent decades due to water pollution, overfishing and habitat fragmentation due to river developments, such as dams, Hogan said. As a result, giant freshwater rays are now listed as endangered, according to the International Union for Conservation of Nature (IUCN) Red List of endangered species.

Originally published on Live Science.

An unidentified monkey spotted in Borneo is a rare hybrid between two different species that are competing for forest space, a new study suggests. 

Researchers concluded that the "mystery monkey" is likely the offspring of a proboscis monkey (Nasalis larvatus) and a silvery langur (Trachypithecus cristatus) — two distantly related species that share the same habitat. 

Coronavirus restrictions prevented the researchers from investigating the forest where the monkey lives, so instead the scientists analyzed photos that began appearing on social media in 2017. The monkey was initially photographed as a juvenile, but more recent photos from 2020 reveal that the animal is now a mature female and may have an infant of her own.

"She appeared to be nursing a baby," study co-author Nadine Ruppert, a primatologist at the Universiti Sains Malaysia (Science University of Malaysia), told Live Science in an email. "We were all in awe, it was quite surreal." 

Related: These endangered monkeys kept getting hit by cars. Scientists had a clever solution. 

While different species typically don't produce viable offspring if they mate, very closely related species may occasionally interbreed in the wild to create hybrids. For example, northern pig-tailed macaques (Macaca leonina) and southern pig-tailed macaques (Macaca nemestrina) interbreed in certain parts of Thailand, according to the International Union for Conservation of Nature (IUCN). However, interbreeding species are typically similar and belong to the same evolutionary group, or genus — proboscis monkeys and silvery langurs do not.

The hybrid monkey was spotted near the Kinabatangan River in Malaysian Borneo (the island is divided among three nations: Malaysia, Brunei and Indonesia), where the ranges of proboscis monkeys and silvery langurs overlap. But these two monkey species are visibly very different. 

Adult proboscis monkeys have pinkish faces with elongated noses, while adult silvery langurs have black faces with shorter, flatter noses. Probosicis monkeys are also larger. A male proboscis monkey can grow up to 30 inches (76 cm) long and weighs 44 to 53 pounds (20 to 24 kg). Silvery langurs only reach about 22 inches (56 cm) long and weigh 14.5 pounds (6.6 kg) on average, according to the New England Primate Conservancy.

Both species live in groups composed of a dominant male and multiple females and their offspring. Males born into these groups are pressured to leave once they mature to start groups of their own, or take over another group. However, habitat decline is limiting the areas where these dispersing males can go, according to Ruppert.

"We concluded from the observations that the photographers made that male proboscis monkeys are mating with female silver langurs in the area and that there are mixed groups where female proboscis monkeys even take care of silver langur babies," Ruppert said.

Male proboscis monkeys may be using their larger size to oust langur males and take over langur groups. The researchers suspect that the "mystery monkey" in the photos is the offspring of a male proboscis monkey and a female langur because it shares characteristics of both species. For example, her nose is pronounced like a female proboscis monkey, but not as elongated, and her face has a gray tinge. 

Most hybrids born from different species are sterile and unable to produce offspring, which makes the so-called mystery monkey and her baby even more unusual. It's possible she was allomothering — or taking care of another female's infant — but the photos showed that she had swollen breasts associated with lactation, which indicates the offspring was her own.

As unique and intriguing as the discovery appears to be, there's a downside. "It’s tragic that both species now cramp together in the remaining narrow riparian forest patches surrounded by oil palm plantations, where they compete for food and mating opportunities," Ruppert said. "I hope that people will start talking about her, not as an attraction, but as a 'flagship' animal of the area that needs to be protected, and with her, her two parent species and their habitat." 

The study was published April 26 in the International Journal of Primatology. 

Originally published on Live Science.

Six newly-described species of miniature frogs from Mexico and Guatemala are so tiny that each can fit comfortably on a human thumbnail. Two of the species are smaller than 0.7 inches (18 millimeters) long, and the tiniest of them — Craugastor candelariensis — is Mexico's smallest frog, measuring no more than 0.5 inches (13 mm) long.

The wee frogs live in moist leaf litter on forest floors and are known as direct-developing frogs, which means that they don't undergo a tadpole stage as part of their life cycle, the researchers who described the species wrote in a new study. Rather, the frogs hatch from eggs as miniature versions of their adult forms. 

Hatchlings are thought to measure less than than 0.4 inches (10 mm) long, but scientists aren't certain about that because no one has ever seen these frogs hatch, said lead study author Tom Jameson, a researcher in the Department of Zoology at the University of Cambridge in the United Kingdom, and a doctoral candidate in the Cambridge Climate, Life and Earth (C-CLEAR) program. 

"We know very little about their reproduction, life history, and behaviour," Jameson told Live Science in an email.

Related: Cannibal toads eat so many of their young, they're speeding up evolution

Other scientists had collected the frogs years ago and placed them in museum collections, cataloging the minuscule amphibians as undefined species in the Craugastor genus or as possibly belonging to the miniature frog species C. pygmaeus or C. hobartsmithii, the study authors reported April 4 in the journal Herpetological Monographs.

However, the diminutive frogs all looked so similar that scientists couldn't be sure exactly where the frogs fit on the Craugastor family tree. 

"We revisited this classification because one of my co-authors, Jeff Streicher [a senior curator of amphibians and reptiles at the Natural History Museum in London], did some genetic analysis back in 2012 and found a pattern that suggested multiple undescribed species," Jameson explained.

The researchers then followed up on Streicher's findings by conducting DNA analysis of the Craugastor specimens in question, and using computed X-ray tomography (CT) scans to create 3D digital models that highlighted differences in the shapes of frog bones and body parts. When their analysis was done, the scientists grouped the specimens into six new species: C. bitonium, C. candelariensis, C. cueyatl, C. polaclavus, C. portilloensis and C. rubinus.

"We found that each species was genetically distinct," Jameson said. "We also found differences in skull shape, level of ossification of the skeleton, and in external features like the number of tubercles [hardened bumps] on the hands and feet." 

Because the frogs are so small, they're on the menu for just about every predator in their woodland ecosystem, including birds, lizards, small mammals, and even large insects and other frogs, Jameson said. But the frogs face much greater risks from human activities, he added.

"The real threat to these frogs comes from habitat loss, climate change (further modifying habitats), and disease," such as the highly infectious fungal disease chytridiomycosis, or chytrid disease, Jameson wrote in the email. Chytrid disease is caused by the fungus Batrachochytrium dendrobatidis, which infects amphibians through their skin and is easily spread to new habitats by humans, according to the Cornell Wildlife Health Lab at Cornell University in Ithaca, New York.

Despite their small size, these frogs could represent the tip of a very big iceberg of unknown amphibian biodiversity in the region, the study authors reported. 

"We suspect that additional species await discovery, particularly in western Mexico and east of the Isthmus of Tehuantepec where our sampling efforts were limited," the authors wrote.

Originally published on Live Science.

Crows and ravens have taken over the world in part because they're so big and brainy, new research suggests.

Researchers found that crows and ravens have bigger wingspans, brains and bodies than other birds in the Corvidae family.

"We hypothesize that these three very convenient combinations of traits are what allowed this group of birds to colonize and diversify across the world," Joan Garcia-Porta, who was a postdoctoral research associate at Washington University in St. Louis, and is now a geneticist at the University of Barcelona, said in a statement.

Crows and ravens (household names that encompass several species of birds in the genus Corvus) have proven their smarts time and again. Crows understand the concept of zero and can use multi-step planning and tools to access tasty treats. Ravens, meanwhile, have been shown to rival great apes in their intelligence, according to a 2020 study in the journal Scientific Reports.

What may be less known is that crows and ravens live in every type of ecosystem around the world, from the hottest deserts to the most forbidding frozen tundras. Just how they were able to reach and thrive in every niche on the planet has been a mystery.

To figure out how these black birds conquered the world, Garcia-Porta and colleagues measured the bones of 96 specimens of modern crow and raven species housed in museums around the world, as well as three extinct species of crows. The team also measured the brain sizes of 76 species in the Corvidae family (or as they're commonly known: corvids).

Related: When humans are gone, what animals might evolve to have our smarts and skills?

The researchers then created a family tree for corvids based on genetic data and developed a computer model to estimate when crows first arrived in new regions and how quickly they adapted to those regions.

It turns out that ravens and crows have bigger bodies and wingspans than similar corvids, such as magpies and jays, the researchers reported in the new study, published April 21 in the journal Nature Communications. This bigger wingspan enabled them to fly farther and populate new ecosystems more easily than their more diminutive cousins could. Being bigger also enabled crows and ravens to physically outcompete other birds, the researchers found.

And once established in a new ecosystem, these birds' greater mental flexibility enabled them to adapt to very different environments (some of these birds, for instance, swapped tropical rainforests for the Arctic tundra over relatively short timeframes). This meant that the species persisted in new environments even when their bodies hadn't yet adapted to the climate in their new homes, the study found.

Eventually, adaptation caught up, and crows and ravens evolved into new species with advantageous traits (such as beaks better suited to the local food) more rapidly than their corvid peers could, the study found.

"It truly seems that their incredible behavioral flexibility may have played a major role in allowing these birds to survive initial periods of maladaptation and hang in there long enough for selection to catch up and produce a range of new species in the process," study co-author Carlos Botero, a biologist at the Washington University in St. Louis, said in the statement.

Originally published on Live Science.

The dodo (Raphus cucullatus) is an extinct species of bird that once lived on Mauritius, an island off the coast of Madagascar. Dodos, distant relatives of pigeons and other doves, are often referenced as an example of human-caused extinction. 

Flightless, slow to reproduce and confined to a single island, dodos were vulnerable to the arrival of humans and rats, as well as the introduction of domesticated animals in the late 1500s. About a century later, all that remained of the dodo were a few paintings and written descriptions, along with a small collection of bones.

What did dodos look like?

The dodo was a heavyset, gray-brown bird with tiny wings, strong legs and a large beak. It stood up to 27 inches (70 centimeters) tall and weighed 28 to 45 pounds (13 to 20 kilograms), according to a 2004 study in the journal Biologist. Males were slightly larger than females; compared with modern wild turkeys and swans, dodos were shorter but heavier. 

Dodos were driven to extinction long before photography could capture their likeness, and no taxidermied specimens of the birds survive. Paleontologist Julian Pender Hume, a research associate at the Natural History Museum (NHM) in London, told Vice that the so-called taxidermied dodo on display at NHM is made of goose and swan feathers that were glued to a plaster model by a man who had never seen a dodo. For evidence of what dodos actually looked like, modern researchers must turn to historical paintings and other artworks, as well as descriptions from early Arab and European visitors to Mauritius, and such records were not always accurate.  

One European artist in particular, 17th-century Flemish painter Roelant Savery, is largely responsible for the rotund image of the dodo that proliferated in other artwork and cartoons. Savery's roly-poly dodo led many to perceive the birds as slow, stupid and clumsy, but evidence from dodo bones suggests that the birds were nimble animals that could outpace humans over rocky terrain, Hume said. According to the NHM, the dodo had a large brain and well-developed olfactory glands, indicating that contrary to its popular reputation, it was relatively intelligent and likely had a keen sense of smell.

Where did dodos live?

Dodos lived on the subtropical volcanic island of Mauritius, now an independent state made up of several islands in the Indian Ocean. Mauritius is located about 700 miles (1,100 km) from Madagascar, off the southeast coast of Africa.  

Mauritius and its neighboring islands harbored no permanent human population before the Dutch East India Company established a settlement there in the 1600s, according to the Stanford University Department of Anthropology. By then, previous visitors to the island had already introduced so many predators that dodos no longer roamed the beaches and mountains. Later, deforestation removed much of the dodo's woodland habitat, researchers reported in 2009 in the journal Oryx. 

Why did the dodo go extinct?

The dodo went extinct through a fatal combination of slow evolution and fast environmental changes, according to National Geographic. Highly specialized to its environment, the flightless and slow-to-reproduce species was vulnerable to the sudden introduction of predators in its once-safe island home.

For millions of years before human explorers set foot on Mauritius, the island had no large, land-based predators. Wildlife on Mauritius evolved to fill various ecological niches, but these isolated species were slow to respond to newly arrived threats from across the ocean, National Geographic reported.For example, dodos were said to have no fear of humans who landed on their island beaches, so the birds were easily caught and killed by hungry Dutch sailors.

And it wasn't just humans who consumed the dodos. Rather, a host of introduced species — including rats, pigs, goats and monkeys — likely caught and ate dodos and their eggs, according to a 2016 study in the Journal of Vertebrate Paleontology. Tragically for the dodos, each devoured egg represented a female dodo's only chance for reproduction that year. But for the new arrivals on the island, those nutritious, easy meals were conveniently located within easy reach on the forest floor. If any of the precious eggs survived and hatched, the introduced animals likely outcompeted juvenile and adult dodos for a limited food supply, Hume wrote in 2006 in the journal Historical Biology. 

Today, the dodo is officially listed as extinct by the International Union for Conservation of Nature.

When did the dodo go extinct?

The dodo's official date of extinction isn't certain. Unlike the thylacine, also called the Tasmanian tiger (Thylacinus cynocephalus), a species whose last known individual died in captivity in 1936, dodo populations dwindled far from human observation, roughly around 1662, according to a   2004 study published in the journal Nature. Some researchers, however, point to reports of dodos on Mauritius in the late 1680s, Live Science reported in 2013. In the Nature study, researchers used a statistical method to estimate the extinction of the dodo, pushing the date  to as late as 1690. 

Could we bring back the dodo?

It's unlikely that we'll see a dodo walking the Earth again anytime soon, according to evolutionary molecular biologist Beth Shapiro, a professor in the Department of Ecology and Evolutionary Biology at the University of California, Santa Cruz. 

There are a number of reasons why dodos would be complicated to resurrect, Shapiro told Live Science: They're not good candidates for cloning, because there are very few sources of dodo DNA; bird reproduction is really complicated; and there isn't necessarily a habitat for them to go back to.

"When most people think about de-extinction, they're imagining cloning," Shapiro said. Cloning, the process that created Dolly the sheep in 1996 and Elizabeth Ann the black-footed ferret in 2020, creates an identical genetic copy of an individual by transplanting DNA from a living adult cell into an egg cell from which the nucleus has been removed. Adult cells contain all the DNA needed to develop into a living animal. Egg cells then use that DNA as a blueprint to differentiate themselves into the many kinds of cells — skin, organs, blood and bones — the animal needs.

But no living cells from dodos exist, nor have they existed for hundreds of years. Instead, Shapiro said, you'd have to start with a closely related animal's genome and then tweak it to resemble that of a dodo. 

For example, mammoths are also extinct, and scientists haven't found any living mammoth cells. But mammoths were very closely related to modern Asian elephants (Elephas maximus), so researchers such as George Church, a professor of genetics at Harvard Medical School in Boston, are attempting to bring mammoths back from extinction by creating a hybrid mammoth, with some mammoth genes replacing part of the elephant genome in an elephant egg cell. However, there are likely millions of genetic differences between the genome of an Asian elephant and that of a mammoth, according to Shapiro. At best, researchers can only hope to produce an animal that has some mammoth features, rather than resurrecting an extinct species. 

As for the dodo, its closest living relative is the Nicobar pigeon (Caloenas nicobarica), a much smaller and more colorful flying bird found on the Andaman and Nicobar Islands in India; the Malay Archipelago; the Solomon Islands; and the Republic of Palau, an island country in the western Pacific Ocean. But whereas mammoths and Asian elephants are pretty closely related (they evolved from a common ancestor 5 million years ago), it's been more than 20 million years since the dodo and the Nicobar pigeon had any common ancestors. Genetic differences between the two bird species are therefore much greater, making it more difficult to create a successful hybrid in the lab, Shapiro said.

In 2022, Shapiro dropped an unexpected dodo bombshell when she acknowledged, in response to an audience question at a Royal Society webinar, that she and her colleagues had successfully sequenced the entire dodo genome. The research has not been peer-reviewed yet, but Shapiro was taken aback by the public and press' excited response to her unintended announcement. The team intends to publish the research in the future.

Reconstructing the dodo genome was no easy feat. First, Shapiro and her team had to find intact dodo DNA, buried in bone marrow that had survived hundreds of years in Mauritius' warm and humid environment (and likely tropical cyclones as well). Then, they had to sort out which recovered DNA belonged to the dodo and which belonged to fungi and bacteria that had invaded the bones as they decomposed.

But that success does not guarantee the resurrection of the dodo. Even with a fully reconstructed dodo genome, researchers face another substantial problem: bird reproductive systems. 

Whereas mammals produce egg cells that scientists know how to harvest and manipulate, bird egg cells are tricky. In order to find and replace a bird egg’s DNA, researchers would have to safely and non-destructively locate the microscopic nucleus of the egg, which could be floating anywhere inside of a bulky egg yolk. Finding the tiny packet of genetic material is like "looking for a white marble in a pool of milk," Ben Novak, a lead scientist with the de-extinction conservation group Revive & Restore, told Audubon magazine. So, replacing that genetic material with altered DNA to produce a clone is impossible, Novak said. In his own research on passenger pigeon de-extinction, the strategy is to alter bird gonads instead. By changing the sperm and eggs produced by parent birds, the researchers hope to produce offspring with the desired genes. 

Even if scientists managed to revive dodos, the island where they once lived is a very different place nowadays. Deforestation, invasive species and human habitation would make it impossible to reintroduce the dodo without major intervention. "If we haven't first solved the problem that caused their extinction in the first place," Shapiro said, "it might not be worth spending all the energy and effort it would take to bring them back."

Additional resources

To learn more about the risks of extinction, read "Beloved Beasts" (W. W. Norton & Co., 2021) by Michelle Nijhuis, which tells the story of the modern movement to preserve Earth's vulnerable species. If you're curious about de-extinction, check out this Wall Street Journal article about scientists who are working to bring species back from the dead. Last, check out this 2021 paper published in the journal Historical Biology on the changing face of the dodo. The paper explores the effects that books and media like Alice in Wonderland have had on the dodo's reputation and renown long after its disappearance.

Bibliography

Angst, D., A. Chinsamy, L. Steel, & J. P. Hume. (2017). Bone histology sheds new light on the ecology of the dodo (Raphus cucullatus, Aves, Columbiformes)." Scientific Reports, 7(1). https://doi.org/10.1038/s41598-017-08536-3

Cheke, A. (1987). The legacy of the dodo—conservation in Mauritius. Oryx, 21(10), 29–36. https://doi.org/10.1017/S0030605300020457

Dissanayake, R. (2004). What did the dodo look like? Biologist, 51(3), 165–68. https://www.academia.edu/11619405/What_did_the_dodo_look_like

Fritts, R. (2021, April 28). The surprising reason scientists haven't been able to clone a bird yet. Audubon. https://www.audubon.org/news/the-surprising-reason-scientists-havent-been-able-clone-bird-yet

Stanford University Department of Anthropology. (n.d.). Mauritanian Archaeology: History. Retrieved April 12, 2022, from https://mauritianarchaeology.sites.stanford.edu/history

Hume, J. P. (2006). The history of the dodo Raphus cucullatus and the penguin of Mauritius." Historical Biology, 18(2), 69–93. https://doi.org/10.1080/08912960600639400

Hume, J. P., Martill, D. M., & Dewdney, C. (2004). Dutch diaries and the demise of the dodo. Nature, 429(6992), 1. https://doi.org/10.1038/nature02688 

International Union for Conservation of Nature. (2016, October 1). Dodo: Raphus cucullatus. IUCN Red List. https://www.iucnredlist.org/species/22690059/93259513 

Kiberd, R. (2015, March 17). The dodo didn't look like you think it does. Vice. https://www.vice.com/en/article/vvbqq9/the-dodo-didnt-look-like-you-think-it-does

Parker, I. (2007, January 14). Digging for dodos. The New Yorker. http://www.newyorker.com/magazine/2007/01/22/digging-for-dodos

Pavid, K. (n.d.). Recreating the lost world of the dodo. Natural History Museum. Retrieved April 12, 2022, from https://www.nhm.ac.uk/discover/the-lost-world-of-the-dodo.html

Rijsdijk, K. F., Hume, J. P., De Louw, P. G. B., Meijer, H. J. M., Janoo, A., De Boer, E. J., Steel, et al. (2015). A review of the dodo and its ecosystem: Insights from a vertebrate concentration Lagerstätte in Mauritius. Journal of Vertebrate Paleontology, 35(1), 3–20. https://doi.org/10.1080/02724634.2015.1113803

Shapiro, B., Sibthorpe, D., Rambaut, A., Austin, J., Wragg, G. M., Bininda-Emonds, O. R. P., Lee, P. L. M., & Cooper, A. (2002). Flight of the dodo. Science, 295 (5560),  1683–1683. https://doi.org/10.1126/science.295.5560.1683

Originally published on Live Science.

Your pet's dinner may contain endangered shark — even if the ingredients on the label don't explicitly include "shark," a recent analysis of commercially produced pet foods has found.

Pet foods often describe their ocean-sourced ingredients with generic terms such as "fish," "white fish," "white bait" or "ocean fish," and researchers wondered if genetic testing might reveal information that was missing from the labels. They collected and sequenced samples from 45 pet food products representing 16 brands sold in Singapore. Though none of the product labels listed sharks among the ingredients, the researchers found that 31% of the samples contained shark DNA. 

In a number of cases, the DNA came from sharks that are classified as vulnerable by the International Union for Conservation of Nature (IUCN); such species included the silky shark (Carcharhinus falciformis) and the whitetip reef shark (Triaenodon obesus).

Related: Will eating pet food kill me?

The scientists tested the samples with DNA barcoding, which identifies species by comparing short DNA sequences to a database of so-called genetic barcodes from the genomes of known species. Because canned pet foods are highly processed, which destroys DNA, the researchers used a technique known as mini-barcoding, which can amplify even small genomic sequences in degraded samples.

Blue sharks (Prionace glauca) were most common in the tested samples, appearing seven times; these sharks are ranked as near-threatened by the IUCN. Other studies have shown that blue sharks are frequently caught as bycatch in commercial fishing, and their occurrence is high in the shark fin trade in Southeast Asia, the scientists said in the study. Both of these factors could explain why blue sharks wind up in pet food, which would prevent the carcasses from going to waste. 

After blue sharks, silky sharks and whitetip reef sharks were most common in the samples; the researchers identified nine species in all, including spottail sharks (Carcharhinus sorrah), sliteye sharks (Loxodon macrorhinus) and sand tiger sharks (Carcharias taurus). They also noted that 16 samples included DNA from sharks that could be identified only by their genus: Carcharhinus.

While it isn't illegal for pet food companies to omit specific mention of shark meat in their products, the vagueness of terminology like "ocean fish" prevents pet owners from making "informed and environmentally conscious decisions" about what they're feeding their animals, the scientists wrote. 

"We argue that many pet owners and lovers would be alarmed to find out that they are likely contributing to the unsustainable fishing practices that have caused massive declines in global shark populations," reducing shark numbers by over 70% worldwide over the past 50 years, the study authors reported.

The findings were published March 4 in the journal Frontiers in Marine Science.

Originally published on Live Science.

Famed naturalist Edward O. Wilson, or E.O. Wilson, has died at the age of 92. The biologist, author and teacher was the world's top authority on the study of ants and called Charles Darwin’s "natural heir." 

Wilson died Dec. 26 in Burlington, Massachusetts, according to a statement released by the E.O. Wilson Biodiversity Foundation, a conservation organization Wilson co-founded in 2005.  

"E.O. Wilson’s holy grail was the sheer delight of the pursuit of knowledge," said Paula Ehrlich, CEO and president of the foundation. "A relentless synthesizer of ideas, his courageous scientific focus and poetic voice transformed our way of understanding ourselves and our planet."

Related: Image gallery: Ants of the world

Among his many titles, Wilson was honorary curator in entomology, the study of insects, and a research professor emeritus at Harvard University. He is the author of more than 430 scientific papers and described more than 400 species during his life. Wilson's legacy also includes being considered the founder of sociobiology, the study of the biological basis for social behavior, among other scientific disciplines and concepts. In 1976, he was awarded the National Medal of Science. 

Many people have paid tribute to Wilson and his work. Actor and environmental campaigner Leonardo DiCaprio wrote on Twitter: "The world lost a true hero for the planet when Dr. E.O. Wilson passed away - "the Darwin of the 20th century", prolific writer, pioneer of groundbreaking new concepts in biology, and one of the towering intellects of our time."

Wilson wrote about science for general audiences and published many books. He won two Pulitzer Prizes in general nonfiction for "On Human Nature" (Harvard University Press, 1978) and "The Ants" (Belknap Press, 1990), the latter of which he co-authored with Bert Holldobler. Wilson was also involved in conservation work, co-founding the Society of Conservation Biology and serving on boards for the Nature Conservancy, Conservation International and other organizations.

In his book "Half-Earth: Our Planet's Fight for Life" (Liveright, 2016), Wilson proposed dedicating half of Earth's surface to nature in order to preserve biodiversity and avert mass extinction. This idea is the basis for the Half-Earth Project, an E.O. Wilson Biodiversity Foundation program, working to conserve half of the Earth's land and sea. 

The E.O. Wilson Biodiversity Foundation did not give a cause of death but said a tribute to Wilson’s life will be held in 2022, with memorial details to be announced.

Originally published on Live Science.

Deep beneath Antarctica's ice shelves, researchers have discovered dozens of life-forms thriving on a tiny patch of the seafloor —— an unprecedented level of species diversity for an environment that has never seen sunlight.

"If you had asked me three questions at the manuscript onset," said study co-author David Barnes, a marine biologist with the British Antarctic Survey, "How much richness of life will we find? Not much. How abundant is it going to be? Not very. What's it's growth going to be like? Very slow. And I would have been wrong on every point."

Far below Antarctic ice, shielded from the energizing rays of the sun, life can exist, but it was thought to be rare. As most ecosystems are built on a foundation of photosynthetic organisms like plants or algae, such dark realms shouldn't have enough food to support a wide variety of life. 

Related: Time-lapse images of retreating glaciers

But when Gerhard Kuhn and Raphael Gromig of the Alfred Wegener Institute used boiling hot water to bore through 656 feet (200 meters) of ice on the Ekström Ice Shelf in 2018, they were surprised by what they were able to scoop from the seafloor another 328 (100 m) down. 

The ice shelves cover 600,00 square miles (1.6 million square kilometers) of ocean, and what lies beneath the ice may very well be Earth's least explored undersea habitat. 

In such a dark and seemingly inhospitable environment, the team found fragments of living organisms. When they realized that they had found more than they expected, Claus-Dieter Hillenbrand, a sedimentologist with the British Antarctic Survey, recommended sending the seafloor sample to Barnes.

The pieces that had been pulled from underneath the ice shelf, when examined with a microscope, were clearly from different animals. All told, Barnes identified 77 different species, far more than he should have reasonably found. This one sample was even richer with species than he would have expected from a survey of the open shelf. 

"Is this a practical joke?" Barnes recalled thinking as he examined the specimens. "This is like a whole research cruise worth of samples, yet it came from just one drill hole." 

Many of the species identified were bryozoans, or stationary filter feeders that often look like a brain or moss, such as Melicerita obliqua and tube-feeding worms such as Paralaeospira sicula, among others. "This discovery of so much life living in these extreme conditions is a complete surprise and reminds us how Antarctic marine life is so unique and special," Barnes told Live Science.

Finding such rich life underneath the ever-present ice sheet is one thing, but explaining why it is there is another matter entirely. Marine life, especially filter feeders like bryozoans, sponges and jellyfish, should, in theory, become scarcer with distance from the open sea; that's because they feed on algae, which needs sunlight, and because they were thought to be too delicate for the brutal 28 degrees Fahrenheit (minus 2.2 degrees Celsius) temperatures. 

But it turns out these animals are feasting on microorganisms like ciliates and dinoflagellates that are swept underneath the ice shelf by oceanic currents. "The surprise is that enough of it gets under there," Barnes said.

When you look at the seafloor communities on the polar continental shelf underneath ice-free water, they are not limited by food. 

Instead, they get way more than they could ever consume. On top of that, they don't consume much. These are animals that stick to the floor, and they don't build big bodies made of energy-hungry tissues. As such, they can survive off of the trickle of food that does come their way.

"It's life in the super-slow lane," Barnes said.

What's more, carbon dating reveals these bottom-dwellers are not new tenants under Antarctica's shelves. 

"Despite living 3-9 km from the nearest open water, an oasis of life may have existed continuously for nearly 6000 years under the ice shelf," Kuhn, the leader of the drilling project, said in a statement. While the oldest remnants were 5,800 years, they have only dated 20 of the hundreds of fragments. Future data may very well push this estimate farther into the past. However long it has existed, it is clear life has existed for millennia here in near-isolation.

"This may be the most undisturbed habitat on Earth," Barnes said of the space between the seafloor and the ice above it. 

That lack of disturbance, he said, may explain the ecosystem's species diversity. Underneath the ice, there are no storms, no floods and no fires, allowing all the species that can survive the time and stability needed to radiate to every available niche.

Yet pristine habitats like these might be some of the first to succumb to human-caused climate change, Barnes said. As  the Antarctic ice shelves recede, these unique environments may be lost.

And once lost, the environment can never be recreated. "People talk about recreating and re-wilding, and trying to protect and preserve," Barnes said, "But there's no doing that here, is there?"

This study was published Dec. 20 in the journal Current Biology.

Originally published on Live Science.

The Cambrian period (543 million to 490 million years ago) brought the first great explosion of biodiversity to Earth, with the ancestors of practically all modern animals first appearing. One of the most feared among them was the penis worm.

Technically known as priapulids — named for Priapus, the well-endowed Greek god of male genitals — penis worms, as they’re commonly known, are a division of marine worms that have survived in the world's oceans for 500 million years. Their modern descendants live largely unseen in muddy burrows deep underwater, occasionally freaking out fishermen with their floppy, phallus-shaped bodies. But fossils dating back to the early Cambrian show that penis worms were once a scourge of the ancient seas, widely distributed around the world and in possession of extendible, fang-lined mouths that could make a snack out of the poor marine creature that crossed them.

But, fearsome as they were, penis worms themselves were not without fear. In a new study published Nov. 7 in the journal Current Biology, researchers discovered four priapulid fossils that were nestled into the cone-shaped shells of hyoliths, a long-extinct group of marine animals.

Related: Image gallery: Bizarre Cambrian creatures

Because all of the worms were found in the same type of shell, and in roughly the same position, it's likely that the worms had appropriated the shells as their homes, just as modern hermit crabs do, the researchers said.

If that's the case, then it would seem that penis worms invented the "hermit" lifestyle hundreds of millions of years before the crustaceans that made it famous.

"The only explanation that made sense was that these shells were their homes — something that came as a real surprise," study co-author Martin Smith, an associate professor of paleontology at Durham University in England, said in a statement via email.

The team discovered the four hermit penis fossils in the collections of the Guanshan fossil deposits, from southern China. These fossil deposits, dating to the early Cambrian (about 525 million years ago) are famous for preserving not just hard structures such as teeth and shells, but also soft tissue — like the bodies of priapulids — which are much rarer to find in the fossil record.

In each shell, the worm's bottom sits squished into the bottom of the cone, while the worm's head and mouth dangle out over the side — sort of like a melting swirl of soft-serve ice cream. According to the researchers, the fossil region contained dozens of other empty shells, but no other free-living priapulids, suggesting the connection between the two was no mere accident. Furthermore, each worm fit snugly in its sheath, suggesting the creatures chose their shells for permanent protection from Cambrian predators, rather than as temporary refuge.

This type of "hermiting" behavior has never been seen in priapulids before, nor in any species before the Mesozoic era (250 million to 65 million years ago), the researchers wrote. For Smith, it's "mind-boggling" that this complex behavior could have emerged so soon after the great burst of biodiversity known as the Cambrian explosion, more than 500 million years ago. In the harsh world of the early ocean, it seems even fearsome penis worms had to get creative.

Originally published on Live Science.

When is a bird not a bird? When it's a bat, according to a New Zealand contest that just named a highly endangered bat "Bird of the Year."

Pekapeka-tou-roa, or New Zealand's long-tailed bat (Chalinolobus tuberculatus), weighs about 0.4 ounces (11 grams) and a fully grown adult is about the length of a human thumb. This species of pekapeka — the Māori word for bat — was once common in New Zealand but is now exceptionally rare, representatives with Forest and Bird, a New Zealand conservation group and organizers of the contest, said in a statement. 

For two weeks, nearly 57,000 voters weighed in on selections for New Zealand's top bird; this year, for the first time in the contest's 16-year history, their choices included a mammal. Contest organizers added the long-tailed bat to the lineup to raise awareness about the species' endangered status, and it quickly flew to the top of the list with 7,031 votes, Reuters reported. Trailing behind in second place with 4,072 votes was the kākāpō (Strigops habroptilus), a tubby, flightless bird that's also known as an owl parrot.

Related: In photos: The eerily beautiful bats of Arizona 

"The campaign to raise awareness and support for this little flying furball has captured the nation," Bird of the Year spokesperson Laura Keown said in a statement. "A vote for bats is also a vote for predator control, habitat restoration, and climate action to protect our bats and their feathered neighbours," she said.

Long-tailed bats now join other Bird of the Year winners — all birds — that are also iconic animal ambassadors for New Zealand. They include the kākāpō; the yellow-eyed penguin (Megadyptes antipodes); and a colorful pigeon called the kererū (Hemiphaga novaeseelandiae), to name just a few, according to the contest website.

Bats are the only land mammals that are native to New Zealand — all others were introduced by humans — and there are three species: the long-tailed bats, and two species of short-tailed bats, according to Bat Conservation International (BCI). The short-tailed species, Mystacina robusta and M. tuberculata, are the most terrestrial of all known bat species, a behavior that may have evolved over millions of years because New Zealand lacked terrestrial predators for much of its history, according to BCI. 

But bat populations in all three species began to disappear when people first settled New Zealand about 1,000 years ago, introducing dogs and rats as the continent's first mammalian predators. The bats' decline then accelerated with the arrival of European colonizers, around 140 years ago. Today, M. robusta is thought to be extinct, and the remaining species are at risk and will likely vanish unless invasive predators such as possums, rats, stoats and cats can be better managed, according to the New Zealand Department of Conservation (DOC).

Other threats to the newly-minted Bird of the Year and its short-tailed bat cousins include habitat loss, as trees in their forest homes are chopped down for firewood and lumber, and to clear ground for agriculture, according to the DOC. 

While the long-tailed bat's designation as Bird of the Year has ruffled some feathers, the contest organizers stand behind their choice. 

"In New Zealand we believe in the underbird," contest representatives said in the statement. "We believe that where you come from doesn't have to determine your future."

Originally published on Live Science.