Nearly 70,000 years ago, modern humans created stunning rock art in an unexpected place: the tropical Indonesian island of Sulawesi. The finding, announced in January, made headlines for being the oldest known rock art in the world.

But the discovery's location also highlighted another surprising finding: that members of our species, Homo sapiens, were thriving in the tropics tens of thousands of years ago.

Researchers have long thought that early humans didn't live in tropical rainforests, as these places haven't yielded human fossils and are teeming with dangerous life, including venomous animals, poisonous plants and parasites that would deter early populations.

But that perspective has been changing over the past few decades. Sulawesi's ancient rock art is one of several clues that modern humans may have lived in tropical rainforests for hundreds of thousands of years. That would mean modern humans could have been living in these hot, wet regions since soon after the emergence of our species in Africa around 300,000 years ago.

Understanding how, when and where modern humans inhabited rainforests — and how that shaped our evolution — "may give us an insight into something about what it means to be uniquely human," Patrick Roberts, an archaeologist and anthropologist at the Max Planck Institute of Geoanthropology and author of the book "Jungle: How Tropical Forests Shaped World History" (Penguin, 2022), told Live Science.

From one origin story to many

Conventional wisdom held that modern humans emerged from one parent population in an East African savanna and did not encounter rainforests until around 12,000 years ago, after agriculture emerged to support survival in these climes. The lack of H. sapiens fossils from Africa's tropics appeared to support this view.

Then, in 2017, scientists identified the oldest modern-human fossils — except they weren't in East Africa, but rather in Jebel Irhoud, Morocco. The following year, Eleanor Scerri, an archaeological scientist at the Max Planck Institute of Geoanthropology in Germany, and her colleagues reviewed archaeological evidence, including the Jebel Irhoud fossils, and integrated it with genetic data from present-day populations. The evidence pointed toward H. sapiens originating from many subdivided populations across Africa.

These populations periodically met and exchanged genes and ideas, but they also spent long periods apart, adapting to different ecosystems and evolving diverse traits. In this new understanding, the earliest members of our species may have evolved not just in the grassy savanna but in tropical rainforests, too.

"One of the implications of the model is, if it's not one place and it's many places, then maybe it's not one ecosystem," Scerri told Live Science. "Maybe it's many ecosystems."

Because rainforests come with their own set of environmental pressures, people who lived there may have evolved traits to handle those challenges. When different early human populations came together, tropical rainforest dwellers would have contributed different gene variants than populations from open savannas. The ability to adapt to a variety of environments, including rainforests, may have come in handy later, when H. sapiens spread out of Africa and into tropical Southeast Asia, including places like Sulawesi.

But establishing what these traits were would first require evidence that humans lived in rainforests close to the dawn of our species.

Rainforests are terrible for fossil hunters

Unfortunately, the highly acidic soil in rainforests degrades organic material like bones. This makes evidence of ancient humans, such as fossils, or human activities, like bone arrows or potential woven fiber baskets, exceptionally rare in rainforests.

Even in the few instances this evidence is found, the conditions make it hard to date and contextualize it. Archaeologists often date early human fossils by measuring radioactive isotopes (versions of elements), such as carbon-14, in distinct, undisturbed layers of sediments — broken-down rocks and minerals that form via erosion and weathering. The more sediment layers there are, the longer the period of history that can be traced. But weather conditions in West and Central Africa's rainforests have left few long sediment sequences.

The lack of long sediment sequences also significantly reduces the odds of finding fossils at all, said Antonio Rosas, a paleobiologist at the National Museum of Natural Sciences in Spain who has been searching unsuccessfully for such fossils in Equatorial Guinean rainforests since 2014. "To be honest, I think I gave up the possibility of finding fossils properly," Rosas said.

Written in stone

As a result, many researchers studying early H. sapiens evolution have focused on a material that does preserve: stone.

In Africa, stone tools reveal humans were in coastal tropical forests in what is now Kenya roughly 78,000 years ago, the tropical rainforests of what is now Equatorial Guinea from around 45,000 years ago, and the rainforests of what is now the Democratic Republic of the Congo around 18,000 years ago.

Then, in 2025, researchers revealed that stone tools previously found in a tropical rainforest in the Ivory Coast in the 1980s were 150,000 years old. Because the area was also a tropical rainforest 150,000 years ago, this is evidence that our species inhabited rainforests "much earlier than previously thought," study first author Eslem Ben Arous, a geochronologist and archaeologist at the National Research Center on Human Evolution in Spain, told Live Science in an email.

The antiquity of these quartz tools — which were a mix of flakes and heavy-duty picks and choppers — show that early H. sapiens were capable of designing technology to survive in dense tropical forests. Dense forests weren't a barrier for early humans at that time, Ben Arous said.

Direct evidence

Although stone tools show ancient people were venturing into forests for food or living there part time, they don't prove humans lived there year-round. To do that, researchers still need fossils.

By analyzing the isotopes of elements found in human tooth enamel, researchers can reveal whether our distant relatives actually lived in rainforests. That's because closed, dense canopy rainforests have low levels of sunlight and high carbon dioxide, and the ratio of isotopes of elements in a person's teeth can reveal if they spent a lot of time in those conditions as a child.

Currently, zinc isotopes in two 46,000- to 63,000-year-old human teeth found in Tam Pà Ling cave in Laos are the oldest evidence of humans eating foods mainly from a tropical rainforest.

Similar evidence is currently lacking from African rainforests. But the ability to adapt to many different environments, including rainforests, and the capacity to develop highly specialized traits for such environments is "what's unique about our species," Roberts said.

Identifying adaptations

Early members of our species would have required certain adaptations to live in rainforests. So what were they?

Without preserved DNA or fossils, anthropologists guess by looking at contemporary populations living in the tropics. Many modern-day rainforest inhabitants are small, because it may help them cool off more easily, reduce their caloric needs, and make it easier to move in dense rainforests.

An analysis published in 2019 also found key differences in genes related to immunity and development in African rainforest hunter-gatherers compared with neighboring farmers. For example, the gene PITX1 — which codes for proteins crucial for limb development — is one of several genes that contributes to small stature and shows strong signs of positive selection in Gabonese hunger-gatherer populations.

There is evidence in multiple rainforest dwelling populations, including in those Gabon hunter-gatherers, of selection against specific pathogens.

Although early H. sapiens living in rainforests likely faced similar pressures, we don't have any evidence that similar adaptations evolved in these ancient members of our species.

Ancient DNA may be the key

But some scientists hope to someday find evidence of these adaptations in ancient DNA.

DNA preservation was historically considered impossible in hot and humid environments, but that assumption "turns out to be only partially true," Miklós Bálint, a functional environmental genomicist at the Senckenberg Biodiversity and Climate Research Centre in Germany, said in a statement.

Bálint and his colleagues recently reviewed ancient environmental DNA (aeDNA) recovered from tropical environments. They found 113 studies reported aeDNA in tropical and subtropical habitats between 1998 and 2025, including 1 million-year-old aeDNA extracted from a lake in Indonesia. This DNA came mainly from nearby plants, not from ancient humans. But because people leave "millions of DNA traces" in their environment during their lifetime, human DNA should also be present and retrievable, Bálint said in the statement.

"Obtaining DNA data will be a truly fundamental breakthrough in tropical forest research," Ben Arous said. For example, these genetic remnants peppered throughout the environment could reveal how humans changed the ecosystem, how they moved and interbred, and which diseases and parasites ancient people faced.

The new discoveries point to the need for more archaeological research in rainforest environments, Scerri said. Current efforts in Benin appear "really, really promising," Scerri said, and she and her team are also working on projects in Guinea, Ghana and Senegal, which are also yielding clues to ancient human habitation. "We're making some incredible finds," she said.

"There is enough evidence now to justify investigating areas that used to be well off the human origins map, considered to be very far from the main stage of human evolution," Scerri said.

The question now is how much further back in time people were living in rainforests and using their resources. "We consider ourselves to really be scratching the surface," Scerri said.

Human evolution quiz: What do you know about Homo sapiens?

Imagine a creature nearly twice the size of a modern African elephant (which can weigh up to 6,000kg [13,000 lbs]). This was Elephas (Paleoxodon) recki, a prehistoric titan that roamed the landscape of what is now Tanzania nearly two million years ago. Now, imagine a group of our ancestors standing over its carcass, then butchering it and eating it.

For decades, archaeologists have debated when the hominin ancestors of humans first started eating megafauna — animals weighing more than 1,000kg [2,200 pounds].

In a new study, our team of archaeologists studying the evolution of the earliest humans in Africa has identified one of the earliest cases of elephant butchery.

This was at Olduvai Gorge in Tanzania, a site famous for containing some of the oldest and best preserved remains of our human ancestors. Dating back to 1.80 million years ago, this discovery at the site known as EAK reveals that our ancestors were engaging with megafauna substantially earlier than previously thought (about 1.5 million years ago was the previous estimate at Olduvai), and in a more sophisticated way.

This finding suggests that hominins (most likely, Homo erectus) may have been living in large social groups at this period, probably because their brains were developing and demanding higher-calorie diets rich in fatty acids.

"Smoking guns"

Part of the reason our ancient diet has been debated is that it is not easy to find evidence of how much animal food early humans were eating and how they were acquiring it.

In traditional archaeology, the "smoking gun" for butchery (cutting up carcasses) is a cut mark left on a bone by a stone tool. However, when dealing with big animals like elephants, these marks are difficult to find. An elephant's skin is several centimeters thick, and its muscle mass is so vast that a butcher's tool might never touch the bone. Furthermore, millions of years of burial can weather the bone surface, erasing any subtle traces. And if a bone is deposited in an abrasive sediment, trampling by other animals may generate marks on bones that look like cut marks.

At the EAK site, we found the partial skeleton of a single Elephas recki individual in the same place as Oldowan stone tools. But to prove that this wasn't just a natural death or the work of scavengers, we couldn't rely on bone marks. Instead, we turned to a new kind of detective work: spatial taphonomy. This is the study of how stone artefacts and bones occur spatially on the same site. We also turned to more direct evidence: bones from those fossilized elephants that had been splintered while they were fresh ("green breaks").

The geometry of a carcass

To solve this 1.8-million-year-old mystery, we analyzed the way the bones were scattered across the site. Every agent that interacts with a carcass — whether it’s a pride of lions, a group of hyenas, or a band of humans — leaves a unique "spatial fingerprint". Lions and hyenas tend to drag bones away, scattering them in predictable patterns based on their weight and the amount of attached meat. Natural deaths, like an elephant dying in a swamp, result in a different, more localised skeletal "collapse".

By using advanced spatial statistics, and later comparing the EAK site to several modern elephant carcasses that we studied in Botswana (not yet published), we found that the spatial configuration at EAK was unique. The clustering of the bones and the density of the stone tools among them did not match the "random" or "scavenger-driven" models. Instead, it reflected a focused, high-intensity processing event. The spatial signature was a match for hominin butchery, which has also been documented at Olduvai sites that are half a million years younger.

This was confirmed by the presence of green-broken long bones not just at EAK, but in several locations in the landscape where other elephant and hippopotamus carcasses were butchered. Today, only humans can break elephant long bone shafts; not even spotted hyenas, which have very powerful jaws, can do it.

Glimpses of this behavior can be detected at other sites too. For example, a cut-marked bone fragment of a large animal (probably a hippopotamus) was documented at El-Kherba (Algeria) dated to 1.78 million years ago.

This intensive and repeated discovery of multiple elephant and hippopotamus carcasses butchered at different landscape locations indicates that humans were butchering the remains of large animals, whether hunted or scavenged.

Why does an elephant meal matter?

This discovery isn't just about a prehistoric menu; it's about the evolution of the human brain and social structure. There is a long-standing theory in paleoanthropology called the "expensive tissue hypothesis". It suggests that as our ancestors’ brains grew larger, they required a massive increase in high-quality calories, specifically fat and protein. Large mammals like elephants are essentially giant "packages" of these calories. Processing even a single elephant provides a caloric windfall that could sustain a group for weeks.

Butchering an elephant is a monumental task, however. It requires sharp stone tools and, most importantly, social cooperation. Our ancestors had to work together to defend the carcass from predators like saber-toothed cats and giant hyenas, while others worked to extract the meat and marrow.

This suggests that even 1.8 million years ago, our ancestors already possessed a level of social organization and environmental awareness that was truly "human".

The discovery also has another dimension. Humans at that time, like modern carnivores, consumed animals whose size was related to their own group size. Small prides of lions eat wildebeests; larger prides eat buffalo and in some places even juvenile elephants. The evidence that those early humans were exploiting large animals comes in parallel with evidence that they were living in much larger sites than before, probably reflecting bigger group sizes.

Why early humans started living in large groups at that time remains to be explained, but this indicates that they certainly needed more food.

A shift in the ecosystem

The EAK site also tells us about the environment. By analyzing the tiny fossils of plants and microscopic animals found in the same soil layers, we reconstructed a landscape that was transitioning from a lush, wooded lake margin to a more open, grassy savanna. Our ancestors were already eating smaller game. There is evidence that two million years ago, they were hunting small and medium-sized animals (like gazelles and waterbucks). A little earlier, they began using technology (stone tools) to bypass their biological limitations.

The evidence from Olduvai Gorge shows that our ancestors were remarkably adaptable, capable of thriving in changing climates by developing new behaviours.

As we look at the spatial layout of these ancient remains, we aren't just looking at the bones of an extinct elephant. We are looking at the traces of a pivotal moment in our own history — when a small group of hominins looked at a giant and saw not just a threat, but a key to their survival.

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

Editor's note: This story was updated at 12:49 p.m. ET on April 13 to change hominids to hominins in the strapline. Hominins are a group that includes humans and our most closely related relatives.

What do you know about elephants? Test your knowledge with our elephant quiz!

Humans have evolved the ability to live anywhere on Earth, thanks to gradual changes to our biology and our knack for developing new technologies, like clothes and shelter. This adaptability is often touted as being unique to our species, Homo sapiens.

In his new book, "Adaptable: How Your Unique Body Really Works and Why Our Biology Unites Us" (Penguin Random House, 2025), Herman Pontzer, a professor of evolutionary anthropology and global health at Duke University, explores how local environments work in tandem with genetics to produce the full spectrum of diversity we see in people today.

The book journeys through the human body and focuses just as much on what connects us as it does on the conditions required for differences to arise. Pontzer weaves in his work with contemporary hunter-gatherer populations, like the Hadza in Tanzania, to explore the lifestyles of pre-farming cultures and how the stark departure from these ways of life for many people today is making us sick.

"Adaptable" is a finalist for the PEN/E.O. Wilson Literary Science Writing Award, which celebrates excellence in nonfiction in the physical or biological sciences. The winner will be announced March 31 at the Literary Awards Ceremony and will receive a $10,000 cash prize.

Live Science spoke with Pontzer about his book and why understanding why and how diversity occurs is essential for questioning and challenging scientific misinformation.

Sophie Berdugo: Why did you decide to write the book now?

Herman Pontzer: In having conversations about "Burn" [Pontzer's book on the science of the metabolism (Penguin, 2022)], it became very clear to me that when you move outside of the ivory tower and start having these conversations more broadly, that there's just a lot of misunderstanding and misinformation about just how the body works in general. It's not just our metabolism. The metabolism is one of those blackbox things that we love to blame everything on and people don't really understand what it means or how it works.

SB: What is your favorite fact about the human body that you feel is completely underappreciated?

HP: I mean, where to start? Your kidneys. Kidneys are the forgotten essential workers of the body. And I could start anywhere, but let's start there ‪—‬ because if I say brains or hearts, people go, "Yeah, those are important; we know that."

Your kidneys, man: 180 liters [47.5 gallons] of water a day [are] filtered through your kidneys. All of the detox stuff that you think you're doing with the supplements you're taking, they're [your kidneys are] doing it for free and better. Somehow our bodies have learned to regulate water in a way that's different from the other apes, because we evolved in a dry environment. So, it's the interplay of water balance across our whole systems.

Spleens ‪—‬ let's do another unappreciated organ. Most people don't even know what their spleen does, I think. But among others, it's an immune function organ. Your spleen is this reservoir for red blood cells. And so, whether you're at altitude and you need a little bit more oxygen, your spleen gets bigger to be this bigger red blood cell reservoir for that.

There's this fascinating population called the Sama in the Philippines. They spend their lives on boats and in the ocean, and they forage underwater. And so there's been local adaptations, local evolution to give them bigger spleens [to have more blood oxygen when holding their breath for long periods under water when diving for food]. The alleles, the gene variants, that give them bigger spleens have become more common, and now people there have bigger spleens, on average, than everybody else.

Literally everywhere you look in the body, there's a story that I bet you haven't heard of.

SB: That case of the spleen being enlarged in this population in the Philippines is a great example of a local adaptation. Could you explain how these local adaptations occur?

HP: To talk about those local adaptations becomes a little bit tricky because they do happen, right? Certain populations do have a trait that gets more common there, or bigger or smaller, whatever it is. Natural selection can shape a trait in a population, but it's actually pretty rare because the conditions have to be just right.

So how do we do it? Local adaptation is just like any other kind of evolutionary adaptation. The reason a certain trait becomes common in a place is because it helps individuals there survive and reproduce. And that could be anything from being the right body shape and size to having a bigger spleen that helps you forage underwater. Anything that helps you survive and reproduce could end up as a local adaptation.

But the important thing here for why we see these localized events happening — and what makes them different from things that affect our whole species — is that it really has to be localized to a specific environment. It can't be that if the same trait is good everywhere, then that trait's going to spread because there's so much interbreeding, gene flow as we call it, that eventually if it's a good trait everywhere, it'll get everywhere.

So it has to be just good there. There has to be something about that trait that makes it really helpful right there but not other places. And that has to persist for generations and generations so that there's enough time for selection, because natural selection acts very slowly over generations. So it has to be good for survival and reproduction, has to be very localized and persistent for generations and generations.

Very few selection pressures meet all those criteria. Skin color is a good example of one that does ‪—‬ the best skin color to have in terms of ultraviolet light production. The darker your skin, the more protected you are against ultraviolet light damage versus having lighter skin if you need to be able to make more vitamin D, because that's the trade-off.

Those conditions have been around since the sun and the Earth have been where they are. There's always been more ultraviolet light at the equator and less towards the poles, and so that gradient has been really consistent. And then we see, surprisingly, a really consistent gradient in local populations' skin tone, how much melanin they make and, therefore, how dark their skin is.

[Then there are] things like high-altitude adaptations. The Himalayas have been thousands of meters tall since forever basically, for our purposes. And so humans living there have always had that selection pressure to be able to handle high altitude. And so you see altitude adaptations there. That's the kind of stories we see with local adaptation.

Where we get into trouble is when people talk about local adaptations with things like heart disease. There's been the argument in the '90s that Black Americans might be more likely to have heart disease because there's some localized set of alleles that affects their heart function that makes them more likely to develop hypertension and heart disease. Well, that doesn't make a lot of sense, because the selection pressures on the heart have been kind of the same for our whole species forever.

Same with all these ridiculous and really dangerous things about IQ evolution in different populations. Having a smart brain has been selected for — it's been a good idea — for our whole species since forever. And so any traits that make us have smarter brains are going to be selected for equally everywhere. Gene flow is going to push them all around.

SB: So hypothetically, if I was born with the same genetics but in the Philippines, like your earlier example, instead of the U.K., would the environment override the genetic hand I've been dealt?

HP: The way I try to talk about genetics in my classes and in the book is, your genetics — the hand you're dealt — kind of gives you a universe of possibilities where you could end up. Now, it's not unlimited. There's nothing that you could ever do to me that would have made me 8 feet [2.4 meters] tall, right? My parents could have given me all the best nutrition. I was never going to be 8 feet tall, or even 7 feet [2.1 m] tall, for that matter. So there are limits.

So I don't think of it as overriding. I think whether nature or nurture is what you see emerging more, it's almost always nurture. The environment usually has a much, much larger effect. But they really work together.

SB: What role does epigenetics play in shaping how you develop over developmental time, rather than evolutionary time?

HP: It's a wonderful example of nature and nurture working together because epigenetics is the environmental effects on your body that actually sort of change the way that your genes act for the rest of your life. An environmental experience, a stress, can affect the body in a way that it actually affects the genome, which affects your DNA so that a particular gene might be turned off or actually amplified. It can have different effects for the rest of your life.

But what's really interesting about epigenetics is this possibility that those changes might persist across generations. And so we know this is true in mice, that the epigenetic effects on the genome that we see within a lifetime are somehow transmitted to the offspring and they will have those same epigenetic effects. So the environment experienced by mom as she's growing up could actually affect her offspring when they're born and for their lives.

We have some interesting hints that it's also happening in humans. It's a really exciting space to watch in biology. I don't think we have the full answer yet for humans; it's just so hard to do the work because you're talking about studies that take decades, basically. But it's an exciting new frontier in the sort of nature-nurture interface.

SB: Would you mind explaining what evolutionary mismatches are, and why they're important?

HP: Our species evolved as hunter-gatherers. And so that environment's been the norm for humans for millions of years actually, even before we were Homo sapiens. Being a hunter-gatherer looks different depending on where you are in the world and what time frame we're talking about, but it always involves a lot of physical activity. It always involves foods that you're getting from the wild environment around you. It generally involves a fair amount of pathogens and stuff — the world's dirty out there in the wild. And so they're the kind of environments that our bodies are evolved to be best at because that's what shaped us.

Our environments today are so different from that, and that's the mismatch. The environment that I'm living in right now —‬ my house is climate controlled; I've got thousands of calories of food in the refrigerator; if I don't want to walk around too much today, I don't have to. I've got all sorts of antibacterial soaps and antibiotics if I need them.

Our environments have shifted so much that we're well outside the kind of micro-adjustments our bodies are used to making over a lifetime. And so our physiologies respond in ways that can be bad ‪—‬ so, heart disease, allergies, all sorts of modern ailments that we know didn't used to be common but are common now because of that mismatch.

SB: You mentioned how you see the human body as an anthropologist. You talk throughout the book about the Hadza and other contemporary hunter-gatherer populations. What can we learn about local adaptations from these populations?

HP: We are an incredibly diverse species. Our ability to adapt to our different environments and the cultural adaptations we see, the biological — that's our superpower. That's why there's 9 billion of us and not 9 billion of some other primate. We are as successful as we are because of this adaptability, this flexibility. And what that means is that if we only look to our own population, if I only did this book pulling what we could understand from my fellow Americans, it would be an impoverished book. There would be less to say, and we'd learn less about our bodies and ourselves because we wouldn't have the full extent of human diversity to pull from and learn from.

SB: Your book covers a lot of ground. What do you hope readers take away from it?

HP: More than anything, I hope it gives them the tool set to engage because they're going to put that book down, and the next day they're going to read the paper or be online, and they're going to see some new study about the brain or about diet or they're going to hear some headline about vaccines. And I want people to have a tool set to digest that, make sense of it, and ask the right questions about how we interpret all of this and move forward.

SB: What are those key questions that you hope readers will start to ask?

HP: First of all, to understand that diversity is multilayered. And so, just because I know the color of your skin, it doesn't mean I know anything else about you. I can understand something about that and why people's skin might be darker or lighter and understand that that's a separate question completely from hearts and heart health, or intelligence or anything, really. All these systems develop independently. So, when we think about diversity, we need to move away from the categories that we're taught and [away from] putting everybody in a bucket, and understand this is multilayered. It's true for yourself; it's true for everybody else.

Science has done a lot of work in the past couple hundred years, at least, on the human body to develop some really important consensus ideas around health. We know what kinds of diets keep us healthy. We know that vaccines keep us healthy. We can understand these things and move forward, comfortable in that knowledge. So the debates, for example, around vaccination, I think, are hurtful because we actually have been debating vaccines for 300 years at least, and the evidence is really clear that they're one of the biggest public health victories ever.

So both the kind of concrete details like that, but also the kind of mental tool kit to how we understand diversity. I think those are two different things to walk away with.

Editor's note: This interview has been condensed and edited for clarity.

When the Spanish first reached the Andes, they found something surprising: Many of the locals had long, pointy heads. They discovered that the Collagua, an indigenous group in Peru that was conquered by the Inca, had a practice of shaping the head starting in infancy, before the skull bones fused and soft spots disappeared.

The Spanish jumped to the worst conclusions.

"They said it was this horrible thing and brains bled out of ears," Christina Torres, a bioarchaeologist at the University of California, Riverside, told Live Science. "But that doesn't seem to be the case."

Prehispanic Indigenous groups were not the only ones to practice head shaping. For centuries, archaeologists have found skulls on every continent except Antarctica that show evidence of "cranial vault modification" — heads shaped to be either flatter or more conical than they would be if left alone.

Given that babies cannot bind their own heads, experts think head shaping was done by caregivers. Now, archaeologists are beginning to uncover clues about why people performed this practice for millennia, particularly in places like the Andes, where the practice has been documented the best.

Through systematic analysis, what experts are uncovering is a profusion of practices and explanations, some of which are baffling or contradictory. In some places, a shaped head may be a marker of group status, while in other places, head shapes differ even among close family members. And in other places, the feature used to identify it — the unusual head shape — may not even have been the intent of the practice, researchers are finding.

"Something as ostensibly shocking as cranial modification may have been almost a routine practice for some children in some time periods," Matthew Velasco, a bioarchaeologist at the University of North Carolina at Chapel Hill who studies head shaping in the Peruvian Andes, told Live Science.

What's more, it likely originated very deep in human history — and emerged in many times and places, Velasco said. "I think we have to start from the assumption that the meaning varies across time and space."

How are heads shaped?

Bone remodels easily when children are young, so a simple strip of wrapped cloth can control how the head grows, much like how a bonsai tree can be shaped and pruned, Torres said. For example, nowadays, babies with plagiocephaly — a flat spot caused by sleeping in one position — are often prescribed helmet therapy to change their head shape.

Experts have identified more than two dozen apparatuses that were used to create different head shapes, but "the most typical method would be just wrapping the baby's head circumferentially and making a longer, more conical shape," Torres explained, as this technique requires the least equipment and the least training.

Based on historical records from groups that practiced it, head wrapping began by around 6 months of age in most cultures and ended within a year or two, Tyler O'Brien, a forensic anthropologist at the University of Northern Iowa, wrote in "Boards and Cords" (Bloomsbury Publishing, 2024), a book about the worldwide history of cranial modification. The shaping was likely done by a mother or midwife.

There's not a lot of information, though, on whether this practice was painful, but it does not appear to have had any major consequences for brain development, Torres said.

"There's one instance where [bioarchaeologists] think a child died because of cranial modification, where the head was compressed too much," she said. "That is anomalous, as far as I can tell. This was a slow and gradual process done with fabric and pillows."

So, although Spanish explorers in the Andes said they were shocked by "brains coming out" and explorers in Borneo and Vanuatu said kids' eyes "bulged from their sockets," these subjective accounts are probably greatly exaggerated, O'Brien wrote. In reality, the child likely adapted quickly to any discomfort, and the brain would have conformed to the shape of the skull, resulting in no ill effects on cognition or intelligence.

If not done properly, however, head shaping that involved overly restrictive or infrequently changed bindings could cause infection. "I think the worst thing you could have is a [skin] ulcer that gets infected and then eats through the bone, which does happen," Christine Lee, a bioarchaeologist at the University of Mississippi, told Live Science. Scalp infections and temporomandibular joint (TMJ) issues also may have occurred, Torres said.

Archaeological evidence for head shaping

To identify a shaped head, archaeologists sometimes used visual inspection as well as human skull measurements, known as craniometry. Craniometry has been around since the 19th century, when American naturalist and eugenicist Samuel Morton used cranial traits to create racial hierarchies that have since been debunked.

Although there is no standardized, agreed-upon method to determine if a head has been shaped, archaeologists often use a 3D, mathematical analysis of cranial measurements to see whether the ratio of certain measurements, such as the width, length and height of the skull, are outside the range of what is expected as part of natural variation and are thus likely to have been intentionally shaped.

That analysis suggests that head shaping is widespread in the archaeological record. Cranial modification has been found in skulls from Europe, the Near East, Africa, Asia and Oceania, and it is most strongly associated with the Americas. But that doesn't necessarily mean it was more common there; rather, evidence of shaped heads may have been better preserved in the Andes, where the cool, dry conditions did not degrade mummified remains as quickly, Velasco said.

In fact, the oldest archaeological evidence of head shaping comes from Australia. Two artificially flattened skulls were discovered in the southern state of Victoria at the site of Kow Swamp, which is at least 13,000 years old.

And ancient skulls reveal the practice boomed in the Neolithic period, appearing in Europe around 12,500 years ago, in China around 11,000 years ago, and in what is now Iran around 10,000 years ago, according to O'Brien.

Early accounts

Some of the earliest explanations for head shaping, which come largely from Spanish explorers in the Americas, are some of the most suspect. That's because few explorers bothered to ask practitioners why they engaged in head shaping. Instead, these wild stories were often based on rumor or hearsay.

For instance, Christopher Columbus first reported head shaping among the Indigenous people of Hispaniola, the island that encompasses the Dominican Republic and Haiti, in 1492. He illogically guessed that the islanders had flat heads because their mothers pressed them tightly between two wooden planks, causing the skull bones to thicken like helmets and protect them from Spanish blows, according to Pilar Zabala Aguirre, an anthropologist at the Autonomous University of Yucatán in Mexico, who has compiled more than 100 Spanish historical records on the practice.

Other explorers invented different possible explanations: ethnic grouping; high military rank; attributes such as courage, bravery or obedience; the ability to carry heavier loads strapped around the forehead; health improvements; and beauty ideals, Zabala found.

These explanations are even more suspect because they were often tied to racism or beliefs in the superiority of Western culture or even used to explicitly make that argument.

For instance, English physician John Bulwer cataloged various types of body modification in his 1650 book "Anthropometamorphosis," condemning them as disfiguring and an affront to God, according to O'Brien.

It wasn't until the early 20th century that anthropologists moved away from "studying abnormal head shape in the living 'other' and describing it as hideous, frightful, and disgusting," O'Brien wrote, and toward a less-biased understanding of cranial variation.

Changing understanding of the practice

Using those robust, less biased methods, archaeologists are gradually unwrapping some of the mystery surrounding the practice, mostly in the Americas. And what they're finding is not an overarching trend, but a range of reasons and practices.

For instance, the Collagua in Peru ostensibly "told the Spanish that they shaped the heads of their children like the mountain from which they come," Velasco said.

Among the Indigenous Caddo people of Oklahoma, meanwhile, different kinds of shaping reflected membership in different clans, Lee said.

Yet head shaping differed not only within cultures but even within families. Velasco's ongoing research, which involves analyzing the DNA of extended families buried together in the Andes, has revealed that the heads of biologically linked people were often shaped in different ways — so one family member might have an elongated head, while another might have an unmodified, rounded head.

In fact, in some cultures or families, the shapes of the heads may have been the unintended result, rather than the goal, of a practice that was more important to them, such as binding.

"The shape itself might actually be collateral to the practice" in the Andes, Torres said.

Instead, in some parts of the Americas, head shaping may have lingered simply as a tradition. For instance, in the Andes, the practice may be part of a rite of passage for either the infant or the mother, Torres said. If head shaping began around 6 months of age, that is a time when the baby's first teeth were coming in and weaning foods may have been introduced. There, head shaping may be similar to putting jewelry on a child or baptizing them to protect them, she said.

Among the pre-hispanic people of the Andes, "it's basically a child-rearing practice," Torres said. "In the same way that some people swaddle their children, the same way that there's religious circumcision, you bind the heads of your children because that is what we do to our children."

A natural conclusion

In fact, the idea of shaping a head into a conical form may have been presented by birth itself. The infant cranium naturally deforms when it passes through the birth canal, Velasco said.

"When my child was born, for example, he had a slightly conical head," he said. "Birthing presents this possibility to every parent, and it doesn't take much of a leap to feel the supple head of a child and to wrap it, to clothe it."

Thus, it's not surprising that many cultures might have stumbled upon head shaping, given that "anyone who has observed or assisted a human birth will recognize that the human head is malleable," Velasco added.

This recognition of the plasticity of a baby's head may have spurred a need to protect it. For example, among the Maya, modifying an infant's head was likened to putting a roof on a house and was thought to protect the child.

That protection may have then become more metaphorical than physical. In some places, it has "an almost talismanic aspect to it," Lee said, as if something bad might happen to the child if the shaping were not done. "That implies there must be almost a fear of not doing it."

Beauty and 'in-group' status

Outside the Americas, few historical records describe head shaping, but "it seems to have been independently invented in multiple places," Torres said.

Each of these places may have had different justifications for the practice. In prehistoric China and Japan, for instance, head shaping was likely a status marker tied to the elite. Lee thinks it's likely that in ancient Asia, head shaping — similar to foot binding in more recent times — represented an extreme way of achieving a beauty standard.

Similarly, during the fourth to seventh centuries in Europe, head shaping surged in popularity among the Huns, skeletons reveal. Without historical evidence from the Huns detailing the reason for this practice, experts have conjectured that it was a "fashion wave" in the Eurasian steppe that conferred higher social status.

But head shaping often leaves subtle traces, meaning people who engaged in the practice may not have looked much different from those who didn't. That suggests the practice was not necessarily a striking visual marker of in-group status, which raises questions about whether that was its purpose.

"Hair hides a lot," Lee said. "There are people today with unusually shaped skulls, and it just doesn't show depending on their haircut." For example, venture capitalist Marc Andreessen and political consultant Roger Stone both have (presumably naturally) pointier-than-average heads.

Modern cases of head shaping

Although cranial vault modification has been going on for tens of thousands of years, it persisted well into the 20th century in parts of Africa, Oceania and Europe.

The Arawe people in Papua New Guinea practiced head shaping as late as the 1930s, according to a study of several villages in 1955. The Arawe used bark-cloth bandages to create what they considered an aesthetically pleasing "long-headed" style.

Among the Mangbetu people of the Congo, the practice of "lipombo" involved tightly wrapping an infant's head with cloth bandages to encourage a long, conical shape thought to be beautiful and powerful. The Belgian colonial government outlawed the practice, which died out in the 1950s.

And in early 20th-century France, some parents chose to band their newborns' heads immediately after birth for up to four years in a practice called "bandeau," which practitioners thought protected babies from injury. The "Toulouse deformity," named after the region where it was practiced, has been captured in a series of historical photos, but bandeau declined in popularity and disappeared by World War I.

"This is not something that is simply a brute barbarian practice that people evolved out of," Velasco said. "It is fairly independent of social complexity."

The practice of shaping an infant's head to look like an "alien's" may seem foreign or bizarre to us in the 21st century. But the human body has long been a canvas for cultural, spiritual and personal expression.

The earliest known tattoos date back at least 5,000 years in Copper Age Europe, tooth filing and "grills" go back 2,000 years to the Maya, and neck elongation was practiced 1,000 years ago in Southeast Asia. Today, we tend to modify the soft tissues of our bodies through common practices like ear piercing and circumcision, but also more uncommon procedures like horn implants, eyeball tattooing and Brazilian butt lifts.

"Cranial modification is part of a practice that is universal: body modification and presentation," Velasco said. "We all invest our future in our children in different ways. That's how I think about cranial modification. It's like an investment in the future of a child. And when you put it in that way, it's hard not to relate to it."

Three Homo erectus skulls previously unearthed in China are almost 1.8 million years old, around 600,000 years older than originally thought, a new study finds.

This revelation has made the Yunxian skulls from Hubei province the oldest evidence of our early human relatives, known as hominins, in East Asia, according to research published Wednesday (Feb. 18) in the journal Science Advances.

Study co-author Christopher Bae, a professor of anthropology at the University of Hawaii at Manoa, told Live Science in an email that he felt "absolute surprise" when he first saw the results of the analysis. This more ancient age may force experts to rethink the date that H. erectus first emerged, which is believed to have occurred around 2 million years ago in Africa.

"What this means is that we need to consider pushing the origin of Homo erectus back" to around 2.6 million years ago, Bae said in an email.

H. erectus has long been considered the first human relative to leave Africa, with 1.78 million to 1.85 million-year-old fossils found at the Dmanisi site in Georgia being the earliest evidence of humans in Asia. But stone tools discovered at two sites in China dated to 2.1 million and 2.43 million years ago have complicated that picture, since they predate experts' theory of when H. erectus originated.

The exact date of the three Yunxian skulls, which were found between 1989 and 2022, has long been debated, but they were previously considered to be around 1 million years old based on the age of animal teeth found close by, although one study dated them to around 1.1 million years ago using electron spin resonance and uranium-series dating. So when the opportunity arose to try a new dating technique at the site, Bae and his colleagues thought it was a good chance to revisit the debate.

Their team used a technique called cosmogenic nuclide burial dating to determine the age of the quartz found in the sediment layers where the skulls were found. This dating technique measures the half-life of two chemical variants — Aluminum-26 and Beryllium-10 — to determine how much time has passed since the quartz was exposed to cosmic rays.

This dating method revealed the hominin fossils were approximately 1.77 million years old, which is about 600,000 years older than the oldest age proposed for the site previously, Bae said.

Because the new date is younger than the stone tools discovered elsewhere in China, there is still a large time gap of around 600,000 years between the earliest fossil evidence and the earliest tool evidence, he added.

But since this date is close in time to the Dmanisi fossils in Georgia, the results suggest that H. erectus moved across Asia relatively quickly, Bae said. The size and shape of the Yunxian skulls, however, shows that these hominins had larger brains than those found in Dmanisi, despite being a relatively similar age. "This points to important variation in the early hominins outside of Africa," Karen Baab, a professor of anatomy at Midwestern University in Arizona who was not involved in the new study, told Live Science in an email.

Chris Stringer, a paleoanthropologist at the National History Museum in London who was not involved in the new study, told Live Science in an email that "it would indeed be remarkable" if the Yunxian skulls were nearly 1.8 million years old, but "placing Yunxian at such a great age would put it completely out of sync with the rest of the fossil record."

According to previous work by Stringer and his colleagues, the Yunxian fossils may belong to a group that gave rise to the Denisovans, which their model suggests emerged around 1.2 million years ago.

The new date for the Yunxian fossils, if correct, may also require experts to reconsider the origin of the ancestor to our own species, Homo sapiens, Stringer said. "I would suggest that further work on the dating of the site is certainly needed!"

Human origins quiz: How well do you know the story of humanity?

Paleoanthropologists have announced the world's most complete skeleton of Homo habilis, a human ancestor that lived more than 2 million years ago in northern Kenya. The collection of fossil bones has revealed unusually strong arms that distinguished H. habilis from later species.

The bones were initially found in 2012 by a team of researchers led by Meave Leakey, of the Turkana Basin Institute, and were subsequently announced in 2015 at a research conference. Now, the complete analysis of the remains has been described in a paper published Tuesday (Jan. 13) in the journal The Anatomical Record.

The skeleton, designated KNM-ER 64061, was found in geological layers dated to between 2.02 million and 2.06 million years ago. A complete set of lower teeth clearly identified the skeleton as H. habilis. The skeleton included the collarbones; pieces of the shoulder blades; all of the upper and lower arm bones; and fragments of a vertebra, a rib, an upper leg bone, and the pelvis, making it the most complete H. habilis skeleton ever recovered, as well as one of the oldest, the researchers noted in the study. (The oldest H. habilis skeleton on record is from Ethiopia and dates to 2.33 million years ago.)

"There are only three other very fragmentary and incomplete partial skeletons known for this important species," study lead author Fred Grine, a paleoanthropologist at Stony Brook University in New York, said in a statement. The find is significant because it represents both the most complete and the oldest partial skeleton of early Homo, the researchers wrote in the study.

H. habilis was a transitional species, in that it's the first named species to kick-start our genus after evolving from australopithecines — the lineage that includes the celebrity fossil skeleton "Lucy" — but was distinct from our much better understood ancestor Homo erectus, which spread around the world. Fossils from H. habilis are therefore key to understanding the adaptations of our early hominin ancestors. Hominins include modern humans and our extinct relatives.

A close analysis of the KNM-ER 64061 fossils revealed that the arm bones of H. habilis were similar to those of other early Homo specimens and to those of some australopithecines. For example, H. habilis had a longer forearm than did the later H. erectus and had heavy, thick arm bones more similar to those of australopithecines.

Based on the length of the humerus (the upper arm bone), the researchers determined that KNM-ER 64061 was a young adult who was about 5 feet, 3 inches (160 centimeters) tall. From the leg bone fragment, they estimated that the individual weighed only about 67.7 pounds (30.7 kilograms). These anatomical traits suggest that H. habilis retained upper-limb proportions similar to australopithecines' and was shorter and weighed less than H. erectus.

But those traits don't necessarily mean H. habilis could swing through the trees, according to the researchers. "The relatively long forearm of H. habilis may have enabled a greater degree of arboreal locomotion in this species than in H. erectus, but whether arboreality was indeed practiced by H. habilis must remain a matter of speculation," they wrote in the study.

"Homo habilis limbs have been coming more and more into focus," study co-author Ashley Hammond, a paleoanthropologist at the Catalan Institute of Paleontology Miquel Crusafont, said in the statement, and the new skeleton "confirms that the arms were fairly long and strong. What remains elusive is the lower limb build and proportions."

Only a few fragments of KNM-ER 64061's pelvis were recovered, but they suggest that this H. habilis individual may have walked more like H. erectus than like earlier australopithecines, the researchers noted in the study.

"Going forward, we need lower limb fossils of Homo habilis, which may further change our perspective on this key species," Hammond said in the statement.

The discovery of a surprisingly complete H. habilis skeleton may also help paleoanthropologists sort out the abundance of hominin groups that lived in eastern Africa between 2.2 million and 1.8 million years ago.

Researchers have found that up to four hominin species — Paranthropus boisei, H. habilis, Homo rudolfensis and probably H. erectus — lived in the same place around the same time. And because H. erectus appeared nearly 500,000 years before H. habilis disappeared from the fossil record, it is currently unclear whether H. habilis was the ancestor to H. erectus or a related species.

Human evolution quiz: What do you know about Homo sapiens?

Neanderthals have fascinated scientists since they were first discovered in the 19th century. Their long heads and low brow ridges initially convinced experts that Neanderthals were some kind of evolutionary wrong turn that ended up in European caves.

It took more than a century for researchers to prove that Neanderthals were actually quite intelligent and that they interbred with modern humans (Homo sapiens). The number of discoveries related to Neanderthals' biology and culture has skyrocketed in recent years — and 2025 was a noteworthy year. While we learned that Neanderthals had biological features that were strikingly different from modern humans', this year's discoveries also showed that some aspects of their behavior and culture were similar to ours.

Here are 10 major Neanderthal findings from 2025 — and what they teach us about our own evolution.

1. Neanderthals were the first to make fire.

The hottest — but also somewhat controversial — Neanderthal discovery of the year was that the first humans to make and control fire were Neanderthals living in England more than 400,000 years ago.

In December, researchers announced that they had found reddened clay and heat-shattered flint hand axes at an archaeological site in Suffolk. But the smoking gun was the discovery of tiny flakes of pyrite, a mineral that produces sparks when struck against flint.

Experts have debated for decades whether early human ancestors deliberately made fire or whether they opportunistically used wildfires that sprang up. The combination of flakes of pyrite and charred soil and tools points to Neanderthals' purposeful creation of fire.

The discovery, however, does not tell us whether Neanderthals invented this technology or they learned it from even earlier ancestors, such as Homo erectus. Regardless, the fire evidence shows that Neanderthals were smart enough to figure out how to survive in cold and dark European climates.

2. Neanderthals cannibalized women and children.

Around 45,000 years ago — very close to when Neanderthals disappeared forever — six members of a Neanderthal group were cannibalized, according to a study published in November. Their remains were discovered in the Goyet cave system in Belgium with butchery marks similar to those on animal bones.

This isn't the first time archaeologists have found evidence of cannibalism in Neanderthals. But it is the best evidence experts have to suggest one group — probably Neanderthals but possibly modern humans — deliberately targeted the women and children of another group, perhaps as a way to eliminate the group's reproductive potential.

3. A Neanderthal left the world's oldest fingerprint.

A curious-looking rock found in Spain contains the world's oldest known fingerprint, and it was probably made by a Neanderthal using ocher 43,000 years ago, researchers announced in May.

The team investigating the rock, which is the size of a large potato, thinks that it has face-like features and that the red dot may be a nose. If they're correct, it would mean Neanderthals were creating symbolic art, which could settle a decades-long debate in paleoanthropology.

Not all experts agree that the rock is an early version of Mr. Potato Head, but they do think the fingerprint and its characteristic whorl pattern represent a clear example of Neanderthals' use of red ocher pigment.

4. Neanderthals may have used "crayons."

Scientists in Crimea found three pointy chunks of red and yellow ocher that Neanderthals may have used as early "crayons" 100,000 years ago, according to research published in November.

The hunks of mineral appear to have been repeatedly sharpened, which suggested to the researchers that the ocher was used for culturally meaningful purposes rather than in practical tasks, such as tanning hides.

Although ocher has been found at other Neanderthal sites, not all experts are convinced of the crayon interpretation. Instead, they suggest Neanderthals may have scraped powder from the ocher chunks for another purpose, such as to leave a fingerprint.

5. Neanderthals were low-energy.

In July, researchers discovered that a key Neanderthal gene variant that is still found in some humans today could be detrimental to athletic performance because it limits the body's ability to produce energy during intense exercise.

Researchers found that the Neanderthal version of an enzyme called AMPD1 was different from the one in most modern humans. The Neanderthal enzyme variant allowed adenosine monophosphate (AMP) to build up in their muscles rather than being quickly removed. This AMP buildup is problematic because it makes it harder to produce adenosine triphosphate (ATP), a molecule that the body uses to store energy.

Modern humans who carry the Neanderthal variant of the gene have a lower probability of achieving elite athletic status, the researchers found. But while the Neanderthal variant may have affected their muscle metabolism slightly, it may not have contributed to their extinction.

6. Neanderthals were more susceptible to lead poisoning compared with humans.

In a study published in October, researchers examined 51 teeth from H. sapiens, Neanderthals and other ancestors for evidence of lead exposure. Lead occurs naturally in our environment, but it is known to be toxic at high levels, causing damage to the brain and other organs. Researchers discovered that human ancestors were affected by episodic lead exposure for nearly 2 million years — and that human brains may have evolved some protection against lead poisoning.

Humans living today have a unique version of a gene called NOVA1 that is important for brain development and language skills. The gene also appears to confer greater resistance to lead than other versions of the gene do, such as the one in our Neanderthal cousins.

Therefore, researchers propose, the modern-human version of NOVA1 may have given us a slight advantage over Neanderthals and may have contributed to the demise of the Neanderthals.

7. Neanderthals had a "fat factory" in Germany.

Neanderthals primarily ate meat (and maggots), which put them at risk of developing protein poisoning, a lethal condition that results from eating too much protein and too few fats and carbohydrates.

But in July, researchers announced their discovery of a "fat factory" that Neanderthals may have used to stave off this condition 125,000 years ago. Their survey of nearly 200 animal bones revealed that Neanderthals smashed the bones to get at the marrow inside, which they boiled to extract the fat.

Fat is high in calories, and Neanderthals may have saved it to eat during food shortages. This innovative food-collection method is similar to what some ancient modern-human foraging groups did, suggesting that, in at least one way, Neanderthals were similar to us.

8. Neanderthals lacked a key DNA-synthesizing gene.

In August, researchers investigating the enzyme adenylosuccinate lyase (ADSL) found that the version in Neanderthals was more active than the one in humans. ADSL helps synthesize purine, which is one of the fundamental building blocks of DNA, and an ADSL deficiency is known to result in intellectual disability in modern humans. So researchers modified mice to have a modern-human-like ADSL gene and found that they were better at completing a task to get water.

But even though ADSL deficiency can cause intellectual and behavioral problems in modern-day people, it's not yet clear whether the Neanderthal variant impaired them.

9. Our cousins suffered a population bottleneck.

Even before Neanderthals disappeared forever, their numbers were dwindling because of a population bottleneck, according to research published in February.

Scientists looked at the tiny inner-ear bones of Neanderthals from various time periods and noticed that, around 110,000 years ago, there was an abrupt decline in the diversity of bone shapes. This decline suggests a bottleneck event, when a species undergoes a sudden reduction in variation due to factors such as genocide or climate change.

While the ear bones alone didn't cause the Neanderthals' downfall, the bottleneck may have been the beginning of the end.

10. Neanderthals' blood may have doomed them.

Biologically, Neanderthals had distinct blood variants that separated them from modern humans — and two of those variants we learned about this year may have hastened our ancient cousins' extinction.

In January, researchers discovered that Neanderthals had a rare blood type that may have been fatal to their offspring when they mated with Denisovans or early H. sapiens.

Neanderthals carried a variation of the blood antigen Rh, which gives the positive and negative signs to blood types. Before modern medical interventions, if someone who was Rh-negative was pregnant with a fetus that was Rh-positive, it caused a miscarriage or stillbirth. The researchers found that, if a Neanderthal female mated with a H. sapiens or Denisovan male, there would have been a high risk of anemia, brain damage and infant death. And that might have spelled the end of the line for Neanderthals.

Another study published in October suggested that a fatal red blood cell incompatibility between Neanderthals and humans also contributed to our ancient cousins' extinction. Researchers focused on the PIEZO1 gene that affects oxygen transportation in red blood cells. Neanderthals' version of this gene essentially let their blood cells trap oxygen efficiently, while the modern-human version more efficiently released oxygen to tissues. When maternal oxygen isn't passed on to the fetus, it can restrict the growth of the fetus or lead to miscarriage. So, if a hybrid Neanderthal-human mother mated with a modern-human father or with a hybrid Neanderthal-human father, their offspring would be more likely to die than the offspring of non-hybrids.

Although Neanderthals' extinction likely did not hinge on any one specific gene variant, the new research into red blood cells and maternal-fetal incompatibility is providing key insight into the demise of our archaic cousins around 35,000 years ago.

Neanderthal quiz: How much do you know about our closest relatives?

Scientists have reconstructed the head of an ancient human relative from 1.5 million year-old fossilized bones and teeth. But the face staring back is complicating scientists' understanding of early human evolution and dispersal, according to a new study.

The rebuilt fossil skull, called DAN5, shares traits with Homo erectus, the first early human relatives to have modern body proportions and to disperse from Africa. But the skull also has some features associated with the earlier species Homo habilis. The findings suggest a complex evolutionary path from early human ancestors to H. erectus, researchers reported Dec. 16 in the journal Nature Communications.

DAN5 was discovered in the Gona study region of northern Ethiopia and was first reported in a 2020 study published in the journal Science Advances. The fossils are between 1.5 million and 1.6 million years old and were thought to belong to a small H. erectus female based on the shape and size of the skull.

"We already knew that the DAN5 fossil had a small brain, but this new reconstruction shows that the face is also more primitive than classic African Homo erectus of the same antiquity," study co-author Karen Baab, a paleontologist at Midwestern University in Arizona, said in a statement. This could mean that the population from the Gona region might have "retained the anatomy of the population that originally migrated out of Africa approximately 300,000 years earlier," she said.

To reconstruct DAN5's face, the researchers used micro-computerized tomographic (CT) scans of 10 fossils — five fragments of facial bones and five teeth — to build a 3D model. The process was like "a very complicated 3D puzzle, and one where you do not know the exact outcome in advance," Baab said. "Fortunately, we do know how faces fit together in general, so we were not starting from scratch."

The shape of DAN5's braincase was similar to that of H. erectus. But some of the facial features such as large molars and a flat and narrow nose were more similar to features in the older human ancestor H. habilis.

A similar mix of old and new traits was previously observed in 1.8 million-year-old H. erectus fossils from Dmanisi in the Republic of Georgia, which led some scientists to believe that the species evolved in Eurasia from an earlier Homo population. Older H. erectus fossils dating back 1.8 million years have also been found in Africa. But DAN5 is the first African fossil to have the same mixture of attributes as the Dmanisi hominins, which could support the hypothesis that H. erectus evolved primarily in Africa like other hominins before it. Further complicating the picture, though, is the fact that the DAN5 fossils are younger than those from Dmanisi, suggesting the mixture of old and new traits persisted in Africa for at least 300,000 years.

In future work, the team plans to compare the DAN5 fossils to 1 million-year-old human fossils from Europe, including some that have been identified as H. erectus and as Homo antecessor — a later human relative that lived 1.2 million to 0.8 million years ago — to better understand variability in face shape in the early Homo genus. The team also plans to investigate whether DAN5 might be a product of interbreeding between multiple Homo species.

"We're going to need several more fossils dated between one to two million years ago to sort this out," study co-author Michael Rogers, an anthropologist at Southern Connecticut State University, said in the statement.

Human evolution quiz: What do you know about Homo sapiens?

Our understanding of how our species evolved has improved dramatically since we first began analyzing ancient DNA. This year, researchers made impressive discoveries across 3 million years of human evolution, most of which relied on DNA, genomic or proteomic analyses.

Here are 10 major findings about human ancestors and our close ancient relatives that scientists announced in 2025.

1. Two new species of human relatives were discovered in Ethiopia.

A handful of teeth found at the Ledi-Geraru site in Ethiopia suggest that diverse species of human relatives unlike any seen before were roaming the area 2.6 million years ago.

In August, researchers announced the discovery of 13 teeth. Ten are estimated to be 2.63 million years old and don't belong to either Australopithecus afarensis or Australopithecus garhi, the two australopithecine species known from the area. Because the teeth don't have any especially unique features and aren't in a skull, the newfound species they may come from does not have an official name. Researchers are calling it the Ledi-Geraru Australopithecus.

In the same study, the researchers found two teeth that are 2.59 million years old and one that is 2.78 million years old. All of them seem to belong to the genus Homo, which would make them some of the earliest remains of our own genus.

The dental discoveries mean that at least three archaic human relatives were living in this region of Ethiopia around 2.5 million years ago.

2. Imported stone tools show our relatives were much smarter than we thought.

Hundreds of stone tools discovered in Kenya revealed that our ancient relatives had a high degree of forward planning 600,000 years earlier than experts previously thought.

In an August study, researchers looked at more than 400 stone tools from the site of Nyayanga dated to 3 million to 2.6 million years ago. The tools were likely not made by our genus. While the tools were fairly basic — flakes chipped off of a larger stone — the stones used to make them came from locations more than 6 miles (9.7 kilometers) away.

The fact that hominins were transporting stones from far away to make tools suggests an excellent ability to plan ahead, long before our genus Homo arose.

3. Earliest evidence of Homo erectus found in Georgia

In July, researchers announced the discovery of a 1.8 million-year-old jawbone from Homo erectus at the site of Orozmani in the Republic of Georgia. In 2022, the paleoanthropologists had found a single tooth that they thought was from H. erectus, and the jawbone discovered this year clinched the identification.

H. erectus was our direct ancestor and evolved around 2 million years ago in Africa. It was also the first human ancestor to leave Africa, and eventually ended up in parts of Europe, Asia and Oceania.

To date, the earliest evidence of H. erectus outside Africa comes from Orozmani and a second site in Georgia called Dmanisi, suggesting human ancestors settled in the Caucasus region shortly after leaving Africa.

4. A mystery human reached Indonesia 1.5 million years ago.

Stone tools discovered on the Indonesian island of Sulawesi this year suggest that either H. erectus or an unknown human relative reached Oceania nearly 1.5 million years ago. This matches up well with previous evidence that H. erectus arrived on the island of Java around 1.6 million years ago.

But because no ancient skeletal remains have been found on Sulawesi yet, researchers are unsure if the toolmaker was indeed H. erectus. Another candidate could be H. floresiensis, the diminutive "hobbit" species, which has been found on the neighboring island of Flores. Some researchers think the hobbits originally came from Sulawesi.

Additional excavation on Sulawesi may eventually clarify which species called the island home.

5. Humans arrived in Australia 60,000 years ago.

Genetic research published in November showed that Homo sapiens reached Australia 60,000 years ago, likely via two different routes through the Western Pacific. This finding appears to settle a long-standing debate about humans' arrival on the continent — a feat that required expert knowledge of watercraft and sailing.

The new DNA evidence supports archaeological evidence, including stone tools and pigments on cave walls, of a "long chronology" in which the first arrivals showed up around 60,000 to 65,000 years ago.

But not everyone is convinced. In a July study, researchers used the fact that some Indigenous Australians have Neanderthal DNA to suggest that Australia wasn't populated until about 50,000 years ago — an idea known as the "short chronology."

More research into the origins of the earliest Australians is forthcoming.

6. Drought may have doomed the "hobbits."

By 50,000 years ago, H. floresiensis seems to have disappeared from Flores. In December, researchers published a study suggesting that drought may have fueled their demise.

While studying the rainfall on Flores, scientists discovered that it declined considerably between about 76,000 and 61,000 years ago and that the population of an elephant relative called Stegodon, which the hobbits hunted, disappeared around 50,000 years ago.

The researchers think decreased rainfall led to the reduction in the Stegodon population, which made life more difficult for the hobbits. And if modern humans also reached Flores — perhaps part of the wave of people who eventually settled Australia — the pressure of competition from another species may have wiped out H. floresiensis.

7. Denisovans got a face.

Our extinct relatives the Denisovans were first discovered in 2010 based on DNA extracted from a tiny finger bone. But until this year, no one knew what a Denisovan skull looked like.

Researchers debated for years what species the thick jawbone, recovered off the coast of Taiwan in 2000, came from, with some suggesting H. erectus and others suggesting H. sapiens. But using paleoproteomic analysis, researchers announced in May that the jawbone was from a male Denisovan.

Ancient proteins also revealed in June that a skull discovered in China in 1933, called the "Dragon Man," is from a Denisovan, finally putting a face to the name. But while Dragon Man has now been slotted into the story of human evolution, it is not yet clear whether the group should be considered a separate species, Homo longi.

And in September, researchers reconstructed a 1 million-year-old squashed skull from China and suggested that it may have been a Denisovan ancestor rather than H. erectus.

These three discoveries are pointing paleoanthropologists to clues about the origins and spread of the mysterious Denisovans — a task that will surely continue in the coming years.

8. Denisovan DNA helped Native Americans survive.

Researchers announced in August that some people with Indigenous American ancestry carry Denisovan genes, likely passed on through Neanderthals who mated with modern humans.

In looking at a protein-coding gene called MUC19, scientists discovered that 1 in 3 Mexicans alive today has a version of the gene similar to Denisovans' and that it likely "hitched a ride" from Neanderthals. Essentially, Neanderthals got the gene from mating with Denisovans and then passed it along when they mated with humans. This is the first time scientists have found a Denisovan gene in humans that came via Neanderthals.

Exactly what the Denisovan variant of the MUC19 gene does is currently unclear, but the researchers think it must have been beneficial to the earliest Americans for it to be preserved in the human genome.

9. Interbreeding was rampant among our archaic relatives.

The story of human evolution has gotten wonderfully messy since the genomic revolution. DNA and protein analyses have revealed new groups like the Denisovans, as well as the mating of Neanderthals, modern humans and Denisovans. But this year brought a few surprise pairings as well.

In August, researchers announced that a handful of 300,000-year-old teeth suggested humans and H. erectus may have interbred in China. The teeth had an unusual combination of ancient features, like thick molar roots, and modern features, like small wisdom teeth, that could mean two different species were sharing their genes.

Researchers announced in March that Neanderthals, modern humans and a mysterious third lineage lived alongside one another in caves in what is now Israel around 130,000 years ago. The Homo groups may have mixed and mingled for 50,000 years, potentially sharing cultural practices in addition to genetic material.

And in November, a DNA study of humans' arrival in Australia suggested that, along the way, these early human pioneers likely interbred with one or more archaic human groups, such as H. longi, Homo luzonensis or H. floresiensis.

Although we can see genetic differences among these groups using 21st-century technology, perhaps our earliest ancestors simply saw Neanderthals, Denisovans and others as fellow humans.

10. Most Europeans had a dark complexion until 3,000 years ago.

In a study published in July, scientists found that the genes for lighter skin, lighter hair and lighter eyes emerged among Europeans only about 14,000 years ago and that, until 3,000 years ago, most Europeans had dark skin, hair and eyes.

The researchers determined this from 348 samples of ancient DNA from archaeological sites spread throughout Western Europe and Asia. The first humans to reach Europe around 50,000 years ago carried genes for dark complexions. Once lighter traits emerged, they appeared only sporadically in the genetic data until fairly recently. By about 1000 B.C., those lighter traits became widespread in Europe.

Whether lighter skin, hair and eyes had any sort of evolutionary advantage for early Europeans is still unclear, though.

Human evolution quiz: What do you know about Homo sapiens?

Archaeologists in France have discovered the remains of a 16th-century gallows where bodies of the condemned were displayed after they were hanged. The corpses of the men — and a few women — were then buried in mass graves nearby.

During an excavation just outside the city of Grenoble in 2024, archaeologists with the French National Institute for Preventive Archaeological Research (INRAP) found a square brick structure and 10 burial pits dating to the 16th century, INRAP announced on Friday (Dec. 12).

These discoveries initially baffled archaeologists, who thought the structure and burials might have been part of a leper colony, a Catholic chapel graveyard or a military cemetery. But the archaeologists looked at historical construction records that showed a timber-framed gallows, which led them to conclude they had found Grenoble's public execution area.

Based on the archaeological finding and construction records from 1544 to 1547, the gallows measured about 27 feet (8 meters) on each side and had eight stone pillars that rose around 16.5 feet (5 m) high. Crossbeams jutting out from the pillars created a gibbet — a hangman-style structure that served to both execute and display the condemned.

The newly identified gallows structure would have enabled the judicial authorities in Grenoble to hang and display up to eight people at once.

Within the mass burial pits, the archaeologists identified 32 people, most of whom were men. Historical archives revealed the names of two of the men who were executed on the gallows and likely buried in one of the pits.

The Protestant Benoît Croyet was accused of participating in an attack on Grenoble in 1573, and Charles Du Puy Montbrun was the leader of the Huguenots of Dauphiné until he was executed in 1575. Both were condemned to death because they rebelled against royal authority.

"Burying a condemned person in this way was a means of prolonging the sentence pronounced during their lifetime into death; the individuals found during the excavations were therefore deliberately denied burial," according to the translated INRAP statement. Some of the people in the pits had also been subjected to "shameful treatment" after death, including dismemberment and decapitation.

The discovery of the gallows and the burial pits is providing archaeologists at INRAP with new insight into historical places of justice. It appears that the Grenoble gallows was abandoned as a method of applying the death penalty in the early 17th century due to changing political and religious norms.

Human skeleton quiz: What do you know about the bones in your body?

Around 1,800 years ago in Roman Britain, people preparing bodies for burial created a plaster-like paste and smeared it over the corpses, leaving behind fingerprints that are still visible today, researchers reported in a recent blog post.

These newfound prints reveal a hands-on approach to funerary practices in the third and fourth centuries A.D., the archaeologists said.

This team of researchers, involved in the "Seeing the Dead" project at the University of York, have been investigating the mysterious practice of using liquid gypsum to fill stone and lead coffins of people who lived in Yorkshire during the Roman Empire.

Gypsum is a calcium-based mineral that was a key ingredient in ancient plaster and cement. When heated and mixed with water, gypsum becomes a pourable liquid sometimes called plaster of paris. This thick liquid, when poured over a dead body, hardens into a plaster and leaves behind a casing or impression of the deceased, much like the casts at Pompeii.

At least 70 liquid gypsum burials have been discovered in the Yorkshire area to date. When investigating one of them — a stone sarcophagus found in the 1870s that had not been properly studied before — the team found a surprising clue to the method of applying the liquid gypsum: Someone had spread it by hand.

"When we lifted the casing and began cleaning and 3D scanning, we discovered the hand print with fingers and were astounded," Maureen Carroll, a Roman archaeologist at the University of York and principal investigator of the Seeing the Dead project, told Live Science in an email. "They had not been seen ever before, nor had anyone ever removed the casing from the sarcophagus."

In a Dec. 10 blog post, Carroll explained that the team had previously assumed the liquid gypsum was heated to at least 300 degrees Fahrenheit (150 degrees Celsius) and poured over the body. But the presence of fingerprints means that the gypsum mixture was probably a soft paste that someone smoothed over the body in the coffin. The gypsum had been spread very close to the edges of the coffin, so the fingerprints were not visible until the team removed the casing from the coffin.

The fingerprints and hand marks reveal the close, personal contact the Romans had with their dead, according to Carroll. "They are a striking trace of human activity that is not otherwise known to survive on a body in a Roman funerary context," she wrote in the blog post.

The marks might preserve additional clues about the person or people who buried the dead — revealing, for example, whether a professional undertaker or a family member last touched the deceased.

"We are hoping to extract potential DNA remains from the handprint for examination at the Francis Crick Institute in London," Carroll said. It's a long shot, but "the best case scenario is that we may be able to infer genetic sex, which would be a huge result!"

Editor's note: This article was updated at 12:55 p.m. ET on Dec. 12 to correct the number of liquid gypsum burials discovered to date to 70.

Roman Britain quiz: What do you know about the Empire's conquest of the British Isles?

Just outside the gate of a 4,000-year-old city in China, archaeologists found a pit full of 80 skulls from human sacrifice victims. Now, a new study has revealed a surprising fact about the victims: Nine out of 10 were men.

In the study, published Nov. 26 in the journal Nature, researchers analyzed DNA collected from skeletons found in the ancient city of Shimao and its satellite towns to figure out the social and kinship structure of this Neolithic society.

The ancient stone-walled city of Shimao was first discovered in Shaanxi province in 2018. Occupied between about 2300 and 1800 B.C., Shimao was roughly 1.5 square miles (4 square kilometers). The city featured a large step pyramid, craft specialization areas and two cemeteries.

Archaeologists also found two different forms of human sacrifice: one involving the heads of decapitated individuals, buried in "skull pits" near the city gate; and another involving the entombing of a lower-status individual — usually a female — as a sacrifice in a higher-status person's burial.

In the new study, the researchers used DNA analysis to figure out the biological sex of the skulls in the pit discovered beneath the foundation of Shimao's Dongmen (East Gate).

"In contrast to previous archaeological reports that identified these sacrifices as female-based," the researchers wrote in the study, the new DNA results "showed no evidence of female bias, with 9 out of 10 victims being men."

This finding surprised archaeologists, because the sacrifices associated with the elite burials at Shimao and its satellite towns were predominantly female.

"These patterns of mostly female sacrifices starkly contrast with Dongmen, in which decapitation and mass burial involved mostly sampled men," the researchers wrote. "This suggests Shimao's sacrificial practices were highly structured, with gender-specific roles tied to distinct ritual purposes and locations," according to a statement from the Chinese Academy of Sciences.

Additionally, when the researchers looked at the sacrificed men's DNA, they found no differences in their ancestry compared to the ancestry of the elite tomb occupants, meaning the sacrificial victims were not "outsiders."

Although the reason for the sex-specific sacrifice customs is still unclear, researchers have offered some possible explanations.

The cemetery-based sacrifices "may represent ancestor veneration, in which women were sacrificed to honour elite nobles or rulers," according to the researchers, while the sacrificed skulls in the pit "were probably connected to a construction ritual of the walls or gate."

Terracotta Army quiz: What do you know about the 'warriors' in the 2,200-year-old tomb of China's 1st emperor?

Humans were isolated in southern Africa for about 100,000 years, which caused them to "fall outside the range of genetic variation" seen in modern-day people, a new genetic study reveals.

The finding supports the idea that "modern" Homo sapiens can have many different combinations of genetic features, even those outside the norm.

In a study published Wednesday (Dec. 3) in the journal Nature, researchers sequenced the genomes of 28 ancient individuals, whose remains were between 225 and 10,275 years old, from southern Africa, south of the Limpopo River, which begins in South Africa and flows in an arc eastward through Mozambique to the ocean.

The team then compared the skeletons' genomes with published data from ancient and modern-day Africans, Europeans, Asians, Americans and Oceanians.

The researchers discovered that all of the people who lived in southern Africa more than 1,400 years ago had dramatically different genetic makeups than modern-day humans, pointing to the relative isolation of the southern part of the continent until relatively recently.

The researchers still aren't sure exactly why humans remained isolated in the region for so long.

"We can speculate that the vast geographic distance has played a role in the isolation, but that is not a very satisfactory speculation, as humans have and often do transcend large geographic areas," study co-author Mattias Jakobsson, a human evolutionary biologist at Uppsala University in Sweden, told Live Science in an email. However, the geographic area around the Zambezi River, which is just north of this isolated group, may not have been particularly suitable for ancient human habitation. "The combination of distance and unfavorable conditions might have isolated the south," Jakobsson said.

Many of the ancient southern Africans, including those who lived between about 10,200 and 1,400 years ago, "fall outside the range of genetic variation among modern-day individuals," the researchers wrote in the study, "and form an extreme end of human genetic variation."

The researchers labeled this previously unknown suite of genetic variation the "ancient southern African ancestry component" and found that there was no clear indication of admixture — or outsiders sharing their genes with the group — until about A.D. 550.

"Our findings therefore contrast with linguistic, archaeological and some early genetic studies pointing to a shared ancestry or long-term interaction between eastern, western and southern Africa," the researchers wrote.

The population living in southern Africa was likely quite large until at least 200,000 years ago, the researchers determined using statistical modeling. Some people may have left the south during favorable climatic conditions, spreading their genes as they moved north. Then, around 50,000 years ago, the population of southern Africans began to decline, and by about 1,300 years ago, farmers arriving from further north met and reproduced with the foragers of southern Africa.

"Really important" genetic variants

The unique genetics of ancient southern Africans gave the researchers further clues to human evolution and variation.

The prehistoric population of southern Africa contains half of all human genetic variation, while people spread throughout the rest of the world contain the other half, Jakobsson said in a statement. "Consequently, these genomes help us to see which genetic variants were really important for human evolution," he said.

When they investigated dozens of DNA variants that are unique to H. sapiens, including in the ancient southern African population, the researchers discovered several linked to kidney function and several related to the growth of neurons in the brain. The kidney variants may have evolved to help humans retain or control water in their bodies, while the neuron variants may be linked to attention spans, suggesting humans had better mental capabilities than Neanderthals or Denisovans.

The new analysis reveals that there is "vast genetic variation still unassessed in ancient genomes from Indigenous peoples globally," the researchers wrote, which is important for understanding the evolution of H. sapiens.

In particular, the presence of human-specific variants in ancient southern Africans lends support to a "combinatorial" genetic model of human evolution, the researchers noted, in which many possible combinations of genetic variants eventually led to "genetically modern" H. sapiens.

"I think that it is certainly possible that humans evolved, at least partly, in multiple places," Jakobsson said. "How — and if — such a process would have happened, and how it combined genetic variation into genetically modern humans, is an open question."

Human evolution quiz: What do you know about Homo sapiens?

By adding a handful of live ants to warm milk, a group of anthropologists and food scientists investigated how to make "ant yogurt" — and they ended up learning that it has the same ingredient as a popular type of bread.

The bacteria in the "ant yogurt," which they made using a traditional Balkan method, is a strain that's commonly used as a sourdough starter today, the team found. They then served the yogurt to patrons at a restaurant to showcase historical methods of fermenting food.

The process behind concocting this ant delicacy is dramatically different from how the fermented dairy food is industrially made today, the researchers wrote in a study published Friday (Oct. 3) in the journal iScience.

"Today's yogurts are typically made with just two bacterial strains," study co-author Leonie Jahn, a researcher at the Technical University of Denmark, said in a statement. The strains, Lactobacillus bulgaricus and Streptococcus thermophilus, are introduced to warm milk as a bulk starter. The bacteria ferment the sugars in the milk, producing lactic acid, which lowers the pH and increases the acidity of milk, causing the milk to coagulate. This also gives yogurt its consistency and flavor.

"If you look at traditional yogurt, you have much bigger biodiversity," Jahn said, because various bacterial strains impart different flavors and textures to the food.

Study co-author Sevgi Mutlu Sirakova, a doctoral student at Ludwig Maximilian University of Munich, previously gathered oral histories from people in Turkey and Bulgaria that described different methods of creating yogurt, including the use of red wood ants (Formica sp.) to kick-start the process. The researchers visited Sirakova's family village in Bulgaria, where locals recalled the tradition of using ants to make yogurt.

"We dropped four whole ants into a jar of warm milk by the instruction of Sevgi's uncle and community members," study co-author Veronica Sinotte, a microbiologist at the University of Copenhagen, said in a statement. After keeping the jar of milk warm in the ant mound overnight, they tried the yogurt that had formed — and described it as "slightly tangy" and "herbaceous."

After making the ant yogurt, the team studied it to understand the role of the ant "holobiont," which includes both the ant and the microbial communities in and on the creature.

Chemical analysis of the yogurt revealed that the dominant bacterium responsible for fermentation was Fructilactobacillus sanfranciscensis, a species that is much better known as a key ingredient in sourdough bread. Additionally, they discovered abundant formic acid in the yogurt. Wood ants produce large amounts of formic acid in their venom gland, and they can spray it as a defense mechanism. The formic acid gave the yogurt a unique taste and texture.

"This study highlights ants as a reservoir of bacteria with potential for food fermentation, and the importance of both ant biodiversity and traditional practices in maintaining this potential," the researchers wrote in the study.

To further test the culinary possibilities of ant yogurt, the researchers partnered with Alchemist, a 2 Michelin-star restaurant in Copenhagen. The chefs created three new dishes from the ant yogurt: an ant-shaped ice cream sandwich, tangy cheeses, and a "milk wash cocktail" from a recipe dating back to the early 1700s.

But amateur cooks should not try this at home, the researchers warned, because ants can harbor parasites. The researchers used a microbiology-grade sieve to remove any potential parasites before passing the yogurt to the restaurant.

The use of ants in yogurt making remains widespread in Turkey and Bulgaria today, and now scientists understand exactly how the ants react with the milk to produce yogurt.

"I hope people recognize the importance of community and maybe listen a little closer when their grandmother shares a recipe or memory that seems unusual," Sinotte said.

Editor's Note: This story was updated at 10:05 a.m. ET on Oct. 6 to note that lactic acid lowers the pH and increases the acidity of milk, causing milk to coagulate.

Jane Goodall, the world's foremost expert on chimpanzees, has died at the age of 91, the Jane Goodall Institute (JGI) confirmed in a statement on Wednesday (Oct. 1). Goodall died of natural causes in Los Angeles, California, while on a speaking tour.

Goodall "was a remarkable example of courage and conviction, working tirelessly throughout her life to raise awareness about threats to wildlife, promote conservation, and inspire a more harmonious, sustainable relationship between people, animals and the natural world," the JGI statement reads.

Dame Valerie Jane Morris-Goodall was born April 3, 1934, in London. As a child, Goodall was fond of animals, including the 1920 book "The Story of Dr. Dolittle," and intrigued by the ecosystems of Africa. On a trip to Kenya in 1957, she met paleoanthropologist Louis Leakey, who convinced Goodall that studying the behavior of chimpanzees (Pan troglodytes) might provide insights into the behavior of early human ancestors.

Goodall began her research into chimpanzees in 1960 after arriving at Gombe Stream National Park in Tanzania. With no formal academic training in a research area dominated by men at the time, Goodall spent months quietly observing the apes, giving them names such as Fifi, Passion and David Greybeard.

"It isn't only human beings who have personality, who are capable of rational thought, emotions like joy and sorrow," Goodall said in a 1996 PBS documentary.

In 1966, Goodall took a break from working at Gombe and completed a doctorate at the University of Cambridge. Her doctoral thesis detailed her years' worth of study at Gombe. One key observation that Goodall made at the national park was that chimpanzees were capable of making and using tools — she famously saw one of the apes strip a stick to "fish" for termites in a mound.

The discovery of chimpanzee tool-making counteracted the prevailing assumption at the time that only humans were intelligent enough to make tools. The revelation inspired Leakey to declare, "We must now redefine tool, redefine man, or accept chimpanzees as human!"

Goodall was the first person to document that chimps hunt and eat meat, revealing they are omnivores rather than the vegetarians scientists thought they were. She also saw chimps embrace one another in mourning after the death of a troop member and develop a kind of primitive language system.

But Goodall also documented disturbing behaviors never seen before, such as dominant females killing the young of other females.

"We found that chimpanzees can be brutal — that they, like us, had a darker side to their nature," Goodall wrote in her book "Reason for Hope: A Spiritual Journey" (Grand Central Publishing, 2000).

In the 1970s, Goodall became increasingly concerned about conservation efforts at Gombe and throughout Africa, and in 1977, she founded the non-profit Jane Goodall Institute. JGI maintains a presence at the Gombe Stream Research Centre — now the longest ongoing chimpanzee study in the world — and also helps teach young people around the world about environmental conservation.

Until her death, Goodall traveled the world nearly 300 days a year, speaking about wildlife conservation and environmental crises, according to the JGI statement. Her public lectures often began with "Dr. Jane" pant-hooting a chimpanzee greeting to her audience, and she would emphasize the collective power of individual actions for the benefit of the environment. In a 2002 essay published in Time Magazine, Goodall wrote that "the greatest danger to our future is apathy."

In a statement, Audrey Azoulay, director-general of UNESCO, said that "Dr. Jane Goodall was able to convey the lessons of her research to everyone, especially young people. She changed the way we see Great Apes. Her chimpanzee greetings at UNESCO last year — she who so strongly supported our work for the biosphere — will echo for years to come."

Goodall is survived by her sister, Judy Waters, her son, Hugo Eric Louis van Lawick, who was nicknamed "Grub" as a child, and three grandchildren. Grub spent his early years at Gombe, and Goodall's observations of chimpanzees helped her understand how to raise her son, she told People Magazine in 1977.

"The chimpanzees have an extremely close bond between mother and child," she said, "and I raised Grub this way."

During her 60 years of working with primates and spreading a message of environmental conservation, Goodall inspired other women to become scientists and received numerous awards, including Commander of the Order of the British Empire (1995), United Nations Messenger of Peace (2002), French Legion of Honour (2006), and the Presidential Medal of Freedom, which she was awarded in January 2025 by U.S. President Joe Biden.

A roughly 1.8 million-year-old Homo erectus jawbone discovered in the Republic of Georgia may be evidence of one of the earliest human groups to live outside Africa.

The discovery, announced July 31 by the Georgian National Agency for Cultural Heritage Preservation, sheds new light on the evolution of our genus, Homo, and "is expected to reveal the reasons for the migration of early hominins out of Africa," Giorgi Bidzinashvili, an archaeologist at Ilia State University in Tbilisi, told Live Science in an email.

Bidzinashvili has been leading an excavation at the early Stone Age site of Orozmani, about 60 miles (100 kilometers) south of Tbilisi, Georgia's capital, since 2020. In those early excavations, researchers discovered stone tools near ancient animal bones, as well as a single tooth from H. erectus, which they unearthed in 2022.

H. erectus evolved around 2 million years ago in Africa. It was the first human ancestor to leave Africa, and explored parts of Europe, Asia and Oceania. The earliest fossil evidence of this journey comes from the site of Dmanisi, which is just 12 miles (19 km) from Orozmani.

In a 2011 study, chemical dating of the lava flows on top of Dmanisi and Orozmani showed that the sites are roughly contemporaneous. Both date to between 1.825 million and 1.765 million years ago.

Excavations at Dmanisi over the past three decades have revealed more than 100 fossil bones, including five skulls. Those skeletons showed that the earliest hominins to leave Africa were significantly shorter and had smaller brains than Homo sapiens. The Dmanisi skeletons were initially given the species name Homo georgicus, but they are now generally considered the earliest known H. erectus individuals in Eurasia.

Related: 1.5 million-year-old footprints reveal our Homo erectus ancestors lived with a 2nd proto-human species

So far, the Orozmani fossils, which include just one tooth and one partial jaw, are not as numerous as those at Dmanisi. "Since we have not yet cleaned the jaw," Bidzinashvili said, "it has not been compared with the Orozmani tooth from 2022."

But the discovery of fossils at Orozmani suggests that Dmanisi was not a unique site. Several early human groups may have settled in the Caucasus soon after leaving Africa.

"Maybe we're seeing that this movement to Georgia wasn't an isolated incident, but maybe there was a broader distribution of Homo erectus in this time period," Karen Baab, a biological anthropologist at Midwestern University in Glendale, Arizona, who was not involved in the research, told Live Science.

The research team is trying to figure out whether one site is older than the other.

"Until we have new dates, we can neither confirm nor deny that the Orozmani human fossils are older than Dmanisi or contemporaneous," Bidzinashvili said. "By the end of the year, we will know."

Human evolution quiz: What do you know about Homo sapiens?

Archaeologists have unearthed a dazzling gold wreath in a 2,100-year-old burial mound of a Thracian warrior and his horse. The unique headpiece is part of a set of gold jewelry excavated from the grave of the "Lord of Sakar," named after the mountain range in southeast Bulgaria where he was found.

"The golden treasures discovered in our lands testify to high craftsmanship, rich spiritual life and prosperous societies," Evelina Slavcheva, president of the Bulgarian Academy of Sciences, said in a statement.

The ancient burial mounds were discovered during digging related to the installation of a solar park in 2024. A team of archaeologists from the Bulgarian Academy of Sciences excavated the burials and found that one contained the bones of a young woman and the other a middle-aged man.

Both tombs included many gold artifacts, but the man's grave is the richest ever discovered in Bulgaria, according to a translated social media post from the Municipality of Topolovgrad, where the site is located.

Due to the opulence of the man's burial, complete with the bones of his war horse, he has been dubbed the Lord of Sakar. He lived during the late Hellenistic period, around 150 to 100 B.C., and may have been a warrior aristocrat, according to the statement. At the beginning of the century, the area of Thrace was partly under Greek rule, but by the end of the century, the Romans had conquered it as part of their empire.

Preliminary research suggests the Lord of Sakar was about 35 to 40 years old when he died. The wreath — made from gilded silver — was found encircling his skull. Other artifacts discovered in his grave included ceramic and glass vessels, iron spears and a shield, silver jewelry and a unique gem-covered knife.

Related: Medieval knight 'Lancelot' and his stunning stone tomb found under ice cream shop in Poland

The man's horse was also honored with numerous grave goods, including a gilded bronze decoration on his harness depicting the mythic hero Hercules defeating a giant. The harness featured other bronze depictions of animals, likely representing more of Hercules' exploits, as well as a gold headpiece with the image of a snake.

Less is known about the burial mound of the woman, who lived at the beginning of the second century B.C. Archaeologists recovered two pairs of well-preserved leather shoes; a wooden chest covered in gold, silver and jewels; and numerous gold, glass and bronze items. Near this mound was a small sanctuary dated to the second half of the second century B.C., where archaeologists found a large number of regional coins.

The Hellenistic period gold objects were revealed to the public on Aug. 12 at Bulgaria's National Archaeological Institute with Museum as part of an exhibition called "The Glitter of Hellenistic Gold. The Lord of Sakar." The exhibition is open through Oct. 17.

The first people to step foot in the Americas were harboring a sliver of DNA from two extinct Eurasian human groups: the Neanderthals and the Denisovans, a new study finds. This genetic relic could have helped the earliest Americans fight diseases they encountered in their new environment, the researchers proposed.

Everyone alive today is "a result of like three different species coming together," study co-author Fernando Villanea, a population geneticist at the University of Colorado Boulder, told Live Science.

"What we think has happened is that humans had this archaic variation," study co-author Emilia Huerta-Sanchez, a population geneticist at Brown University, told Live Science. As people expanded into the Americas, they did not have to wait to develop new mutations to fight off new pathogens and could instead draw from the arsenal of genetic variants they gained from other human groups, she said.

In the new study, published Thursday (Aug. 21) in the journal Science, the researchers detailed their analysis of MUC19, a protein-coding gene with various functions, including coding for the consistency of mucus. They found that 1 in 3 Mexicans alive today has an MUC19 gene similar to that of Denisovans, a mysterious group of ancient humans who lived throughout Asia from about 200,000 to 30,000 years ago.

Research into MUC19 in Indigenous Americans has focused on two different aspects. One set of researchers previously showed that people with Indigenous American ancestry carry a high number of ancient human variants of MUC19, whereas the other set found that the MUC19 gene as a whole became more common over time in North American Indigenous populations because it was evolutionary advantageous.

But in the new study, the researchers discovered that the length of the Denisovan MUC19 DNA segment in Indigenous Americans has increased over time and that the variant hitched a ride from Neanderthals in an Oreo-like gene sandwich, Villanea said in a statement. This is the first time scientists have found a Denisovan gene that came to humans via Neanderthals.

"It's wild," Villanea said. "Is this the only instance of this happening, or are there more? We are still trying to figure [it] out."

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

A DNA sandwich

To test whether the Denisovan-specific variants of MUC19 were beneficial for Indigenous Americans, the team compared the genetic data available on modern Mexican, Peruvian, Colombian and Puerto Rican individuals from the 1000 Genomes Project with the genetic sequences of 23 Indigenous people, most of whom lived in the Americas prior to the 13th century, as well as three Neanderthals and one Denisovan.

The team found that modern-day Mexicans had the highest frequency of the Denisovan-specific MUC19 variants, with about 33% of the population carrying this version of the gene. About 20% of Peruvians carried the variant, whereas only around 1% of Colombians and Puerto Ricans did. The researchers think this is because, on average, Mexicans have more Indigenous American DNA in their genomes than the other populations do.

When the team investigated which archaic human group had passed on these gene variants, they were surprised to see that the Denisovan section of the gene was sandwiched between Neanderthal-specific DNA. The most likely explanation for this is that Neanderthals first acquired these variants from mating with Denisovans, and when Neanderthals later mated with modern humans, they passed on this surprise genetic parcel, the researchers said.

"The researchers took this complex pattern, and they were able to parse it out in the context of past human demographic events," Ripan Malhi, a molecular anthropologist at the University of Illinois at Urbana-Champaign who was not involved in the new study, told Live Science in an email. The work is impressive, he said, and now we need to learn more about the function of the Denisovan MUC19 gene.

This is the next step for Villanea and his team, who are planning to look at new research collections of biological samples that have both genomic and trait data from Latino or Indigenous American people to see how the Denisovan-specific variants affect protein function.

Depending on exactly what the Denisovan MUC19 variant does, it may help the immune system fight some specific pathogens or regulate particular immune responses, Huerta-Sanchez said. "We suspect that it's going to be doing something drastically different" from what the modern human variant does, Villanea said.

Human evolution quiz: What do you know about Homo sapiens?

In a series of "victory" celebrations more than 6,000 years ago in northeastern France, a group of defenders severed the left arms of their conquered enemies and buried them in pits, archaeologists have found.

The discovery provides a glimpse into a time when warfare was rampant in the region and when invaders pushed into northeastern France from the area around Paris.

The "lower limbs were [fractured] in order to prevent the victims from escaping, the entire body shows blunt force traumas and, what it is more, in some skeletons there are some marks — piercing holes — that may indicate that the bodies were placed on a structure for public exposure after being tortured and killed," study co-author Teresa Fernández-Crespo, an osteoarchaeologist at Valladolid University in Spain, told Live Science in an email.

In a paper published Wednesday (Aug. 20) in the journal Science Advances, researchers analyzed the remains of 82 people buried in pits in northeastern France sometime between 4300 and 4150 B.C. Some of the bodies were mutilated, with their left arms and hands dismembered. Bodies that were not mutilated were buried in different pits.

To investigate whether the burial treatments reflected people's origins, researchers analyzed the chemical signatures of the teeth and bone, which gave clues about where the people grew up and the food they consumed. The people who were mutilated came from outside the local area, possibly around Paris. The chemical signatures also suggested that this group of people ate food that originated from different areas, hinting that they moved around a lot, the researchers wrote in the study.

But the chemical analysis showed that those who were not mutilated were locals. This could mean they died defending their territory, the researchers suggested.

Related: Stone Age family may have been cannibalized for 'ultimate elimination' 5,600 years ago, study suggests

Some of the invaders were likely captured by the defenders, and their left arms or hands were severed as "trophies" in one of the earliest well-documented instances of martial victory celebration in prehistoric Europe, the researchers wrote.

"We believe they were brutalized in the context of rituals of triumph or celebrations of victory that followed one or several battles," Fernández-Crespo said. Because the burial pits were located in the middle of a settlement, this "firmly suggests that the act would have been a public theater of violence intended to dehumanize the captive enemies in front of the entire community."

A time of conflict

There is other evidence for widespread conflict in this region around 4500 to 4000 B.C.

Detlef Gronenborn, an archaeology professor at the Leibniz Center for Archaeology in Germany who was not part of the research team, told Live Science in an email that the "period in question is a time of considerable unrest Europe-wide and is linked to a period of high climate volatility, a continent-wide crisis period, all [culminating] around 4100" B.C. Breaks in occupation of sites suggest "a sudden high mobility due to a general increase in warfare," Gronenborn said. "The entire period is also characterized by a general population push originating from southern France and possibly bringing unrest and an increase in [warfare] in the wake of these migrations."

Linda Fibiger, an osteoarchaeologist at the University of Edinburgh who was not part of the research team, told Live Science in an email that "it's an exciting, well executed and carefully interpreted find that gives important insights into the varied practice of violence in the Neolithic."

The chemical analysis has "made it possible to achieve something as important as distinguishing between captives and attackers in prehistoric contexts of interpersonal violence as far back as the Neolithic," Miguel Ángel Moreno-Ibáñez, an osteoarchaeologist at the University of Edinburgh who was not part of the research team, told Live Science in an email.

This was a time of warfare when people in the region lived in fortified settlements, and skeletons frequently reveal evidence of violence. Pottery from the Paris area shows up in greater amounts, and archaeologists believe that people from the Paris area were invading what is now northeastern France.

"Injuries provoked in Neolithic battles usually targeted the head and very less often other body parts," Fernández-Crespo said, but these pits in France reveal "an unprecedent[ed] intensity of violence to the body that can only be understood in a context of torture, mutilation and dehumanization of the victim." These brutal attacks may have been carried out as an act of revenge, the researchers noted in the study.

Stone Age quiz: What do you know about the Paleolithic, Mesolithic and Neolithic?

Ancient human relatives moved diverse stones over substantial distances, researchers report, revealing a surprisingly high degree of forward planning 600,000 years earlier than experts previously thought possible.

In a study published Friday (Aug. 15) in the journal Science Advances, a team of researchers pored over 401 stone tools from the archaeological site of Nyayanga in Kenya, dated to 3 million to 2.6 million years ago. The tools were made in the earliest known style called Oldowan, which involved chipping flakes off one stone using another stone to make a basic tool. But the kinds of rocks used were surprising — most of them came from locations over 6 miles (9.7 kilometers) away.

Chimpanzees (Pan troglodytes) are also known to carry granite hammerstones for cracking nuts as far as 1.2 miles (2 km), but only through cumulative, shorter-distance bouts, previous research has shown. The new finding establishes that human relatives could move tools more substantial distances, suggesting a better ability to plan ahead.

"People often focus on the tools themselves, but the real innovation of the Oldowan may actually be the transport of resources from one place to another," study co-author Rick Potts, a paleoanthropologist at the National Museum of Natural History in Washington, D.C., said in a statement. "The knowledge and intent to bring stone material to rich food sources was apparently an integral part of toolmaking behavior at the outset of the Oldowan."

The oldest stone tools date back about 3.3 million years, nearly 1 million years before experts think our genus, Homo, originated. These tools were probably created by human ancestors like the australopithecine Lucy. But these early tools were made out of materials sourced locally or from a short distance — roughly 1.7 miles (3 kilometers) away at the most.

Around 2 million years ago, human ancestors such as Homo erectus went through some big changes: There were increases to their brain size and body size, some migrated out of Africa, and some began cooking and eating meat. There is also evidence that these early ancestors began to plan ahead, becoming more selective about the rocks they chose to make into tools, and procuring them from significant distances.

But the stone tools from Nyayanga are 600,000 years older than the earliest evidence that human relatives were selecting and transporting rocks long-distance, and also likely predates the emergence of the Homo genus. This means that these groups were figuring out what they needed to process food and how to mentally map their environment, according to Potts.

Related: 1.5 million-year-old stone tools from mystery human relative discovered in Indonesia — they reached the region before our species even existed

It is not clear, however, which species made the tools discovered at Nyayanga.

"Unless you find a hominin fossil actually holding a tool, you won't be able to say definitively which species are making which stone tool assemblages," study co-author Emma Finestone, a biological anthropologist at the Cleveland Museum of Natural History, said in the statement.

In this case, the tools were found alongside some fossils attributed to the genus Paranthropus, which "calls into question whether the transport of core and flake technology was exclusive to genus Homo," the researchers wrote in the study.

Regardless of which species of human relative produced the tools, the fact that they transported them long distances suggests they were far more intelligent than they have been given credit for.

"Humans have always relied on tools to solve adaptive challenges," Finestone said in the statement. "By understanding how this relationship began, we can better see our connection to it today — especially as we face new challenges in a world shaped by technology."

Human evolution quiz: What do you know about Homo sapiens?

Our species is the last living member of the human family tree. But just 40,000 years ago, Neanderthals walked the Earth, and hundreds of thousands of years before then, our ancestors overlapped with many other hominins — two-legged primate species.

This raises several questions: Which other populations and species did our ancestors mate with, and when? And how did this ancient mingling shape who we are today?

"Everywhere we've got hominins in the same place, we should assume there's the potential that there's a genetic interaction," Adam Van Arsdale, a biological anthropologist at Wellesley College in Massachusetts, told Live Science.

In other words, different hominin species were having sex — and babies — together. This means our evolutionary family tree is tangled, with still-unknown relatives possibly hiding in the branches.

Emerging DNA evidence suggests this "genetic interaction" resulted in the diversity and new combinations of traits that helped ancient humans — including our ancestors — thrive in different environments around the globe.

"It's all about variation," Rebecca Ackermann, a biological anthropologist at the University of Cape Town in South Africa, told Live Science. "More variation in humans allows us to be more flexible as a species and, as a result, be more successful as a species because of all the diversity."

Cutting-edge techniques may illuminate the crucial periods deeper in our evolutionary past that led to Homo sapiens evolving in Africa, or even shed light on periods before the Homo genus existed. That knowledge, in turn, could improve our understanding of exactly what makes us human.

Related: Lucy's last day: What the iconic fossil reveals about our ancient ancestor's last hours

A braided stream

In the early 20th century, scientists thought there was a clear evolutionary line between our ancestors and us, with one species sequentially evolving into another and no contribution from "outside" populations, like the branches on a tree.

But 21st-century advances in ancient DNA analysis techniques have revealed that our origins are more like a braided stream — an idea borrowed from geology, where shallow channels branch off and rejoin a stream like a network.

"It becomes very hard when you think about things in more of a braided stream model to divide [populations] into discrete groups," Ackermann said. "There are not, by definition, any discrete groups; they have contributed to each other's evolution."

Ackermann studies variation and hybridization — the exchange of genes between different groups — across the evolutionary history of hominins, to better understand how genetic and cultural exchange made us human. And she thinks hybridization both within and outside Africa played a significant role in our origins.

Evidence of such hybridization has come out in a steady stream since the first Neanderthal genome was sequenced in 2010. That research program, which earned geneticist Svante Pääbo a Nobel Prize in 2022, revealed that H. sapiens and Neanderthals regularly had sex. It also led to the discovery of the Denisovans, a previously unknown population that ranged across Asia from about 200,000 to 30,000 years ago and that also had offspring with both Neanderthals and H. sapiens.

When species share genes with one another through hybridization, the process is known as introgression, and when those shared genes are beneficial to a population, it's known as adaptive introgression.

Emerging from two decades of gene studies of humans and our extinct relatives is the understanding that we may be who we are thanks to a proclivity to pair off with anyone — including other species.

Connecting with other groups — socially and sexually — was an important part of human evolution. "For us to survive and become human probably really depended on that," Van Arsdale said.

Benefits of hybridization

Since the first Neanderthal genome was sequenced, researchers have attempted to identify when and how often our H. sapiens ancestors mated with other species and groups. They've also investigated how Neanderthal and Denisovan genes affect us today. Many of these studies rely on large datasets of genomes from humans living today and tie them back to ancient DNA extracted from the bones of extinct humans and their relatives who lived tens of thousands of years ago.

These analyses show that many genes that originated in now-extinct groups may confer advantages to us today. For instance, modern Tibetans have a unique gene variant for high-altitude living that they likely inherited from the Denisovans, while different versions of Neanderthal skin pigment genes may have helped some populations adapt to less-sunny climates while protecting others from UV radiation.

There is also evidence that Neanderthal genes helped early members of our species adapt quickly to life in Europe. Given their long history in Europe prior to the arrival of H. sapiens, Neanderthals had built up a suite of genetic variations to deal with diseases unique to the area. H. sapiens encountered these novel diseases when they spread into areas where Neanderthals lived. But, by mating with Neanderthals, they also got genes that protected them from those viruses.

Beyond specific traits that may confer advantages in humans today, these episodes of mating diversified the human gene pool, which may have helped our ancestors weather varied environments.

The importance of modern genetic diversity can be illustrated with human leukocyte antigen (HLA) genes, which are critical to the human immune system's ability to recognize pathogens. Humans today have a dizzying array of these genes, especially in eastern Asia. This area of the world is a "hotspot" for emerging infectious diseases due to a combination of biological, ecological and social factors, so this diversity may provide advantages in an area where new diseases are frequently emerging.

When genetic diversity is lost through population isolation and decline, groups may become particularly susceptible to new infections or unable to adapt to new ecological circumstances. For instance, one theory holds that Neanderthal populations declined and eventually went extinct around 40,000 years ago because they lacked genetic diversity due to inbreeding and isolation.

Related: Did we kill the Neanderthals? New research may finally answer an age-old question.

Discovery of "ghost populations"

Some of the newest research goes deeper into evolutionary time, identifying "ghost populations" — human groups that went extinct after contributing genes to our species. Often, archaeologists have no skeletal remains from these populations, but their echoes linger in our genome, and their existence can be gleaned by modeling how genes change over time.

For instance, a "mystery population" of up to 50,000 individuals that interbred with our ancestors 300,000 years ago passed along genes that created more connections between brain cells, which may have boosted our brain functioning.

The population that hybridized with H. sapiens and helped boost our brains may have been a lineage of Homo erectus. This species was once thought to have disappeared after evolving into H. sapiens in Africa, but anthropologists now think H. erectus survived in parts of Asia until 115,000 years ago.

In fact, our evolutionary history may include the mating of populations that had been separated for up to a million years, Van Arsdale said. These "superarchaic" populations are increasingly being discovered as we mine our own genomes and those of our close relatives, Neanderthals and Denisovans.

For instance, a genetic study published in 2020 identified a superarchaic population that separated from other human ancestors about 2 million years ago but then interbred with the ancestors of Neanderthals and Denisovans around 700,000 years ago. Experts don't know exactly what genes this superarchaic ghost population shared with our ancestors or who it was, but it may have been a lineage of H. erectus.

Evolutionary blank space

But there's a large, unmapped region of human evolutionary history — and it's crucial for our identity as a species.

The period when H. sapiens was first evolving in Africa, and the more distant period of human evolutionary history on the continent that predates the Homo genus, remains a huge knowledge gap. That's in part because DNA preserves well in caves and other stable environments in frigid areas of the world, like those found in areas of Europe and Asia, while Africa's warmer conditions usually degrade DNA. As a result, the most ancient complete human DNA sequence from Africa is just 18,000 years old. By contrast, a skeleton discovered in northern Spain produced a full mitochondrial genome from a human relative, H. heidelbergensis, who lived more than 300,000 years ago.

"Maps of human ancient DNA are overwhelmingly Eurasian data," Van Arsdale said. "And the reality is that's a marginal place in our evolutionary past. So to understand what was happening in the core of Africa would be potentially transformative."

This is where current DNA technology falls short.

Small hominins that walked on two legs, called australopithecines, evolved around 4.4 million years ago in Africa. And between 3 million and 2 million years ago, our genus, Homo, likely evolved from them. H. sapiens evolved around 300,000 years ago in Africa and then traveled around the world. But given the scarcity of ancient DNA from Africa, it is difficult to figure out which groups were mating and hybridizing in that vast time span, or how the fossil skeletons of human relatives from the continent were related.

Related: 'It makes no sense to say there was only one origin of Homo sapiens': How the evolutionary record of Asia is complicating what we know about our species

A new technique called paleoproteomics could help shed light on our African origin as a species and even reveal clues about the genetic makeup of australopithecines and other related hominins. Because genes are the instructions that code for proteins, identifying ancient proteins trapped in tooth enamel and fossil skeletons can help scientists determine some of the genes that were present in populations that lived millions of years ago.

Still, it's a very new technique. To date, paleoproteomic analysis has identified only a handful of incomplete protein sequences in ancient human relatives and has thus far been able to glean only a small amount of genetic information from those.

But in a landmark study published this year, researchers used proteins in tooth enamel to figure out the biological sex of a 3.5 million-year-old Australopithecus africanus individual from South Africa. And in another study, also published this year, scientists used tooth enamel from a 2 million-year-old human relative, Paranthropus robustus, to identify genetic variability among four fossil skeletons — a finding that suggests they may have been from different groups, or even different species.

Paleoproteomics is still pretty limited, though. In a recent study, scientists analyzed a dozen ancient proteins found in fossils of Neanderthals, Denisovans, H. sapiens and chimpanzees. They found that these proteins could help reconstruct a family tree down to the genus level, but were not useful at the species level.

Still, the fact that protein data can be used to reconstruct part of the braided stream of early humans and to identify the chromosomal sex of human relatives is encouraging, and further research along these lines is needed, experts told Live Science.

Some are confident new approaches could help us unpack these early interactions.

"I think we're going to learn a lot more about Africa's ancient past in the next two decades than we have so far," Van Arsdale said.

Ackermann is more cautious. To really understand when, where and with whom our human ancestors mated and how that made us who we are, "we need to have a whole genome" from these ancient human relatives, she said. "With proteins, you just don't get that."

Sheela Athreya, a biological anthropologist at Texas A&M University, is optimistic that we can use these new techniques to tease apart our more distant evolutionary past — and that it will yield surprises. For instance, she thinks what we now call Denisovans may actually have been H. erectus.

"Absolutely in my lifetime, someone will be able to get a Homo erectus genome," Athreya said, likely from colder areas of Asia. "I'm excited. I think it'll look Denisovan."

Either way, it's clear that a whole lot of mixing made us human.

The Homo lineage may have first evolved in Africa, Athreya said. "But once it left Africa, you have so much complexity that it makes no sense to say there was only one origin of sapiens. There can't be one universal model that explains literally every human on Earth."

The story of our ancient ancestors began in Africa millions of years ago. But there are considerable gaps between the first and current chapters of that tale, and some anthropologists are looking to Asia to fill in missing information about how humans evolved.

"The genus Homo evolved in Africa," Sheela Athreya, a biological anthropologist at Texas A&M University, told Live Science. But as soon as Homo left the continent, "all bets are off because evolution is going to treat every population differently."

One bet Athreya is investigating is the notion that there wasn't a single origin of our species, Homo sapiens. Rather, the ancestors of today's humans living in different geographic regions took different evolutionary paths, before eventually coalescing into the human tribe we know today.

Once humans left Africa, "you have so much complexity that it makes no sense to say there was only one origin of Homo sapiens," Athreya said.

Key to this story is a different understanding of human evolution in Asia — and the possibility that Denisovans, a group of little-understood extinct human ancestors known from just a handful of fossils, were actually the same as a much earlier member of our family tree: Homo erectus, Athreya argues.

Related: Strange, 300,000-year-old jawbone unearthed in China may come from vanished human lineage

Early humans in ancient Asia

There's a big gap in human evolutionary history. We know Homo evolved in Africa and that a human ancestor, Homo erectus, was already in Asia and parts of Europe by about 1.8 million years ago. But what happened in Asia between that point and the time when Homo sapiens arrived around 50,000 years ago? That picture is much less clear.

To help fill it in, Athreya has considered the emergence of our species, Homo sapiens, during the Middle and Late Pleistocene epoch (780,000 to 11,700 years ago). Her "deep-dive" into the human fossil record of Asia has convinced her that there are evolutionary pathways in places like Java, Indonesia, that differ from the Pleistocene patterns seen in Africa and Europe.

H. erectus reached Java at least 1.5 million years ago, and the species likely lasted there until 108,000 years ago. But the lack of more recent H. erectus bones doesn't necessarily mean they went extinct, Athreya wrote in a 2024 study with co-author Yousuke Kaifu, an anthropologist at the University of Tokyo. Instead, these Javanese H. erectus could have persisted until H. sapiens appeared in Sumatra as early as 73,000 years ago and interbred with them.

The fossil record in China is similarly complicated. Around 300,000 years ago, there was a shift in what H. erectus fossils looked like, Athreya said. Skeletons in the Middle Pleistocene in China became more variable in form, and traits that were common in Western Eurasian groups like H. sapiens and Neanderthals, such as smoother bicuspid teeth, began to appear in these fossils.

This means that — instead of completely dying out — H. erectus in China may have made a genetic contribution to populations living today, Athreya said, just as Neanderthals left genetic traces in people with European ancestry and Denisovans contributed DNA to people with Oceania ancestry.

The idea isn't impossible, one expert told Live Science.

Groups of ancient human relatives could have mated anywhere they met up, Adam Van Arsdale, a biological anthropologist at Wellesley College in Massachusetts, told Live Science. No matter where they lived, "I just think humans aren't that different" during the Pleistocene.

What's more, anthropologists are starting to realize that many of these groups that looked very different could still have interbred. Twenty years ago, scientists would have said "there's no possible way" they could have interbred, Van Arsdale said. "And I just don't think we can assume that anymore."

So far, no DNA has been recovered from H. erectus fossils, largely because most of their fossils are too old, so there's no genetic support for this idea. But emerging methods for extracting ancient proteins from fossils may soon make it feasible to identify some H. erectus genes.

Another route to understanding the fate of H. erectus in Asia may be to look more closely at the enigmatic Denisovans.

Since the only known skull of a Denisovan looks similar, in many ways, to that of H. erectus, those two groups may actually be one and the same.

"I don't think that genetics is going to find that Homo erectus was a separate dead-end lineage," Athreya said. "I would expect Denisovans to be Homo erectus."

But until more work is done that combines DNA, artifacts and fossil bones in Southeast Asia, the full picture of human evolution cannot yet come into focus the way it has in places like Europe, Athreya said.

Human evolution quiz: What do you know about Homo sapiens?

Two people who lived in England during the Early Middle Ages had recent sub-Saharan African ancestry — likely from a grandparent, a new DNA analysis reveals.

"The DNA shows that there is human, as well as material, connection and that it extends into West Africa," study co-author Duncan Sayer, a historical archaeologist at the University of Lancashire in the U.K., told Live Science in an email.

Archaeologists discovered the burial of an adolescent girl at Updown cemetery in Kent and the burial of a young man at Worth Matravers cemetery in Dorset. Both cemeteries, located in southern Britain, were dated to the seventh century, after the fall of the Roman Empire, when Anglo-Saxon peoples occupied the island.

DNA analysis of five people buried at Updown and 18 people buried at Worth Matravers found that most of these individuals had Northern European or western British and Irish ancestry, researchers reported in 2022. But when they sequenced the DNA of the girl buried in grave 47 at Updown, they realized her ancestry came from an entirely different continent.

In two studies published Wednesday (Aug. 13) in the journal Antiquity, researchers detailed the unusual genetic backgrounds of the girl from Updown and the young man from Worth Matravers.

Analysis of the young people's mitochondrial DNA, which is passed from mother to child, revealed that both had mothers who were likely from Northern Europe. But their autosomal DNA, which comes from chromosomes that do not code for biological sex, showed clear signals of non-European ancestry.

Related: Archaeologists discover rare liquid gypsum burial of 'high-status individual' from Roman Britain

"Both individuals thus show genetically and geographically mixed descent," and had an estimated 20% to 40% ancestry characteristic of sub-Saharan Africa, Sayer and colleagues wrote in the study. Updown girl's DNA had affinity to that of present-day Yoruba, Mende, Mandenka and Esan groups, the team found.

Based on a statistical model, the researchers propose that both people had a grandparent with African ancestry, possibly from similar groups that left sub-Saharan Africa between the mid-sixth and early seventh centuries.

The fact that these individuals were buried with their communities suggests they were valued by their peers, the authors wrote in the study.

The Updown girl was buried with a knife, a spoon, a bone comb near her left hip, and a decorated pot from Frankish Gaul at her feet. DNA analysis also revealed that she had biological relatives in the same cemetery. The Worth Matravers young man, on the other hand, was buried in a double grave with an older man he was not biologically related to.

Tracy Prowse, a bioarchaeologist at McMaster University in Ontario who was not involved in the studies, told Live Science in an email that the researchers "do a good job of discussing the historical evidence for trade between parts of Africa and northern countries."

Given previous discoveries of diverse individuals dating back to the Roman Empire — including the Ivory Bangle Lady found in York, who may have had North African ancestry — "the presence of these individuals at Updown and Worth Matravers in 7th century Britain isn't terribly surprising," Prowse said.

But Sayer does not think there is continuity between the Roman period people with African ancestry and the seventh-century people found in southern Britain. After the Germanic Vandals sacked Rome in A.D. 455, they founded a kingdom in North Africa. But then the Byzantine Empire conquered them in A.D. 534.

"At the end of the Roman period, North Africa was conquered by the Vandals," Sayer said. "It is the reconquest in the middle sixth century AD — around 533 to 535 — which seems to be the significant event here."

The DNA data showing African ancestry is "unexpected but congruent" with archaeological and historical evidence, the researchers wrote in the study, and is shedding new light on the early medieval period in Britain.

Roman Britain quiz: What do you know about the Empire's conquest of the British Isles?

A prehistoric skull discovered half a century ago in an Italian cave is the oldest example of artificial cranial modification ever discovered in Europe, new research reveals. The unusually long skull, which is about 12,500 years old, confirms that this practice dates back to at least the Stone Age.

"Body modification — including cranial shaping — was one of many strategies used by past societies to construct and communicate identity, status, and belonging," study co-author Irene Dori, a bioarchaeologist at the University of Florence, told Live Science in an email.

In the new study, published July 30 in the journal Scientific Reports, researchers analyzed a skull from Arene Candide Cave, a Late Upper Paleolithic site on the northwestern coast of Italy. Between about 12,900 and 11,600 years ago, generations of hunter-gatherers used the cave to bury their dead. In the 1940s, archaeologists found dozens of human skeletons at the site, and most had been rearranged after death in an ancient ritual. One particular skull of an adult male, called AC12, was discovered in a niche on top of another burial.

In the 1980s, researchers suggested that the long, narrow skull of AC12 may have been the result of a disease or accident that altered the growth of the skull when the man was a child.

But Dori and colleagues were intrigued by another potential explanation: artificial cranial modification. For the new research, they virtually reconstructed the skull and statistically demonstrated that the best explanation for the "oddly shaped head" of AC12 was childhood body modification, they wrote in the study.

The practice of artificial cranial modification involves applying pressure to an infant's head during growth and development. When done consistently for months or years, this results in a permanent reshaping of the person's skull. It is unclear whether the practice would have affected the person's brain function.

The AC12 skull had been reconstructed and glued together in the 1970s, so the researchers had to take it apart to properly measure the skull fragments. They opted to do this nondestructively by performing CT scans of the skull and virtually separating the bones. Then, the researchers digitally reconstructed AC12 in four ways and used a technique called geometric morphometrics, which quantifies the biological shape of a bone, to compare the virtual reconstructions to skulls from around the world.

Related: 'Cone-headed' skull from Iran was bashed in 6,200 years ago, but no one knows why

All of the results of this analysis revealed that AC12 was similar to other artificially modified skulls rather than to normal skulls or those affected by disease or trauma. Specifically, the shape of the AC12 skull was probably made by wrapping strips of fabric tightly around the circumference of his head, the study authors said.

"This would be the earliest known case of artificial cranial modification in Europe," the researchers wrote in the study, as the bones have been dated to between 12,190 and 12,620 years ago.

The reasoning behind the practice of artificial cranial modification is still unknown, and its meaning probably varied among the cultures that performed it.

"Cultural body modification was likely an ancient and widespread practice," Dori said, and "it may have been one of the several practices used to express identity and transmit social norms." At Arene Candide, there is also evidence from people's teeth that they decorated their faces with cheek plugs. But because the skeletons are very fragmentary, Dori said, it is unclear how common artificial cranial modification was.

One idea the researchers are investigating is whether AC12 was somehow different from others buried in the Stone Age cemetery. Analysis of the Arene Candide skeletons' DNA is ongoing, Dori said, and it could shed light on possible long-distance migration or genetic affiliation with other groups.

But artificial cranial modification has been practiced around the world. The oldest example from Asia dates to about 11,200 years ago, while the oldest example in Australia is from 13,500 years ago. Although the practice may be best known from Central and South America, where it was performed for almost 10,000 years, it "has its roots in the Palaeolithic," the researchers wrote.

"It is possible that this practice arose independently in different regions," Dori said, as a practice "rooted in shared human tendencies to use the body as a medium of expression." But given the number of modified skulls throughout Eurasia, "the available evidence does not allow us to determine definitively whether cranial modification was independently invented or culturally transmitted between groups," Dori said.

Stone Age quiz: What do you know about the Paleolithic, Mesolithic and Neolithic?

Stone tools discovered on the Indonesian island of Sulawesi are rewriting what experts thought they knew about human evolution in this region. The tools date to about 1 million to 1.5 million years ago, which suggests that Sulawesi was occupied by an unknown human relative long before our species evolved.

"These are simple, sharp-edged flakes of stone that would have been useful as general-purpose cutting and scraping implements," study co-author Adam Brumm, professor of archaeology at Griffith University in Australia, told Live Science in an email.

In a study published Wednesday (Aug. 6) in the journal Nature, researchers analyzed a set of stone tools that represent the oldest evidence of human relatives in Wallacea, a vast expanse of islands that lie between the Asian and Australian continental shelves.

During excavations between 2019 and 2022, the team discovered seven stone artifacts at Calio, a locality on Sulawesi. The artifacts were made from chert, a hard and fine-grained sedimentary rock, and were created using a percussion flaking technique, where a core rock is struck with a hammer stone to create sharp flake tools. One of the tools was even retouched, which involves trimming the edges of a flake tool to make it sharper.

Using a combination of dating methods, the researchers dated the sediments in which the tools were found to between 1.04 million and 1.48 million years ago. This matches up chronologically with Homo erectus, which reached the Indonesian island of Java around 1.6 million years ago after first evolving in Africa. But Sulawesi does not have as extensive a fossil record as Java.

"So far, the oldest human skeletal element found anywhere on this island [Sulawesi] is a modern human maxilla [upper jaw] fragment that is around 25,000 to 16,000 years old," Brumm said. Sulawesi is also home to the world's oldest narrative cave art, which dates to at least 51,200 years ago. And the oldest stone tool found on Sulawesi, besides the new finds, is about 194,000 years old, the researchers noted in the study.

Related: 140,000 year old bones of our ancient ancestors found on sea floor, revealing secrets of extinct human species

This new stone tool discovery reveals that human relatives occupied Sulawesi much earlier than previously assumed, likely before they made it to the island of Luzon to the north and the island of Flores to the south. And this means that the mystery group on Sulawesi could be the ancestors of Homo luzonensis or Homo floresiensis, both of which were "hobbit"-size human relatives.

The researchers aren't yet sure which species made the tools.

"Until we have found fossils of archaic hominins on Sulawesi," Brumm said, "it would be premature to assign a hominin species to the tool-makers."

But the most likely scenario, given the date range, is that the tools were made by H. erectus or a species similar to H. floresiensis, Brumm said. "We think the Flores hominins came from Sulawesi originally."

It is also still unclear what the hominins were using the tools for.

"Hominins could have used them for tasks involved in the direct procurement of food," Brumm said, "or to fashion tools from wood or other perishable plant materials." So far, though, none of the animal bones that the team has found have cut marks or other signs of butchery.

Human evolution quiz: What do you know about Homo sapiens?

A small collection of 21 teeth may have big implications for the evolution of humans in Asia. The dentition, which comes from a mystery human ancestor that lived at least 300,000 years ago in China, shows an unusual combination of features that may suggest early humans interbred with Homo erectus, a new study reveals.

"It's a mosaic of … traits never seen before — almost as if the evolutionary clock were ticking at different speeds in different parts of the body," study co-author María Martinón-Torres, a paleoanthropologist at the Spanish National Research Center for Human Evolution (CENIEH), said in a statement.

In a study published in the September issue of the Journal of Human Evolution, researchers studied a handful of teeth from the Hualongdong archaeological site in South China and found that they had a mixture of ancient and modern traits.

The teeth belonged to the Hualongdong people, a mysterious group of hominins discovered in 2006. They lived during the Middle Pleistocene epoch around 300,000 years ago. Researchers have found at least 16 individuals to date.

An early analysis of the skeletons suggested they might have been a form of East Asian H. erectus, which reached China by 1.7 million years ago. But a more recent analysis showed that the bones and teeth of the Hualongdong people had a mix of traits typically seen in Homo sapiens and H. erectus. Specifically, Hualongdong people had facial features more similar to humans but limb proportions more often seen in H. erectus.

The new study similarly revealed a mix of traits in the teeth of the Hualongdong people. Most of the dental features appeared modern, including the small size of the wisdom teeth. But the roots of the molars were quite thick and robust, more similar to those found in H. erectus.

Related: Ancient 'Dragon Man' skull from China isn't what we thought

Researchers aren't sure why the Hualongdong teeth look like this, since paleoanthropologists are still piecing together the evolutionary history of humans in China, but they suggested several ideas in the study.

One possible explanation is that the Hualongdong population was closely related to H. sapiens but distinct from Neanderthals and Denisovans, both archaic populations of humans that interbred with some of our ancestors.

Another possibility is that the bones and teeth of the Hualongdong people "could be the result of genetic drift or gene flow with a more archaic form, such as Homo erectus," the researchers wrote in the study. Essentially, the Hualongdong population could be the result of H. erectus and humans having babies or could have come about because of another change in their genetic makeup.

Human ancestors from the Middle Pleistocene epoch are being discovered and analyzed at a rapid pace, paving the way for a better understanding of human origins in Asia.

In 2019, the diminutive species Homo luzonensis was found in the Philippines; in 2021, a newfound species called H. longi was identified in northern China (although the specimen was later found to be a Denisovan); and in 2024, the discovery of Homo juluensis from China was announced. All of these newly identified species of ancient humans date to around 300,000 to 150,000 years ago, and paleoanthropologists are only just beginning to understand how they are all related.

"The Hualongdong discovery reminds us that human evolution was neither linear nor uniform, and that Asia hosted multiple evolutionary experiments with unique anatomical outcomes," study co-author José María Bermúdez de Castro, a paleobiologist at CENIEH, said in the statement.

Human evolution quiz: What do you know about Homo sapiens?

Around 850,000 years ago, a toddler was decapitated and cannibalized, cut marks on one of their neck bones suggest.

The bone, which belonged to an archaic human relative, was found at the Gran Dolina cave at the archaeological site of Atapuerca in northern Spain. An analysis of the bone indicates that the child was between 2 and 5 years old when they died.

"This case is particularly striking, not only because of the child's age, but also due to the precision of the cut marks," Palmira Saladié, co-director of the Gran Dolina excavation, said in a statement Thursday (July 24). "It is direct evidence that the child was processed like any other prey."

The research team excavated a set of 10 skeletons this month, many of which show defleshing cuts and intentional fractures typically found on the bones of animals that were eaten.

All of the newly uncovered skeletons belonged to Homo antecessor, a species of archaic human that went extinct around 770,000 years ago. H. antecessor has only been identified at the Atapuerca site, so its position in the human family tree is unclear. Since it was discovered in 1997, experts have debated whether this ancient human group was the ancestor of Neanderthals and humans or whether it was an offshoot of the human lineage. Either way, H. antecessor is one of the earliest human relatives found in Europe.

Gran Dolina cave has already revealed more than two dozen examples of human cannibalism over three decades of excavation at the site. And roughly 30% of the bones found in the cave so far have cut marks that suggest these early humans were eaten.

"The preservation of the fossil surfaces is extraordinary," Saladié told Live Science in an email. "The cut marks on the bones do not appear in isolation. Human bite marks have been identified on the bones — this is the most reliable evidence that the bodies found at the site were indeed consumed."

The newfound skeletons reinforce the idea that early humans used their companions as a food resource and perhaps as a means of controlling territory, the researchers said.

Related: Human ancestors arrived in Western Europe much earlier than previously thought, fossil face fragments reveal

"What we are documenting now is the continuity of that [cannibalism] behaviour," Saladié said. "The treatment of the dead was not exceptional, but repeated."

The 10 skeletons, including the decapitated and cannibalized toddler, were found in a level that's been dated to between 850,000 and 780,000 years ago. These dates make the bones the earliest evidence of human relatives in Europe — and also the earliest definitive example of human cannibalism to date. (Earlier evidence of cannibalism among human relatives dates to 1.45 million years ago in Kenya, but it's less clear whether those cut marks are from cannibalism or something else.)

Gran Dolina has not yet been fully excavated, however, and it may be hiding more human remains that could shed light on the enigmatic human relative H. antecessor.

"Every year we uncover new evidence that forces us to rethink how they lived, how they died, and how the dead were treated nearly a million years ago," Saladié said.

Editor's note: This article was updated at 11:35 a.m. ET on July 28 to clarify that H. antecessor is an early human relative found in Europe but may not be the earliest.

Human evolution quiz: What do you know about Homo sapiens?

Just before the first COVID lockdown in March 2020, Carlos Neto de Carvalho and his wife, Yilu Zhang, were walking along Monte Clérigo beach in southern Portugal. As the geologist and geographer couple scrambled over rocky outcrops and an old collapsed cliff, they stumbled on a series of ancient Neanderthal footprints.

"It was early in the morning of a sunny day, with perfect light for checking tracks," Neto de Carvalho told Live Science in an email. But when they brought colleagues back to the site to take photos of the tracks, "we were almost trapped by the sudden rise of the tide and needed to swim and climb a 15-meter [49 feet] nearly vertical cliff with all our gear," Neto de Carvalho said.

Their daring adventure paid off. The researchers ultimately discovered five trackways comprising 26 footprints at Monte Clérigo and, in turn, substantially increased experts' understanding of Neanderthals' activities along the Atlantic coast 78,000 years ago.

"The fossil record of hominin footprints, and especially the ones attributed to Neanderthals, is exceedingly rare," Neto de Carvalho and colleagues wrote in a study published July 3 in the journal Scientific Reports, since Neanderthal footprints are nearly identical to humans'.

In this case, the footprints were identified as Neanderthal because modern humans weren't in Europe at that time. Rather, evidence suggests that besides a few earlier failed attempts, Homo sapiens started leaving Africa around 50,000 years ago.

Only six sets of Neanderthal footprints had been discovered previously. Along with the Monte Clérigo tracks, the researchers have reported the new finding of a single footprint from Praia do Telheiro, also in southern Portugal, bringing the total number of Neanderthal trackways discovered in Europe to eight.

At Monte Clérigo, the ancient footprints were made near the shoreline in a coastal dune. Optically stimulated luminescence dating, which measures the last time a mineral was exposed to sunlight, placed the footprints in the range of 83,000 to 73,000 years old.

Related: DNA of 'Thorin,' one of the last Neanderthals, finally sequenced, revealing inbreeding and 50,000 years of genetic isolation

Based on the size and shape of the Monte Clérigo prints, the researchers think an adult Neanderthal male walked up and down the dune, accompanied by a child between 7 and 9 years old and a toddler under 2 years old.

"The fact that in the context of Monte Clérigo infant footprints were found together with those of older individuals suggests that children were present when adults performed day-to-day activities," the researchers wrote.

Because the trackways were heading both toward and away from the shore, these Neanderthals may have been foraging for food, such as shellfish. But another possibility is that the Neanderthals were practicing ambush hunting or stalking prey such as horses, deer or hares, according to the researchers, since some of the Neanderthal footprints were "overprinted" with large mammal tracks.

"At the Monte Clérigo site, the presence of footprints attributed to, at least, one male adult, one child and one toddler, negotiating the steep slope of a dune, allow us to speculate about close proximity to the campsite," the researchers wrote.

But if the Neanderthals had established a camp at Monte Clérigo, no evidence of it remains today.

"The presence of Neanderthals in these environments was intentional even if seasonal," the researchers wrote, "taking benefits from ambush hunting or stalking prey in a rugged dune landscape."

Neanderthal quiz: How much do you know about our closest relatives?

Have you ever stopped by the grocery store on your way to a dinner party to grab a bottle of wine? Did you grab the first one you saw, or did you pause to think about the available choices and deliberate over where you wanted your gift to be from?

The people who lived in western Iran around 11,000 years ago had the same idea — but in practice it looked a little different. In our latest research, my colleagues and I studied the remains of ancient feasts at Asiab in the Zagros Mountains where people gathered in communal celebration.

The feasters left behind the skulls of 19 wild boars, which they packed neatly together and sealed inside a pit within a round building. Butchery marks on the boar skulls show the animals were used for feasting, but until now we did not know where the animals came from.

By examining the microscopic growth patterns and chemical signatures inside the tooth enamel of five of these boars, we found at least some of them had been brought to the site from a substantial distance away, transported over difficult mountainous terrain. Bringing these boars to the feast — when other boars were available locally — would have taken an enormous amount of effort.

A big feast from before the dawn of agriculture

Feasting activities are widely documented in the archaeological record, primarily from communities that rely on agriculture to generate a food surplus. In fact, it has been suggested feasting may have been a driving force behind the adoption of agriculture, although this theory has been widely debated.

While evidence from after the adoption of agriculture is plentiful from all reaches of the globe, evidence pre-dating agriculture is more sparse.

What is special about the feast at Asiab is not only its early date and that it brought together people from wider reaches of the region. It is the fact that people who participated in this feast invested substantial amounts of effort, so that their contributions involved an element of geographic symbolism.

Related: 'Cone-headed' skull from Iran was bashed in 6,200 years ago, but no one knows why

Food and culture

Food and long-standing culinary traditions form an integral component of cultures all over the globe. It is for this reason that holidays, festivals, and other socially meaningful events commonly involve food.

We cannot imagine Christmas without the Christmas meal, for example, or Eid without the food gifts, or Passover without matzo ball soup.

What's more, food makes for gifts that are highly appreciated. The more a food item is reminiscent of a specific country or location, the better. It is for this reason that cheese from France, crocodile jerky from Australia, and black chicken from Korea make for good currency in the world of gift giving.

Just like today, people who lived in the past noticed the importance of reciprocity and place, and formulated customs to celebrate them publicly.

At ancient feasts at Stonehenge, for example, research has shown people ate pigs brought from wide reaches of Britain. Our new findings provide the first glimpse of similar behaviour in a pre-agricultural context.

How to read a tooth

Did you know that teeth grow like trees? Much like trees and their annual growth rings, teeth deposit visible layers of enamel and dentine during growth.

These growth layers track daily patterns of development and changes in the dietary intake of certain chemical elements. In our study, we sliced the teeth of wild boars from Asiab in a way that allowed us to count these daily growth layers under the microscope.

We then used this information to measure the composition of enamel secreted at approximately weekly intervals. The variability in the isotopic ratios we measured suggests at least some of the wild boars used in the feast at Asiab came from considerable distance: possibly from at least 70 km, or two or more days' travel.

The most likely explanation is that they were hunted in farther reaches of the region and transported to the site as contributions to the feast.

Reciprocity is at the heart of social interactions. Just like a thoughtfully chosen bottle of wine does today, those boars brought from far and wide may have served to commemorate a place, an event and social bonds through gift-giving.

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

While installing a water pipeline in Argentina last month, workers stumbled upon the skull of a child who was buried at least 700 years ago. The archaeological discovery quickly garnered media attention because of the asymmetry of the skull, drawing comparisons to aliens.

But the flattening on the back of the skull, which belonged to a 3- to 4-year-old child, is simply the result of the cultural practice of head shaping, Cristian Sebastián Melián, director of the Provincial Directorate of Anthropology in Catamarca, Argentina, told Live Science in a translated email.

The skull was found on May 27 in the town of San Fernando del Valle de Catamarca in northwestern Argentina. When archaeologists investigated the pits made in the infrastructure project, they found broken and burned llama remains, along with a ceramic vessel typical of pottery from the Inca occupation there between 1430 and 1530, Melián said.

But the child's skull was found several feet away along with the rest of the skeleton, which was placed in the grave in the fetal position. Although the child had no grave goods, pottery fragments in the dirt suggested a date of death around 1100 to 1300.

The archaeologists did not see any trauma on the child's skeleton, but they noted the "pronounced cultural cranial alteration of the oblique tabular type," Melián said.

The practice of head shaping, or cranial modification, dates back thousands of years and has been found in all parts of the world. While some cultures used long stretches of cloth wrapped around a baby's head to create an elongated shape, others applied padding to the front or back of the baby's head to create a flatter shape. Nowadays, often for medical purposes, parents may employ a special helmet to ensure their baby has a round, symmetrical head.

Related: 'Cone-headed' skull from Iran was bashed in 6,200 years ago, but no one knows why

The child's skull found in San Fernando was likely shaped using padding to encourage the "oblique tabular" shape, which is flat or sloping at the front and back of the skull. This practice can cause the sides of the skull to widen and appear bulged.

Most scholars of ancient head shaping agree that the practice had few, if any, negative health consequences. Instead, experts say the practice was linked to social identity or to child-rearing preferences.

Currently, the Provincial Directorate of Anthropology has more than 100 skulls from ancient people in its skeletal collection, Melián said, and evidence of head shaping is extremely common.

"Approximately 90% of them have an erect or oblique tabular shape" to their skulls, Melián said.

Women headed communities in eastern China about 4,500 years ago, a DNA analysis reveals.

While analyzing the ancient DNA of skeletons buried in Stone Age cemeteries in China, archaeologists discovered that the society was organized in an extremely rare way: Everyone belonged to one of two clans headed by women, and people were buried in their maternal clans for at least 10 generations.

At the archaeological site of Fujia in eastern China, researchers discovered two cemeteries roughly 330 feet (100 meters) apart flanking an ancient residential area. More than 500 burials were excavated and radiocarbon-dated to between 2750 and 2500 B.C.

In a study published June 4 in the journal Nature, an international team of researchers detailed their analysis of the DNA of 60 skeletons discovered at Fujia — 14 from the north cemetery and 46 from the south cemetery.

All 14 people from the north cemetery shared the same type of mitochondrial DNA (mtDNA), which is transmitted only from mother to child. This suggests that all of the people had the same maternal lineage, the researchers wrote in the study.

In the south cemetery, the researchers identified a different mitochondrial DNA lineage that was shared by 44 of the 46 people they tested. And when the researchers analyzed the Y chromosomes from the male skeletons, they found a high degree of diversity. Together, those findings suggest that the fathers of those buried in the cemeteries came from different lineages while the mothers were related.

"By integrating mtDNA and Y-chromosome analyses, we provide evidence that most individuals at Fujia, irrespective of their sex, were buried according to their maternal lineage," the researchers wrote in the study. In particular, both teenage and adult males were buried exclusively in their maternal clans, which "aligns with the common norms of a matrilineal society," according to the study.

Such findings of ancient societies organized along maternal lines are rare. Only three other studies have used DNA analysis to identify matrilineal communities: Chaco Canyon in New Mexico, Celtic elites in southern Germany, and the Durotriges in Iron Age Britain. Similar practices, however, have been found in contemporary Southeast Asian matrilineal societies.

Related: 'Overkill' injuries on Bronze Age skeletons reveal fierce feuding in ancient China

Deeper analysis revealed high rates of "consanguinity" — marrying a blood relative — over the span of 10 generations. While many people likely married their second or third cousins, four individuals showed signs of mating with first cousins or closer relatives.

While such consanguinity may not be the preferred marriage pattern, it inevitably occurs when you have small, closed-off societies, the researchers wrote.

This "unique social organization" has not been found previously in Stone Age East Asian populations, according to the researchers.

"It is exciting to find a matrilineal society in Neolithic China," Yu Dong, an archaeologist at Shandong University who was not involved in the study, said in a statement.

The Fujia study provides key insights into the social and environmental conditions during the transition from smaller to more complex societies, the researchers wrote. Future DNA and archaeological research should help clarify matrilineal social organization in early human societies, they added.

Terracotta Army quiz: What do you know about the 'warriors' in the 2,200-year-old tomb of China's 1st emperor?

Using cutting-edge DNA analysis, scientists have uncovered the true identity of an ancient human relative nicknamed the "Dragon Man."

The mystery began with a giant, human-like skull discovered by a Chinese laborer in Harbin City, China, in 1933. In 2018, the man's family recovered the Harbin skull, which the laborer had buried in a well, and donated it to science. The enormous cranium features a long, low braincase and a massive brow ridge, along with a broad nose and big eyes. Based on the skull's unusual shape and size, experts gave it a new species name — Homo longi, or "Dragon Man" — in 2021.

But in the past several years, there has been intense debate about whether Dragon Man, who lived at least 146,000 years ago, is a separate species. Instead, some researchers have claimed that the Dragon Man skull may be from a group of ancient humans called the Denisovans, since no Denisovan skull had ever been found.

Now, in two studies published Wednesday (June 18) in the journals Science and Cell, researchers have proved that Dragon Man is indeed the face of Denisovans.

Scientists first attempted to retrieve an ancient genome from the bones and teeth of the Harbin skull, without success. But they were able to recover some DNA from plaque that had hardened on the teeth and some information on proteins from an inner ear bone.

Mitochondrial DNA (mtDNA), which is passed from mother to child, recovered from the skull showed that Dragon Man was related to an early Denisovan group that lived in Siberia from around 217,000 to 106,000 years ago, which means that Denisovans inhabited a large geographical range in Asia, the researchers wrote in the Cell study.

Additionally, the researchers investigated the skull's "proteome," the set of proteins and amino acids found in the skeleton. By comparing the proteome to those of contemporary humans, Neanderthals, Denisovans and nonhuman primates, the researchers found a clear connection between the Harbin cranium and early Denisovans, they wrote in the Science study.

Related: 43,000-year-old human fingerprint is world's oldest — and made by a Neanderthal

"We now have the first comprehensive morphological blueprint for Denisovan populations, helping to address an unresolved question that has persisted over the last decade on what Denisovans looked like," they wrote in the Science study. In short, Denisovans looked like Dragon Man.

While the mystery of the enormous skull has been largely resolved, experts still need to discuss its assignment to the H. longi species.

"This work makes it increasingly likely that Harbin is the most complete fossil of a Denisovan found so far," Chris Stringer, a paleoanthropologist at the Natural History Museum in London who has worked on the Harbin cranium but was not involved in these new studies, told Live Science in an email. Stringer added that "Homo longi is the appropriate species name for this group," although at this point, the group is small.

But Harbin's new identification as a Denisovan also requires experts to reconsider what they thought they knew about the evolution of humans in Asia, particularly in the Middle Pleistocene epoch, around 789,000 to 126,000 years ago. During this period, Eurasia was home to at least three different hominins — humans, Neanderthals and Denisovans — that frequently mated with one another, giving rise to the "muddle in the middle" nickname for this confusing period of evolution.

Until now, the Denisovan group of early humans has been known mostly from their DNA and a tiny handful of fossils. This is in stark contrast to Neanderthals, whose skulls have been found throughout Europe and Western Asia for more than 150 years.

With the identification of the Harbin skull as Denisovan and the identification of a jawbone found off the coast of Taiwan as Denisovan in a study published in the journal Science in April, this means paleoanthropologists have definitive examples that other unknown skulls can be compared to.

Studies of the size and shape of Middle Pleistocene fossil skulls will remain crucial for testing relationships, Stringer said, particularly because DNA does not preserve well in most fossils, and these studies are important for identifying what Denisovans actually looked like. But "there is certainly much more to come from extractions of ancient DNA and proteomes from human fossils," Stringer said.

Human evolution quiz: What do you know about Homo sapiens?

A mysterious type of pitting on the dental enamel of Paranthropus, a genus of extinct human relatives, has baffled experts for decades. But new research suggests the clusters of pits are genetic rather than evidence of a disease, making them key to further understanding the human family tree.

"Teeth preserve an incredible amount of biological and evolutionary information," study co-author Ian Towle, a researcher in the Palaeodiet Research Lab at Monash University in Australia, told Live Science. "This specific type of pitting might turn out to be a unique marker for certain evolutionary lineages, helping us identify fossils."

Towle and colleagues detailed their findings in a study published in the July issue of the Journal of Human Evolution. The team revealed that "uniform, circular and shallow" (UCS) pits in the thick enamel of the back molars of Paranthropus relatives is an unusual and interesting pattern.

During growth and development, the enamel layer on the teeth can be disrupted by environmental issues such as malnutrition, leading to defects in the thickness or composition of the enamel. But those defects typically appear as lines or individual pits rather than as UCS clusters.

To better understand which ancient human relatives had UCS pitting, the researchers looked at dozens of teeth from hominins who lived in eastern and southern Africa 3.4 million to 1.1 million years ago. The researchers discovered that the unusual UCS pitting was common across South African sites where Paranthropus lived, and roughly half of the individuals had this type of pitting.

But they found only a handful of instances of possible UCS in other ancient hominin species.

Related: 2.2 million-year-old teeth reveal secrets of human relatives found in a South African cave

For example, in a sample of more than 500 teeth from South African Australopithecus africanus, Towle said that there was no compelling evidence of UCS pitting. This suggests that the Paranthropus hominins found in South Africa did not evolve directly from A. africanus. But East African australopithecines showed some evidence of UCS pitting, suggesting the Paranthropus genus may have evolved from them.

Only a few teeth from individuals in the Homo genus had UCS-type pitting, including H. juluensis and H. floresiensis (the "hobbits"), both hominin species that lived around 200,000 years ago in eastern Asia, the researchers found. The unusual pitting may suggest that these species are more closely related to australopithecines than to other members of the Homo genus, Towle noted in The Conversation.

But with only a few examples in our lineage, it's currently difficult to draw conclusions about these evolutionary relationships, Towle said. "Further research is essential before UCS pitting can be confidently used as a taxonomic marker in hominin studies" to identify individual species, he said.

One potential way of getting more information from these teeth is through paleoproteomics, the study of ancient proteins trapped in tooth enamel.

"Paleoproteomics could be vitally important for providing further information on UCS pitting and an exciting direction for future research," Towle said, particularly for investigating whether the pitting is more common among male or female Paranthropus individuals.

Based on the researchers' work, UCS pitting seems to have been a common genetic trait for millions of years of our Paranthropus relatives' evolutionary history.

"What we've found in our new research is that even tiny surface features like pits or dimples may be useful for understanding hominin biology and ancestry," Towle said.

Human evolution quiz: What do you know about Homo sapiens?

Small pieces of tooth enamel from deep in a South African cave have begun to reveal secrets held for 2 million years by a distant human relative, a new study finds.

Archaeologists recovered teeth from four members of the species Paranthropus robustus, a two-legged human relative who lived between 1.8 million and 1.2 million years ago, from Swartkrans, a fossil-bearing cave in Africa's Cradle of Humankind World Heritage site. Using cutting-edge techniques that can analyze fossils’ amino acid sequences, the researchers were able to determine the sex of the individuals and discovered surprising genetic variation that could point to the existence of a previously unknown species.

These techniques are part of the field of proteomics, or studying sets of preserved proteins — a relatively new area of science that is shedding much-needed light on the evolution of early hominins, a group that includes humans and our closest relatives.

"Figuring out the human family tree using proteins is the goal," Claire Koenig, a postdoctoral researcher at the University of Copenhagen and co-author of a study published Thursday (May 29) in the journal Science, told Live Science in an email co-written with lead author Palesa Madupe and co-author Ioannis Patramanis. But currently "our ability to distinguish between different species is limited by the small number of different proteins present in enamel."

Although DNA has been recovered from ancient skeletons in Africa, so far that technique has only successfully worked on hominin material dating to no more than 20,000 years ago — well within the lifetime of our own species, Homo sapiens — because DNA degrades quickly in that environment. To get at the roughly 6 million-year history of hominin evolution, analysis of the harder and more stable tissue of dental enamel is needed.

In the new study, an international team of researchers led by Madupe employed paleoproteomic analysis to move beyond the limits of ancient DNA and understand the genes of four hominins who lived around 2 million years ago.

"Proteomics is inherently a destructive technique, but we take great care to minimize impact, especially when working with rare or precious specimens," Koenig said.

Related: In a 1st, ancient proteins reveal sex of human relative from 3.5 million years ago

The researchers focused their proteomic analysis on four P. robustus individuals who likely all died around the same time. They were able to identify AMELY-specific peptides, which are found in the tooth enamel of males, in two individuals. The other two individuals had a high AMELX intensity, meaning they were likely female.

Correctly determining the sex of a fossil is important in paleoanthropology because most hominins are sexually dimorphic, with males being, on average, larger than females. Experts therefore expect that any species will have some larger and some smaller individuals.

But Madupe and colleagues discovered a surprising result: one P. robustus individual who was thought to be female, based on tooth size and shape, was actually male, based on proteomic data. "Our results thus indicate that measurements of dental size are not necessarily accurate for correct sex estimation," the researchers wrote in the study.

Diversity in our ancient relatives

Since sex alone could not explain the differences in the appearance of P. robustus, the team investigated whether the diversity they were seeing could be the result of different groups or species they didn't know about, or the result of interbreeding, as P. robustus overlapped in time with australopithecines and early members of the Homo genus.

The researchers found a couple amino acid sequence positions that varied among the P. robustus specimens they examined, and that were different from the amino acid sequences seen in present-day humans, Neanderthals and Denisovans. This analysis revealed that one of the individuals — SK-835, whose molecular sex and morphological sex did not match up — was more distantly related to the other three individuals than they were to each other.

"It would be premature to classify SK-835 as a member of the newly proposed Paranthropus [capensis] taxa," Koenig said, but it remains a possibility that the amino acid difference reflects its position in a different species than the rest.

It could also be explained, however, by microevolution at different sites, study co-author Rebecca Ackermann, a biological anthropologist at the University of Cape Town, told Live Science in an email. "We need to analyse more Paranthropus material from different sites to get a better handle on the variation within southern African Paranthropus," she said.

Because the enamel proteome is so much smaller — and provides less information — than a full genome, reconstructions of fossil human relatives need to be cautiously interpreted, Ackermann said.

Koenig expects that further methodological developments will be beneficial, including less invasive methods such as acid etching to remove an extremely thin layer of dental enamel, and the development of faster and more sensitive protein-sequencing instruments.

"It remains to be seen, for example, whether or not we can molecularly tell apart a Paranthropus robustus from an Australopithecus africanus," Koenig said, "because these species are closely related and therefore their proteins are going to look very similar."

Evolution quiz: Can you naturally select the correct answers?

An 800-year-old mummy donated to a museum in Italy a century ago has revealed new clues about ancient face tattoos. But the mummy's origin remains shrouded in mystery.

Some time prior to 1930, the mummy of an adult female was donated to the Museum of Anthropology and Ethnography (MAET) at the University of Turin, with no records of its archaeological context. The mummy recently caught the attention of a team of researchers due to the surprising presence of tattoos on her face.

In a study published in the May-June issue of the Journal of Cultural Heritage, the international team of researchers detailed their analysis of the mummy and her tattoos, noting that they were extremely unusual both in their location and in the composition of the ink used to make them.

The mummy has straight black hair cropped short and is tightly flexed into a seated position, typical of mummy burials in the Andes. Researchers carbon-dated textile fragments stuck to the body and determined the woman died between A.D. 1215 and 1382.

"On the basis of current evidence — particularly preservation, body placement, associated materials and documents — a South American origin is strongly supported," study lead author Gianluigi Mangiapane, an anthropologist at the University of Turin, told Live Science in an email.

Related: Lasers reveal hidden patterns in tattoos of 1,200-year-old Peru mummies

But while looking closely at the mummy using infrared reflectography, a technique often used to "see through" paint layers of artwork to find older brush strokes, the research team noted a series of unusual tattoos: three lines on the mummy's right cheek, one line on the left cheek and an S-shape on the right wrist.

"Skin marks on the face are rare among the groups of the ancient Andean region and even rarer on the cheeks," the researchers wrote in the study, and the S-shaped tattoo "is so far unique for the Andean region."

To identify the ink used to make the tattoos, the researchers used a suite of non-destructive techniques. Although they expected to find evidence of charcoal in the ink, they instead discovered that the unusual ink was made with magnetite, an iron oxide mineral, with traces of the mineral augite. In South America, augite and magnetite can be found together in southern Peru, suggesting a potential homeland for the mummified woman.

"There are a small number of ethnographic accounts from the Americas that describe the use of mineral or earth pigments such as hematite or magnetite for tattooing, and the new study fits quite nicely with those," Aaron Deter-Wolf, an archaeologist at the Tennessee Division of Archaeology who was not involved in the study, told Live Science by email.

But Deter-Wolf, who is an expert in ancient tattooing, is not convinced that the mystery mummy hails from the Andes.

"Stylistically, these particular face markings have far more in common with historic Arctic or Amazonian traditions than with Andean practices," Deter-Wolf said. "It would be fascinating to see what oxygen isotopes or other studies might be able to tell us about the origins of this individual."

At this stage, though, isotope analyses have not been carried out. "Since these types of analyses are invasive, we have currently decided to limit such procedures in order to preserve the integrity of the remains," Mangiapane said.

But the MAET that houses the mummy is interested in further investigation, Mangiapane said, and this may include future cultural comparisons to better understand the nature of the mysterious mummy's facial tattoos.

Mummy quiz: Can you unwrap these ancient Egyptian mysteries?

During the last ice age, humans crossing from Asia along the Bering Land Bridge underwent three major population splits as they traveled through the Americas, a new genetic analysis reveals. This journey, which the team identified as the "longest human migration out of Africa," led to a group that settled in Patagonia 14,500 years ago.

In a study published Thursday (May 15) in the journal Science, an international team of scientists detailed their analysis of 1,537 genomes of people from 139 different ethnic groups to identify genetic characteristics of the earliest Americans.

"Many Indigenous populations are small and genetically unique," study co-author Hie Lim Kim, a population genomics professor at Nanyang Technological University in Singapore, told Live Science by email. "One of the main findings of our study is their extremely low genetic diversity."

By analyzing genetic material collected by the GenomeAsia 100K consortium, which includes data from Asian populations whose ancestors made early migrations into the Americas, Kim and her team were able to identify the genetic background of Indigenous people throughout the Americas and pinpoint three key time periods when they split up.

The first population split occurred between 26,800 and 19,300 years ago during the Last Glacial Maximum, the researchers wrote in the study, as Indigenous Americans split from North Eurasian people. These dates are consistent with Native American presence at White Sands in New Mexico in the form of ancient footprints and vehicle drag marks dated to 23,000 to 21,000 years ago.

Related: Ancient Indigenous lineage of Blackfoot Confederacy goes back 18,000 years to last ice age, DNA reveals

According to the study, the next major population split happened between 17,500 and 14,600 years ago, when the Indigenous population in North America split, and some people made their way south. This Mesoamerican group then split rapidly into four native genetic lineages around 13,900 years ago, the researchers wrote: Chaco Amerindians or ancestral Pueblo peoples in the southwest U.S. and Amazonians, Andeans and Patagonians in South America.

"Our estimation actually fits well with the archaeological records" of people in Patagonia, Kim said, which place people living in the furthest southern reaches of the continent by about 14,500 years ago. "It takes some time to accumulate genetic differences between the populations after they have settled in different regions in South America," Kim explained.

But as people made their way into the new continent tens of thousands of years ago, they experienced a reduction in their genetic diversity — due first to geographic barriers, and later to populations being decimated after the arrival of European colonists.

One key loss, the research team discovered, was in the variation in human leukocyte antigen (HLA) genes. A high diversity of HLA genes in a population is important for immune system health. Previous studies found that, in regions such as Southeast Asia with a high number of disease-causing organisms, there was a higher diversity of HLA genes. But in the Indigenous South American genomes, the team found that there was significantly lower diversity in the HLA genes, which may have led to these people being more vulnerable to novel pathogens, Kim said.

The researchers wrote in the study that one of their aims is to emphasize the special medical needs of contemporary Indigenous peoples, as some have gene variants associated with problems like adverse drug reactions.

"Most existing medicines were developed based on studies of European populations, often excluding Indigenous populations," Kim said. "It is critical to provide tailored healthcare and disease prevention strategies that consider their specific genetic profiles."

A gene variant that helps protect people from HIV infection likely originated in people who lived during the span of time between the Stone Age and the Viking Age, a new study of thousands of genomes reveals.

"It turns out that the variant arose in one individual who lived in an area near the Black Sea between 6,700 and 9,000 years ago," Simon Rasmussen, a bioinformatics expert at the University of Copenhagen and co-senior author of the study, said in a statement. The variant must have been helpful for something else in the past, since HIV in humans is less than a century old.

In a study published May 5 in the journal Cell, Rasmussen and his colleagues detailed their search for the origin of a genetic mutation known as CCR5 delta 32. CCR5 is a protein predominantly found in immune cells that many — but not all — HIV strains use to break into those cells and trigger infection.

But in people with two copies of the CCR5 delta 32 mutation, the protein gets disabled, essentially "locking out" the HIV virus. Scientists have taken advantage of this mutation to cure a handful of people of HIV.

Related: Mysterious case of the 'Geneva patient,' the latest person in long-term remission from HIV, raises questions

Scientists have learned that this variant makes up 10% to 16% of CCR5 genes seen in European populations. However, attempts to identify its origin and trace its spread have previously come up short, since ancient genomes are often extremely fragmentary.

In the new study, the research team identified the mutation in 2,504 genomes from modern humans sampled for the 1000 Genomes Project, an international effort to catalog human genetic variation. Then, they created a model to search 934 ancient genomes from various regions of Eurasia ranging from the early Mesolithic period to the Viking Age, from roughly 8000 B.C. to A.D. 1000.

"By looking at this large dataset, we can determine where and when the mutation arose," study co-author Kirstine Ravn, a researcher at the University of Copenhagen, said in the statement.

The team's genetic detective work revealed that the person who first carried this mutation lived near the Black Sea around 7000 B.C., around the time early farmers arrived in Europe via Western Asia. The researchers also discovered that the prevalence of the mutation exploded between 8,000 and 2,000 years ago, suggesting it was extremely useful as people moved out of the Eurasian steppe.

The study's findings contradict previous assumptions that the mutation emerged more recently. For instance, this means that the increase in the frequency of the mutation did not result from medieval plagues or from Viking exploration, which may have introduced pressure for humans' immune cells to evolve.

When it's not being ransacked by HIV, the CCR5 protein helps control how immune cells respond to signals called chemokines, likely helping direct cells to sites of inflammation in the body.

The researchers suggest that people who carried the special CCR5 variant had an advantage. "People with this mutation were better at surviving, likely because it dampened the immune system during a time when humans were exposed to new pathogens," study co-author Leonardo Cobuccio, a postdoctoral researcher at the University of Copenhagen, said in the statement. While this sounds negative, an overly aggressive immune system can be deadly, he said — when facing new germs, you want just enough of an immune response to subdue the threat without hurting the body itself.

"As humans transitioned from hunger-gatherers to living closely together in agricultural societies," Cobuccio said, "the pressure from infectious diseases increased, and a more balanced immune system may have been advantageous." Of course, this is a hypothesis; the exact pressures that lead to the variant's increase aren't known for sure.

Stone Age quiz: What do you know about the Paleolithic, Mesolithic and Neolithic?

Deep in an underground cave in Guatemala, archaeologists stumbled upon hundreds of fragmented human bones showing signs of injury. The discovery paints a chilling picture: The people here were sacrificed during the dry season to appease the Maya rain god — or parts of them were.

"The emerging pattern that we're seeing is that there are body parts and not bodies," Michele Bleuze, a bioarchaeologist at California State University, Los Angeles, told Live Science. "In Maya ritual, body parts are just as valuable as the whole body," she said.

In the early 1990s, a survey underneath the archaeological site of Dos Pilas in Petén, Guatemala, revealed more than a dozen caves that were used by the Maya between 400 B.C. and A.D. 250. One of them — called the Cueva de Sangre, or "Blood Cave" — had a large collection of human bones scattered on the floor, many of which showed evidence of traumatic injuries around the time of death.

In a presentation at the annual Society for American Archaeology meeting on April 24, Bleuze detailed the team's analysis of the Cueva de Sangre bones and explained why they believe the cave was the site of an ancient Maya sacrifice two millennia ago.

Related: Mysterious Tikal altar that wasn't Maya after all includes at least 4 skeletons — and 1 was a child

"There are a few lines of evidence that we used to determine that this was more likely a ritual site than not," Ellen Fricano, a forensic anthropologist at Western University of Health Sciences in California who examined the injuries to the bones, told Live Science. For example, the bones were on the surface, rather than buried, and the injuries to the bones suggest ritual dismemberment, rather than immediate burial.

A fragment of the left side of the forehead, for instance, had a mark suggesting that someone used a tool with a beveled edge — like a hatchet — on the skull, Fricano said. A child's hip bone had a similar cut. Both appear to have been made around the time of death.

Some human remains were also arranged in a nonanatomic way, pointing to a ritualistic nature to their collection. On the ground in one part of the cave, excavators found a series of four stacked skull caps.

The combination of injuries discovered on the bones; the high density of human remains in the cave; and the presence of ritual items, such as red ocher and obsidian blades, strongly suggests that Cueva de Sangre was the site of an ancient Maya ritual sacrifice rather than a standard burial practice, Fricano said.

Sacrifices for a rainy season

Cueva de Sangre is accessed via a small opening and a descent into a low passageway that opens onto a pool of water. Both today and in the past, the cave would have been flooded for most of the year.

The cave was likely accessible only during the dry season, between March and May, and the researchers think this timing is a clue to the meaning of the sacrifice. One important contemporary Maya ritual celebration is called the Day of the Holy Cross. Occurring on May 3, the celebration happens just before the onset of the rains, and people visit caves to pray for rain and a good harvest.

A clear answer to the mystery of the bones in the cave will need to wait a bit longer, Bleuze said. Analysis of the bones from Cueva de Sangre has only just begun. Further work, including ancient DNA and stable isotope analyses, is planned, followed by peer-reviewed publications.

"Right now, our focus is who are these people deposited here, because they're treated completely differently than the majority of the population," Bleuze said.

A Sherlock Holmes-style investigation has revealed the ancient method for the stunning pigment known as Maya blue — and it's different from a previous method uncovered nearly 20 years ago by the same researcher.

Maya blue, discovered by modern researchers in 1931, is not an easy pigment to make. Echoing the color of an azure sky, the indelible pigment was used to accentuate everything from ceramics to human sacrifices beginning in the Late Preclassic period (300 B.C. to A.D. 300).

Maya blue is a highly unusual pigment because it is a mix of organic indigo and an inorganic clay mineral called palygorskite. The rich blue color does not fade over time; it has maintained its vibrancy even in the harsh tropical forests of southern Mexico and Guatemala where the Maya Maya civilization thrived.

For decades, scientists tried to decode the precise method of manufacturing Maya blue, but they did not succeed until 2008. By analyzing traces of the pigment found on pottery at the bottom of a well at Chichén Itzá, a Maya site in the Yucatán Peninsula, a team of researchers led by Dean Arnold, an adjunct curator of anthropology at the Field Museum in Chicago, determined that the key to Maya blue was actually a sacred incense called copal. By heating the mixture of indigo, copal and palygorskite over a fire, the Maya produced the unique pigment, he reported at the time.

But at the annual meeting of the Society for American Archaeology in Denver on April 25, Arnold presented his discovery of a second method for creating Maya blue. The new research has been published in Arnold's book "Maya Blue" (University Press of Colorado, 2024).

Related: Strange altar found at Tikal wasn't made by the Maya — and it has at least 4 people buried inside it

After closely examining a dozen Maya bowls found at Chichén Itzá, Arnold realized that white residue in the vessels was probably palygorskite that was ground when wet, which would have left traces in the tiny fractures that grinding tools left in the pots. Microscopic examination of the 12 bowls further revealed tiny, burnt plant stems, and the bases of the bowls showed that they were heated from below, his detective work showed.

"Consequently, the observations of these bowls provide evidence that the ancient Maya used this method as a second way to create Maya blue," Arnold said in the presentation.

But Maya blue was not just a pretty paint, Arnold told Live Science. It's also part of Maya cultural heritage. "This is a genius discovery that they made, and apparently the knowledge of it was limited to specialists like priests," he said.

Arnold thinks Maya blue was particularly important in sacrifices made to the Maya rain god Chaak (also spelled Chaac and Chac) during periods of drought. The result of mixing indigo, palygorskite and copal, Arnold said, "is also perhaps an incarnation of the rain god Chaak in this bowl after you heat it."

The question of how the Maya made this blue pigment is still not completely solved, however. Arnold said future research will include a microscopic study of the plant remains found in the bowls to see if the genus and species that produced the blue color can be determined.

Editor's note: This story was updated at 10:36 a.m. ET on May 7 to clarify when the Maya started using the blue pigment.

Archaeologists in Peru have discovered a 2,500-year-old secret drug room filled with hollowed-out bird bones containing traces of psychedelic snuff and tobacco. The presence of the "snuff tubes" in a hidden room suggests the elite held secret, drug-fueled rituals in pre-Inca times.

"The tubes are analogous to the rolled-up bills that high-rollers snort cocaine through in the movies," Daniel Contreras, an archaeologist at the University of Florida, told Live Science in an email.

In a study published Monday (May 5) in the journal PNAS, Contreras and a team of archaeologists analyzed the chemical residue in 23 bone and shell artifacts from the archaeological site of Chavín de Huántar in the north-central highlands of Peru. They set out to investigate a long-standing assumption that rituals at the site involved psychoactive substances.

This study is the first to show the specific drugs that were inhaled at Chavín, where ritual activity was high but there was little direct evidence of drug use.

Chavín was a major center of ritual activity between 1200 B.C. and 400 B.C., before the birth of the Inca empire. The complex included stone structures built around open plazas. As people added to the buildings over the centuries, several rooms became interior spaces called galleries.

Related: Secret ancient Andean passageways may have been used in rituals involving psychedelics

One particular gallery was sealed around 500 B.C. and not opened again until archaeological excavation in 2017. When archaeologists explored the gallery, they discovered 23 artifacts carved from animal bone and shell into tubes and spoons.

An analysis of the chemical residue on the artifacts revealed that six contained the organic compounds nicotine, likely from tobacco, and dimethyltryptamine (DMT), a naturally occurring hallucinogenic drug commonly found in ayahuasca tea.

Further microbotanical analysis showed that four of the artifacts once contained roots of wild Nicotiana species and the DMT-containing seeds and leaves of vilca (Anadenanthera colubrina), which were likely dried, toasted and ground up to produce a potent snuff.

"The tubes would have been used — we think — as inhalers," Contreras said, "for taking the snuff through the nose."

The bone snuff tubes, which may have been made from the wings of a peregrine falcon (Falco peregrinus), were also concentrated in restricted-access areas of Chavín, suggesting that psychoactive substance use was controlled by select participants, the researchers noted in the study.

Because only a handful of people could fit in the small gallery areas at Chavín, the researchers think drug use reinforced the social hierarchy, creating an elite class separate from the workers who built Chavín's impressive monuments.

"One of the ways that inequality was justified or naturalized was through ideology — through the creation of impressive ceremonial experiences that made people believe this whole project was a good idea," Contreras said in a statement.

Controlled access to ritual drug use also may help to explain a major social transition in the ancient Andes — from more egalitarian societies to the more hierarchical Tiwanaku, Wari and Inca empires.

These results suggest that additional work is needed to fully understand the importance of psychoactive substances in the ancient Andes, the researchers wrote.

While analyzing an 18th-century Austrian mummy, researchers discovered that the man died from tuberculosis and was preserved in a very unusual way: with wood chips, twigs and fabric packed into his abdomen through his anus.

The mummified body was located in a church crypt in St. Thomas am Blasenstein, a small village in Austria near the Danube River. Known locally as the "air-dried chaplain," the mummy was assumed to have been the preserved remains of a parish vicar named Franz Xaver Sidler von Rosenegg, who died in 1746.

Over the years, Sidler's body has been associated with various healing miracles. But his cause of death remained a mystery, heightened by an X-ray analysis in 2000 that suggested his mummy contained a poison capsule.

In a study published Friday (May 2) in the journal Frontiers in Medicine, researchers conducted a new analysis, using multiple techniques to quash rumors about Sidler's puzzling death. In the process, they discovered a remarkable embalming method missing from historical records.

"Our investigation uncovered that the excellent preservation status came from an unusual type of embalming, achieved by stuffing the abdomen through the rectal canal with wood chips, twigs and fabric, and the addition of zinc chloride for internal drying," study lead author Andreas Nerlich, a researcher at Ludwig-Maximilians University in Munich who specializes in mummy research, said in a statement.

Related: 'Pregnant' ancient Egyptian mummy with 'cancer' actually wasn't pregnant and didn't have cancer, new study finds

Following a macroscopic observation of the body, which revealed male external genitalia, the research team performed a CT scan of the mummy to identify the organs and other material inside the body. They also took samples of skin, tissue and dental enamel for chemical analyses, to establish when the man died, what he ate and whether he had been poisoned.

The CT scan revealed a minor-but-chronic infection in the man's nasal sinuses, and several of his front teeth were worn in a semicircular pattern, both of which suggested long-term pipe smoking. Additionally, the researchers discovered calcifications and cysts in his lungs, both of which are common in people with chronic tuberculosis. These lung issues may have resulted in acute pulmonary hemorrhage, the researchers noted in the study. This was his likely cause of death, the research team said, since the toxicology analysis did not reveal any evidence of poisoning.

But the afterlife of the mummy and the way it was created have baffled the researchers.

After making a small incision in the chest wall, the team closely examined the foreign material found inside the body of the mummy. This material included mud, wood chips from spruce and fir trees, and branches from unidentified tree species. Intermingled in this mixture were swatches of hemp, flax and silk fabric, along with wooden buttons that presumably adorned the fabric. The round, hollow object that researchers previously believed was a poison capsule was extracted and found to be a glass bead from a rosary.

Historically, mummies have often been created by opening the body's abdominal wall, removing the organs, and inserting packing material. But in this case, the mummy's abdomen was intact, leading the researchers to conclude that his pelvis was packed via his anus, which they found to be somewhat enlarged.

Based on the radiocarbon date from the mummy's skin, the age at death determined from the skeleton, and historical records, the researchers concluded that the mummy could indeed be positively identified as Franz Xaver Sidler, who died in St. Thomas in 1746 at only 37 years old. Because most people at that time were not mummified, however, it is still unclear why Sidler merited this treatment.

"We have some written evidence that cadavers were 'prepared' for transport or elongated laying-out of the dead," Nerlich said. "Possibly, the vicar was planned for transportation to his home abbey, which might have failed for unknown reasons."

Mummy quiz: Can you unwrap these ancient Egyptian mysteries?

Dozens of skeletons buried in a 3,700-year-old cemetery in China show evidence of extreme trauma, suggesting that assailants felt a need to "overkill" their victims in bloodthirsty raids during the Bronze Age.

"One individual had 18 separate stab wounds to the cranial vault, which is obviously more than is needed to incapacitate or kill a person," Elizabeth Berger, a bioarchaeologist at the University of California, Riverside, said in a presentation April 24 at the Society for American Archaeology annual meeting in Denver, Colorado.

Berger and colleagues presented new results — which are not yet published in a peer-reviewed journal — from their analysis of a cemetery called Mogou in Gansu Province, China. Part of the Bronze Age Qijia culture, Mogou was used for burials between 1750 and 1100 B.C. The large cemetery contains more than 1,600 graves with more than 5,000 people buried in them. These people lived a mostly agricultural lifestyle and exchanged metal and ceramic goods with other groups in the region.

In 2019, the researchers published a preliminary study of some of the Mogou skeletons, discovering a shockingly high frequency of trauma on adult skulls. Their new work, which focused on 348 skulls from adults and adolescents, also revealed a lot of trauma: 11.1% of the heads had evidence of unhealed injuries, such as stab wounds, blunt trauma and projectile damage.

What surprised the researchers, though, was their discovery that the majority of the adults with trauma had suffered multiple injuries rather than just one fatal blow; 55% of the adults had three or more cranial wounds.

"None of the other sites in the region has violence like this — it is unique," Berger told Live Science.

Related: 2,200-year-old grave in China contains 'Red Princess of the Silk Road' whose teeth were painted with a toxic substance

Males were more likely than females to have multiple-injuries on their crania, Berger said in the presentation, and several males had defensive injuries such as violent fractures of their hand bones. The researchers also found injuries to different parts of the skulls — such as the front and rear — that suggest the possibility of multiple attackers.

The results of intense violent interactions can be seen on numerous male skulls, including one with a large slash through his face showing sharp trauma, and one who had chop marks on his lower leg in addition to 18 separate stab wounds on his skull.

Why "overkill"?

The extreme nature of the violence inflicted on the skeletons, Berger said in the talk, suggests the idea of "overkill," a term used by forensic specialists to describe homicides in which a murderer does significantly more damage than necessary to kill their victim.

"I think it is a useful term," Berger said in the talk, "because there seemed to have been an emotional or psychological or performative aspect to the violence."

The researchers are still unsure of the reason for the Bronze Age violence. Warfare and raiding are two potential interpretations, particularly because the Qijia culture was situated at a kind of ancient crossroads between different groups of people.

But Berger believes the explanation might lie in an ancient blood feud, in which there was both a lethal intent but also a need "to destroy the social identity of the people who were being killed and cause psychological damage to the people who were not killed," she said in the talk.

"Violence is a cultural component of society," co-author Jenna Dittmar, a biological anthropologist at Edward Via College of Osteopathic Medicine in Louisiana, told Live Science. "It's important that we go back and revisit previously published collections of skeletons," particularly to look for evidence of trauma, she said.

Additional research is ongoing at Mogou, the researchers said, including the study of animal bones, parasites and ancient DNA, with a goal of understanding what life was like during a key transition to a drier and cooler climate.

Terracotta Army quiz: What do you know about the 'warriors' in the 2,200-year-old tomb of China's 1st emperor?

A "groundbreaking" DNA analysis of a small Pueblo tribe in New Mexico supports what their oral tradition has long described — that they're related to ancestral people who lived on their land, as well as to Indigenous people who lived a few hundreds miles away at Chaco Canyon.

The new research is the first DNA evidence that the federally recognized tribe, known as Picuris Pueblo, has ancestral ties to Chacoans buried at Chaco Culture National Historical Park, a UNESCO World Heritage Site and a place many Southwest Indigenous peoples consider sacred.

"We've always said we have this deep connection to Chaco Canyon," study co-author Craig Quanchello, the lieutenant governor of Picuris Pueblo, said at a news conference on April 29. "It not only runs through our veins, but now through science."

Pueblo peoples

Picuris Pueblo, where the tribe lives, is in the Sangre De Cristo Mountains of northern New Mexico, about 60 miles (100 kilometres) north of Santa Fe. It was historically one of the most populated pueblos, with over 3,000 tribal members around 1600. But in the decades following European contact in 1591, death, disease and religious persecution reduced the Picuris population significantly. Now, tribal membership is around 300 individuals.

Related: Ancient Indigenous lineage of Blackfoot Confederacy goes back 18,000 years to last ice age, DNA reveals

Oral histories from Picuris elders have long connected the tribe to Chaco Canyon, Picuris Pueblo Governor Wayne Yazza said at the news conference. But knowledge lost over centuries of violence has led to gaps in historical knowledge.

To learn more about their genetic heritage, Picuris Pueblo leadership contacted researchers in 2020.

In that study, whose results were published Wednesday (April 30) in the journal Nature, researchers analyzed ancient DNA from 16 individuals buried in Picuris Pueblo dated to between 500 and 700 years ago, as well as 13 genomes from currently enrolled members of Picuris Pueblo. They compared these genomes to 590 ancient and modern genomes from the Americas and Siberia, since the first Americans traveled across a land bridge connecting Siberia with Alaska during the last ice age at least 23,000 years ago.

Their results revealed that the modern Picuris are related to those who lived in the pueblo centuries ago. The analysis also indicated that the Picuris are related to Anzick-1, a child who lived 13,000 years ago in what is now Montana and was part of an Indigenous American group called the Clovis. But "part of their [the Picuris] ancestry is actually older than the ancestry that we find in the Clovis individual," study lead author Thomaz Pinotti, a geogeneticist at the University of Copenhagen, said at the news conference.

The study also found a genetic link between the Picuris and nine individuals buried centuries ago in Chaco Canyon's Pueblo Bonito between 800 and 1130. Those individuals were analyzed in a 2017 Nature Communications study that faced backlash from tribal nations and researchers for failing to consult with local tribes during the study's design.

"We were pretty twisted up about using these data, because we knew how controversial they were," study co-author Mike Adler, an associate professor of anthropology at Southern Methodist University, said at the news conference. "When we brought this up to the tribal council, it was a very simple response: 'That's not your call. That's our call. You should use these data, because it's an avenue to better our understanding of our own past.'"

Meradeth Snow, an associate professor of anthropology at the University of Montana who wasn't involved in the study, told Live Science the new study is "groundbreaking in a lot of ways."

"The fact that this was really something that was initiated by the Picuris [people] — that is amazing and really interesting," she said. However, she emphasized that this type of partnership may not be of interest to other Indigenous peoples. Western scientists have a long history of taking Native American ancestral remains and conducting studies without permission from tribes.

"I understand that there's definitely going to be different tribes in that region that are not going to be for this [type of DNA analysis]. And that's totally understandable. There's certainly been plenty of abuse of DNA data."

Archaeologists believe they have found two mass graves of Black Union soldiers in Kentucky thanks to remote sensing techniques and the dogged work of a local historian, allowing them to tell the story of a forgotten Civil War tragedy.

On Jan. 25, 1865, a company of Black Union soldiers was ambushed by Confederate guerrillas in Simpsonville, Kentucky. Kentucky was technically neutral during the Civil War, but it was also home to Company E of the United States Colored Cavalry (USCC). This company was based at Camp Nelson, a Union Army depot where many enslaved men enlisted in order to be freed. The soldiers there had been driving 900 head of cattle toward Louisville as part of the Union supply chain when, unexpectedly, they were attacked by better-armed Confederate guerrillas.

These guerrilla troops — often called bushwhackers — generally included men who wanted to fight outside the confines of the military by surprising, ambushing and killing troops rather than following the rules of war.

"What followed wasn't a battle — it was a slaughter," Philip Mink, an archaeologist at the University of Kentucky, said in an April 24 presentation at the Society for American Archaeology conference in Denver. "Most of the 22 men were shot in the back while fleeing, despite wearing the uniform of the U.S. Army," he said. "Guerrillas definitely targeted them because they were Black," Mink told Live Science.

At the time, local newspaper coverage of this event was minimal, with reports that Simpsonville residents buried the bodies in a trench. But no formal record of the burial site was made, and the Union burial commission did not attempt to locate the soldiers' bodies after the war.

Related: Remains of 4 Confederate soldiers, amputated legs and gold coins found at a Civil War battlefield in Virginia

More than a century later, local historian and retired State Rep. Jerry Miller scoured through oral histories, archival documents and old maps in an attempt to find the mass grave from the Simpsonville massacre. He joined forces with Mink and his colleagues in the search for the grave in 2008, when they investigated a local African American cemetery, without any success. Their research is not yet published in a peer-reviewed journal.

But a big break in the cold case came in the fall of 2023, when Miller found a single 1936 map that clearly marked a Civil War burial mound in what is now the field of a soybean farmer. The farmer confirmed the researchers' suspicions: His father and grandfather had always told him there were Civil War soldiers buried on their property.

Mink and his team then launched a geophysical study of the land in December 2023, using a drone-mounted magnetometer to scan underneath the ground for metallic objects like bullets or belt buckles and terrestrial ground-penetrating radar to search for the location of the mass grave.

As the archaeologists analyzed the data they had gathered, they zeroed in on one anomaly that was about 5 feet (1.5 meters) deep, 13 feet (4 m) wide and 65.6 feet (20 m) long, which is "consistent with a mass grave," Mink said in the presentation. However, their research also revealed a second, similarly shaped anomaly.

"This is not what I expected," Mink said. "There's a possibility that there may be two mass graves because, out of the 22 men who were killed, 14 were instantly killed and were buried immediately." The remaining soldiers were wounded and died later and then may have been buried in a second grave.

Because the landowner has a crop of soybeans currently growing in the field, Mink said, the team plans to dig a shallow trench this fall to find conclusive evidence of the graves.

"As soon as we see that, we stop, we cover it back up, and then we decide what our next steps forward are," Mink said, including consulting with the descendant community, military representatives and preservation experts.

"I'm so impressed with the use of modern technology to give dignity to these long-ignored and forgotten African American soldiers," Holly K. Norton, the state archaeologist of Colorado, who was not involved in the research, told Live Science.

The Simpsonville massacre is a story of injustice, Mink said, and the men deserve to be remembered. Headstones have been made by Kentucky's Shelby County Historical Society with the names of the USCC soldiers who were targeted by Confederate guerrillas, and the Commonwealth of Kentucky has erected a historical marker in remembrance of the massacre.

"In an ideal world, these men will be removed and reburied with full military honors at the Camp Nelson National Cemetery, where many of their other comrades are buried," Mink said.

Archaeologists have long assumed that Stone Age tombs in Ireland were built for royalty. But a new analysis of DNA from 55 skeletons found in these 5,000-year-old graves suggests that the tombs were made for the community, not for a ruling dynasty.

In Ireland's Neolithic period, which lasted from about 3900 to 2500 B.C., people built "megalithic monuments" — large stone structures that contained human bones and cremated remains. While the monuments clearly marked burials, archaeologists have argued about who was interred in them and whether the tombs served other purposes, such as being focal points for rituals, ceremonies or performances.

Early DNA work found that the people who built these monuments were early farmers who herded cattle and grew grain. It also concluded that these tombs were built for ancient elite dynasties with incestuous marriages. But a study published April 2 in the Cambridge Archaeological Journal suggests archaeologists may have been wrong about the identity of the people buried in the tombs — and their relationships.

Instead of being royal tombs, the megalithic monuments may have been spots where people came together in different seasons to work, feast and bury their dead, study lead author Neil Carlin, an archaeologist at University College Dublin, told Live Science in an email. And this society built the tombs following a major shift away from four centuries of simpler burial practices, the study suggests.

Related: Neolithic women in Europe were tied up and buried alive in ritual sacrifices, study suggests

Archaeologists have identified four different kinds of ancient graves in Ireland, including three simple types used in the earlier part of the Neolithic and a fourth type called the "developed passage tomb" that originated around 3300 B.C. Passage tombs consisted of a large circular mound entered through a stone corridor. They are older than Stonehenge and the Egyptian pyramids, and many still dot the landscape of Ireland, including the well-known Newgrange passage tomb.

Carlin and his team noted that most individuals buried in the passage tombs did not have close genetic ties. Given this, the researchers wrote in the study, "we cannot say that these tombs were the final resting places of a dynastic lineage who restricted access to 'burial' within these tombs to their relatives."

Because megalithic monuments were obviously important to Neolithic people but were not necessarily linked to biological relationships, the researchers wanted to "develop a deeper understanding of changes in kinship during the Neolithic," Carlin said. By looking closely at the DNA evidence and at the subtle differences in burials throughout the Neolithic period, the researchers discovered a major shift after the first four centuries of farming in Ireland.

In the early Neolithic, the small, simpler tombs are paralleled in the genetic work, which has shown that there were smaller communities with closer biological ties. But in the later Neolithic period, when people built larger passage tombs, most of the people buried there were relatively diverse and more distantly related, the DNA analysis showed.

"We argue that this reflects how the kin groups using these tombs were interacting on a larger scale and more frequently choosing to have children with others from within these extended communities," Carlin said.

What caused this shift isn't clear. But the researchers suggest that the clusters of passage tombs in Neolithic Ireland show that disparate groups of people came together, perhaps seasonally, to participate in ceremonial activities together.

Instead of seeing the Neolithic period as one ruled by powerful dynasties, the researchers view it as "a more equal society," Carlin said. But more work is needed — including new studies of DNA, artifacts and monumental architecture — to fully understand the social changes that happened in Ireland after 3600 B.C., the researchers wrote in their study.

Stonehenge quiz: What do you know about the ancient monument?

Around 2,500 years ago, an elite Celtic warrior was gravely injured by an arrowhead, but his wound partly healed thanks to meticulous medical treatment, a new study reports.

"Healing took at least several weeks," study first author Michael Francken, an osteologist at the State Office for the Preservation of Monuments in the Stuttgart Regional Council, told Live Science in an email. "Most men of this period were familiar with combat, but the elites were probably more focused on it."

In the new study, published online Feb. 23 in the International Journal of Osteoarchaeology, researchers analyzed a skeleton found in an Iron Age burial mound after noticing severe trauma to the pelvis. The man, who lived until he was between 30 and 50 years old, appeared to have been shot with a projectile.

The skeleton was discovered decades ago as the central burial beneath a large mound at the prehistoric hillfort site of Heuneburg in southern Germany. The mound was about 140 feet (43 meters) in diameter and nearly 10 feet (3 m) high. A limited number of artifacts were found in the burial due to grave robbers raiding the site in antiquity, but archaeologists identified fragments of a chariot, metal belt and jewelry that helped them date the burial to 530 to 520 B.C.

The researchers determined that the wound was located on the man's left ischial bone — part of the pelvis sometimes referred to as the "sitz" bone — close to his hip socket. Based on the wound track's direction through the bone, the researchers concluded that the man was struck in the pelvis from his front left, likely when he was running, sitting or riding.

Related: Were the Celts matriarchal? Ancient DNA reveals men married into local, powerful female lineages

Although no weapon was found embedded in the bone or in the grave, the researchers figured out what it was based on 3D CT scanning, which let them make a negative imprint of the wound.

The overall shape and size of the imprint suggested a small arrowhead caused the trauma to the man's pelvis. Based on archaeologically known weapons of the time, it was most likely a long arrowhead with a diamond-shaped tip used in combat.

Because the ischial bone was not fully perforated, the arrow must have been pulled out, the researchers wrote. "The healing of the injury implies that the arrowhead was expertly removed and the wound received proper medical treatment," they said.

No written records of medical treatment in the early Iron Age survive. However, based on evidence that the wound channel in the man's pelvis had to be enlarged to remove the arrow, the researchers suspect that medical practitioners of the time had specialized implements to help treat injuries.

After the arrow was removed, the man likely needed several weeks to convalesce, the researchers said. "This suggests the injured person probably belonged to a social class exempt from daily physical labor for sustenance," they wrote.

The smooth edges of the wound indicate that the injury occurred at least several months prior to the man's death, Francken said, but "unfortunately, I can't say whether there is a connection between the individual's death and the injury."

The exact nature of the battle this man was injured in is also unknown, as these Iron Age people did not keep written records of combat. But given this man's access to medical care, the researchers think he was part of the elite social class, honored at death with a "princely burial" in a massive mound.

In medieval Europe, some handcrafted books were bound with skin from an unexpected source: seals.

A new analysis of ancient DNA found in medieval books from European abbeys reveals that these seals came from the northwestern Atlantic Ocean, where they were hunted in the 12th and 13th centuries for their skins. The sealskins were then traded by the Norse descendants of the Vikings before ending up as book covers.

In the study, published Wednesday (April 9) in the journal Royal Society Open Science, a team of researchers subjected 32 medieval books to biocodicological analyses — a series of methods aimed at revealing biological information preserved in codex-style books.

Medieval codices were written on pieces of parchment made of animal skin, that were bound together with wood, leather, cord or thread. Some also had a second protective cover, called a chemise, which was often made from boar or deer skin.

But the new study revealed that some chemises were actually made from seals instead.

The researchers began their investigation at the Library of Clairvaux Abbey in Champagne, France, which holds 1,450 medieval books produced by scribes at this Cistercian abbey, part of a Catholic religious order. Focusing on 19 books created between 1140 and 1275, the experts used mass spectrometry, a technique that can reveal the chemical makeup of an object, and ancient DNA analysis to reveal that they were all bound with skin from pinnipeds, a group that includes seals.

Related: People in Scandinavia may have used boats made of animal skins to hunt and trade 5,000 years ago

The researchers identified an additional 13 "hairy books" from "daughter abbeys" in France, England and Belgium dated to between 1150 and 1250 that were also bound in sealskin.

The ancient DNA analysis helped the researchers narrow down which pinniped species eight of the skins came from, pinpointing harbor, harp and bearded seals. Additionally, they were able to tell that the seals came from a surprisingly diverse geographic area, including Scandinavia, Denmark, Scotland and either Greenland or Iceland.

"The skins were either obtained through trade or as part of the church tithe," study lead author Élodie Lévêque, an expert in book conservation at Paris 1 Panthéon-Sorbonne University, told Live Science in an email. "It is doubtful," she said, that these bindings "would have existed without the availability of sealskins from Norse sources."

All of the sealskin books were made in abbeys located along known 13th-century European trading routes, the researchers noted in their study; these were also Norse trading routes. In particular, the Norse traded walrus ivory and furs from Greenland to mainland Europe, and historical records suggest they used sealskins to pay tithes to the Catholic church in the 13th century.

"The Cistercians had a particular preference for white and discreet forms of luxury, which aligns well with the aesthetic qualities of sealskin," Lévêque said. Another well-known sect, the Benedictines, favored darker hues.

However, the monks may not have known that their prized book-binding skins were actually from seals, she said, since there was no term for the animal in the French language at the time.

The widespread use of sealskins in medieval libraries has challenged previous assumptions about which species were used to bind books, the researchers wrote in their study. It has also revealed that the trade network between the Norse in Greenland and abbeys in France was extensive and robust.

But there is no obvious correlation between the actual contents of the books and the use of sealskin covers, and no written explanation for the use of sealskins in book-binding survives, the researchers noted in their study.

"The distinctive white, furry bindings may therefore have been appreciated solely for their visual and environmental qualities – they're waterproof – rather than for any knowledge of their zoological and geographical origin," Lévêque said.

Five millennia ago, Bronze Age people in Mesopotamia built elaborate stone tombs full of spectacular grave goods and human sacrifices. Researchers are unsure of the meaning of this ritual, but a new study of the skeletons points to a clue: the age at which people were sacrificed and their biological sex.

"The fact that they are mostly adolescents is fascinating and surprising," David Wengrow, a professor of comparative archaeology at University College London, told Live Science. "It highlights how little thought scientists and historians have really given to the importance of adolescence as a crucial stage in the human life cycle."

The finding may also upend assumptions about the type of government this culture practiced. Previously, it was thought to be a king-led hierarchical society, but these burials hint at a more egalitarian organization.

Ancient burials in Turkey

Wengrow and colleagues have studied a series of skeletons found at the archaeological site of Başur Höyük on the Upper Tigris River in southeastern Turkey. Once part of ancient Mesopotamia, Başur Höyük is dated to between 3100 and 2800 B.C. Several stone tombs were discovered there a decade ago, full of hundreds of copper artifacts, textiles and beads.

In a previous study, researchers identified a burial of two 12-year-old children flanked by eight violently killed people and suggested the funeral ritual indicated the rise of an early state that included "royal" tombs with "retainer sacrifice."

But in a new study, published March 17 in the Cambridge Archaeological Journal, the researchers conducted ancient DNA analysis on a separate set of skeletons and presented a more nuanced view of the cemetery, focusing on the idea of adolescence as an important life stage in this society.

Related: Massive Mesopotamian canal network unearthed in Iraq

Ancient DNA analysis of nine skeletons from Başur Höyük showed that the people were not biologically related to one another. The DNA also showed that most of the people the researchers tested were female.

"So we are dealing with adolescents brought together, or coming together voluntarily, from biologically unrelated groups to carry out a very extreme form of ritual," Wengrow said. The meaning of the ritual, however, is still unclear.

Previously, researchers thought that the main burials represented young royals with their sacrificed attendants. But this interpretation was based on the idea that early Bronze Age societies had evolved into large-scale states with a king at the top of the social hierarchy.

There is now more archaeological evidence that Bronze Age political systems were more flexible. Societies in Mesopotamia could have regularly switched between hierarchical, king-based rule and a more egalitarian social organization where people collectively make decisions.

"The idea that humans evolved to live in just one form of society almost all the time is almost certainly wrong," Wengrow said. If Başur Höyük was one of these more fluid societies, the "royal" burial may be better explained as a complex and potentially age-related funeral tradition.

"Much more likely, what we see in the cemetery is a subset of a larger group, other members of which survived the ritual process and went on to full adulthood," Wengrow said. This larger group can be called an "age set," according to the study.

In general, in egalitarian societies, leadership is earned instead of inherited, but "age sets" and gender can also come into play. For instance, elders may be valued for their wisdom and experience, while adolescents may be valued for their hunting skills. In the case of the Bronze Age burials in Turkey, this "age set" of adolescents could represent initiates into an ancient cult or victims of inter-group competition or violence, the researchers note in their study.

Few researchers focus on adolescence in ancient societies, the researchers noted in their study, so the Başur Höyük burials suggest that it is important to investigate age sets in early Bronze Age states rather than assuming the society was led by kings and other royals at the top of a political hierarchy.

Further research on the skeletons is forthcoming, Wengrow said, in terms of stable isotope analysis to figure out the origins of the people buried at Başur Höyük.

"For now, all we can say is that many of the teenagers buried in the tombs were not local to the area of the cemetery," he said.

Modern humans have uniquely small and flat faces, especially compared with our Neanderthal cousins' notoriously robust faces and large noses, but the reason for this difference has eluded paleoanthropologists. Now, researchers have determined that human faces grow slowly and stop growing during early adolescence, whereas Neanderthals' faces kept growing into early adulthood.

"These two human species followed different developmental trajectories for their facial bones," Alexandra Schuh, a postdoctoral researcher at the Max Planck Institute for Evolutionary Anthropology in Germany, told Live Science.

In a study published Monday (March 24) in the Journal of Human Evolution, Schuh and colleagues analyzed the midface region of 174 skulls of Homo sapiens, Neanderthals and chimpanzees. By including skulls from individuals throughout childhood and into adulthood, the researchers were able to investigate facial ontogeny — how the facial bones of the skull develop and grow.

The researchers used two techniques to closely examine the skulls. First, they created virtual 3D models of the skulls and digitized over 200 landmarks on the upper jawbone to look at patterns of growth and development. Then, they undertook microscopic analysis to look for bone formation and bone resorption, a normal process in bone remodeling that helps the tissue retain its structure and strength.

Related: 28,000-year-old Neanderthal-and-human 'Lapedo child' lived tens of thousands of years after our closest relatives went extinct

"We found that bone formation is predominant in Neanderthals — from birth on — who develop larger and more projecting faces," Schuh said. "In contrast, present-day humans exhibit significantly higher levels of bone resorption."

The new research showed that both chimpanzees and Neanderthals had larger, faster-growing faces, while modern humans have smaller faces that stop growing sometime during adolescence.

"Earlier growth cessation is a distinctive feature of our species," Schuh said. "We have identified a unique developmental pattern seen exclusively in Homo sapiens."

Experts have put forth numerous explanations for why Neanderthals had such large faces and noses, including adaptation to a cold climate, higher energy needs, the chewing of tough foods, and the use of their teeth as tools. Explanations for humans' small faces, on the other hand, include the invention of cooking and increases in brain size.

But the reason humans evolved these uniquely small faces is a particularly complex question in paleoanthropology that has not yet been solved. "However, our study addresses aspects of the 'how,'" Schuh said, "providing an important first step toward understanding these processes."

Neanderthal quiz: How much do you know about our closest relatives?

Kanzi, a male bonobo with advanced language aptitude, has died at the age of 44 according to a statement by the Ape Initiative, the conservation and research center in Des Moines, Iowa, where he had lived since 2004.

As an infant, Kanzi, who was born at the Emory National Primate Research Center in Atlanta, Georgia, accompanied his adoptive mother Matata to language lessons. But while Matata was not interested in learning from her human caretakers, Kanzi surprised them by quickly learning the lexigrams, or symbols that map to words, that the researchers were trying to teach his mother, in much the same way human children learn language by listening to their parents talking.

Primatologists have used lexigrams since the 1970s to understand how chimpanzees and bonobos think and communicate. Using a special lexigram keyboard, the great apes are encouraged to communicate with their caretakers by pressing different buttons or pointing to pictures.

Researchers taught Kanzi more than 300 lexigrams, and Kanzi combined them to create new meanings, an important aspect of symbolic thinking — something which experts previously assumed only humans were capable of.

But Kanzi was also able to understand and respond to requests in spoken English. In a study undertaken when Kanzi was 8 years old, he and a 2-year-old human child were given 660 spoken instructions. Kanzi outperformed the child, suggesting his linguistic ability was at least as good as a human toddler's.

Related: Chimps learned tool use long ago without human help

In another study, Kanzi learned some American Sign Language (ASL) simply by watching videos of Koko the gorilla, who had previously been taught to use ASL. And when separated by a wall from his sister, Panbanisha, Kanzi vocalized a sound for 'yogurt' that Panbanisha understood.

Although Kanzi showed one-of-a-kind linguistic abilities for an ape, he didn't speak in the same way humans do. Researchers think this is related to the anatomical differences between chimpanzee and human vocal tracts. However, a 2024 study published in Scientific Reports suggests that chimpanzee vocalization abilities may have been underestimated, as these apes can produce novel sounds and have the brain capacity necessary for speech.

Beyond his language skills, Kanzi showed off his ability to make and use stone tools, earning him the epithet "bonobo genius." He was then taught to build a fire and cook food, demonstrating his ability to learn behaviors key to human evolution.

Later in life, Kanzi was even taught to play video games. He seemed to understand how to beat the arcade game Pac-Man and defeated the final boss of Minecraft.

On March 18, staff at the Ape Initiative found Kanzi unresponsive. He was being treated for heart disease, according to the statement, but necropsy results clarifying his cause of death are pending.

Evolution quiz: Can you naturally select the correct answers?