Around 18,000 years ago, ice age people in what is now Ukraine likely weathered the extremely harsh climate by building parts of their shelters out of mammoth bones, a new study finds.

The mammoth dwellings show how communities thrived in extreme environments, turning the remnants of giant animals into protective architecture," the archaeologists wrote in a statement.

The bones were originally found near the village of Mezhyrich, about 70 miles (110 kilometers) southeast of Kyiv. When it was excavated between 1966 and 1974, the archaeological team at the time found the mammoth remains arranged in such a way that suggested they had been used to make houses sometime during the ice age. While this interpretation has found much support among archaeologists, questions still remain about exactly when these bone dwellings were used and for how long. Earlier dates from the site gave a broad range from roughly 19,000 to 12,000 years ago, the team noted in their paper.

To investigate these questions, archaeologists re-examined the site to try and get a better idea of when it was built and how long it stayed in use. They dated the remains of about a dozen small animals found near the mammoth dwellings to try and get a more precise chronology.

The largest structure at Mezhyrich dates to 18,323 to 17,839 years ago, the team reported in the study, published on Nov. 21 on the publishing platform Open Research Europe. These dates are just after the Last Glacial Maximum (26,500 to 19,000 years ago), the coldest part of the last ice age. The researchers noted that the dwelling may have been used for up to 429 years. This indicates that the "shelters were practical solutions for survival rather than permanent settlements," they wrote in the statement.

The foundation of the shelters may have had "mammoth skulls and large long bones, set vertically into the ground [which] formed a kind of plinth or 'foundation,'" study co-author Pavlo Shydlovskyi, an archaeology professor at the Taras Shevchenko National University of Kyiv, told Live Science in an email.

A wooden framework may have covered parts of the shelter, along with hides from smaller animals or possibly birch bark. In addition, "tusks and large flat bones were placed on the upper part of the structure [the roof] functioning as weights and wind protection," Shydlovskyi said.

Five to seven people likely lived within each shelter, Shydlovskyi said. A variety of activities such as flint knapping, animal skin processing and small animal butchering were likely done inside.

Francois Djindjian, an honorary professor at the University of Paris 1 Panthéon Sorbonne has done research on other possible mammoth bone shelters but was not involved in the new paper. He was cautious about the team's dates, and said that he thought that more dates were needed from more of the site. Getting more radiocarbon dates from across the site would give a better idea of when it was used.

Last ice age quiz: How much do you know about Earth's frosty past?

For the first time, scientists have successfully sequenced woolly mammoth RNA, shattering the assumption that this fragile genetic molecule couldn't survive from so long ago.

RNA, or ribonucleic acid, carries instructions between DNA and an organism's protein-building machinery, acting as a messenger to turn genetic information into proteins. RNA can reveal which genes are active in a cell at a given moment, as well as how gene-activity patterns within a cell change over time. Thus, ancient RNA can inform scientists about the cellular states of extinct species.

Although the technology behind ancient DNA research has surged over the past 20 years, ancient RNA research has seen few successes. This is due in part to its construction, as DNA molecules are double-stranded and therefore sturdier than the single-stranded RNA.

While DNA offers the blueprint of an organism, there are limits to the information it reveals. RNA "opens a window into how" that blueprint is implemented within each cell of the organism, said study co-author Zoé Pochon, a doctoral student at Stockholm University.

The aptly-named messenger RNA (mRNA) "is DNA's messenger," she told Live Science in an email. "In other words, it carries working copies of DNA instructions from the nucleus to the cell." Other parts of the cell then follow these instructions, she added.

In the new study, published Friday (Nov. 14) in the journal Cell, the researchers turned to 10 well-preserved woolly mammoth (Mammuthus primigenus) specimens from Siberia that dated to 10,000 to 50,000 years. The team hoped that the frozen conditions had preserved more of the specimens and so would produce better results.

One specimen in particular — Yuka, a ginger-colored juvenile mammoth — yielded spectacular results. Yuka is about 39,000 years old, making this the oldest RNA sequenced to date. Previously, that distinction was held by tissues sampled from a canid dated to approximately 14,300 years.

Remarkably, the scientists found definite genetic signals that Yuka, previously believed to be a female based on its physical attributes, is actually a male.

Additionally, the RNA offered insights into Yuka's muscle function — specifically, the RNA "creating the proteins that are stretching and contracting the muscles," said study lead author Emilio Mármol Sánchez, who was working at the Center for Evolutionary Hologenomics, University of Copenhagen at the time of the paper. The team "also found a whole set of regulatory genes,' he told Live Science.

When cells die, what is left behind is the last function of the RNA. "What we are capturing here is, in a sense, a snapshot of the last moments of the life of these mammoths" within their cells, Mármol Sánchez said.

What the team saw in Yuka's muscle RNA reflects the potential horror of its last moments. Mármol Sánchez explained that they uncovered "molecular evidence of metabolic cell stress in Yuka's muscle," which corresponds with what a separate scientific team described in 2021. In that study, the researchers noted many claw marks that may have been made by cave lions (Panthera spelaea), as well as bite marks from smaller predators on the mammoth's body and tail. But whether Yuka was hunted and killed by large predators or simply scavenged after death is unknown. The researchers do not know what caused the cell stress observed in the RNA.

Federico Sánchez Quinto, a paleogenomicist at the National Autonomous University of Mexico's (UNAM) International Laboratory for Human Genome Research who was not involved in the research, considers this "a breakthrough publication in the field of paleogenomics." He described the study as "fascinating since it accomplishes something that had been previously unimaginable, as RNA is extremely unstable even in favorable conditions." Moreover, "this study obtains RNA from an older sample [than other recent RNA work], in larger amounts and with more certainty," he told Live Science in an email.

The findings have revealed that it's possible to extract RNA from extremely old specimens and showcases a new area of potential study for other researchers, the team said. In addition, the team has included a roadmap to help others successfully obtain ancient RNA.

"Being able to recover RNA from ancient samples, in addition to DNA, is like opening a new window into the biology of extinct animals," study co-author Love Dalén, professor of evolutionary genetics at the Centre for Palaeogenetics at Stockholm University, told Live Science. "It's yet another powerful tool that lets us see which genes were active in different cell types, which ultimately can help us better understand which genes made a mammoth a mammoth!”

Researchers have discovered the oldest-known wooly mammoth fossil in North America and uncovered its genetic secrets, according to a new study.

The 216,000-year-old tooth, found along the Old Crow River in the Yukon territory in Canada, confirms that wooly mammoths (Mammuthus primigenius) arrived in North America at least 100,000 years earlier than scientists initially thought.

Study lead author Camilo Chacón-Duque, a researcher at the Centre for Palaeogenetics at Stockholm University in Sweden, told Live Science in an email that the find was unusual because most North American mammoth specimens of this age likely belong to other species that existed before wooly mammoths.

"To our knowledge, the Old Crow mammoth is the oldest North American mammoth fossil that can be morphologically identified with confidence as a woolly mammoth," Chacón-Duque said.

The researchers extracted DNA from the Old Crow mammoth as part of an extensive study of mammoth genetics. In the study, the researchers revealed "long-lost" genetic diversity from different mammoth lineages across more than a million years of their evolutionary history, according to a statement from Stockholm University.

The Old Crow mammoth's DNA was in the oldest group of samples in the analysis, described as "deep-time DNA," but it wasn't the oldest. The oldest DNA, from Russia, was around 1.3 million years old. The researchers published their findings online April 9 in the journal Molecular Biology and Evolution.

Related: 130,000-year-old mammoth calf smells like 'fermented earth and flesh,' necropsy reveals

The ancestors of mammoths evolved in tropical Africa and were closely related to living elephants. These ancestors then began moving into the Northern Hemisphere around 3 million years ago, slowly adapting to life in the cold as they spread and diversified.

To learn more about mammoth evolution, the researchers analyzed 34 newfound DNA samples alongside data from more than 200 samples published in previous studies. Chacón-Duque noted that the new samples came from across the Northern Hemisphere, mainly Siberia and North America.

Dating mammoth DNA

The team extracted and analyzed mitochondrial genomes, or mitogenomes, which represent the fraction of the genome located in a cell's mitochondria and are passed on from mother to offspring. The team then dated the samples using a combination of radiocarbon dating and molecular clock dating, which estimates the age of DNA based on gene mutations and the rate at which they occur in DNA over time.

Most of the samples were less than 50,000 years old, which is the limit for radiocarbon dating. For the older samples, the researchers developed a refined version of molecular clock dating to improve its accuracy. Chacón-Duque noted that they tried different setups and parameters for their experiments and found that molecularly dating a single sample at a time was more accurate than trying to date several samples, as has been done in some previous studies.

"We built upon previous methodologies and carefully fine-tuned these to get more reliable age estimates," Chacón-Duque said.

The team used the younger samples that could be confidently radiocarbon dated and the ages of rocks where the fossils were found (if available) as a reference while honing their approach. Chacón-Duque said that dating the Old Crow mammoth sample was a "eureka moment" for him as the DNA-based age estimate coincided perfectly with data from rock formations and other evidence.

"It was a very exciting moment for me, since I worked for months trying to refine the DNA-based dating approach for samples beyond the radiocarbon limit," Chacón-Duque said.

When did mammoths arrive in North America?

The first mammoths arrived in North America long before the Old Crow mammoth. The earliest were Columbian mammoths (Mammuthus columbi), which descended from mammoths in Eurasia. These mammoths crossed a stretch of land that once connected what is now eastern Russia to North America around 1.5 million years ago.

Columbian mammoths could grow up to around 13 feet (4 meters) tall at the shoulder, according to the National Park Service. Woolly mammoths had a shoulder height of around 11 feet (3.4 m), so Columbian mammoths were typically the taller of the two species. However, researchers still have a lot to learn about Columbian mammoths and woolly mammoths, as well as the relationship between the two in North America.

Woolly mammoths first evolved in eastern Siberia around 700,000 years ago and later spread to North America. Chacón-Duque noted that a popular theory was that woolly mammoths crossed between Siberia and Alaska between 120,000 and 10,000 years ago, but researchers have since found older evidence of their arrival.

"Other studies using genetic inferences or modelling have suggested the presence of mammoths as far back as 400,000 years, but Old Crow confirms with a physical specimen that mammoths indeed had a longer presence in the American continent than initially expected, at least >200,000 years," Chacón-Duque said.

Overall, the new research supports previous studies that point to major mammoth lineages originating in ancient Siberia, according to the statement. The team also demonstrated how climate influenced mammoth diversity over time.

"We observe that during warm periods mammoth diversity seemed to be pushed back to refugia and then to spread again during cold periods, such as the initial stages of glacial periods (i.e. ice ages)," Chacón-Duque said.

Most mammoths died out by the end of the last ice age as the world became warmer around 10,500 years ago. Isolated island populations of woolly mammoths held on in Alaska and Siberia for a few more millennia, but the last of those went extinct around 4,000 years ago.

Mammoth quiz: Test your knowledge of the ice age beasts

Russian scientists have cut open and examined a 130,000-year-old baby mammoth preserved in Siberian permafrost.

The yearling mammoth, nicknamed "Yana," was first unveiled in December 2024. The researchers who discovered Yana said she was the best-preserved mammoth ever found, the Associated Press reported at the time. The front part of Yana's body is almost entirely intact and looks very similar to a baby elephant.

Researchers took a closer look at Yana by performing a necropsy — the animal equivalent of an autopsy. The necropsy took several hours and was conducted in late March at the Mammoth Museum in North-Eastern Federal University in Yakutsk, according to reporting by Agence France-Presse (AFP), a French news agency, via France 24.

This necropsy "is an opportunity to look into the past of our planet," Artemiy Goncharov, head of the functional genomics and proteomics of microorganisms laboratory at the Institute of Experimental Medicine in Russia, told AFP.

Related: 'Closer than people think': Woolly mammoth 'de-extinction' is nearing reality — and we have no idea what happens next

Yana was encased in permafrost, or permanently frozen earth, for millennia until climate change thawed that permafrost and exposed her carcass. The front part of her body started to tumble down a cliff, but she was held in place by her hindquarters, which remained embedded in the earth, AFP reported.

During the necropsy, researchers spent several hours examining Yana's remains. The mammoth smelled like a "mixture of fermented earth and flesh," according to AFP's reporting. Yana's carcass was 3.9 feet (1.2 meters) tall at the shoulder and weighed almost 400 pounds (180 kilograms). Her head and trunk were intact, and the researchers were able to locate her milk tusks. These tusks fall out as the mammoth matures, just as baby teeth do in humans, AFP reported. The researchers also identified Yana's internal organs.

"We can see that many organs and tissues are very well preserved," Goncharov said. "The digestive tract is partly preserved, the stomach is preserved. There are still fragments of the intestines, in particular the colon," enabling scientists to take samples of Yana's last meal.

Researchers hope to find unique bacteria on Yana and analyze the plants and spores she consumed in life to learn more about her ancient environment and the relationship between ancient and modern microorganisms.

Researchers haven't yet determined why Yana died so young, but they know modern humans (Homo sapiens) weren't involved. Modern humans didn't arrive in Siberia until at least 30,000 years ago, some 100,000 years after Yana died.

Mammoth quiz: Test your knowledge of the ice age beasts

Scientists have unearthed the remains of five enormous 25,000-year-old woolly mammoths in Austria — and they appear to have been hunted and butchered by ancient humans.

The mammoths were discovered during an excavation of the Langmannersdorf site, about 40 miles (65 kilometers) west of Vienna; the bones and tusks were clustered in two distinct zones about 49 feet (15 meters) apart, researchers said in a statement.

In one of the two zones, the research team found the mammoth bones of several individuals piled up together, many of which had marks and scars from human tools — a sign they had been butchered — as well as stone tools scattered nearby.

In the second zone, the team unearthed the remains of at least three separate mammoths. They found the fragmented and whole remains of the mammoth's enormous tusks clustered together, separate from the bones, which shows Paleolithic humans were likely processing the mammoths' ivory. This ivory could have been used to make spearheads, the archaeologists suggested.

"The fact that we found not just individual bones here, but intensively used areas in which several animals were processed, has more than exceeded our expectations," Marc Händel, an archaeologist at the Austrian Archaeological Institute of the Austrian Academy of Sciences (ÖAW), said in a statement. Previous evidence has shown that ancient humans used mammoth ivory to craft tools, such as implements to make ropes, ornaments, accessories and spears and arrowheads for hunting.

Woolly mammoths (Mammuthus primigenius) were large, elephant-like mammals that measured about 11 feet tall (3.5 meters) and had huge, curved tusks. They roamed across North America, Europe and Asia during the last ice age, which ended around 11,700 years ago.

These enormous animals were a crucial resource for Paleolithic hunter-gatherers; they provided food, bones for tools and shelter, and hides for warmth. Most went extinct around 10,000 years ago, likely due to climate change and human hunting, but small populations survived on isolated islands until about 4,000 years ago.

Related: 200000-year-old 'mammoth graveyard' found in UK

The Langmannersdorf site was first excavated between 1904 and 1907, and evidence of two mammoth hunter camps was unearthed in 1919 and 1920. In the years since, researchers from across Europe have worked at the site to discover more relics, in hopes of better understanding the relationship between ancient humans and woolly mammoths.

Around 25,000 years ago, just before the peak of the last ice age about 20,000 years ago, herds of mammoths are thought to have used the Perschling Valley in Austria as a migration route, where they grazed on grasses and shrubs as they traveled. The discovery of the mammoth processing site in Langmannersdorf indicates that ancient humans understood the annual movement of the mammoths and hunted them specifically when they were passing through the valley, the researchers said.

This discovery therefore gives researchers important insight into the hunting culture of humans during the last ice age.

Researchers at the ÖAW will study the mammoth bones and tusks, as well as the stone tools, to determine more details about the lives of these ancient creatures and the humans who hunted them. The remains will then be stored at the Natural History Museum in Vienna, and others will be displayed at the Perschlingtaler Heimatmuseum (Perschling Valley Local History Museum).

A hunter looking for deer on a West Texas ranch instead discovered a rare mammoth tusk, researchers say.

The tusk was sitting in the drainage area of a creek bed on the O2 Ranch in Brewster and Presidio counties near Big Bend National park, according to a statement released by Sul Ross State University in Texas.

Columbian mammoths (Mammuthus columbi), a distant southern cousin of woolly mammoths (Mammuthus primigenius), lived on the grasslands of what are now North and Central Texas up until around 11,700 years ago, according to the Texas Master Naturalists website, hosted by Texas A&M University. However, the discovery of mammoth remains in West Texas is very rare.

"Seeing that mammoth tusk just brings the ancient world to life," Will Juett, the O2 ranch manager, said in the statement. "Now, I can't help but imagine that huge animal wandering around the hills on the O2 Ranch. My next thought is always about the people that faced those huge tusks with only a stone tool in their hand!"

Related: Poll: Should we bring back woolly mammoths?

Columbian mammoths coexisted with humans until the animals went extinct at the end of the last ice age. Researchers have proposed several potential causes for their extinction, including climate change, hunting by humans and disease, according to Texas Master Naturalists.

The hunter who found the tusk, who isn't named in the statement, took photos of the fossil inside the creek bed and showed them to Juett. The ranch manager then contacted Bryon Schroeder, director of the Center for Big Bend Studies at Sul Ross State University, and another archeologist. They contacted additional researchers and investigated the discovery.

Schroeder verified that it was a mammoth tusk, and the researchers spent two days excavating it from the ranch. They covered the tusk in strips of plaster-covered burlap to protect it and then built a frame to transport it to Sul Ross State University. During the excavation, the researchers didn't find any other mammoth parts.

"We realized pretty quickly there was not more to the skeleton, just an isolated tusk that had been separated from the rest of the remains," Schroeder said in the statement.

The researchers are now awaiting the results of carbon dating tests to tell them how old the mammoth tusk is, according to the statement.

Mammoth quiz: Test your knowledge of the ice age beasts

There's been a lot going on in animal news this year.

Perhaps the best animal story of 2024 came right at the end of the year, when orcas (Orcinus orca) started wearing salmon hats again after a 37-year hiatus from the fabulous fad. And while scientists don't really know why orcas are balancing dead fish on their heads, the best guess is there is so much of their favorite food — chum salmon (Oncorhynchus keta) — available, it's a way to save it for later.

But there was plenty of other news from the animal kingdom this year. We found out that female gibbons do the robot and "vogue" — but only if they're sure someone else is watching. Researchers aren't sure why the apes do it (the dancing was seen in wild and captive gibbons), but it seems to relate to sex, food and their social lives.

Speaking of food, we had two never-before-seen cases of predators eating each other. In the sea, a pregnant portbeagle shark (Lamna nasus) got gobbled up by another shark — likely a great white shark (Carcharodon carcharias) or a shortfin mako (Isurus oxyrinchus). And on land, a Burmese python (Python bivittatus) was seen feasting on an even bigger reticulated python (Malayopython reticulatus) from the tail up, while it was still alive. A Burmese python in Florida also swallowed a deer whole by stretching its mouth to almost the limit of what is physically possible for the species.

In the insect world, scientists discovered that ants carry out life-saving operations by performing amputations on injured nestmates — becoming the only known animal in the world other than humans to do so.

Cassius, the world's largest captive crocodile, died in November, having potentially reached the ripe old age of 120. He was captured in the Finniss River, near Darwin, Australia, in 1984 after he started eating livestock, attacking boat engines and fighting other crocodiles. Scientists are now studying his bones to find out exactly how old he was when he died.

And it wasn't just living animals making headlines. In August, Siberian gold miners accidentally stumbled upon the mummified remains of a woolly rhino (Coelodonta antiquitatis) with its horn and soft tissues still intact. A winemaker in Austria found hundreds of mammoth bones while renovating his cellar, and scientists performed an autopsy on a 44,000-year-old mummified wolf pulled from the permafrost.

Related: 35,000-year-old saber-toothed kitten with preserved whiskers pulled from permafrost in Siberia

Researchers in the U.K., meanwhile, discovered what could have been the biggest marine reptile ever found. This ichthyosaur, which lived 200 million years ago, is estimated to have been a whopping 82 feet (25 meters) long. Also from the age of the dinosaurs, palaeontologists in Morocco discovered a never-before-seen species of marine lizard with "dagger-like" teeth; and in Brazil, heavy rains exposed one of the oldest dinosaur skeletons ever discovered.

And where the living and long-dead collide, scientists now say the de-extinction of species like the woolly mammoth (Mammuthus primigenius) and Tasmanian tiger (Thylacinus cynocephalus) is "closer than people think." Researchers working on the effort claim bringing back ice age megafauna could help restore ancient ecosystems, boost carbon storage and mitigate climate change — but it remains to be seen whether it will cause catastrophic, unintended consequences.

"We have this hubris as humans that we can control our technology," Oswald Schmitz, a professor of population and community ecology at Yale University, told Live Science. "I'm not so convinced."

Animal news quiz 2024

Early Indigenous Americans relied heavily on meat from mammoths to survive, according to a new study, which suggests they were top-notch experts at hunting the massive beasts.

The findings, reported in a study published Wednesday (Dec. 4) in the journal Science Advances, are based on chemical analyses of the bones of an 18-month-old boy — dubbed Anzick-1 — who lived almost 13,000 years ago in what is now Montana.

The boy was probably still breast-feeding, and the results reveal that the diet of his mother was "closest to that of [the now-extinct] scimitar cat, a mammoth specialist," the researchers wrote in the study.

To investigate the diet of the boy's mother, the team looked at stable radioisotopes — atoms of an element that have a different number of neutrons in their nuclei — in the boy's bones. The technique measures the distinctive abundance of specific radioisotopes, which can be used to reconstruct the diet of an ancient person.

The boy's "isotopic fingerprint" was probably inherited directly from his mother and showed that mammoths were an important source of food for his entire family group, the authors wrote in the study.

That, in turn, suggests that people from the Western Clovis culture, to which the boy belonged, were regularly hunting mammoths — and to a lesser extent elk (Cervus canadensis), bison (Bison bison and B. antiquus) and a now-extinct genus of camel (Camelops).

The results are direct evidence of Western Clovis diets about 12,800 years ago, showing they preferred the meat of mammoths (mainly Mammuthus columbi) above all other sources — contrary to theories they mainly hunted smaller game, the authors wrote in the paper.

"These data suggest that Western Clovis people … were more focused on larger-bodied megafauna grazers, primarily Mammuthus [mammoths], and were not generalists who regularly consumed smaller-bodied herbivores," the authors wrote in the study.

Ancient Americans

The Clovis people lived in North America between about 13,000 and 12,700 years ago. They were once thought to have been the earliest humans in North America, but recent studies suggest the first Americans arrived even earlier, possibly around 23,000 years ago.

Mammoths also roamed the Americas at that time and migrated for long distances, making them a reliable source of fat and protein for early humans, the authors wrote.

"The focus on mammoths helps explain how Clovis people could spread throughout North America and into South America in just a few hundred years," co-lead author of the study, James Chatters, an archaeologist and paleontologist at McMaster University in Canada, said in a statement.

Co-lead author Ben Potter, an archaeologist at the University of Alaska Fairbanks, added that the results of the study confirmed what had been found at other archaeological sites. He said that hunting mammoths provided a flexible way of life and allowed the Clovis people to move into new areas without having to rely on smaller game animals, which could vary from one region to the next.

"This mobility aligns with what we see in Clovis technology and settlement patterns," Potter said in the statement. "They were highly mobile."

The new study modeled the diets of Clovis people by analyzing previously-published isotopic data from Anzick-1, and then adjusting it for nursing to estimate the isotopic values of his mother's diet.

The resulting isotopic fingerprint showed that about 40% of her diet came from mammoth meat, while other large animals like elk and bison made up most of the rest.

The results also show that small mammals played a very minor role in the ancient woman's diet, contrary to ideas that they may have been an important food source. The authors also suggest that the Clovis preference for mammoth meat may have played a part in the demise of these giant beasts in the Americas toward the end of the last ice age.

Mammoths (Mammuthus) are prehistoric beasts that roamed tundra ecosystems during the last ice age (2.6 million to 11,700 years ago), but their evolutionary history goes back farther than that. The now-extinct creatures branched off from African elephants (Loxodonta) around 6 million years ago and split from their closest known relatives, Asian elephants (Elephas maximus), about 440,000 years later.

Research suggests a small, isolated population of mammoths survived until 4,000 years ago before going extinct due a random, sudden event — although scientists still don't know what that event could be.

There are many things we may never know about mammoths, but scientists are working to obtain a clearer picture of how and where the animals lived — and some researchers are even trying to bring them back to life. In the meantime, how much do you know about mammoths? Find out by taking this quiz, and if you need a hint, tap the lightbulb in the top left corner.

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Clouds of pollen floating over the mammoth steppe at the end of the last ice age may have helped drive woolly mammoths to extinction, a new study claims.

Researchers say a boom in vegetation due to global warming may have released so much pollen, it triggered allergic reactions in animals — blocking their sense of smell and preventing them from communicating normally with one another. The inability to sniff each other out during the breeding season would have prevented mammoths from finding sex, the team argue, leading to a precipitous drop in population size and, eventually, extinction.

"One of the possible mechanisms for the extinction of animals during climate change could be a violation of the sense of smell due to the development of allergies when the flora changes," the researchers wrote in the study, which was published Aug. 27 in the journal Earth History and Biodiversity. "The purpose of this work is to propose a new evolutionary mechanism for the extinction of mammoths and other animals based on the disruption of communication."

Woolly mammoths (Mammuthus primigenius) lived during the Pleistocene epoch (2.6 million to 11,700 years ago). They disappeared across much of their range around 10,000 years ago, although a small population survived on Wrangel Island — a remote island off northeastern Russia — until 4,000 years ago. Researchers think a combination of inbreeding, hunting by humans and major changes in vegetation all pushed mammoths to extinction, but there is ongoing debate about how much each of these factors contributed to their demise.

Related: 'Closer than people think': Woolly mammoth 'de-extinction' is nearing reality — and we have no idea what happens next

Allergies would have disturbed several vital functions of mammoth life, the researchers argue. Animals use their sense of smell to find food and mates, to navigate during migration and to evade predators, so the mammoths' stuffed-up trunks may have doomed them, the researchers wrote in the paper.

One way to test if mammoths suffered from allergies is to examine their stomach content for plants and pollen that trigger allergies, the authors of the new study suggest. Some carcasses also have pollen embedded in the mummified tissues or preserved plant material around them that could help identify past irritants, according to the study.

Next, to determine whether these chemicals actually triggered an allergic reaction in mammoths, the researchers suggest looking for the immune system proteins the body produces during an allergic response. One of the main ones is immunoglobulin E (IgE), which is produced in the intestine and then pooped out, so testing fossilized mammoth feces, or coprolites, could be a way to see if the mammoths had bad cases of hay fever. So far, no published research has looked for traces of IgE in ancient mammal samples, according to the study.

One expert isn't convinced that allergies played a big part in the downfall of mammoths. "This idea seems pretty far out there and I'm not sure how you would ever prove it," Vincent Lynch, an evolutionary biologist and associate professor at the University at Buffalo in New York, told Live Science in an email.

Ancient DNA samples do indicate that the last-surviving woolly mammoths lost the ability to smell certain plants, Lynch said. The reconstructed genome of a mammoth from Wrangel Island showed mutations in genes associated with the ability to detect floral scents, suggesting the last mammoths couldn't smell flowering plants.

However, until the authors' idea is experimentally tested and supported by further research, Lynch said he still thinks a combination of environmental factors and human impacts caused mammoths to die out.

For about seven minutes in 2003, scientists reversed extinction.

The resurrected lineage was the Pyrenean ibex (Capra pyrenaica pyrenaica), and the last known member of the subspecies, a female named Celia, had died three years earlier.

Scientists had collected DNA from Celia's ear before her death and injected her genetic material into a domesticated goat egg cell with its nucleus removed. The resulting clone — the first and only extinct creature to have been revived at the time — died soon after birth due to a lung defect.

Although that effort failed to produce a healthy animal, "de-extinction" science has advanced dramatically in the past two decades. Technology is no longer a significant hurdle to reviving recently extinct species, and in many cases, we have enough DNA to piece together functional genomes for cloning. The question isn't so much whether we can resurrect lost species but if we should.

Some companies aren't waiting to answer that question. For instance, Colossal Biosciences, a Texas-based biotechnology and genetic engineering company, plans to bring back three iconic extinct species: the dodo (Raphus cucullatus), the Tasmanian tiger (Thylacinus cynocephalus; also known as the thylacine) and the woolly mammoth (Mammuthus primigenius). The ultimate goal for these de-extinction efforts, according to Colossal's website, is to "enrich biodiversity, replenish vital ecological roles and bolster ecosystem resilience."

But a catastrophic outcome cannot be ruled out, other experts say.

"We have this hubris as humans that we can control our technology," Oswald Schmitz, a professor of population and community ecology at Yale University, told Live Science. "I'm not so convinced."

Even in the best-case scenario, conservationists are skeptical that bringing back creatures that died out centuries or millennia ago will offer as much benefit as preserving the ones that are still hanging on.

"What's gone is gone," Schmitz said.

Closer than people think

Recent breakthroughs have brought scientists "closer than people think" to reviving long-extinct species, Ben Lamm, co-founder and CEO of Colossal Biosciences, told Live Science. The company aims to produce its first mammoth look-alike calves by 2028, and "it is highly likely that one could see another species before then," Lamm said, referring to Colossal's other de-extinction projects.

Woolly mammoths lived in the Arctic between 300,000 and 10,000 years ago. To produce the calves, Colossal scientists will first identify the genes encoding the woolly mammoth's most emblematic physical traits, such as shaggy hair, curved tusks, fat deposits and a dome-shaped cranium. They will then insert these genes into the genome of closely related, and therefore genetically similar, Asian elephants (Elephas maximus).

"De-extinction" can have different meanings — and our capability for de-extinction depends on how we define it, Love Dalén, a paleogeneticist and professor of evolutionary genomics at Stockholm University, told Live Science in an email. De-extinction in the sense of "creating a form of hybrid species that looks like the extinct one by replacing a limited number of key genes" is possible if there is available DNA from the extinct species, said Dalén, who sits on Colossal's advisory board. (There is no available DNA from dinosaurs, so creating a Jurassic Park is currently more of a pipe dream.)

Creating an animal that is genetically identical to the extinct species is trickier and depends on the species. For species that went extinct very recently and for which there are high-quality DNA samples, like Celia, "this could be possible," Dalén said. That's not the case for mammoths, however.

Dalén and his colleagues have come close to sequencing complete woolly mammoth genomes, but a few regions of DNA, such as some strings of repeat code, still prove challenging.

So far, Colossal Biosciences has acquired more than 60 partial woolly mammoth genomes, which it will use to edit elephant genomes in the lab, Lamm said. Once they have settled on a DNA sequence, Colossal representatives say they will implant a hybrid elephant-mammoth embryo into an Asian or African elephant (Loxodonta) surrogate.

The company also plans to resurrect the dodo and thylacine. "On the dodo project, we have one nearly complete genome," Lamm said, while on the thylacine, which only went extinct last century, "we've got much better genetic data right out of the gate." For the dodo, Colossal plans to implant the genetic material into domesticated chickens (Gallus domesticus) and, for the thylacine, into mouse-like marsupials called fat-tailed dunnarts (Sminthopsis crassicaudata).

Filling a gap in the ecosystem

The goal of de-extinction is to fill ecological niches that have stood empty since the original species disappeared, said Ronald Goderie, an ecologist and the director of the Taurus Foundation, a branch of Rewilding Europe that aims to create a substitute for extinct aurochs (Bos primigenius). Aurochs, the wild ancestors of domestic cattle (Bos taurus), once roamed across North Africa, Asia and nearly all of Europe. They likely played a vital role in maintaining animal and plant biodiversity through grazing and trampling the soil, according to the Taurus Foundation.

Goderie and his colleagues are bringing aurochs back through back-breeding, which doesn't involve genetic engineering. Humans hunted aurochs to extinction in 1627, but their DNA lives on in ancient cattle breeds living in Southern Europe, Goderie told Live Science. By selecting and breeding together cattle with physical attributes, behavioral traits and genes similar to those of aurochs, ecologists are inching toward reviving the lost species.

"We're very close," Goderie said. "We see very large, steep progress with each generation."

Woolly mammoths, which thrived during the Pleistocene epoch, maintained Arctic grasslands by trampling the snow, suppressing tree and shrub growth, and dispersing nutrients across huge distances via their dung. Without mammoths and other now-extinct megaherbivores, the so-called "mammoth steppe" has given way to a waterlogged landscape of mossy tundra, shrubs and forest. Research suggests this new landscape stores less carbon than grasslands did and is more susceptible to permafrost thaw. Some scientists have proposed that reintroducing megaherbivores to the Arctic could help restore the ecosystem, boost carbon storage and mitigate climate change.

The dodo was one of the largest terrestrial animals in its ecosystem in Mauritius. Evidence suggests dodos were seed dispersers and thereby influenced vegetation growth — although some experts question the extent to which the birds shaped their ecosystem. Colossal's plans to reintroduce dodos include ridding Mauritius of invasive species so that the birds can thrive, which the company argues has a beneficial "halo effect" for other species, Lamm said. The company is working with the Mauritian Wildlife Foundation, a non-governmental organization, and intends to partner with the Mauritian government, according to its website.

As for the thylacine, it was Tasmania's only marsupial apex predator, according to the University of Melbourne's TIGRR Lab, which is also working on de-extinction. As such, the species was important for predator-prey relationships that stabilized the ecosystem.

Scaling up

But de-extinct species can fulfill their ecological roles only if they survive in the wild and their populations are large enough, Goderie said. In the case of mammoths, that's a behemoth task.

Researchers recently estimated that Alaska's vast North Slope could support 48,000 woolly mammoths.

But to fulfill their ecological role — which may include increasing the albedo effect, where snow cools Earth by reflecting light back into space — mammoths would likely need to be reintroduced across the Arctic, said Vincent Lynch, an evolutionary biologist and associate professor at the University at Buffalo.

"You can't just put them in Alaska and fix the permafrost problem; you have to put them everywhere," Lynch told Live Science.

There would need to be several hundred thousand mammoths to have a significant impact on the climate, and that could put living endangered species in peril, Lynch said.

Both Asian and African elephants, which Colossal plans to use as surrogates to grow mammoth calves, are endangered, and every elephant gestating a "mammoth" calf can't grow babies of its own. "That's going to reduce population size," Lynch said.

The alternative would be to implant embryos into artificial wombs, but those have yet to be fully developed. "There would be like hundreds or thousands of artificial uteruses in a warehouse somewhere, churning out genetically engineered mammoths," Lynch said. "This is like '1984' scary stuff."

Unintended consequences

In addition to facing technological hurdles, de-extinction could have serious repercussions. For one, de-extinct animals may be sickly, given that the pool of available DNA for each species is relatively small.

Sustaining populations requires a sufficient number of creatures that are genetically different enough to buffer against diseases and harmful mutations.

It's also worth considering who would be liable if large-scale mammoth reintroductions went wrong. "The ecosystem has been adapting to the absence of mammoths since mammoths started going extinct," Lynch said. "What if there's an unintended consequence and something bad happens?"

Other experts echoed these concerns. "To get some impact, you need to have a lot of animals," Sophie Monsarrat, an ecologist and the rewilding manager at Rewilding Europe, told Live Science.

Reintroductions can lead to clashes between humans and wildlife. "In Africa, if you look at elephant conservation and reintroductions, then there are conflicts," Monsarrat said. In Kenya alone, human-elephant conflicts killed 200 people between 2010 and 2017, according to WWF. If scientists were to succeed in creating a viable mammoth population, they would have to roll out continent-wide education programs "teaching people how to react in front of a mammoth," Monsarrat said.

The makeup of the reintroduced population matters too, Schmitz said. Brown bears (Ursus arctos) that were brought from Slovenia to the Italian Alps in the 2000s are thriving, but it turns out that the source population was particularly aggressive, Schmitz said. Ecologists "didn't necessarily do their homework," he said. "They reintroduced them, and now they're attacking livestock and people."

There's also no guarantee that animals will stay where we release them, Schmitz said. In 1995, gray wolves (Canis lupus) were reintroduced to Yellowstone National Park but have roamed far beyond the park's boundaries. "If you unleash something in nature, these animals are going to find places that are the most suitable for them and may not be the places where you think they will stay," Schmitz said.

And although megaherbivores helped with carbon storage during the last ice age, "restoring megafauna may just as well have a negative impact on climate change," Dalén said. For instance, mammoths could theoretically contribute to global warming by eroding the permafrost during the warm season and by emitting methane, he said. They could also reduce the amount of carbon stored in woody plants, as elephants do when they eat plants in African savannas.

"A pet project of billionaires"

While proponents think de-extinction is a valuable conservation tool, critics say money would be better spent on existing initiatives. Colossal Biosciences has raised at least $225 million to fund its de-extinction programs, with some of that money also going toward conservation and genetic research across the globe, Lamm said.

Instead of using that money to bring back three extinct species whose ecological impact is unknown, the funds could be put toward saving roughly 100 species that are currently facing an uncertain future, Schmitz said.

In some cases, de-extinction targets species with a living equivalent fulfilling similar ecological functions. For example, one reason the thylacine went extinct was that people perceived it as a predator of livestock, Schmitz said. "But we have a similar animal right now that's facing similar persecution, and that's the dingo [Canis lupus dingo]," he said.

Lynch agreed that the best way to support conservation is to spend money on existing, proven initiatives. It's probably impossible to introduce an ecologically significant number of de-extinct species, which also raises questions about the purpose of de-extinction companies like Colossal, he said.

Adam Searle, a research fellow in cultural, historical and environmental geography at the University of Nottingham in the U.K., said de-extinction is unlikely to contribute to solving the ecological crisis. "It's literally a pet project of billionaires," he said.

In response to Searle's comments, Lamm told Live Science in an email that "for every de-extinction target, the technology and techniques developed will benefit closely related species." He further argued that "technological innovations made and funded by private sector companies are vital to this fight."

Regardless of Colossal's ecological impact, the company could still see a big return on investment, Lynch said.

"If they're successful — and I have no doubt that they will be — they're going to make a ton of money," he said.

For the rest of us and for nature, however, de-extinction "could do a lot more harm than good," Schmitz said.

Researchers who thought ancient hunters threw spears to kill mammoths and mastodons may have got the wrong end of the stick, archaeologists say. Instead of hurling weapons at prehistoric beasts, hunters likely used their weapons like pikes, impaling the beasts as they charged, a new study suggests.

Pikes propped up at an angle would have inflicted much deeper wounds on charging animals than flying spears, even if the spears were thrown by the strongest prehistoric hunters, according to the study. Evidence suggests hunters designed the pikes to split in two upon impact with bone, widening the internal wound and causing deadly injuries.

"This ancient Native American design was an amazing innovation in hunting strategies," lead study author Scott Byram, a research associate with the University of California Berkeley's Archaeological Research Facility, said in a statement. Not only could the weapon kill huge animals swiftly, it also protected the hunter who stood behind it, Byram and his colleagues said in the statement.

The new study, which was published Aug. 21 in the journal PLOS One, builds on decades of research into ancient weapon tips known as Clovis points. Clovis points, which date to around 13,000 years ago, get their name from a small town in New Mexico where they were first discovered nearly a century ago during archaeological excavations.

Since then, archaeologists have found thousands of these flattened stone points across North America. They are carved from rocks including chert, flint and jasper, with scalloped edges that could easily pierce the hide and skin of animals. But the most distinctive features of Clovis points are fluted indentations at the base on either side that act as shock absorbers.

Related: The 1st Americans were not who we thought they were

Archaeologists disagree about how early Americans used Clovis points. While some researchers are confident that hunters mounted the points on wooden shafts to make weapons, others argue that they were too broad to penetrate deep and inflict serious wounds in large animals. Instead, these experts argue, ancient communities used Clovis points like knives to cut meat off scavenged animal carcasses.

Wood disintegrates quickly, meaning archaeologists have never recovered wooden shafts dating to the Clovis culture, according to the statement. They have found bone shafts, however, which they think hunters attached to the front end of wooden spears to hold the Clovis point in place.

The authors of the new study think the Clovis points were indeed placed on wooden shafts but they argue the weapons would have been too valuable to risk throwing around. Finding the right rocks to shape points from and collecting suitable wooden poles to make spears took time, Byram said, so it's more likely that hunters kept hold of their weapons and used them as pikes.

To test their idea, Byram and his colleagues reconstructed an ancient weapon using a replica Clovis point, a long pine shaft and a resin cast of an original bone shaft. The researchers then measured the force that this weapon could withstand if it was used like a pike.

They found that the weapon could withstand forces equivalent to and higher than a mammoth charging into it, meaning the spear would pierce the animal's skin and penetrate its tissues if hunters braced it like a pike. The spear broke in half when the researchers applied forces equivalent to hitting the bone of a charging mammoth, meaning a pike would eventually break, but only after impaling the animal.

The way the spear broke in the experiment suggests hunters designed it to inflict a maximum amount of tissue damage, according to the researchers. If the weapon penetrated an animal's flesh so deep that it struck bone, the Clovis point likely receded into the gap between the wood and bone shafts, splitting the weapon in half. This may have widened the animal's wound and caused massive internal injuries, similar to a modern-day hollow-point bullet.

The experiments, as well as historical accounts from all around the world of spears being used as pikes to impale large animals, suggest mammoth hunters may have braced their weapons against the ground instead of throwing them, according to the study.

"The kind of energy that you can generate with the human arm is nothing like the kind of energy generated by a charging animal," co-author Jun Sunseri, an associate professor of anthropology at UC Berkeley, said in the statement. Ancient hunters likely knew this and took advantage of attacking animals' momentum to impale them on pikes, Sunseri said, adding that "these spears were engineered to do what they're doing to protect the user."

A 52,000-year-old woolly mammoth carcass was so well preserved, scientists were able to determine the 3D structure of the prehistoric creature's genetic code, a first-of-its-kind study shows.

The new breakthrough is a significant step on the path to sequencing a complete woolly mammoth (Mammuthus primigenius) genome, which has been challenging due to the degraded nature of ancient DNA. With a completely sequenced genome, scientists may finally be able to identify every single DNA mutation that differentiates modern elephants from their woolly mammoth relatives. A full overview of these genetic differences could in turn boost ongoing efforts to "de-extinct" the woolly mammoth.

"Until now, we could only read small fragments of ancient DNA," co-author Juan Antonio Rodríguez, an assistant professor of hologenomics at the University of Copenhagen in Denmark, told Live Science in an email. "These fragments were about 100 letters of DNA, but we did not know what order they had in the mammoth genome. It is like separated pages of a book, but without the page number." 

The results of the new study, published Thursday (June 11) in the journal Cell, will enable researchers to "put an order to those pages," Rodríguez said. This is the oldest 3D genome analysis ever completed and the first done in a woolly mammoth, he said.

The woolly mammoth in question is a late Pleistocene specimen discovered in 2018 near Belaya Gora, in the Sakha Republic of Siberia. The animal, nicknamed "YakInf," was still covered in hair, indicating it was "exceptionally well preserved," Rodríguez said.

Related: Mystery 'random event' killed off Earth's last woolly mammoths in Siberia, study claims

The mammoth died and froze in a way that crystalized not only its carcass, but also its cells and chromosomes, which stayed intact for 52,000 years. According to the study, this suggests the mammoth underwent both freeze-drying — dehydration at cold temperatures — and a process called glass transition, where under cold conditions, certain dry materials — including glass and, seemingly, woolly mammoth tissues — can become extremely viscous. This process slows down degradation and preserves their structure in a "glassy" state.

To explore the mammoth's genome architecture, Rodríguez and his colleagues extracted DNA from a piece of skin that was taken from behind the creature's ear. They used a method called High-Throughput Chromosome Conformation Capture Technique (Hi-C), which allows scientists to detect sections of DNA that sit close to each other in modern samples, and adapted it to work on the ancient sample.  

Using this uniquely adapted technique, called PaleoHi-C, the team determined, for the first time, that woolly mammoths had 28 pairs of chromosomes — the same as modern elephants.

The research also revealed "how exactly those chromosomes were folded in 3D in the mammoth skin nuclei, which is very cool, because…we know that the way chromosomes are folded has a lot to do with cell function," co-author Olga Dudchenko, an assistant professor in the department of genetics at Baylor College of Medicine in Houston, Texas, told Live Science in an email.

The way chromosomes were folded in the mammoth skin sample highlighted genes that were active at the time of the creature's death, including genes encoding hair growth, Rodríguez said. By comparing this gene activity to that of an elephant, scientists could pinpoint differences that may bolster ongoing woolly mammoth de-extinction efforts, he said. 

But de-extinction was not the motivation behind the new study. "We did not do it specifically for reconstruction efforts, but to learn from the past to inform future decisions," Dudchenko said.

Genome architecture "is one more step" toward de-extinction, Rodríguez said, "but there are many other known and unknown steps that scientists need to figure out before bringing a mammoth back."

 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."

A winemaker in Austria has discovered hundreds of mammoth bones underneath his wine cellar.

Andreas Pernerstorfer came across the bones in March while renovating his cellar in the village of Gobelsburg, northwest of Vienna, CNN reported. At first, he mistook a bone for wood. 

"I thought it was just a piece of wood left by my grandfather," Pernerstorfer told the Austrian Broadcasting Corporation (ORF), according to BBC News. "But then I dug it out a bit, and then I remembered that in the past, my grandfather said he had found teeth. And then I immediately thought it was a mammoth."

Researchers uncovered around 300 bones from at least three individual mammoths. A comparable discovery of bones and human artifacts was made in a neighboring cellar 150 years ago, according to a statement released by the Austrian Archaeological Institute (OeAI), part of the Austrian Academy of Sciences.

Researchers from the OeAI are excavating the bones and think the two cellars probably sit on the same ancient site, Smithsonian Magazine reported. But the new discovery is an "archaeological sensation," according to the statement. 

Related: Woolly mammoth de-extinction inches closer after elephant stem cell breakthrough

"Such a dense bone layer of mammoths is rare," Hannah Parow-Souchon, an archaeologist at the OeAI, said in the statement. "It's the first time we've been able to investigate something like this in Austria using modern methods."

The team estimated the bones were between 30,000 and 40,000 years old. They also found stone artifacts and charcoal in the wine cellar, according to the statement. 

There are still a number of unknowns that researchers are trying to piece together, including how the near-complete remains of the mammoths ended up so close to one another. One possible explanation is that humans hunted the three animals.

"We know that humans hunted mammoths, but we still know very little about how they did it," Parow-Souchon said in the statement. 

Humans might have killed the mammoths by chasing them to the site and setting a trap for them there, according to the statement.

Scientists have made a stem cell breakthrough in elephants, which could mean researchers are one step closer to bringing back long-extinct woolly mammoths, the de-extinction company Colossal Biosciences has announced.

In a statement shared with Live Science, Colossal's Woolly Mammoth team says it has successfully derived induced pluripotent stem cells (iPSCs) from Asian elephants (Elephas maximus). iPSCs are cells that have been reprogrammed so they can give rise to any cell type in the body, meaning researchers will now be able to investigate the adaptations that differentiate woolly mammoths (Mammuthus primigenius) from their closest living relatives and test gene edits without having to take tissue from living animals.

"These cells definitely are a great benefit to our de-extinction work," Eriona Hysolli, the head of biological sciences and mammoth lead at Colossal Biosciences, told Live Science. What's crucial about them, Hysolli said, is that they can reveal the cellular and genetic processes behind features that helped woolly mammoths thrive in the Arctic. These features include shaggy hair, curved tusks, fat deposits and a dome-shaped cranium. 

iPSCs also open a path to creating elephant sperm and egg cells, which are essential for mammoth de-extinction, in the lab. With fewer than 52,000 Asian elephants left in the wild, according to WWF, harvesting cells from these animals would prove difficult and undesirable.

Previously, deriving elephant iPSCs proved challenging because these animals have a complex gene pathway not found in other species. The researchers overcame this by suppressing core genes called TP53 that regulate cell growth and prevent cells from duplicating indefinitely, Hysolli said.

Related: 'That's a huge amount of movement for a single mammoth': Woolly female's steps retraced based on chemistry of 14,000-year-old tusk

"One of the things that we had to overcome for elephant cells is that they do have this expansive TP53 pathway," Hysolli said. "We had to suppress this pathway via two means in order to get these iPSCs, so we had to go through a multistep process in order to achieve them."

The breakthrough may also shed light on early development in elephants, which is currently considered the biggest hurdle to woolly mammoth de-extinction. If researchers succeed in creating a woolly mammoth embryo by fusing ancient mammoth DNA with elephant cells, they will need to implant this embryo into an elephant surrogate to complete a 22-month gestation period. "Elephant gestation is so long and complex, so really understanding the developmental biology aspect of elephant biology is so important," Hysolli said. 

Engineering a woolly mammoth embryo no longer poses a huge challenge, Hysolli said, but birthing a healthy calf will take more time and work. The team is still researching alternative methods to generate elephant iPSCs and maturing the ones they have newly developed. The iPSCs breakthrough, which will be published on the preprint database bioRxiv, has yet to be peer-reviewed.

"There is more validation to be done, so until you do the experiment you can never be sure, but we think that the pluripotency potential [to differentiate into any cell type] is fully there," Hysolli said.

This is an important breakthrough and an essential step to create a woolly mammoth-like elephant, said Vincent Lynch, a developmental biologist and associate professor at the University at Buffalo in New York who was not involved in Colossal's work. "The goal, I think, is to turn these iPSCs into sperm and eggs, which would allow for in vitro fertilization and, eventually, surrogacy," Lynch told Live Science in an email. "Those methods are pretty challenging and haven’t been developed yet, but it is only a matter of time."

Reprogramming elephant cells into iPSCs has applications beyond woolly mammoth de-extinction, according to the statement. The technology could provide a boost to elephant conservation, for example, by enabling researchers to produce and fertilize reproductive cells artificially.

"We can derive gametes, so oogonia and spermatogonia-like cells, from these pluripotent stem cells," Hysolli said. "And that's crucial over the longer term, because they can really hold the key to saving species."

Scientists have retraced the journey of a female woolly mammoth from her birthplace in present-day Canada to eastern central Alaska, where she met her end around 14,000 years ago at the hands of hunter-gatherers.

The mammoth, whose name Élmayuujey'eh translates to "hella lookin" in the aboriginal Kaska language, was likely killed by early Beringian hunter-gatherers when she was 20 years old. Her existence is known thanks to a complete tusk discovered at Swan Point, one of the oldest archaeological sites in the Americas.

Élmayuujey'eh, or Elma for short, was born toward the end of the last ice age in what is now the Canadian province of the Yukon, where she likely stayed for the first decade of her life. A new analysis of the mammoth's tusk suggests she then set off across the frozen landscape, covering roughly 620 miles (1,000 kilometers) in under three years. 

"That's a huge amount of movement for a single mammoth," study co-author Hendrik Poinar, a professor of anthropology at McMaster University in Canada and the director of the McMaster Ancient DNA Center, said in a video released by the university. Elma trekked all the way into Alaska and eventually slowed down, Poinar said.

Her remains indicate she was closely related to both a juvenile and a newborn woolly mammoth whose bones were also unearthed at Swan Point. The trio may have belonged to one of two matriarchal herds that roamed an area within 6.2 miles (10 km) of Swan Point, according to the study, published Wednesday (Jan. 17) in the journal Science Advances.

Related: Huge mammoth jaw at least 10,000 years old pulled up from Florida river

To piece Elma's life together, researchers split her tusk lengthwise and examined thin layers of ivory that formed like the rings of a tree trunk throughout her years. The proportion of different versions of chemical elements, or isotopes, in these layers contained valuable information about the mammoth's diet and location, enabling the team to retrace her steps.

The researchers also analyzed ancient DNA in Elma's tusk and compared it with the remains of eight other woolly mammoths found in and around Swan Point, including the two youngsters. Their results revealed the mammoths belonged to at least two distinct herds that may have gathered in the region along with other mammoth herds — a congregation that would have attracted humans.

"Indigenous hunters clearly saw that the mammoths were using this as a really important location for feeding," Poinar said in the video. "The data to me suggest that these were Indigenous people that appreciated, looked at, loved these phenomenal beasts walking on this landscape. But it would make sense too, that in times of need, that you would kill them — a mammoth like that could provide food for a huge number of people over a long period of time." 

Elma's remains indicate she was in the prime of early adulthood and well nourished at the time of her death. She likely died in late summer or early autumn, which coincides with when humans would have set up their seasonal hunting camp at Swan Point and suggests she died at the hands of hunters, according to the study.

Very little is known about the geographic movements and behaviors of woolly mammoths — or about how these animals interacted with early Americans — but stories like Elma's can paint us a picture.

"This analysis of lifetime movements can really help with our understanding of how people and mammoths lived in these areas," co-author Tyler Murchie, a postdoctoral researcher and former member of the MacMaster Ancient DNA Center, said in a statement. "We can continue to significantly expand our genetic understanding of the past, and to address more nuanced questions of how mammoths moved, how they were related to one another and how that all connects to ancient people." 

Coal miners in North Dakota made an astonishing find when they unearthed a partial mammoth skeleton with a complete, 7 foot (2.1 meter) tusk.

The miners discovered the well-preserved mammoth tusk while working at the Freedom Mine, near the city of Beulah, over Memorial Day weekend last May. According to KFYR, the tusk was scooped up and loaded onto a truck before the miners noticed it. 

The area was quickly closed off to allow paleontologists at the North Dakota Geological Survey, the State Historical Society of North Dakota, and the Bureau of Land Management to excavate the old streambed where the fossils were buried.

They gradually unearthed more than 20 bones from the mammoth skeleton, including ribs, a shoulder blade, a tooth and parts of the hips, at the site.

This discovery is remarkable, said Clint Boyd, senior paleontologist for the North Dakota Geological Survey, in a statement, because most mammoth fossils found in North Dakota are single bones and teeth.

"This specimen is one of the most complete mammoth skeletons discovered in North Dakota, making it an exciting and scientifically important discovery," he said.

Jeff Person, a paleontologist with the North Dakota Geological Survey told the Associated Press it was "miraculous" the tusk had not been damaged during removal. 

The bones were covered in protective plastic wraps before being transported to the Paleontology Lab at the North Dakota Heritage Center and State Museum in Bismarck. They will be carefully cleaned so they can be examined in detail.

Then, the bones will be used to educate the general public about life during the last ice age (2.6 million to 11,700 years ago), although it's not yet known where they will be kept.

Several species of mammoth lived in North America during the Ice Age, including the woolly mammoth (Mammuthus primigenius) and the Columbian mammoth (Mammuthus columbi). Once the bones are fully cleaned, paleontologists will be able to identify from which mammoth species they belong.

Mammoths went extinct around 10,000 years ago. Warmer temperatures caused a loss of habitat for these megafauna, which — combined with human hunting — led to huge population declines. 

Scientists have used mammoth fossils to discover more about these gigantic creatures. Genetic testing has found woolly mammoths to be more closely related to the modern African elephant (Loxodonta africana) than to the Asian elephant (Elephas maximus). Research has also shown that woolly mammoths' distinctive traits, including their smaller ears, large fat deposits and fluffy coats, became more pronounced over 700,000 years as they adapted to freezing conditions.

In 2021, scientists sequenced the DNA recovered from mammoth remains to find that the Columbian mammoth was a hybrid between the woolly mammoth and a previously unknown genetic lineage of mammoth.

A fossil hunter made an astonishing discovery while diving in a Florida river — the fossilized  jawbone of a mammoth. 

John Kreatsoulas, who runs Fossil Junkies Dig and Dive Charters, an organization that runs fossil-hunting trips for the public, discovered the intact fossil while exploring a section of the Peace River near the city of Arcadia.

He initially thought the item was a log, but on closer inspection, realized it was a large mandible. 

Kreatsoulas doesn't know exactly how old the specimen is, but believes it could be at least 10,000 years old.

"I grabbed onto it just to hold on for a second, and I realized — 'wait for a second, that's not a tree, that was a mammoth jaw,'" he told NBC2, a local Florida outlet.

Related: Dwarf elephants and shedding mammoths shine at NYC's 'Secret World of Elephants'

Kreatsoulas is planning to take the jawbone to be cleaned and analyzed by experts in Tampa, who will be able to determine the fossil's age with radiocarbon dating. This is where researchers determine the levels of particular radioactive elements — often radiocarbon — in a fossil to work out when an animal died. The bone will also be registered with the State of Florida, so it may end up in a museum rather than in Kreatsoulas' personal collection at home.

It's not known exactly what kind of mammoth the fossil belonged to, but Columbian mammoths (Mammuthus columbi) inhabited North America — and as far south as Costa Rica — during the Pleistocene epoch (2.6 million years to 11,700 years ago). 

The Columbian mammoth was likely a hybrid between the woolly mammoth (Mammuthus primigenius) and an unknown lineage of mammoth that arrived in North America from Siberia around 1.5 million years ago, according to DNA research.

Columbian mammoths went extinct between 13,000 and 10,000 years ago, at the end of the last ice age. Warmer temperatures caused a loss of habitat for these megafauna, which combined with humans hunting led to huge population declines. 

This isn't the first time mammoth fossils have been found in Florida's Peace River. In 2021, divers discovered a 4-foot (1.2 meters) mammoth leg bone in the water. Meanwhile, in northern Florida, researchers have unearthed a 5.5 million-year-old "graveyard" of gomphotheres, a four-tusked relative of modern elephants, that had likely drowned in a prehistoric river there. 

Editor's note: The explanation in this article about how radiocarbon dating works has been corrected. 

Male woolly mammoths turned into sex fiends when in heat, just like modern elephants do, a new study of ancient hormones preserved in the tusks of the extinct giants has revealed.

By charting the annual surges of testosterone in a 33,000-year-old mammoth tusk, researchers have discovered that mammoths underwent musth. The word, which means "drunk" in its original Persian, is a months-long period of heightened sexual activity and aggression towards rivals experienced by modern male elephants. During musth, a male elephant's testosterone can soar to up to 60 times its natural levels. 

"Tusks hold particular promise for reconstructing aspects of mammoth life history because they preserve a record of growth in layers of dentin that form throughout an individual's life," study co-author Daniel Fisher, a paleontologist at the University of Michigan, said in a statement.

Related: Woolly mammoths weren't always shaggy. Here's when they evolved some of their trademark features.

Dentine, the hardest tissue in mammalian bodies besides enamel, is a type of tooth tissue that forms the majority of an elephant's tusk. After being deposited at the tusk's base in the form of a cone-shaped packet, the dentine grows outward over an elephant's life, joining with previous dentine packets to elongate the tusk in a series of tree-like concentric rings. Hormones are deposited along those rings, giving researchers a year-by-year record of the animals' lives. 

Paleontologists have long thought that mammoths underwent musth. To confirm their hypothesis, they analyze the testosterone levels found in three tusks: two from adult mammoths and another from an adult African bull elephant. The bull elephant tusk was taken from a male killed by a hunter in Botswana in 1963, and the mammoth tusks belonged to a female and a male — the first, around 5,700 years old, was found on Wrangel Island, Russia, and the second is roughly 37,000 years old and was unearthed in a Siberian diamond mine in 2007.

By measuring testosterone levels in both pulverized samples of tusk tissue, and in CT scans of the intact tusks, the paleontologists found that both the male bull elephant and the male mammoth experienced massive seasonal spikes in testosterone levels — rising to 20 times higher than baseline in the elephant and 10 times higher in the mammoth. This strongly suggests male mammoths experienced musth and the behavioral changes that go with it.

The team now plans to use their technique to study fluctuations of other hormones, giving them a unique window into the lives of mammoths. And they say that their technique needn't stop with these particular shaggy beasts.

"These methods could be used to investigate records of organisms with smaller teeth, including humans and other hominids," the researchers wrote in the study. "Endocrine records in modern and ancient dentin provide a new approach to investigating reproductive ecology, life history, population dynamics, disease, and behavior in modern and prehistoric contexts."

The researchers published their findings on May 3. in the journal Nature.

Woolly mammoths weren't always the shaggy beasts depicted in books and movies. And now, scientists have a better idea of when these behemoths evolved some of their most iconic traits.

Researchers from Sweden compared the genomes of 23 Siberian woolly mammoths (Mammuthus primigenius) to the genomes of 28 modern-day Asian elephants (Elephas maximus) and African elephants (Loxodonta). They found that over the course of the megafauna's more than 700,000 years of existence, its "trademark features" — such as woolly fur, small ears and large fat deposits — evolved too, according to a study published April 7 in the journal Current Biology.

"We wanted to know what makes a mammoth a woolly mammoth," lead author David Díez del Molino, a paleontologist at the Centre for Palaeogenetics in Stockholm, said in a statement. "Woolly mammoths have some very characteristic morphological features, like their thick fur and small ears, that you obviously expect based on what frozen specimens look like, but there are also many other adaptations, like fat metabolism and cold perception, that are not so evident because they're at the molecular level."

Related: The CIA wants to bring woolly mammoths back from extinction

The researchers found that "overall, the [more than] 700,000-year-old Chukochya genome, which represents one of the earliest woolly mammoths, shared approximately 91.7% of the mutations that caused protein-coding changes in the more modern woolly mammoths." That means the species' defining traits — such as fluffy fur, fat deposits and ability to weather cold conditions — were present when the woolly mammoth diverged from the steppe mammoth (Mammuthus trogontherii), one of its ancestors, according to the statement.

They also discovered that woolly mammoths evolved to have dry earwax and a reduction in body odor, according to the study.

"We found some highly evolved genes related to fat metabolism and storage that are also found in other Arctic species like reindeer and polar bears, which means there's probably convergent evolution for these genes in cold-adapted mammals," Díez del Molino said in the statement.

The CIA is funding research into resurrecting extinct animals — including the woolly mammoth and tiger-like thylacine — according to news reports.

Via a venture capital investment firm called In-Q-Tel, which the CIA funds, the American intelligence agency has pledged money to the Texas-based tech company Colossal Biosciences. According to Colossal's website, the company's goal is to "see the woolly mammoth thunder upon the tundra once again" through the use of genetic engineering — that is, using technology to edit an organism's DNA.

Colossal has also stated an interest in resurrecting the extinct thylacine, or Tasmanian tiger — a wolf-like marsupial that went extinct in the 1930s — as well as the extinct dodo bird.

For their part, the CIA is less interested in thundering mammoths and roaring thylacines than it is in the underlying genetic engineering technology that Colossal intends to develop, according to an In-Q-Tel blog post.

"Strategically, it's less about the mammoths and more about the capability," In-Q-Tel's senior officials wrote.

De-extinction may sound like science fiction — and, to an extent, it is. There is no way to bring back the woolly mammoth as it was ten thousand  years ago; however, by using DNA editing tools, scientists can insert cold-resistant characteristics into the DNA sequences of modern elephants, making them genetically similar to woolly mammoths. The resulting creature wouldn't be a mammoth, per se; rather, it would be a proxy animal that's more like an elephant with mammoth-like characteristics.

The foundation of this process is a gene editing method called CRISPR — genetic "scissors" that scientists can use to cut, paste and replace specific gene sequences into an organism's DNA. (Several of the researchers behind CRISPR won the 2020 Nobel Prize in chemistry).

According to the In-Q-Tel blog post, investing in this project will help the U.S. government to "set the ethical, as well as the technological, standards" for genetic engineering technology, and keep the U.S. a step ahead of competing nations that may also be interested in reading, writing and altering genetic code.

Not everyone is so optimistic about using genetic engineering tools to revive extinct animals. Critics have warned that, even if a company is able to engineer a healthy proxy mammoth, the mammoth's natural habitat no longer exists — and, even if it did, genetic code cannot teach an animal how to thrive in an unfamiliar ecosystem, according to Gizmodo. Some scientists also argue that money spent on de-extinction projects could go much further if applied to the conservation of living animals.

A near-perfectly mummified, 30,000 year-old baby woolly mammoth has been unearthed from Canadian permafrost by a miner in the Klondike region's gold fields.

The stunningly preserved baby, which measured just 4.5 feet (1.4 meters) long and has much of its hair and skin intact, was described by officials  as "the most complete mummified mammoth found in North America." 

As the discovery was made in Eureka Creek, on the land of the Tr'ondëk Hwëch'in First Nation in Canada's Yukon, the animal has been named "Nun cho ga" or "big baby animal" in the Hän language. Analysis suggests that the calf is female and was around one month old at the time of death, putting her at roughly the same biological age as another woolly mammoth calf that was discovered in Siberia in 2007 — the 42,000 year-old infant called "Lyuba." 

Related: 200,000-year-old 'mammoth graveyard' found in UK

"As an ice age paleontologist, it has been one of my life long dreams to come face to face with a real woolly mammoth. That dream came true today," ​​Grant Zazula, a paleontologist for the Yukon government's Department of Tourism and Culture, said in a statement. "Nun cho ga is beautiful and one of the most incredible mummified ice age animals ever discovered in the world. I am excited to get to know her more."

The remains were discovered when a mine worker who was digging near a creek in the Klondike gold fields south of Dawson City, felt his front-end loader strike something unexpected. He called his boss over to investigate and the two found the mummified mammoth buried in the mud. All mining work stopped so that two geologists could drive to the location, recover the extinct animal's remains and take samples of the site.

"And the amazing thing is, within an hour of them being there to do the work, the sky opened up, it turned black, lightning started striking and rain started pouring in," Zazula told the Canada Broadcasting Corporation (CBC). "So if she wasn't recovered at that time, she would have been lost in the storm."

This isn't the first time that mummified mammoths have been found by miners in the region. For example, partial remains of a mammoth calf, nicknamed Effie, were discovered at a gold mine in the neighboring U.S. state of Alaska, in 1948. But none of the previous discoveries were so incredibly well preserved.

"It's amazing. It took my breath away when they removed the tarp. We must all treat it with respect," Tr'ondëk Hwëch'in Elder Peggy Kormendy said in the statement.

Woolly mammoths wandered the icy arctic plains of northern Europe, Asia and North America alongside wild horses, cave lions and giant bison, and went extinct as recently as 5,000 years ago, Live Science previously reported. If Nun cho ga had grown to be an adult, she likely would have stood as tall as 13 feet (4 m) at the shoulder and would have sported enormous, curved tusks to ward off her adversaries.

Grass in the infant's stomach suggested that Nun cho ga may have been grazing at the time of her death, and possibly met her demise after straying just a few too many steps beyond her mother's sight, which led to her getting stuck in the mud, becoming engulfed and suffocating. "That event, from getting trapped in the mud to burial was very, very quick," Zazula said.

Earth scientist Dan Shugar, an associate professor at the University of Calgary who worked on the mammoth recovery, wrote on Twitter that unearthing the remains "was the most exciting scientific thing I have ever been part of, bar none," and that the remains had been preserved down to the intestines and individual toe nails.

"This is as a remarkable recovery for our First Nation, and we look forward to collaborating with the Yukon government on the next steps in the process for moving forward with these remains in a way that honours our traditions, culture, and laws," Tr'ondëk Hwëch'in Chief Roberta Joseph said in the statement.

Originally published on Live Science.

Prehistoric giants used to populate the Earth. These behemoths included mighty dinosaurs, airplane-size pterosaurs, massive crocodiles and snakes, and even armadillos the size of cars. But today, there are just a few big animals on our planet.

What happened? Why aren't there many giants left anymore?

First of all, there's plenty of fossil evidence that the ancient past really did have larger animals — beasts that were humongous but also larger, on average, than today's creatures, Greg Erickson, a vertebrate paleobiologist at Florida State University in Tallahassee who specializes in ancient reptiles, told Live Science. Ever since scientists unearthed the first known stash of dinosaur bones, in the 19th century, researchers have put forth ideas to explain why giants were common millions of years ago but less so today. But no one can point to one definitive answer, Erickson said. "It's so multifactorial." 

Related: Why are there so many giants in the deep sea?

Several major differences between dinosaurs and today's largest animals, the mammals, may help explain the loss of behemoths, however. Along with other giant reptiles, dinosaurs could adapt to different niches as they grew bigger over life, hunting smaller prey as juveniles and larger victims as adults. In part, they could do this because they swapped out sets of teeth over a lifetime. "They replace their teeth constantly, just like sharks do. But along the way they could change the type of teeth," Erickson said. Crocodiles, for instance, go from "needle-like teeth to more robust teeth. Mammals don't have that luxury."

Put another way, as some reptilian youngsters ballooned into hulking adults, they traded their relatively puny juvenile teeth for bigger weapons, allowing them, in turn, to hunt bigger meals to fuel their larger bodies.

In dinosaurs, too, air sacs likely extended from their lungs to their bones, creating sturdy but light scaffolding, Edinburgh University paleontologist Steve Brusatte told Scientific American. That gave dinosaurs skeletons that were "still strong and still flexible, but lightweight. That helped them get bigger and bigger and bigger," Brusatte said. "The same way that skyscrapers are getting bigger and bigger and bigger because of the internal support structures." (Of course, though air sacs helped make for strong, lightweight bones, no animal could actually get as big as a skyscraper. That's because body weight grows much faster than bone strength as animals increase in size, as physicist Neil deGrasse Tyson has explained.) 

Mammals lack such air sacs, though, "that can invade the bone and lighten up the bone," Brusatte said, "So elephant size or a little bit bigger, that might be the limit as to where mammals, at least on land" can get. … You can't really get mammals, it doesn't seem, to be the size of dinosaurs."

As warm-blooded, or endothermic creatures, mammals also need a lot of fuel. "Elephants are full endotherms, and the dinosaurs, at least the herbivorous dinosaurs, probably mostly were not," Geerat Vermeij, a professor of geobiology and paleobiology at the University of California, Davis, told Live Science. "So the food requirement for, say, a gigantic elephant would be … perhaps 5 times greater than that of even the very largest dinosaurs." 

Paleontologists have debated whether dinosaurs were cold- or warm-blooded. But current science places many animal species on a gradient between cold- and warm-bloodedness, and dinosaurs were probably "on the low end of the warm-blooded range," Erickson said. That made a large body less energetically expensive for dinos.

Huge size also requires the right environment. In a 2016 study published in the journal PLOS One, Vermeij concluded that giantism depends mostly on sufficient resources produced and recycled by "highly developed ecological infrastructure." In other words, the ecology needs to produce sufficient oxygen, food and habitat to grow a truly giant creature. Such ecologies had seen great development by the middle Triassic period, near the beginning of the age of dinosaurs, Vermeij wrote.

In one potentially important environmental change, ancient atmospheres had higher concentrations of oxygen. This may have played a role in gigantism, particularly among insects. Wingspans among prehistory's biggest bugs tracked ancient increases in oxygen concentration, a 2012 study in the journal Proceedings of the National Academy of Sciences reported.

Brewers of gigantism shouldn't forget the crucial ingredient of time, either. Though animal lineages tend to get larger over the generations, it takes a vast amount of evolutionary time to reach giant sizes, Erickson said. And mass extinction events tend to wipe out larger creatures, Vermeij said, so these events can leave giant-animal slots unfilled for tens or hundreds of millions of years. "It took about 25 million years for the first mammals to reach a ton in weight," he said. In the case of woolly mammoths, decimated by climate change and human hunters just 10,000 years ago, it may not be a coincidence that we modern humans don't see such huge creatures: Our own ancestors helped kill them off not so long ago.

For Vermeij, the most comprehensive explanation for decreasing size comes not from physiology or environment, but from social structure. "The evolution of … organized social behavior, not just herds but really organized hunting" in mammals introduced a new form of dominance, he said. "Group hunting by relatively small predators makes even very large prey vulnerable. Individual gigantism has in effect been replaced on land by gigantism at the group level," he wrote in the 2016 study. That is, smaller individuals working together, as happens with wolves and hyenas for example, may constitute a more effective way of getting big than building a huge body. As a result, "gigantism lost its luster on land," Vermeij wrote. 

Social organization may also help explain a rather, ahem, giant exception to the timeline traced here: In the ocean, the biggest animals to ever live still exist today: blue whales. Sea life, Vermeij said, makes long-distance communication more difficult, hindering the development of complex hunting groups. The evolution of such groups "has happened on land much more than, at least until recently, that has happened in the ocean," such as with killer whales, he said.

Originally published on Live Science.

Woolly mammoths may have survived in North America thousands of years longer than scientists previously thought, vials of Alaskan permafrost reveal. 

The hairy beasts might have persisted in what is now the Yukon, in Canada, until around 5,000 years ago — 5,000 years longer than experts previously estimated, a new study suggests. That conclusion comes from snippets of mammoth DNA that were found in vials of frozen dirt that had been stored and forgotten in a laboratory freezer for a decade.

Related: Mammoth resurrection: 11 hurdles to bringing back an ice age beast

"Organisms are constantly shedding cells throughout their life," said study lead author Tyler Murchie, a postdoctoral researcher in the Department of Anthropology at McMaster University in Ontario. For instance, He explained thata person sheds roughly 40,000 skin cells per hour, on average, meaning we are constantly ejecting bits of our DNA into our surroundings. 

That's also true of other life-forms; nonhuman animals, plants, fungi, and microbes are constantly leaving microscopic breadcrumb trails everywhere. Most of this genetic detritus doesn't linger in the environment, though. Soon after being discarded, the vast majority of the DNA bits are consumed by microbes, Murchie said. The fraction of the shed DNA that does remain might bind to a small bit of mineral sediment and be preserved. Though only a tiny proportion of what was initially shed remains centuries later, it can nevertheless provide a window into a vanished world teeming with strange creatures.

"In a tiny fleck of dirt," Murchie told Live Science, "is DNA from full ecosystems."

Murchie analyzed soil samples taken from permafrost in the central Yukon. Many of the samples dated to the Pleistocene-Holocene transition (14,000-11,000 years ago), a period marked by rapidly changingclimatic conditions in which many large mammals — such as saber-toothedicats, mammoths and mastodons — vanished from the fossil record.

The DNA fragments in Murchie's samples were small — often no larger than 50 letters, or base pairs. However, on average, he was able to isolate roughly 2 million DNA fragments per sample. By analyzing DNA from soil samples of known ages, he indirectly observed the evolution of ancient ecosystems over this turbulent period.

The main advantage to studying ancient DNA is that researchers can observe organisms that tended not to fossilize well. "An animal has only one body," said Murchie, and the odds of it fossilizing are not that great. On top of that, you have to find it. But that same animal constantly ejected innumerable amounts of DNA into the environment throughout its lifetime.

The soil samples — which span a period of time from 30,000 years ago to 5,000 years ago — revealed that mammoths and horses likely persisted in this Arctic environment much longer than previously thought. Mammoths and horses were in steep decline by the Pleistocene-Holocene transition, the DNA data suggest, but they didn't disappear all at once due to changes in climate or overhunting. 

An earlier study, published in October in the journal Nature, suggested that some mammoths survived on isolated islands away from human contact until 4,000 years ago. However, the new study is the first to determine that small populations of mammoths coexisted with humans on the mainland of North America well into the Holocene, as recently as 5,000 years ago.

. Megafauna extinctions from this era have largely been blamed on one of two explanations: human paleo-hunters or climate catastrophe, said lead author Hendrik Poinar, an evolutionary geneticist and director of the McMaster Ancient DNA Centre. 

However, the new study "changes the focus away from this two-pitted debate that has plagued [paleontology] for so long," Poinar said. 

The team's research provides evidence that the extinction of North American megafauna is much more nuanced, he said. There's no doubt that the animals were under pressure from both human hunters and a rapidly changing climate. The question is, "how much were they hunted and whether or not that was truly the tipping point," Poinar told Live Science. 

Analyzing ancient DNA from dirt has the potential to tell us a lot about ancient life; Poinar and Murchie said Arctic permafrost is ideal for these types of ancient DNA studies because freezing preserves ancient DNA very well. But that might not be possible forever: As ice in the Arctic melts due to rapid increases in temperature, "we're going to lose a lot of that life history data," Murchie said. "It's just going to fall away before anyone gets a chance to study it."

This study was published Dec. 8 in the journal Nature Communications. 

Originally published on Live Science.

Researchers have unearthed a mammoth "graveyard" filled with the bony remains of five individuals — an infant, two juveniles and two adults — that died during the last ice age at what is now a quarry in Swindon, a town in southwest England.

Alongside the mammoth remains, researchers discovered stone tools crafted by Neanderthals, including a hand ax and small flint tools known as scrapers, which were used to clean fresh animal hides, according to DigVentures, the crowdsourced archaeological outfit in the U.K. that led the excavation. However, the team has yet to analyze the mammoth bones to determine whether they have Neanderthal tool marks on them.

"Finding mammoth bones is always extraordinary, but finding ones that are so old and well preserved, and in such close proximity to Neanderthal stone tools is exceptional," Lisa Westcott Wilkins, the co-founder of DigVentures, said in a statement.

Related: Photos: See the Ancient Faces of a Man-Bun Wearing Bloke and a Neanderthal woman

Two amateur fossil hunters, Sally and Neville Hollingworth, discovered the graveyard and Neanderthal tools. Soon after, DigVentures organized two field seasons in 2019 and 2020 to excavate the site. The archaeologist-led work uncovered more ice age remnants, including delicate beetle wings, fragile freshwater snail shells and mammoth remains, such as tusks, leg bones, ribs and vertebrae belonging to a species of Steppe mammoth, a group whose descendants include the woolly mammoth. Although early Steppe mammoths stood up to 13.1 feet (4 meters) high at the shoulders, the five mammoth individuals at the graveyard were small, an indication that the species might have shrunk during an especially cold spell during the ice age, according to DigVentures.

Researchers dated the site to between 220,000 and 210,000 years ago, toward the end of an interglacial, or warm period, when Neanderthals still lived in Britain. Once temperatures dropped, however, the Neanderthals moved farther south.

Going forward, the team plans to figure out why so many mammoths died at one spot and whether Neanderthals hunted the beasts or scavenged their remains. Some previously found prehistoric evidence suggests Neanderthals stalked mammoths and other large pachyderms. For instance, Neanderthal footprints were found at a 100,000-year-old "nursery" for straight-tusked elephants (Palaeoloxodon antiquus) in southern Spain, Live Science previously reported. 

The new graveyard findings are described in the new BBC documentary "Attenborough and the Mammoth Graveyard," with Sir David Attenborough and Ben Garrod, an evolutionary biologist at the University of East Anglia in the United Kingdom, who joined DigVentures on site to film the excavations. The show airs at 8 p.m. GMT on Dec. 30 on BBC One.

"The findings have enormous value for understanding the human occupation of Britain, and the delicate environmental evidence recovered will also help us understand it in the context of past climate change," Duncan Wilson, the chief executive of Historic England, a British historical preservation body, said in a statement. "Through these finds and the research that will follow, we look forward to further light being shed on life in Britain 200,000 years ago."

The work was funded by Historic England and supported by Keith Wilkinson of ARCA at the University of Winchester, the site's landowners Hills Group Quarry Products and a wider specialist team from several U.K. research institutions.

Originally published on Live Science.

Refrigeration is a pretty new phenomenon, so for millennia, people had to find clever ways to preserve food. These practices slowed the growth of microorganisms that could cause foodborne illnesses or lead food to rot. Many preservation practices other than refrigeration — like salting, drying, smoking, pickling and fermenting — have been used for a long time. 

These methods aside, how did ancient people store their leftovers?

It turns out that early hunter-gatherers had some pretty creative ways to extend the "shelf life" of their larder.

Related: Does salt make water boil faster?

Fishing for mammoth

One fall morning in 2015, two farmers in Michigan made an unexpected discovery: a pelvis bone from a mammoth. After a few phone calls and an excavation, a research team uncovered additional paleontological and archaeological evidence that brought the scene into greater clarity.

More than 11,000 years ago, mammoth herds roamed North America. For hunter-gatherers, bringing down an animal the size of an African elephant would be like winning the lottery — a prize you don't want to lose. So, some Indigenous people put their mammoth leftovers into ponds to keep it for later use.

"The pond offers a place to stash carcass parts," Daniel Fisher, a professor and curator in the University of Michigan Museum of Paleontology, told Live Science. "What is the alternative when there are other predators and scavengers on the landscape who will gladly partake of a meal?"

The carcass was purposely placed in one of the many small, shallow ponds that dot the postglacial landscape of the Upper Midwest. But the meat's preservation wasn't due to the water, exactly; it was largely the hard work of the bacteria, Lactobacilli, that live in the water. 

Lactobacilli produce lactic acid, a chemical byproduct of anaerobic respiration. The bacteria colonize the meat, and the lactic acid preserves the muscle mass. Fisher also credited the low temperature and the low oxygen content of the lake water in aiding the preservation process. 

Fisher believes the hunt probably occurred in the autumn. Felled animals were butchered where they died, and large pieces were deposited in the water in nearby small ponds. The meat remained edible until the following summer. Fisher knows this because he has conducted experiments using deer, lamb and even horse. He found that the meat was still edible (after cooking it first to kill any harmful bacteria that might have taken up residence in the meat), even after spending months submerged in similar small, cold ponds. 

"The lactic acid also tenderizes the meat," Fisher said. "It does impart a strong odor and taste, like Limburger cheese. It makes an interesting meal."

Pass the bog butter and jam

Keeping food cool makes sense, but not everyone had a lake in their backyard. Burying food is another ingenious way to keep food fresh. Burial shields food from sunlight, heat and oxygen, all of which increase the rate at which food spoils.

Bogs offer an intriguing burial option. A bog is a freshwater wetland of soft, spongy ground consisting mainly of partially decayed plant matter, called peat. The cool, low-oxygen, highly acidic environment is perfect for preserving perishable foods.

Related: Why does mint make your mouth feel cool?

In Northern Europe, ancient civilizations would put food, including butter, into the bog to preserve it. Archaeologists have pulled wads of a waxy, paraffin-like substance from the waterlogged muck. Researchers performed chemical analyses on the waxy substance and identified it as a dairy product, giving it the fun alliterative name "bog butter." 

"Within two or three years, the fat in the fresh butter degrades into constituent components," said Jessica Smyth, an assistant professor in the University College Dublin School of Archaeology who published a 2019 study on bog butter in the journal Nature. "You have a lump of fatty acids."

Bogs offered early agricultural communities a way to preserve perishable foods, like dairy products, for a longer period. According to Smyth, there are ethnographic mentions of people burying their summer butter in bogs for storage. The curated butter is edible, but it may take on the tangy flavors of the surrounding peat that is an acquired taste. 

"It is easy to look at bog butter as an anomaly or freak event, but it was probably a common practice," Smyth told Live Science. "The peatlands are providing a window into prehistoric agricultural practices that have vanished from the world."

Originally published on Live Science.

A mammoth that lived in Alaska about 17,000 years ago traveled so far and wide that, if it had walked in a straight line, it would have gone all the way around the world — nearly twice. 

Recent analysis of the woolly ice age beast's preserved tusk revealed that in 28 years, it walked almost 50,000 miles (80,500 kilometers). To retrace the adult mammoth's steps, researchers did something that had never been done before: They sliced open a mammoth tusk along its length, investigating the chemistry of the layers that built up in the tusk year after year during the animal's lifetime. 

Then, they compared that data to chemical signatures in locations across Alaska that were identified from the teeth of small ice age mammals. By matching chemical element ratios in different parts of the tusk to similar ratios from the small-mammal teeth, scientists were able to create a regional map that showed where the mammoth lived from year to year.

Related: Photos: A 40,000-year-old mammoth autopsy 

In woolly mammoths (Mammuthus primigenius) and their elephantine relatives (living and extinct), tusks preserve information about their habitats in an element called strontium, which the tusks absorb from plants the animals eat. Ratios of strontium isotopes — versions of the element with different numbers of neutrons — vary between geographic locations, and incremental records of local isotope ratios in tusks can reveal where the animals were dining during different stages of their lives, researchers reported in a new study. 

However, most prior analyses of mammoth tusks relied on short cores drilled vertically from tusks. Those cores reveal some of the tusk layers, "but you're not getting the whole record," said study lead author Matthew Wooller, director of the Alaska Stable Isotope Facility and the Water and Environmental Research Center at the University of Alaska Fairbanks (UAF), and a professor in the UAF College of Fisheries and Ocean Sciences.

At the base of a mammoth's tusks are cone-shaped cavities coated by enamel layers that resemble inverted ice cream cones, Wooller told Live Science. New layers coat this cavity every day, and over years and decades, tusks grow longer as new layers build up from the bottom, much as a tower of ice cream cones gets taller if you keep inserting new cones into the open end of the stack. Reading the record of a mammoth's life from infancy to death therefore required splitting a tusk lengthwise, so that all the internal "ice cream cone" layers would then be exposed for sampling, Wooller explained.

Six scientists, one band saw

For the study, the scientists used one of the tusks of an adult mammoth in the collection of the University of Alaska Museum, collected on Alaska's Arctic Coastal Plain above the Arctic Circle in 2010. DNA analysis revealed that the mammoth was male; it lived about 17,000 years ago and its tusk measured 7.9 feet (2.4 meters) long. Figuring out how to bisect the enormous, spiraling tusk evenly (and without damaging it) took the researchers about a year, and splitting the tusk ultimately required six people, an enormous band saw and nearly an entire day of very, very careful cutting, Wooller said. 

"We may have broken a blade or two along the way," he said.

After splitting the tusk, the scientists collected about 400,000 individual data points on the concentrations of strontium and other isotopes, such as oxygen and nitrogen, taken from the center of the preserved "timeline" covering the animal's entire life span. The tip of the tusk represented the mammoth as a baby and juvenile, and the base of the tusk showed the last years of the mammoth's life.

To know where, exactly, the mammoth had been walking, the study authors compared their data to a map of the same isotopes for the mammoth's Arctic habitats, preserved in the teeth of tiny plant-eating rodents from the Pleistocene epoch (2.6 million to about 11,700 years ago). Because small rodents like shrews and voles remain in very localized habitats throughout their lives, the regional data could then be used to identify locales where the mammoth lived or visited. 

The scientists then generated mammoth "walks" that spanned 28 years and contained 1,133 data points, called "steps," with 40 steps representing approximately one year of life. 

Step by step

As a baby, the mammoth lived mostly in the lower Yukon River basin. During the mammoth's juvenile years, it moved into the lowlands of interior Alaska, probably traveling with a herd, where it stayed until it was about 15 years old. The mammoth's range broadened as it reached sexual maturity at age 15 and left the herd, as young male elephants also do, according to the study.

And then, during its last two years of life, the mammoth stayed at higher elevations, in the western end of Alaska's Brooks Range. A spike in nitrogen isotopes before the animal died hinted at a period of starvation, perhaps because of an exceptionally harsh winter, the researchers reported.

"Until this point, we didn't have this level of detail about the movement patterns of mammoths at all," Wooller said. Future studies of other mammoth tusks could fill in even more details about their travels, including how their migration behavior may have changed as the last ice age waned and Earth's climate became wetter and warmer — a challenge that large animals in Alaska are confronting right now, Wooller added.

"Megafauna that are living in the Arctic today are actually facing very substantial and significant climate change," he said. "I think it shines a light on concerns of how all those animals will adapt their behavior in response to very unprecedented changes that we're seeing in the Arctic today."

The findings were published Aug. 12 in the journal Science.

Originally published on Live Science.

Gold miners have discovered three partial  skeletons of three woolly mammoths, which may have been part of the same family, at Little Flake Mine near Dawson City, Yukon, in Canada. 

They turned over the bones to the Yukon government. "We seem to have one large full-grown mammoth, one younger adult and one juvenile," said Grant Zazula, the head paleontologist for the Yukon government. 

Some of the bones are still articulated (connected) with each other, Zazula told Live Science in an email. The way the bones were found suggests "that these three mammoths were probably living together and died together very close to where the fossil bones were found," Zazula added. Even if they weren't family members, they may have been part of a larger herd, he said.

Related: Mammoth resurrection: 11 hurdles to bringing back an ice age beast

Glacial environment

The miners found the mammoth skeletons near a layer of volcanic tephra that likely dates to around 29,000 years ago when a volcano on the Aleutian Islands erupted, Zazula said. The mammoths therefore likely lived around the time of the eruption. At that time, much of Canada was covered in glaciers, with the area around Dawson City being one of the few areas that was ice-free, Zazula said. 

"The mining region in the interior of the Yukon was part of the unglaciated landscape called Beringia, which connected with Alaska and Siberia via the Bering Land Bridge," Zazula said. "The climate was incredibly cold and dry, likely treeless, leading to the prevalence of grazing mammals," Zazula noted. From about 35,000 to 18,000 years ago, woolly mammoths (Mammuthus primigenius) crossed that land bridge into North America, according to the University of California Museum of Paleontology.

The dry environment there helped to preserve the three mammoths. The climate was arid and the wind would have easily blown dust around, Zazula said. "This windblown silt, or loess, filled these valleys with sediment" that rapidly covered the mammoths after they died." Because they were covered so quickly, the remains would have been less exposed to oxygen and to scavengers.

The "miners need to remove all this frozen silt to get to the gold-filled gravel in the valley bottoms, and when they do that, they often uncover the remains of ice age animals," such as the three mammoths, said Zazula, who noted that more mammoths may be found at the mine site.

"The miners will be resuming mining at this spot in a few weeks and our crews will be on hand to see if there are more bones from the skeletons," Zazula said. It’s uncertain what the three mammoths died from and Zazula hopes that ongoing research will provide an answer.

Originally published on Live Science.

The oldest DNA ever decoded belonged to a mammoth from a mysterious, previously unknown lineage that lived about 1.2 million years ago, a new study finds. 

Previously, the oldest known sequenced genome came from a horse that lived up to 780,000 years ago, in what is now Canada's Yukon Territory. Now, the mammoth discovery, "is, with a wide margin, the oldest DNA ever recovered," study senior researcher Love Dalén, a professor of evolutionary genetics at the Center for Palaeogenetics in Stockholm, said at a news conference Tuesday (Feb. 16). 

The remains of the mysterious mammoth were discovered near Siberia's Krestovka River (now the mammoth's namesake). After studying its ancient DNA, along with the newly sequenced genomes of two other mammoths — a roughly 700,000-year-old woolly mammoth (Mammuthus primigenius) and an approximately 1 million-year old woolly mammoth predecessor — the scientists made a surprising discovery: Woolly mammoths mated with a mammoth from Krestovka's mysterious line about 420,000 years ago, leading to a hybrid mammoth we know today as the Columbian mammoth (Mammuthus columbi). 

Related: Mammoth resurrection: 11 hurdles to bringing back an ice age beast

The Krestovka mammoth lineage, the researchers found, would have migrated from Siberia to North America, crossing over the Bering Strait land bridge, about 1.5 million years ago; fossil evidence suggests that the woolly mammoth crossed over about 100,000 years ago, but the researchers say it could have come earlier, perhaps 500,000 to 400,000 years ago.

It's unknown where the hybridization occurred, but when they met up, "these two lineages hybridized and formed what we now call the Columbian mammoth," lead researcher Tom van der Valk, a postdoctoral researcher at the Swedish Museum of Natural History and the Center for Palaeogenetics, said at the news conference.

The genetic discovery of the Columbian mammoth's origins is remarkable, said Daniel Fisher, a professor and curator in the Museum of Paleontology of the University of Michigan, who was not involved with the study. "Hybrid origins of new species have certainly been proposed before, but few cases have placed the phenomenon in such a clear historical, geographic and evolutionary context," Fisher told Live Science in an email. 

Woolly project

When the researchers began the project, they hoped to learn about woolly mammoth evolution — "Our main aim was to recover genomes from before and after the origin of the woolly mammoth," Dalén said. They chose to study three mammoths whose remains had been found in northeastern Siberia by the late Russian paleontologist Andrei Sher in the 1970s. These included one of the oldest woolly mammoths on record, the 700,000-year-old pachyderm nicknamed Chukochya, and the woolly mammoth predecessor, called Adycha, which looked like a European steppe mammoth (Mammuthus trogontherii), a direct ancestor of the woolly mammoth. 

The third mammoth, Krestovka, also looked a bit like a steppe mammoth, even though it had diverged from that lineage more than 2 million years ago. So, despite evolving on entirely different lineages for more than 1 million years, the mammoths from the woolly mammoth and Krestovka lines were still able to mate, the researchers found. 

"It looks like hybridization of lineages that were long separated, on the order of 1 million years, [were] coming together and successfully producing an apparently new species, which is really mind-blowing," said Ross MacPhee, a senior curator of vertebrate zoology at the American Museum of Natural History in New York City, who was not involved with the study. 

By studying woolly mammoth genetics, the researchers made another discovery: "Many of the adaptations that we know woolly mammoths had, such as thermoregulation, changes in their circadian rhythm, fat deposits and hair growth were already present in the steppe mammoth," van der Valk said. In other words, the woolly mammoth didn't evolve to have these adaptations to the cold. Rather, its predecessor already had them, meaning that these adaptations likely emerged slowly over time, rather than quickly under selective pressures. However, the woolly mammoth did continue to evolve; woolly mammoths that lived closer to the extinction had more genetic variants associated with sensing temperature than earlier woolly mammoths did, the researchers found.

Related: Wipe out: History's 7 most mysterious extinctions

How they did it

DNA starts degrading the moment an animal dies, so how did the international team of scientists piece together these three mammoth genomes? They had the already mapped the genome of the African savannah elephant (Loxodonta africana) and the mitochondrial genome (DNA inherited through the maternal line) of the Asian elephant (Elephas maximus). These previously sequenced genomes were like the image on a puzzle box; elephants are relatives of mammoths, so their genetic data served as a useful reference for the mammoths' genomes.  

The tiny fragments of ancient DNA, which the team extracted from the mammoths' molar teeth, were the puzzle pieces. Though Siberia's cold permafrost helped preserve the mammoth's DNA, bacteria and other degrading elements like enzymes had broken that DNA into small fragments, some as short as 35 base pairs, the "letters" that make up DNA. Using an algorithm, the researchers discarded the foreign DNA that had contaminated the mammoth samples, including DNA from microbes. They also discarded any uncertain puzzle pieces of DNA that appeared to fit in the mammoth genome, but could have come from other animals that had contaminated the samples.

After the algorithm analyzed billions and billions of DNA puzzle pieces, the researchers had the mammoth's genomes, some more complete than others. The 1.2 million-year-old mammoth, Krestovka was the least complete at about 49 million base pairs, "which is a relatively small fraction of [the] genome, but still more than enough to confidently place the genome on the [family] tree," van der Valk said.

The 1 million-year-old steppe mammoth, Adycha, had about 884 million base pairs, or 25% to 30% of its genome completed. And the 700,000-year-old woolly mammoth, Chukochya, had about 3.6 billion base pairs, or 70% to 80% of its genome sequenced, van der Valk said. Meanwhile, the team was able to completely reassemble the mitochondrial genomes of each mammoth. 

The mitochondrial DNA was key, because researchers know the rate at which mitochondrial gene mutations occur, which helped them date the samples. The team also dated the mammoths' based on geological data, such as biostratigraphy (dating the specimens based on the ages of neighboring fossils and geologic formations) and paleomagnetism (dating signatures left by Earth's changing magnetic field in the samples).

So, how long can ancient DNA survive? The scientists think that it's possible to retrieve even older genomes. "An educated guess would be that we could recover DNA that is 2 million years old, and possibly go even as far back as 2.6 million," study co-researcher Anders Götherström, a professor in molecular archaeology and joint research leader at the Center for Palaeogenetics, said in a statement. "Before that, there was no permafrost where ancient DNA could have been preserved."

The study was published online Wednesday (Feb. 16) in the journal Nature.

Originally published on Live Science.

More than 10,000 years ago on the playa of what is now New Mexico, a woman on a journey set down the toddler she was carrying on her hip, readjusted, then picked up the child and set off again. 

The remnants of this all-too-human moment are preserved in a trackway found in White Sands National Park — the longest late Pleistocene double human trackway found anywhere in the world. At 0.9 miles (1.5 kilometers) long, the set of tracks preserves an out-and-back journey taken at a fast clip by a single adult and a child under the age of 2. 

During the journey, the adult — probably a woman, though possibly an adolescent male — came in close proximity to a giant sloth and a woolly mammoth, the trackway reveals.

Related: In photos: Mummified woolly mammoth discovered

"It's giving us these amazing snapshots in time," said Sally Reynolds, a paleontologist at Bournemouth University in the U.K. and the senior author of a new paper on the tracks published online ahead of its print publication in the December issue of the journal Quaternary Science Reviews.

Human tracks

The trackway was first discovered in 2017, thanks to National Parks employee David Bustos, who invited a group of scientists — including Reynolds' husband, Matthew Bennett, a geoscientist at Bournemouth University — to view the site. Bustos had noticed possible signs of footprints on the flat, arid playa landscape while patrolling the park, then a national monument. 

Excavations revealed fossilized footprints just below the loose white gypsum sand. These tracks were originally made on wet ground. As the water evaporated, it left behind the minerals dolomite and calcite, which created rocky molds of the footprints. 

The tracks run north/northwest in a straight line in one direction before disappearing into the dunes. Next to them are the remains of the return south/southwest return journey, which appears to have been made by the same person, judging by the size of the footprints and the stride length. 

Along the way, the adult tracks are sometimes accompanied by the footprints of a child under 3 years old. Northbound, the adult tracks are a little asymmetrical, evocative of a woman holding a child on one hip. At times, the child's footprints appear, perhaps during rest breaks when the adult put the squirmy toddler down. There are no child footprints on the return southbound journey, suggesting that perhaps the trip was taken in order to drop off the child somewhere. 

Related: Photos: Stone Age human footprints discovered

"Motivation is something we can't really speak to in the fossil record, but it's something we want to know," Reynolds told Live Science. Reynolds speculated that perhaps the child was ill and needed to be taken to another camp where someone could help him or her. Whatever the reason for the journey, it seemed very goal-oriented: The footprints didn't deviate and the walker didn't dawdle. The stride length suggests that the person was walking about 5.5 feet (1.7 meters) per second, a brisk pace. The region was arid, but the journey was near an ancient, now-vanished lake, and the ground was muddy and slippery. 

"We do know the journey was faster than normal speed and over terrain that would have been more tiring than normal," Reynolds said. 

Animal encounters

The journey would have taken the pair through a landscape prowled by predators such as dire wolves and saber-toothed cats. Fortunately, the woman and child seem not to have been menaced; instead, they may have scared some of the animals that encountered their trackway. After the pair passed north, a set of animal tracks shows that a giant sloth approached their tracks, reared up — perhaps sniffing the air? — and then shuffled in a circle before veering away. The human then stepped on these sloth tracks when returning southbound. Previous research in the area suggests that humans hunted giant sloths, perhaps explaining why the sloth footprints reveal signs of nervousness on the part of the animal.

At another point, a mammoth crossed the humans' northbound trail (before the southbound return journey). The mammoth showed no signs of slowing or stopping, perhaps suggesting that it did not see the recent presence of a human as a threat.

There was no organic material under or around the footprints that could be analyzed with radiocarbon dating to reveal the age of the trackway, Reynolds said. Based on the known extinction dates for mammoths and giant sloths, the tracks must be at least 10,000 years old and possibly as old as 13,000 years, she said. She and her colleagues plan to publish data next year on the age of seeds found beneath other tracks in the park. 

What is clear, Reynolds said, is that the playa at White sands preserves human footprints spanning over thousands of years. The region was a hub of human activity in the late Pleistocene, she said, and the footprints left there might help reveal how humans affected animal populations during this time period. (Large megafauna like mammoths and sloths went extinct shortly after humans arrived on the scene, and there is controversy over whether human hunting was to blame.) There are tracks in White Sands that show humans stalking sloths, Reynolds said, and even tracks left by children splashing in puddles that gathered in animal footprints. 

"It's safe to say that the whole of White Sands is just one gigantic archive of fossil footprints," Reynolds said.

Originally published on Live Science.

A man following a reindeer herd in northwestern Siberia made the discovery of a lifetime when he passed by a lake on July 20; poking out of the water was the enormous skull of a woolly mammoth dating back at least 10,000 years.

When scientists came to investigate the mammoth skull, they made an even larger discovery — recovery efforts unearthed most of the woolly mammoth's (Mammuthus primigenius) remaining skeleton, some of its soft tissues and wool, and even a piece of fossilized poop (called a coprolite) that the mammoth may have passed before its death at the end of the last ice age.

The accidental finding was made possible by low water levels in Lake Pechenelava-To, in the Yamal peninsula of the Yamalo-Nenets region, said Pavel Kosintsev, a senior researcher at the Institute of Plant and Animal Ecology in Russia at the Urals Branch of the Russian Academy of Sciences, who supervised the mammoth's excavation.

"If the water level hadn't fallen, the mammoth wouldn't have been found," Kosintsev told Live Science in an email.

Related: Mammoth resurrection: 11 hurdles to bringing back an ice age beast

During the excavation, the researchers built a wooden fort around the mammoth's remains, and then they used a sump pump to remove water from the enclosure. After wading through the muck, the researchers were able to unearth about 90% of the mammoth's bones, two large pieces of skin, parts of the mammoth's woolly coat and one coprolite, Kosintsev said.

To honor Konstantin "Kostya" Tadibe, the man who found the mammoth, the researchers named it the Tadibe mammoth. The skeletal remains indicate that the Tadibe mammoth was male, stood about 6.5 to 8.2 feet (2 to 2.5 meters) tall and was about 15 years old when it died, Kosintsev said. The coprolite, however, was small, just 2 inches (5 centimeters) in diameter. 

It's uncommon to find soft tissue on mammoth remains, but "coprolites are even rarer," Kosintsev said. "Scientists know no more than 10 [mammoth] coprolites." Studying coprolites can reveal information about mammoth diets and intestinal parasites, he added. 

Meanwhile, the study of soft tissues "allows scientists to learn how mammoths adapted to the cold climate of the ice age," Kosintsev said. According to the Associated Press, the preserved soft tissues included the Tadibe mammoth's ligaments, the band of tough tissue that connects bones or cartilage together at a joint. 

The ligaments, which are largely made of collagen — the same material that's found in skin, cartilage and bone — likely survived in Siberia's normally cold temperatures where they would be slow to decay, said Daniel Fisher, a curator at the Museum of Paleontology at the University of Michigan, who wasn't involved with the Tadibe mammoth discovery. "Ligaments are one of the last soft tissues to break down under bacterial activity," Fisher told Live Science. 

After looking at a photo of the Tadibe mammoth's skeletal remains, Fisher noted that one of the pachyderm's ribs looks like it had been broken or fractured, but had later healed. 

"It sometimes happens that animals get in a fight or there's an injury and they break a rib, but then it heals with a bit of an offset,” he said. “And it looks to me like that could be a bit of a broken healed fracture on that rib." 

However, Fisher said he or another paleontologist would have to take a closer look at the rib to be sure. 

Related: Photos: Ice age mammoth unearthed in Idaho

Even with this injury, it remains a mystery as to why the mammoth died, although Kosintsev noted that "there is no indication that this mammoth was killed by a human." That wasn't the case for a 25,000-year-old mammoth found in Poland that had a javelin embedded in its rib, Live Science previously reported. However, other research offers a clue about this mammoth's demise: Woolly mammoth bachelors were more likely than females to die in natural traps, such as falling through thin ice, tumbling into holes or getting stuck in mudflows, according to a 2017 study published in the journal Current Biology. These deaths likely came to pass because inexperienced male mammoths tended to travel alone, the researchers of that study said. 

Disappearing mammoths

Mammoths went extinct in mainland Russia about 10,000 years ago (although dwarf woolly mammoths survived until about 4,000 years ago on Wrangel's Island, north of Russia), and now their remains are disappearing fast.

In fact, there may be more mammoth findings as Siberia's temperatures rise and its permafrost melts. 

When permafrost melts, mud at lakes "slumps and slides and goes into deeper portions of lake basins, so things like this are exposed, maybe around [the] edges of lakes," Fisher said. Once exposed, previously frozen specimens resume their decay. 

"As you can see, [the team in Russia] put a lot of work into recovering this. But they're not going to be able to recover every specimen," Fisher said. "For every one that they do recover, there are 10 if not 20 lost."

Fisher added that mammoth remains face another threat: people looking to make a profit by selling the ivory from their tusks. "There is a growing commercial market for these kinds of specimens," he said.

So far, Tadibe is the third mammoth uncovered on the Yamal peninsula, according to The Siberian Times. The other two are younger mammoths: the baby Lyuba, a calf discovered in 2007, who died just a month after birth; and the youngster Masha, a female found in 1988, who died between 1 and 3 months of age. 

Originally published on Live Science.

Researchers have found a "graveyard" of about 60 mammoths ahead of the construction of an airport just outside Mexico City, according to the National Institute of Anthropology and History (INAH) in Mexico.

In addition to the ice age findings, researchers at the airport-construction site uncovered remains from an entirely different time period — pre-Hispanic times, when 15 humans were buried there, the INAH reported. 

Both discoveries shed light on Mexico's history, and give experts an unprecedented opportunity to delve into more than 30,000 years of history, the INAH wrote in a May 22 statement. 

Related: 10 extinct giants that once roamed North America

Until now, this area was used by the Santa Lucía Military Air Base, about 45 miles (73 kilometers) north of Mexico City. But it wasn't until October 2019, when construction of the new General Felipe Ángeles International Airport began, that researchers uncovered the ancient remains.

Scientists found the pachyderm bones — including those from male, female and young mammoths — at three sites within the airport's vicinity, said Pedro Francisco Sánchez Nava, the national coordinator of archaeology at the INAH. When the mammoths were alive during the last ice age, this area was on the shore of Lake Xaltocan. It's possible that these heavy animals got stuck in the mud there, and that human hunters took advantage of that, targeting the beasts there, Sánchez Nava said.

The ancient beasts were Columbian mammoths (Mammuthus columbi), a species that lived throughout North America during the Pleistocene epoch (which began 2.6 million years ago and lasted until about 11,700 years ago). The researchers did not find any remains of the furrier woolly mammoth, which lived farther north. 

Going forward, a team of 30 archaeologists and three preservationists plan to study the mammoths' remains, which may reveal clues about Pleistocene life, including what the beasts ate, any health conditions that affected their bones, and exactly when they lived. 

Meanwhile, the 15 human burials are likely the remains of farmers, given they were buried with grave goods indicative of that lifestyle, including pots, bowls and clay figurines — one of which was of a dog. The ceramic goods found with the  individuals suggest they likely lived during the Epiclassic period (A.D. 750 - 950). This pottery was from the Coyotlatelco phase, meaning that it has a distinctive red-on-buff painted style, according to Archaeology Wordsmith. 

About 6 miles (10 km) away from the excavations for the new airport is another Pleistocene treasure: two large pits filled with mammoth bones dating to about 15,000 years ago, which archaeologists discovered in November 2019. However, it's unclear whether the mammoths ended up in these pits by chance, or whether indigenous peoples intentionally drove them there during hunts, Adam Rountrey, a collection manager at the University of Michigan Museum of Paleontology, told The New York Times. 

There is evidence of humans intentionally hunting mammoths during the last ice age, although not at this site. For instance, this past summer, researchers in Poland announced they had found a javelin embedded in a 25,000-year-old mammoth rib. 

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Originally published on Live Science.

Archaeologists in Russia have found a large circle made out of the stuff of horror movies: the bones of mammoths and other ice age creatures that lived more than 20,000 years ago, a new study finds.

Among the remains are the bones of more than five dozen mammoths, as well as bones from reindeer, horses, bears, wolves, red foxes and Arctic foxes, the study researchers said.

"It is made up of thousands of bones that come from at least 60 different woolly mammoths," study lead researcher Alexander Pryor, a lecturer of prehistoric archaeology at the University of Exeter in England, told Live Science. "All parts of the mammoth bodies are represented, from very large bones like skulls and leg bones to smaller bones like vertebrae."

Related: Archaeologists are hot on the trail of these 16 spectacular mysteries

There are about 70 other ice age "bone circles" at about 25 sites in Ukraine and Russia already known to archaeologists, but the newly discovered one is the oldest on record, Pryor said. It was found by study co-researcher Alexander Dudin, the director of the Kostenki Museum-Preserve in Voronezh, Russia, who was doing survey work in 2015 at the archaeological site of Kostenki 11, about 350 miles (560 kilometers) south of Moscow.

The bone circle measures about 36 feet (11 meters) in diameter. It's difficult to say what this and other bone-made structures would have looked like during the last ice age, Pryor said, "but at Kostenki 11, we can imagine a ring of mammoth bones piled up on top of each other. Some of the bones were still in articulation [joined together], indicating that at least some of the bones still had flesh on them when they were added to the pile."

He added that, "beyond this, some have speculated about wooden poles used to support a roof made of animal hides, but there is no evidence for this yet at Kostenki 11."

The bones used to construct the structure were likely scavenged, Pryor said. There is some evidence that during the ice age people hunted mammoths, as evidenced by the discovery of a javelin embedded in a 25,000-year-old mammoth rib in Poland, but this may have been an exception, not the norm, Pryor said.

Extreme cold

The last ice age swept northern Europe between 75,000 and 18,000 years ago, but it reached its most bone-chilling temperatures during a period lasting from about 23,000 to 18,000 years ago, when the circle at Kostenki 11 was built. 

During this time, the summers were short and cool, while the winters were long and cold, reaching temperatures as low as minus 4 degrees Fahrenheit (minus 20 degrees Celsius). These freezing temperatures prompted many human groups to head south, where prey and other resources were more abundant. Eventually, the community that built this bone circle left, too, even though there was a river nearby that could have provided them with fresh water, Pryor said.

That community didn't leave behind many clues about how it used this structure. Maybe it was a dwelling, archaeologists have suggested. But Pryor and his colleagues have another idea; perhaps these boney buildings were used for rituals or even for food storage, given that each mammoth had a "mammoth" amount of meat on it, he said.

It's unlikely that it was a dwelling because there's less evidence of human activity there than would be expected of a full-blown abode, he said. Moreover, this sort of house wouldn't have been safe. "The fact that some of the bones are still articulated means that they would have still been smelly," because they would have had meat on them, Pryor said. "They would have been attractive to wolves and foxes and other scavengers."

An analysis of tiny debris found within the bone circle and three pits located outside of it revealed burned pieces of charcoal and bone. These findings indicate that, despite the bitter cold, there were trees nearby that could be burned, Pryor said. In addition, it shows that these people were burning bone, which produces a brighter fire with less heat compared with a wood fire, he said.

The debris analysis also revealed 300 tiny stone and flint chips, likely produced when ancient people there knapped stones into sharp tools for butchering animals and scraping hides. It also turned up more than 50 small charred seeds, the remains of plants growing locally or maybe food remains from cooking and eating.

"This is a story about our human ancestors innovating to survive the coldest point of the last ice age and using all resources and materials that they had," Pryor said. "It would have been a challenging place to live, but they were making a success out of it."

The suggestion that the bone structure was used for storage and the pits around it as trash cans "are not Earth-shattering revelations, [but] they do provide useful insights into the lives of the people who once occupied the site," said E. James Dixon, an emeritus professor of anthropology at the University of New Mexico who was not involved in the study.

The last ice age is a "fascinating time period in Eurasian archeology," Dixon told Live Science in an email, and the study "clearly demonstrates that modern humans were adapted to higher latitudes at the very height of the last ice age."

The study was published online March 17 in the journal Antiquity.

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Originally published on Live Science.

Dwarf woolly mammoths that lived on Siberia's Wrangel Island until about 4,000 years ago were plagued by genetic problems, carrying DNA that increased their risk of diabetes, developmental defects and low sperm count, a new study finds.

These mammoths couldn't even smell flowers, the researchers reported. 

"I have never been to Wrangel Island, but I am told by people who have that in the springtime, it's just basically covered in flowers," study lead researcher Vincent Lynch, an assistant professor of biological sciences at the University at Buffalo in New York, told Live Science. "[The mammoths] probably couldn't smell any of that."

Related: Mammoth resurrection: 11 hurdles to bringing back an ice age beast

Wrangel Island is a peculiarity. The vast majority of woolly mammoths died out at the end of the last ice age, about 10,500 years ago. But because of rising sea levels, a population of woolly mammoths became trapped on Wrangel Island and continued living there until their demise about 3,700 years ago. This population was so isolated and so small that it didn't have much genetic diversity, the researchers wrote in the new study. 

Without genetic diversity, harmful genetic mutations likely accumulated as these woolly mammoths inbred, and this "may have contributed to their extinction," the researchers wrote in the study.

The team made the discovery by comparing the DNA of one Wrangel Island mammoth to that of three Asian elephants and two other woolly mammoths that lived in larger populations on the mainland.

"We were lucky in that someone had already sequenced the [Wrangel mammoth's] genome," Lynch said. "So, we just went to a database and downloaded it."

After comparing the mammoths' and elephants' genomes, the researchers found several genetic mutations that were unique to the Wrangel Island population. The team had a company synthesize these tweaked genes; then, the researchers popped those genes into elephant cells in petri dishes. These experiments allowed the researchers to analyze whether the proteins expressed by the Wrangel Island mammoth's genes carried out their duties correctly, by sending the right signals, for instance, in the elephant cells.

The team tested genes involved in neurological development, male fertility, insulin signaling and sense of smell. In a nutshell, the Wrangel Island mammoths were not very healthy, the researchers found, as none of those genes carried out their tasks correctly.

That said, the study looked at only one Wrangel Island mammoth, so it's possible that this individual's comrades didn't have similar genes. But "it's probably unlikely that it was just this one individual that had these defects," Lynch said.

In fact, the case of the Wrangel Island mammoths is a cautionary tale about what can happen to a population that is too small and therefore lacks genetic diversity, he said.

The findings build on those from a study published in 2017 in the journal PLOS Genetics that found that the Wrangel Island mammoth population was accumulating damaging mutations.

The new study was published online Feb. 7 in the journal Genome Biology and Evolution.

• Photos: A 40,000-year-old mammoth autopsy
• In photos: Mummified woolly mammoth discovered
• Photos: Ice age mammoth unearthed in Idaho

Originally published on Live Science.

A handful of 28,0000-year-old woolly mammoth cell parts were recently "woken up" for a short time in a new experiment, but cloning the ice age beasts is still a long way off.

In the experiment, the researchers extracted cells from Yuka, a woolly mammoth mummy (Mammuthus primigenius) whose remains were discovered in the Siberian permafrost in 2011. Then, the scientists recovered the least-damaged nuclei (structures that contain genetic material) from each cell and popped the nuclei into mouse eggs.

At first, this maneuver "activated" the mammoth chromosomes, as several biological reactions that occur before cell division actually happened within the mouse cell. But these reactions soon came to a crashing halt, probably, in part, because the mammoth DNA was severely damaged after spending 28,000 years buried in permafrost, the researchers said. [In Photos: Mummified Woolly Mammoth Discovered]

But why did the researchers put mammoth DNA into mouse eggs? The answer has to do with an egg's ability to replicate DNA and divide into more cells.

"The eggs have all of the living cellular machinery that you might need to do error correction and fix damage that has happened within the nuclei," said Beth Shapiro, a professor of ecology and evolutionary biology at the University of California, Santa Cruz, who was not involved with the study. "[The scientists] basically just stuck [the mammoth nuclei] in there and said, 'All right, cellular machinery, do your thing.'"

And, at first, the cellular machinery did try to fix damaged DNA within the chromosomes and piece together the broken bits, Shapiro said. "But [the egg] can only do so much," she told Live Science. "When the nuclei are badly damaged, then it's just not possible to reconstitute this to what you would need to do to actually bring it back to life."

As a result, none of the mouse-mammoth hybrid cells entered cell division, a step that is necessary to create an embryo and, perhaps one day, clone a mammoth.

"The results presented here clearly show us again the de facto impossibility to clone the mammoth by current NT [nuclear-transfer] technology," the researchers wrote in the study, published online March 11 in the journal Scientific Reports.

Put another way, "it's a pretty clear demonstration that this approach is not going to work to clone a mammoth," Shapiro said. "The cells are too damaged."

As soon as the mammoth died, its DNA began degrading. That's because bacteria from the mammoth's gut and the surrounding environment began chomping down on the dead mammoth's cells. Ultraviolet (UV) radiation from the sun also broke down more of the genetic material, and those processes continued for eons. As a result, DNA fragments in the nucleus that survived to today may be only tens to hundreds of bases long, rather than the millions that are found in the DNA of modern elephants, Shapiro said.

However, the study is still exciting, said Rebekah Rogers, an assistant professor of bioinformatics at the University of North Carolina at Charlotte, who was not involved with the research. For instance, if researchers can insert even small fragments of mammoth DNA into a cell line, that could reveal what that DNA does in a living creature, she said. [Mammoth Resurrection: 11 Hurdles to Bringing Back an Ice Age Beast]

In the study, the researchers added that "our approach paves the way for evaluating the biological activities of nuclei in extinct animal species."

However, Rogers said she would like to see more evidence that the mammoth chromosomes actually made it into the mouse egg. "It's possible that you could have a highly modified mouse chromosome or potentially some other DNA contamination," she said. "They have this extraordinary claim that they put mammoth chromosomes into a mouse [egg]. I would really like to see a lot of evidence for that kind of claim."

Other research groups are also trying to resurrect the mammoth, using different technology. George Church, a geneticist at Harvard University and the Massachusetts Institute of Technology who is heading the Harvard Woolly Mammoth Revival team, is taking one approach. He's using CRISPR — a tool that can edit DNA's bases, or letters — to insert woolly mammoth genes into the DNA of Asian elephants, which are closely related to the extinct animals.

"They're not trying to revive a mammoth genome," Shapiro said. "They are trying to create one by tweaking an elephant genome. In that way, they could have a living cell as an end product."

Bringing back the ice age mammals is controversial, however. Many conservationists argue that resources should be spent on currently threatened or endangered animals rather than beasts that died off long ago.

• Photos: Mammoth Bones Unearthed from Michigan Farm
• Photos: Ice Age Mammoth Unearthed in Idaho
• 6 Extinct Animals That Could Be Brought Back to Life

Originally published on Live Science.

About 25,000 years ago, ice age hunters in what is now Poland threw a light spear known as a javelin at a mammoth. Now, the discovery of that javelin has revealed a major surprise.

Previously, researchers wondered whether our ancestors had killed mammoths by trickery, for instance, by chasing them into pits or off cliffs. Or, perhaps ice age hunters targeted weak or sick mammoths that were easy to finish off.

But now, "we finally have a smoking gun, the first direct evidence of how these animals were hunted," Piotr Wojtal, an archaeozoologist at the Institute of Systematics and Evolution of Animals at the Poland Academy of Sciences in Kraków, told Science in Poland, a site run by the Ministry of Science and Higher Education. [Photos: A 40,000-Year-Old Mammoth Autopsy]

Deadly weapon

Researchers initially found the mammoth rib in 2002, at a mammoth hotspot in Kraków, where scientists, over the years, have discovered the remains of at least 110 mammoths that lived between 30,000 and 25,000 years ago, the researchers said.

"Among tens of thousands of bones, during a detailed analysis of the remains, I came across a damaged mammoth rib," Wojtal told Science in Poland. "It turned out that a fragment of a flint arrowhead was stuck in it."

It wasn't until February 2018 that they took a detailed look at the specimen.

During this examination, scientists found the 0.3-inch-long (7 millimeters) fragment of the flint tip, which likely broke when a hunter drove the spear into the mammoth's body.

"The spear was certainly thrown at the mammoth from a distance, as evidenced by the force with which it stuck into an animal," Wojtal told Science in Poland. "The blade had to pierce 2-centimeters-thick [0.7 inches] skin and an 8-centimeter [0.04 inches] layer of fat to finally reach the bone."

This blow probably didn't kill the mammoth, but if the hunt involved several armed hunters, it's likely that strikes from other weapons, "probably directly into soft tissues and one of the organs," killed the giant, Wojtal said.

Ice age hunters?

Over the past 20 years, researchers have found mammoth remains containing human-made weapons at two sites in Siberia, but "I believe this is the first find of a weapon embedded in a mammoth bone in Europe," said Adrian Lister, a professor of vertebrates and anthropology at the Natural History Museum in London, who wasn't involved with the finding.

"It is important because it proves beyond reasonable doubt that mammoths were hunted," Lister told Live Science. Until now, there was only circumstantial evidence that ice age people in Europe hunted mammoths. For instance, the Polish site of Kraków Spadzista Street contains burnt bones involved in supporting the tongue, indicating that ancient people feasted on roasted mammoth tongue, Lister said.

"But you can never be absolutely sure that such animals were actually hunted rather than scavenged," Lister said. Or, if the mammoths did appear to be hunted, it remained a mystery what weapons were used against them, such as spears or traps.

The new find shows, without a doubt, that a spear was used against the beast, Lister said.

What killed off the mammoths?

Mammoths lived in Europe starting about 500,000 years ago and started dying out about 15,000 years ago. However, they survived longer in Alaska and lived on Wrangel Island, off northeast Russia, until about 4,000 years ago. [In Photos: Mummified Woolly Mammoth Discovered]

A mix of changing climatic conditions (the ice age was ending) and hunting likely caused the mammoth's extinction, but researchers still debate which played a larger role. In this case, however, this specific example is not necessarily evidence that humans played a big role in their extinction, Lister said.

"That doesn't prove people killed them in [large enough] quantities to drive them to extinction," Lister said. Moreover, this particular mammoth died about 25,000 years ago, at least 10,000 years before mammoths died out in Europe, "so 'sustainable' hunting is implied, at least at that time," Lister said.

• Photos: Mammoth Bones Unearthed from Michigan Farm
• Photos: Ice Age Mammoth Unearthed in Idaho
• Photos: Is Ice Age Cat Mummy a Lion or a Lynx?

Originally published on Live Science.

WASHINGTON — Tens of thousands of years ago, the chilly Siberian steppes were vibrant grassland ecosystems, supporting diverse communities of lumbering herbivores such as mammoths, woolly rhinos, moose, horses and bison. But after most of those species disappeared at the end of the Pleistocene epoch (2.6 million to 11,700 years ago) the grassland habitats foundered, with much of the grasses disappearing.

Today, a team of Russian scientists is working to re-create that ancient landscape. In a fenced-off zone in northern Siberia named "Pleistocene Park," researchers seek to restore a vanished world where oversized grass-eaters roamed 20,000 years ago. In doing so, the scientists also hope to address the global problem of climate change, according to research presented on Dec. 12 at the annual meeting of the American Geophysical Union (AGU). [Image Gallery: 25 Amazing Ancient Beasts]

In the Arctic, permafrost cover is currently vulnerable to melt, and melting permafrost releases stored greenhouse gases, said Nikita Zimov, a researcher with the Pacific Institute for Geography at the Russian Academy of Sciences and the director of Pleistocene Park. An estimated 1,400 gigatons of carbon — 1 gigaton is equal to 1 billion tons — is thought to be frozen in Earth's permafrost, according to the National Snow and Ice Data Center (NSIDC).

But reintroducing large herbivores to the Siberian park and bringing back grasslands to the steppes could help protect the permafrost, Zimov said at AGU. Establishing healthy, productive grasslands could also create a more efficient system for storing atmospheric carbon in the soil, he added.

Unlike the fictional Jurassic Park that inspired its name, Pleistocene Park isn't a tourist playground featuring animals brought back from extinction. The park covers 6 square miles (16 square kilometers) and is home to reindeer, moose, musk ox, bison and horses, all of which were brought to the site by Zimov and his colleagues, according to the park's website.

The first animals arrived in 1988, and in the decades since, the ecosystem has adjusted to the presence of big grazers. Changes have already begun to emerge in the park's vegetation, with more grass — which increases in response to being eaten, Zimov told Live Science.

And soil covered by grasses and shrubs retains more carbon than soil topped with forests, Zimov and his colleagues discovered. The scientists sampled soil from within the park and outside its borders, and found higher carbon concentrations in locations where animals had been grazing for the past 20 years. As local vegetation transformed to more grasses, those areas sequestered more carbon from the atmosphere and stored it in the Arctic soil, Zimov explained.

"Where we had the most animals and highest grasses, we had the highest carbon content in soil," he said. Highly grazed areas also demonstrated deeper carbon storage than locations where there was no grazing, he added.

More grass in Siberia could also combat excess methane in the soil, Zimov said at AGU. Since the end of the last ice age, almost 12,000 years ago, Siberian steppes have become wetter, with more methane being produced in the soil as organisms decay. But re-creating ancient grasslands will bring back root systems that leach moisture from the soil, which could reduce methane production, Zimov said. (In wetter soils, where oxygen becomes depleted, the microbes that break down carbon produce methane rather than carbon dioxide.)

Meanwhile, increased snowfall during the past three winters has further jeopardized the permafrost, by creating an insulating layer that warms the earth underneath and prevents it from freezing, according to Zimov. In many locations, researchers found that layers of ground remained unfrozen year-round — a warning that the permafrost could be starting to degrade.

"And once it starts, it's a rapid process and it's very hard to stop," he said.

Though Siberia's mammoths and woolly rhinos are long gone, other large herbivores alive today could safeguard the permafrost by doing what their predecessors did when they roamed the tundra — trampling down the top layers of snow, Zimov said.

"This will allow soil underneath to cool and will prolong the life of permafrost in the Arctic — which will buy us some time," he said.

• Photos: Ice Age Mammoth Unearthed in Idaho
• 10 Extinct Giants That Once Roamed North America
• Mammoth Resurrection: 11 Hurdles to Bringing Back an Ice Age Beast

Original article on Live Science.

ALBUQUERQUE, N.M. — Upward of 20 mammoths may have succumbed to disease from a poop-infested watering hole in Waco, Texas, during a severe drought in the last ice age. The new findings counter a past interpretation of this mammoth graveyard that suggested the animals died in a flood.

A new chemical analysis of mammoth teeth, as well as horse and bison chompers, from the 67,000-year-old graveyard, suggests that the thirsty animals converged at a water source in what is now Waco before they bit the dust.

The dental analysis also contained another bombshell: It revealed that the adult and juvenile mammoths weren't from one nursery herd, as was previously thought, but rather from two or more herds, said study researcher Don Esker, a doctoral candidate in the Department of Geosciences at Baylor University in Waco. [Mammoth Resurrection: 11 Hurdles to Bringing Back an Ice Age Beast]

Esker presented the research, which has yet to be published in a peer-reviewed journal, on Wednesday (Oct. 17) here at the 78th annual Society of Vertebrate Paleontology meeting.

Mammoth graveyard

Waco's mammoth graveyard is famous among paleontologists. The site contains the remains of 24 juvenile and adult Columbian mammoths (Mammuthus columbi). In 2015, it became a protected national monument.

Hoping to learn more about the mammoths buried there, Esker looked at a single mammoth tooth, analyzing its isotopes (isotopes are variants of an element that have different numbers of neutrons in their nucleuses). The results were surprising, he said. About seven years before the animal died, the isotopes in this tooth matched those found in bedrock located about 100 miles (170 kilometers) southwest of Waco, in the Austin, Texas, area, Live Science reported last year. The mammoth would have absorbed these isotopes by munching on vegetation growing in the bedrock.

The trip from Austin to Waco was a long way for a mammoth to travel, Esker said.

In the latest phase of his project, Esker got tiny samples from the teeth of two more mammoths, a bison and a horse whose remains lay in the Waco graveyard. He also got samples from a control mammoth from another site in Waco that died at a different time. Then, Esker took the teeth to East Tennessee State University, where he could use the only known high-precision micromill, which would help him drill miniscule samples from the teeth. (Esker said he tried to fly from Texas to Tennessee, but the airline wouldn't let him bring the teeth in his carry-on bag. "So, I got off the airplane and I drove 17 hours to the university" he told Live Science.)

Once at the Tennessee site, Esker worked with Chris Widga, head curator at East Tennessee's Natural History Museum. Widga had invented a computer-controlled micromill that could drill tiny samples, each representing 10 days of enamel growth, from each tooth.  

"It's a really amazing system," Esker said.

Next, Esker sent the samples to Doug Walker, co-director of the Isotope Geochemistry Laboratories at the University of Kansas, for a strontium-isotope analysis. "[The results] kind of made my jaw drop," Esker said, "because they were not what I was expecting."

The animals in the graveyard had barely moved more than 40 miles (60 km) away from that spot during their lifetimes. The control mammoth "seems to have basically stood in one spot and munched its entire life," Esker said. "I'm exaggerating, but not too much." [Photos: Ice Age Mammoth Unearthed in Idaho]

Mammoth mystery

So, why were the new results so different from those taken from the first mammoth, the one that had traveled from the Austin area?

One possible explanation is that the first analysis was contaminated, Esker said. He didn't use the high-precision micromill technique on the first tooth, so for consistency's sake, Esker said he plans to reanalyze the first tooth on the micromill to see if the Austin results hold up.

However, if the results hold true, this finding indicates that there is more than one mammoth nursery herd in the Waco graveyard, Esker said.  [See Images of the Baby Woolly Mammoths]

This finding prompts another question: Why were there so many nursery herds in one spot? One hypothesis is that there was a drought. "Maybe Waco National Monument is the last good watering hole in central Texas," Esker said. "The mammoths are congregating there and dying."

There is another idea, introduced by Dava Butler, a graduate student in science education on the paleo track at Montana State University, but more research is needed to see if that explanation holds up, Esker said. Bulter proposed that it's possible that with all of the animals pooping there, the watering hole was a prime location for Microcystis, an extremely poisonous blue-green algae.

"Maybe what we've got here is all of these animals congregating around a watering hole, eutrophication [nutrients from poop entering the water] happening and an algal bloom" occurring, killing the animals there, Esker said. "That's why they're not going elsewhere to look for other water."

Moreover, recent analyses of ancient aquatic reptiles at the site reveal strange conditions that are reminiscent of algal poisoning. Reptiles have a slower metabolism than mammals, like mammoths, which means it takes longer for them to die from poisonous algae, Esker said. And because these animals die more slowly, they have more time to develop health conditions, he said. "There are lots of other things that could have caused these pathologies, but it is consistent with what we see with Microcystis," Esker said.

Next, Esker said, he's planning to look for markers of Microcystis in the soil, as well as investigate more ancient teeth.

"Providing I can replicate these [isotope] results [for the first mammoth tooth] with the new machine, there's more than one nursery herd at that site," Esker said. "And that goes better with a drought than a flood, because you generally don't have animals congregating to die in a flood."

Originally published on Live Science.

Pity the male woolly mammoth: These poor creatures were more likely to meet their end in natural traps — falling through thin ice, tumbling into holes or getting stuck in mudflows — than their female counterparts, a new study finds.

Researchers made the discovery after determining the sex of 95 woolly mammoths (Mammuthus primigenius) whose remains were found across different parts of Siberia. In all, 66 of the specimens (69 percent) were male, while just 29 (31 percent) were female, they found.

The woolly mammoth lifestyle may be the cause of this skewed sex ratio. Inexperienced male mammoths were more likely to travel alone, away from the herd, so perhaps it's no surprise that these males were more likely to stumble into danger and die as a result, the researchers said. [Image Gallery: Stunning Mammoth Unearthed]

But there is an upside to these pachyderms' untimely deaths: Being buried in a natural trap — such as a bog, crevice or lake — tended to preserve their remains for thousands of years, allowing researchers to discover and study them.

"Most bones, tusks and teeth from mammoths and other ice age animals haven't survived," study researcher Love Dalén, a professor of evolutionary genetics at the Swedish Museum of Natural History, said in a statement. "It is highly likely that the remains that are found in Siberia these days have been preserved because they have been buried, and thus protected from weathering."

The discovery is part of a larger, long-term project researchers are undertaking to study the genomes of woolly mammoth populations. Some of the analyses required knowing the sex of the mammoths, and the results were unexpected, the researchers said.

"We were very surprised because there was no reason to expect a sex bias in the fossil record," lead study researcher Patrícia Pečnerová, a doctoral student of bioinformatics and genetics at the Swedish Museum of Natural History, said in the statement. "Since the ratio of females to males was likely balanced at birth, we had to consider explanations that involved better preservation of male remains."

The findings suggest that, like modern elephants, woolly mammoths had matriarchal hierarchies. As such, mammoth herds of young and female mammoths were likely led by an experienced adult female, the researchers said. Male mammoths, also like modern elephants, likely lived in bachelor groups or spent time alone, engaging in risky behavior, they said.

"Without the benefit of living in a herd led by an experienced female, male mammoths may have had a higher risk of dying in natural traps," Dalén said.

This discovery — that seven of every 10 mammoths found in natural traps were male — sheds light on the socioecology and behavior of these extinct animals, the researchers said. It's also a reminder that uncovered specimens don't necessarily represent a random sample of a species, they noted. 

The study was published online today (Nov. 2) in the journal Current Biology.

Original article on Live Science.

CALGARY, Alberta — About 67,000 years ago, a gigantic mammoth chowed down on enormous mouthfuls of grass in Texas, just west of where modern-day Austin is located, according to new research.

The finding is surprising, given that the beast's remains were discovered in Waco, Texas, more than 120 miles (200 kilometers) away from the Columbian mammoth's (Mammuthus columbi) ancient picnic spot near Austin, the researchers said.  

"They really weren't in the Waco area until right before they died, which is a little unexpected," the study's lead researcher, Don Esker, a doctoral candidate in the Department of Geosciences at Baylor University in Waco, told Live Science. "Two hundred kilometers is within the largest distance that we've known Columbian mammoths to travel, but only just." [Mammoth Resurrection: 11 Hurdles to Bringing Back an Ice Age Beast]

Esker and his colleagues made this discovery by studying the isotopes (an isotope is a variation of an element that has a different number of neutrons in its nucleus) in the mammoth's teeth. So far, Esker has studied just one tooth, but he has plans to examine more teeth from different mammoths in the coming months.

Esker could have a lot of work in front of him. There are remains from at least 23 mammoths dating to the late Pleistocene in Waco. The prehistoric graveyard was found in 1978 by two local youngsters, Paul Barron and Eddie Bufkin, who were searching for fossils and arrowheads when they discovered the fossilized mammoth bones. In 2015, President Barack Obama issued a presidential proclamation, with bipartisan support, that made the site a national monument, according to the National Park Service.

It's likely, but not certain, that these fossils are from the same mammoth nursey herd, Esker said. His goal is to confirm whether these mammoths traveled together as a social group, and to learn where they traveled and what they ate, he said.

If his research reveals these mammoths gulped down the same kind of water and gobbled up the same types of food, then it's likely they did travel as a herd, he told Live Science here at the 2017 Society of Vertebrate Paleontology meeting.  

Mammoth menu

To get started, Esker analyzed the carbon, oxygen and strontium ratios in a single mammoth tooth, which helped him reconstruct "an itinerary and menu for the mammoth over the last six years of its life," he said.

When mammoths dined on vegetation, the plants' nutrients eventually ended up in their teeth. This information can reveal what types of plants the mammoths ate, because the way plants photosynthesize energy from the sun governs what type of carbon isotopes they produce: Carbon 4 (C4) indicates that the beasts ate grasses and sedges, and carbon 3 (C3) shows that they ate most other vegetation, including honey locust, Osage orange and mesquite.

"The carbon told us that the mammoth in question ate 65 percent to 75 percent warm season C4 grasses year-round," Esker said. This supports evidence from mammoth fossilized poop, or coprolites, that also revealed that Columbian mammoths ate plants containing C4.

Meanwhile, the oxygen isotopes in the mammoth's tooth showed that conditions "may have been a good deal more arid than [they are] today," Esker said.

Finally, the strontium isotopes revealed that the mammoths "spent a good deal of time eating grass growing on granite-derived soil," Esker said. The only place Esker could find with this type of soil was west of Austin, he said.

In addition to studying mammoth teeth, Esker and his colleagues plan to analyze chompers from a horse, camel and pronghorn that also perished at the Waco site. The results will show whether these animals' ranges overlapped with the mammoths' stomping grounds, Esker said. [Photos: Mammoth Bones Unearthed from Michigan Farm]

"Serially sampling teeth for isotopic analysis can be unpopular, as it does cause slight damage to the fossils," Esker said. "Nevertheless, it is an unparalleled record of an animal's life, and has much to offer us."

The research, which has yet to be published in a peer-reviewed journal, was presented Wednesday (Aug. 23) at the 2017 Society of Vertebrate Paleontology meeting.

Original article on Live Science.

"Perfect forms" carved in ivory reveal humanity's oldest set of ropes, research suggests.

At first glance, the discovery in Germany's Hohle Fels cave looked like it could be the mock-up for a 42,000-year-old set of brass knuckles: four carefully carved small holes placed close together on an 8-inch-long (20 centimeters) strip of mammoth ivory.

But the Hohle Fels cave dwellers had neither brass nor the know-how to make it. Also, the inner surfaces of the holes were intricately carved in a spiral pattern, like the rifling inside a modern gun barrel. [Top 10 Mysteries of the First Humans]

"These people were interested in making these perfect forms," said Nicholas Conard, an archaeologist at the University of Tuebingen, who helped to discover the ivory. 

Conard and his multinational team said they may have found the earliest evidence of human rope-making. In the study, Veerle Rots, of Belgium's University of Liege, an expert in scientific analysis of Paleolithic materials, fed raw fibers through the rifled holes in a bronze replica of the ivory artifact to create four separate twisted strands. Subsequent experiments reinforced the initial results.

"This is completely new," Conard told Live Science. "What we've done strongly suggests that it could be used to make rope. I've never run into anyone else who can suggest" that any artifact this old could be used to make rope. Still, he added, "there is no real proof."

This is because figuring out how humanity's ancestors lived is a two-sided conundrum, and scientists usually have only one side of the evidence. Stone and bone tools survive, said University of Tulsa archaeologist Danielle Macdonald, a materials analyst who did not participate in the Hohle Fels discovery, but hides, wood, fibers and foods — the materials worked by the tools — do not.

"There is never a stand-alone object," MacDonald added. "We look at the microscopic records of wear and tear on stone and bone materials, and make inferences of what people were doing with them." 

Hohle Fels, in the Ach Valley of southwestern Germany, is a rich source of human prehistory, best known for artifacts made by the first modern humans in Europe, around 42,000 years ago.

The mammoth ivory tool was found 50 feet (15 meters) inside a narrow tunnel leading to the Hohle Fels amphitheater — "protected from the weather but with enough daylight to make it easy to work," Conard said. The team found the four-holed mammoth ivory tool in 15 "little broken pieces, crushed in place and beautifully preserved," Conard added.

Initially, the scientists interpreted the find as artwork, but archaeologists had never found anything that remotely resembled the ivory piece, the researchers said. Instead, the rifling, etched in the bone with incredible care, suggested a practical use: fiber forced through the holes could produce four strands of rope with a right-hand twist that could in turn be fashioned into a larger rope, the study said. Using a bronze casting of the artifact (it is illegal to take such objects out of Germany), Rots and her Liege staff made 10 feet (3 m) of rope in 15 minutes.

Yet, although "rope seems the most likely product, they may [also] have been winding fibers to make mats," Conard said. "We're not ruling that out." The team published preliminary results last July in the German journal Archaologische Ausgrabungen Baden-Wurttemberg. Conard said the team is testing different materials over the course of a full year to see whether the tool proves effective for all seasons.

The Liege researchers used cattails, common, reedy wetlands plants, "but it seems you can use inner [tree] bark or any plant with long fibers," Conard said. Each of the fibers is about 3 feet (about 1 m) long, and "you wind the next one into the previous one," he said. "They shoot out the other side like large strands of spaghetti."

Original article on Live Science. 

Many mammoth questions

The road to bringing back the mammoth — a giant that went extinct at the end of the last ice age — is filled with barriers.

Scientists have pieced together the genomes of four different mammoths over the past few years, but more hurdles remain: If researchers decide to create new mammoths, how will they do it? If a mammoth calf is born, how will it learn how to behave without a parent or herd to guide it?

Beth Shapiro, a professor of ecology and evolutionary biology at the University of California, Santa Cruz, discusses these queries in "How to Clone A Mammoth: The Science of De-Extinction" (Princeton University Press, 2015). Here are 11 of the many challenges she considers, including those that are scientific, ethical and environmental.

Editor's note: This story was updated on Sept. 15, 2017, to include the fact that several mammoth genomes are now available.

DNA degradation

DNA begins to degrade the moment an organism dies. This happens because enzymes from the body cells and environment, as well as ultraviolet radiation from the sun, start to break down the genetic code. Oxygen and water can also alter DNA, breakings its strands.

Some mammoth DNA, however, has survived because it was frozen in permafrost. Some of these frozen remains contain short fragments of DNA — mostly between 30 to 90 base pairs long (one base pair is made up of two "letters" of DNA linked together: cytosine and guanine, or adenine with thymine). To put this number in perspective, there are 3 billion base pairs in the human genome.

However, researchers are working around this "short fragment" challenge by using the modern elephant genome as a scaffold, Shapiro told Live Science.

DNA contamination

Anient DNA is often contaminated with foreign DNA from fungus, bacteria, plants, animals and even from humans handling it for research purposes.

This DNA contamination can make it difficult for researchers to know which DNA molecule belongs to the animal, and which is from contamination, especially if the extinct animal doesn't have a living relative whose DNA can serve as a roadmap, Shapiro wrote.

Luckily, this isn't a big deal for mammoths, because "we can distinguish mammoth [DNA] from human and bacteria [DNA]," she told Live Science.

Close relatives

Scientists may have only fragments of mammoth DNA, but they can use DNA from the mammoth's close relatives — modern-day elephants — to help fill in the genetic gaps.

Mammoths are more closely related to Asian elephants (Elephas maximus) than they are to African elephants. Researchers in India described the Asian elephant genome in 2015 in the Journal of Biosciences, and another effort is underway at the Broad Institute in Cambridge, Massachusetts, to sequence the genome of an Asian elephant.

The mammoth and the Asian elephant diverged between about 2.5 million and 5 million years ago. If they, let's say, diverged about 4 million years ago, then about 2 percent of their genomes would be different, amounting to 70 million genetic differences, Shapiro wrote.

"The reads that I get are short, but — as long as there is a close relative that has a sequenced genome — I can still map those short reads onto that closest relative's genome and, piece by piece, put the genome together," Shapiro told Live Science in an email, referring to the "reads" of a DNA sequence. "There will be missing pieces … but it will be mostly there."

Back breeding

Scientists could try to bring back the mammoth through back breeding — that is, breeding the hairiest, most cold-tolerant Asian elephants together until generations later, a population of mammoth-like elephants emerge, according to "How To Clone a Mammoth."

There are several challenges to back breeding, however. Elephants don't reach sexual maturity until they're between 10 and 18 years old, and their pregnancies last nearly two years, Shapiro wrote in the book. This means that any back-breeding project would take a long, long time.

Furthermore, the result would not be a mammoth, but rather an elephant with mammoth-like traits. Some traits may never be passed on: Mammoth hemoglobin (the protein in blood that carries oxygen) is better suited to help large animals survive in cold climates. This hemoglobin differs from elephant hemoglobin by four mutations, but there aren't any elephants alive today that have these mutations, meaning they can't pass them on to future generations, Shapiro wrote. 

Mammoth cloning

Now that researchers have sequenced mammoth genomes (although some of these genomes might be contaminated, according to a March 2017 study in the journal PLOS Genetics), could they clone a mammoth using somatic cell nuclear transfer — the process used to make Dolly the sheep? With somatic cell nuclear transfer, scientists extract the cell nucleus (which contains DNA) from an animal, called the donor. They then insert that nucleus into the egg cell, which has had its own nucleus removed, of another animal.

It would be difficult. Cloning with nuclear transfer is not very efficient, and it's usually done with a limitless supply of cells harvested from living animals, according to "How to Clone a Mammoth." As we know, there are no living mammoths, Shapiro wrote.

Moreover, scientists would have to implant the mammoth embryo into an Asian elephant, which is endangered, largely from habitat loss and fragmentation and poaching, according to the International Union for Conservation of Nature. It would be hard to justify implanting a mammoth embryo into an elephant when every Asian elephant pregnancy counts, Shapiro wrote. 

CRISPR-Cas9

By using the gene-editing tool called CRISPR-Cas9, scientists can cut DNA in a precise location, remove genetic code and then paste that section in a new sequence created in a lab.

This method could be used to bring back the woolly mammoth in just two years' time, according to George Church, a geneticist, molecular engineer and chemist at Harvard University, who made this announcement just before the American Association for the Advancement of Science (AAAS) meeting in Boston in February 2017.

"Our aim is to produce a hybrid elephant-mammoth embryo," Church told The Guardian. "Actually, it would be more like an elephant with a number of mammoth traits. We're not there yet, but it could happen in a couple of years."

The epigenome

If a mammoth is brought back to life — through back breeding, cloning or genetic engineering — it would be challenging to recreate the creature's epigenome, which would be passed on to a developing mammoth in utero. The epigenome is a system of tags that determine which genes are turned on or off. These tags do not change the genetic code, but rather select when to activate certain genes.

An elephant epigenome would be different than a mammoth epigenome, but it's not clear what those changes are, Shapiro wrote.

It would be possible to recreate the mammoth's epigenome, Church, said at a Q&A following a panel at the American Museum of Natural History (AMNH) in April 2017, but the technology is still a ways away. 

Mammoth microbiome

Babies pick up bacteria when they exit their mother's birth canal, and continue getting new types of bacteria throughout their lives. The bacteria within and on the body is known as the microbiome, and it aids and influences digestion and health.

The mammoth's microbiome is unknown, but mammoth mummies offer hints. For instance, a necropsy (an animal autopsy) of a 42,000-year-old mummified baby mammoth showed that the youngster had feces in its digestive tract, according to "How To Clone A Mammoth."

Modern elephant calves eat their mother's feces to seed their own microbiomes — bacteria that are needed to break down the fibrous plants they eat. The finding indicates that mammoth calves did the same.

Environmental challenges

In the thousands of years since mammoths died, the environment has changed. This raises several questions, according to Shapiro: Will the new mammoths have appropriate food that they can digest?; will they be susceptible to disease, parasite or pollutants?; will the changes in temperature and precipitation impair them?

Nonetheless, two wildlife parks in Russia — Pleistocene Park and Southern Pleistocene Park — are ready to accept mammoths, should they be brought back. The goal of these parks is to turn the currently frozen Siberian tundra into pastures supported by mammoths and herbivores that once lived and supported the grassland ecosystem, according to the Pleistocene Park website.

This transformation would happen when large animals break up the ice, snow and dirt and then disperse nutrients and seeds as they roam and eat vegetation, the website reports. 

Acting like a mammoth

If scientists were to succeed in bringing back a mammoth, would the resulting calf know how to be a mammoth?

Elephants are social creatures, an indication that mammoths were too, Shapiro wrote. But without other living mammoths, it's unclear if a new mammoth would be able to behave as its predecessors did before they went extinct.

On another note, even if these calves didn't know how to act, scientists would have to breed several thousand of them, so that the newbies would have genetic diversity and become a self-sustaining population. 

Ethical dilemmas

The largest question might not revolve around the science of de-extinction, but rather whether we should attempt it.

Is it ethical to bring back an extinct animal? Should we be spending our time and resources on maintaining currently endangered animals? If de-extinction is made possible, how long are humans responsible for the animals they resurrected?

However scientists choose to move forward, it's important to engage with the public and be as transparent as possible about the parameters and goals of the project, the researchers on the AMNH de-extinction panel said. 

The discovery of ice age mammal bones — one belonging to an extinct camel and the other to either a mastodon or a mammoth (it's hard to say which) — temporarily stopped construction of Los Angeles' subway line extension last month.

Paleontologists found the fossils just down the street from the La Brea Tar Pits in L.A.'s Miracle Mile district, where a future subway station will be built. On April 12, scientists discovered the camel bone, and on April 13, they uncovered the bone of the proboscidean (the ancient elephant relative).

"It's one thing to read in a history book that these animals used to live all over North America, but it makes it more real when they're found in your city," said Ashley Leger, the paleontological field director for Cogstone Resource Management Inc., a company that surveys sites for paleontological and archaeological remains before construction projects begin. "[For] the people of Los Angeles, this is their history. This is what lived there thousands of years before they were ever there." [Photos: Ice-Age Animal Skull Unearthed During LA Subway Construction]

The bone from the extinct camel (Camelops hesternus) is an exceptionally rare find, Leger said. The La Brea Tar Pits hold the preserved remains of more than 600 species of plants and animals, including the bones of thousands of saber-tooth cats and dire wolves. But researchers have found the remains of only about 40 camels in the tar pits, Leger said.

Camels originated in North America about 45 million years ago before spreading across the world. The last known Camelops died about 13,000 years ago, said Emily Lindsey, an assistant curator at the La Brea Tar Pits.

The roughly 20-inch-long (50 centimeters) camel bone is a radioulna — the combination of forearm bones between the wrist and elbow, according to The Source, a transportation blog about the L.A. Metro. The radioulna helped Camelops support itself, allowing the animal to carry its body weight over its front and hind legs, according to The Source.

C. hesternus is related to, but a different from the modern dromedary camel, a one-humped ungulate more commonly known as the Arabian camel. C. hesternus hadlonger legs, knobbier knees and a larger head than dromedary camels do, according to The Source.

Two other camel genera lived in what is now California during the last ice age: Hemiauchenia and Palaeolama, Lindsey told Live Science.

The other fossil is an approximately 36-inch-long (91 centimeters) thighbone, or femur, of either a mastodon or mammoth. Both animals trampled through what is now Los Angles more than 10,000 years ago, before going extinct, Leger said.

She noted that the mammoth would have been a Columbian mammoth (Mammuthus columbi), not a woolly mammoth (Mammuthus primigenius), a shaggy beast that would have preferred the colder climate up north. Columbian mammoths were about the same size as their distant relatives, the modern-day African elephant, and about 15 percent larger than that species' close relative, the Asian elephant, Lindsey said.

Paleontologists will continue to look for more ancient bones as subway construction continues. All of the fossils uncovered during the Wilshire/La Brea station excavation will be donated to the Natural History Museum of Los Angeles County, according to The Source.

Leger noted that although the newfound bones aren't completely fossilized (that is, with minerals replacing original bone), they are referred to as fossils because they are 10,000 years old or older.

These aren't the first ice age animal fossils uncovered during the subway extension. In November of 2016, paleontologists found a tooth, tusks and a skull from either a mastodon or a mammoth, Live Science previously reported. 

Original article on Live Science.

A prehistoric campfire and a number of archaeological treasures — including a large tusk of a mammoth, and tools fashioned out of stone and ivory — remained hidden for thousands of years in the Alaskan wilderness until researchers discovered them recently.

Researchers found the 55-inch-long (140 centimeters) mammoth tusk, the largest ever found at a prehistoric site in the state, during a 2016 excavation at the Holzman site, located about 70 miles (110 kilometers) southeast of Fairbanks, Alaska. A radiocarbon dating analysis revealed that the tusk was about 14,000 years old, the researchers told Live Science in an email.

"The radiocarbon dates on this mammoth place it as one of the last surviving mammoths on the mainland," Kathryn Krasinski, a co-principal investigator of the excavation and an adjunct faculty member in the anthropology department at Adelphi University in Garden City, New York, told Live Science in the email. [Image Gallery: Stunning Mammoth Unearthed]

The research team found the tusk in soil deposits about 5 feet (1.5 meters) underground. Though other sites have ivory fragments, this discovery marks only the second time that researchers have uncovered an entire mammoth tusk from an archaeological site in Alaska, the researchers said.

The findings suggest that the earliest documented people in Alaska likely went out of their way to acquire mammoth ivory, and that they were creating tools with the material, the researchers said.

The team plans to investigate whether prehistoric people obtained the tusk through hunting or whether it was scavenged by humans who happened to live at the site a few hundred years later, said Krasinski and her colleague Brian Wygal, a co-principal investigator of the excavation and an associate professor of anthropology at Adelphi University. The other two co-principal investigators are Charles Holmes, an affiliate research professor the University of Alaska Fairbanks, and Barbara Crass, a faculty researcher in the Department of Religious Studies and Anthropology at the University of Wisconsin - Oshkosh.

"This question is significant because it could provide further evidence that the first Americans were involved in the extinction of the woolly mammoth," Krasinski and Wygal told Live Science in an email.

Mammoths went extinct at the end of the last ice age about 10,000 to 12,000 years ago, although a small population of mammoths survived on Wrangel Island, off the Siberian coast, until about 3,700 years ago, Live Science previously reported. But the mammoth's extinction is still shrouded in mystery, and scientists continue to debate whether an abruptly warming climate, human hunters or a combination of both drove the animals to extinction.

In a study published in 2016 in the journal Science Advances, researchers suggested that a perfect storm of both factors doomed the ice age giants, but earlier works, such as a 2014 study published in the journal PLOS ONE, placed more of the blame on humans, Live Science previously reported.

"Such questions are essential to understanding the greater impact of people on their environments," Krasinski and Wygal wrote in the email. These questions may also help researchers understand "the timing and circumstances surrounding the initial peopling of the Americas from Asia," they said.

The finding has yet to be published in a peer-reviewed journal. The tusk is now at the Adelphi University archaeology laboratory, where it will undergo further analysis.

Original article on Live Science.

NEW YORK — If humans were to go extinct, would it be ethical to revive the species, to allow us to live once more on this blue planet?

It's a tough call, but maybe not, according to a panel of five experts who debated "de-extinction" during the annual Isaac Asimov Memorial Debate at the American Museum of Natural History (AMNH) in New York City on Wednesday (March 29). Astrophysicist Neil deGrasse Tyson, director of the AMNH Hayden Planetarium, moderated the debate, which honors Isaac Asimov (1920-1992), a biochemist and science-fiction writer who famously wrote the "three laws of robotics."

Were another intelligent life to de-extinctify humans, would they put us in a zoo-like environment? For a sentient being, that would be "extremely frightening and scary," said panelist Greg Kaebnick, a research scholar at the Hastings Center, an independent bioethics research institute in Garrison, New York. "The animal welfare concerns just get overwhelming." [6 Extinct Animals That Could Be Brought Back to Life]

Then, to further muddy the waters, Kaebnick asked, "Do we deserve to be brought back?"

Yes, we do, said panelist George Church, a professor at Harvard University and the Massachusetts Institute of Technology, who is working on reviving bits and pieces of the woolly mammoth. But then again, Church, a geneticist, molecular engineer and chemist, has often opined that the science of de-extinction is already here or within reach, and should be pursued.

The panel grappled with the issues of de-extinction for more than 2 hours, discussing not only logistics but also ethical quandaries. Logistically, scientists need an animal's entire genetic code to bring it back. But this can be a challenging task: The oldest authenticated DNA is from the bone of a 700,000-year-old horse found in Yukon, Canada, said panelist Beth Shapiro, who co-wrote a 2013 study about the horse in the journal Nature.

It's difficult to get authenticated DNA from extinct animals, even those younger than that horse, including the mammoth, thylacine (a marsupial from Tasmania that's also called the Tasmanian tiger), dodo and passenger pigeon, Shapiro said. But Church disagreed, saying that there are ways to move forward.

Researchers could either find DNA in these animals' frozen nuclei, or re-create "a successful approximation" of the genome through DNA modification, Church said at a roundtable discussion later that evening.

"These are exponential technologies that improve very, very quickly and have many biomedical uses, like transplants," Church said. "I have no particular reason to doubt that we could make all of the genetic and epigenetic changes we will want to if we wanted to bring back an entire genome."

However, Church's comments were met with disbelief from some of the other panelists. Epigenetic changes are external influences on the genome that can change how much or little a gene is turned on or off, and could be difficult to modulate in a de-extinctified animal.

Lawful look

Even if the science will one day be possible, the legal framework addressing de-extinction is murky at best. If the "resurrected" animal is not a perfect copy, would it be considered the same species? Would it immediately be classified as an endangered species?

Moreover, what if its environment, microbiota (bodily bacteria) and food sources no longer exist? How many animals of a species should be brought back, so that they can have genetic diversity and mate on their own? When does human responsibility toward these revived animals end? [WipeOut: History'sMostMysteriousExtinctions]

"I think one of the toughest moral issues about de-extinction is animal welfare. How many maimed, deformed, stillborn, quasi-mammoths, quasi-elephants is it worth to bring back a sort of mammoth?" asked panelist Henry (Hank) Greely, a professor of law at Stanford University. "There are actually laws in this country, the Animal Welfare Act, that deal with some of those issues."

In addition, why not spend that money for de-extinction efforts instead on saving still-living animals, the panel asked.

De-extinction is a dangerous road, said panelist Ross MacPhee, the curator of mammalogy and vertebrate zoology at the AMNH. For instance, it's hard to know what ramifications an extinct animal will have on modern ecosystems, he said.

Rather than use science to bring back extinct animals, perhaps researchers could use these technologies to design bacteria that would help humans, for instance, by producing fuel or meat alternatives, MacPhee said. Or maybe this science could be used to insert or activate genes in plants and animals that could help them survive in an era of climate change, he added.  

Some of this work is already a reality, said Church, who pointed out that scientists have made some plants more resistant to drought and pests.

Also, there have been other successful de-extinction efforts, albeit for local, not worldwide extinctions. For instance, horses used to live in North America, but went extinct at the end of the last ice age. When European explorers arrived in the New World, they inadvertently re-introduced horses to the continent, where they have since flourished.

Likewise, a fungus has rendered the American chestnut functionally extinct, meaning the species is still around (at least in lab-monitored spaces), but not in its natural environment; but scientists have tweaked the chestnut's genome to make it fungus-resistant, Greely said.

The experts agreed that this technology could also be used for evil — for instance, to bring back an extinct virus or to alter an existing virus to make it more contagious.

As this science moves forward, it's crucial to educate and involve the public, the panel said.

"We actually have to have that [discussion] to some degree, case by case, because each effort at de-extinction raises its own unique considerations," Kaebnick said.

Original article on Live Science.

By the end of the ice age, the last remaining woolly mammoths had acquired so many genetic mutations that their numbers were practically guaranteed to spiral toward extinction, a new study has revealed.

Mammoths were once among the most common large herbivores that roamed across North America, Siberia and Beringia, a geographic area that once stretched from Siberia to the Canadian Yukon but is now mostly submerged under the Bering Strait. The giant beasts first appeared about 700,000 years ago. But, at the end of the last ice age, about 10,000 years ago, their population suddenly declined.

Scientists think a warming climate and the effects of human hunters led to the extinction of woolly mammoths on the mainland. Small populations continued to persist on isolated northern islands until they, too, vanished about 3,700 years ago. [Wipe Out: History's Most Mysterious Extinctions]

Researchers from the University of California, Berkeley, recently compared the existing genomes of two different mammoth specimens. One was a 45,000-year-old woolly mammoth found in northeastern Siberia, and the other was a 4,300-year-old mammoth from Wrangel Island, off the coast of Russia. The scientists found that the DNA of the Wrangel Island mammoth, which represents the last members of the species, had multiple harmful mutations that would have interfered with normal functions and compounded the difficulties of survival.

"It's sort of like a Greek tragedy that's written into the DNA of the poor mammoth," said lead study author Rebekah Rogers, an evolutionary geneticist at the University of North Carolina in Charlotte. "You look at this mammoth's DNA and you see all these bad mutations."

The findings suggest that in the end, as sea levels rose and cut off Wrangel Island mammoths, their small population and resulting inbreeding would have rendered the process of natural selection ineffective.

In larger populations, mutations that occur naturally are weeded out by competition, Rogers said. But with such a small population, there would have been no mechanism to prevent these mutations from being passed on to the next generation of mammoths. As such, harmful changes in the mammoth genome that deleted large chunks of DNA, or messed up how genes were read and translated, would have accumulated, according to Rogers.

By looking at which genes were affected by these harmful mutations, Rogers and her colleague, Montgomery Slatkin, a population geneticist at the University of California, Berkeley, were able to guess what functions or behaviors might have been affected as mammoth populations dwindled. The animals probably lost many olfactory receptors, which detect odors, as well as urinary proteins, the researchers found. This could have affected their social status and mate choice, Rogers said. The genome also revealed that the island mammoth had certain mutations that likely created an unusual translucent satin coat, as well as several other mutations with effects that scientists don't fully understand yet.

While the researchers said that their analysis was limited to one individual from the Wrangel Island mammoth population, they said they were fairly certain that this "genetic meltdown" would have occurred in the remaining mammoths as well.

"We would expect that if you got another mammoth from the island and you looked at its genome, that it would also have an excess of bad mutations," Rogers told Live Science. "They might not be the exact same mutations — some of them would be shared, and some of them might be different — but we would expect the same pattern." [Photos: 6 Extinct Animals That Could Be Brought Back to Life]

Other biologists agreed that the findings support a long-standing theory that genomes start unraveling as animal populations decline.

"It makes sense that the researchers would find an accumulation of deleterious mutations in a population that was very small," said Beth Shapiro, an evolutionary biologist at the University of California, Santa Cruz, who was not involved in the new study. "[This] reveals that it's not necessarily just a small population size that is potentially dangerous for populations but also the content of those genomes that's important."

The study offers a warning to conservationists, Shapiro said. If bad mutations start accumulating in small groups of isolated animals, it might not be sufficient to try and preserve endangered species after they have already undergone generations of inbreeding and genomic meltdown. Conservationists probably need to intervene much sooner, she said.

It might also provide an interesting twist to mammoth "de-extinction" experiments. If some mammoth genomes carry an overabundance of negative mutations, researchers need to carefully screen the genes before they are inserted into mammoth-elephant hybrid genomes, Rogers said. In fact, screening the mutations and testing what their functions are could also inform scientists about how the mutated genes affected mammoths just before they went extinct, she added.

Rogers and her colleagues detailed their analysis of the mammoth's genetic mutations in a study published online today (March 2) in the journal PLOS Genetics.

Original article on Live Science.

Archaeologists found 16 limestone tablets dating to the Aurignacian period, named for the first known people to settle in Europe. The tablets were engraved with pictures of horses, mammoths and aurochs (extinct wild cows). Most notably, the pictures were drawn using a series of dots and lines — or as archaeologists call the technique, pointillism.

Modern pointillism was invented in the 1880s by Georges Seurat and Paul Signac, who developed the technique by using small dots to create the illusion of a larger image. Other artists, including Camille Pissarro and Roy Lichtenstein, followed suit. [Photos: Ancient Cave Painting Mystery Solved by DNA]

"We're quite familiar with the techniques of these modern artists," study lead researcher Randall White, an anthropologist at New York University, said in a statement. "But now we can confirm this form of image-making was already being practiced by Europe's earliest human culture, the Aurignacian."

This isn't the first time archaeologists have visited the site, known as Abri Blanchard, which is located in France's Vézère Valley. When the site was first excavated in 1927, archaeologists found 15 limestone blocks that were either engraved, pierced or both, the researchers said. (In this context, "engraved" means that a sharp point was dragged "across a surface, creating a continuous line," the researchers wrote in the study.)

In 2014, White and his colleagues journeyed to the valley to reexamine the site. The new discovery took them completely by surprise, they said. By looking at black-and-white photos taken during the 1927 excavation, it appears that the newfound tablets had already been unearthed, but no one had studied them at the time, the researchers said. During the recent excavation, the researchers rediscovered the tablets at the site, including an additional one that they excavated during the project, they said.

One of the blocks had been prehistorically broken in half, but the other 15 were preserved well enough for the researchers to study them, they said. Many of the engraved marks are rudimentary and challenging to interpret, but the team was able to determine which animals were modeled on each, the researchers added.

The newfound blocks are currently housed at the French National Museum of Prehistory in Dordogne, in southwestern France.

The new findings are similar to earlier, isolated discoveries in France. For instance, researchers found another pointillist creation depicting a rhinoceros at the Grotte Chauvet in France. However, unlike the newly discovered blocks, the ancient people at that site created the rhinoceros image by painting the palm of their hand and then transferring it to a cave wall, the researchers said.

Earlier this year, White's team reported the discovery of a 38,000-year-old pointillist image of an aurochs. This aurochs is the earliest graphic imagery known to exist in Western Eurasia, and sheds light on the complex nature of the early humans who made the imagery, the researchers said.

The new study was published online today (Feb. 24) in the journal Quaternary International.

Original article on Live Science.

A bulldozer operator at a sand pit in northwestern Oklahoma got quite a surprise this month when he spotted a huge skull that belonged to a Columbian mammoth.

These giants were plentiful across the plains of Oklahoma during the Pleistocene epoch, which lasted from about 1.8 million to 11,700 years ago, said Leland Bement of the Oklahoma Archaeological Survey.

The discovery was not unheard of, as the Survey typically receives about three "mammoth-sighting" calls a year, Bement said. That made it now less exciting, though. "Archaeological fieldwork is always exciting. You never know what you are going to find," Bement told Live Science in an email.

He added, "When it comes to mammoth finds, we are always on the lookout for the next one that has projectile points or stone tools associated with it to indicate that the animal was killed and butchered. We have so few of these sites across North America and only one so far in Oklahoma." [Photos: A 40,000-Year-Old Mammoth Autopsy]

The skull had been deposited on the sandbar of a river channel, the archaeologists said. So far, the archaeologists have unearthed the animal's skull with a single tooth in place; apparently, another tooth had been removed from the skull during the clearing of the sand.

"We don't know the cause of death. There is no sign that people killed or butchered it," Bement told Live Science in an email. "Its skull was washed around in the river. The rest of the animal could be anywhere."

Though the scientists have not pinpointed an exact age for the skull, they know it’s more than 11,000 years old — the period when mammoths and other megafauna went extinct at the end of the Pleistocene.

Scientists have put forth several reasons for the extinctions, ranging from rapid climate warming to ice age human hunters. Others have suggested a perfect storm of culprits. One group of dwarf mammoths is thought to have survived in the Arctic, on Wrangel Island, until about 3,700 years ago.

Like other Columbian mammoths (Mammuthus columbi), this one was not the cold-adapted type and preferred more temperate stomping grounds in southern and central North America. The woolly mammoth (Mammuthus primigenius), the kind portrayed in the "Ice Age" movies, would have called the chilly tundra home.

The Columbian variety was also much larger than the woollies, with Columbian males reaching up to twice the size of woolly males, according to Hendrik Poinar, an evolutionary geneticist at McMaster University in Hamilton, Canada. Columbian mammoths also arrived in North America about 1.5 million years ago, whereas woolly mammoths stepped onto the continent some 400,000 years ago, said Poinar, who spoke with Live Science in 2011.

Finding mammoth bones, while a mammoth discovery, seems relatively common across the United States. This past January, a construction crew discovered the femur of a mammoth (possibly a Columbian mammoth) under the Oregon State University's football field. Last September, two Michigan farmers found a mammoth's skull and tusks while they were installing a drainage pipe. And, in October 2014, a volunteer "paleontologist" unearthed the skeleton of a mammoth on the banks of a reservoir in Idaho. That skeleton dated back more than 72,000 years, said the scientists involved in the excavation.

Next, the researchers, including Oklahoma State University geographer Carlos Cordova, will analyze the mammoth teeth for particles from plants encased in tartar buildup, Bement said. "That will tell us what the mammoth was eating and also help in reconstructing the environment at the time he lived."

The findings will be included in a broader study, by doctoral student Tom Cox, of the distribution of mammoths in Oklahoma, he added.

Follow us @livescience, Facebook& Google+. Original article on Live Science.

Oregon State University might want to consider changing its mascot after a monumental find yesterday (Jan. 25): The discovery of bones belonging to an ice-age mammoth within throwing distance of the school's football field.

A construction crew working on an expansion and renovation of the OSU Beavers' Valley Football Center uncovered the remains of the beast while digging in the north end of Reser Stadium. They found a large femur bone — likely a mammoth's — as well as bones from other extinct, ice-age mammals, including a bison and what is either an ancient horse or a camel.

"There are quite a few bones, and dozens of pieces," Loren Davis, an associate professor of anthropology at OSU, said in a statement. "Some of the bones are not in very good shape, but some are actually quite well preserved." [Image Gallery: Stunning Mammoth Unearthed]

Davis and his students have yet to determine the mammoth's species — for instance, it could be a Columbian mammoth (Mammuthus columbi) or a woolly mammoth (M. primigenius), although the latter tended to live farther north.

Davis' team also plans to use radiocarbon dating to determine how long ago the mammoth lived. Radiocarbon dating can date once-living organisms back to about 50,000 years, although different methods can help date older organic material.

In Siberia, researchers recently found a 45,000-year-old mammoth carcass with injuries indicating that ancient humans had butchered it. But the newfound mammoth in Oregon bears no such injuries, suggesting that it died of natural causes, Davis said.

"They weren't hunted by people, that's clear," he said. "Animals who were sick would often go to a body of water and die there, so it’s not unusual to find a group of bones like this."

Perhaps when these animals died, at least 10,000 years ago, the area where the stadium now stands was a bog or marsh that served as a watering hole for ice-age animals, Davis said.

Construction workers found the animal bones in a 10-foot-deep (3 meters) plot. They stopped work as soon as they uncovered the femur, said Tim Sissel, the senior project manager of Hunt/Fortis, a joint venture and general contractor on the project.

However, because there were no human artifacts or remains found, the site is not considered an archaeological site, Davis said. So, he and his colleagues removed the dirt containing the bones, and construction on the stadium continued.

Now that he has the bones, Davis said he would soak them in water to thwart further deterioration. The members of the team will also continue to examine the pile of dirt that encased the bones to see whether they can find any more ice-age remains.

"It just goes to show that there's a whole world of the past that exists under the ground, and [it's] so neat that we could actually find it here at Reser stadium," Davis said. "As you're watching a football game, you can be thinking that beneath your foot lie the bodies of extinct animals that relate to the past."

Follow Laura Geggel on Twitter @LauraGeggel. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.