anthropology

lead-poisoning-has-been-a-feature-of-our-evolution

Lead poisoning has been a feature of our evolution

anthropology, Archaeology, australopithecus, hominins, lead poisoning, Neanderthals, paleoanthropology, Science / /

A recent study found lead in teeth from 2 million-year-old hominin fossils.

Our hominid ancestors faced a Pleistocene world full of dangers—and apparently one of those dangers was lead poisoning.

Lead exposure sounds like a modern problem, at least if you define “modern” the way a paleoanthropologist might: a time that started a few thousand years ago with ancient Roman silver smelting and lead pipes. According to a recent study, however, lead is a much more ancient nemesis, one that predates not just the Romans but the existence of our genus Homo. Paleoanthropologist Renaud Joannes-Boyau of Australia’s Southern Cross University and his colleagues found evidence of exposure to dangerous amounts of lead in the teeth of fossil apes and hominins dating back almost 2 million years. And somewhat controversially, they suggest that the toxic element’s pervasiveness may have helped shape our evolutionary history.

The skull of an early hominid, aged to a dark brown color. The skull is fragmentary, but the fragments are held in the appropriate locations by an underlying beige material.

The skull of an early hominid. Credit: Einsamer Schütze / Wikimedia

The Romans didn’t invent lead poisoning

Joannes-Boyau and his colleagues took tiny samples of preserved enamel and dentin from the teeth of 51 fossils. In most of those teeth, the paleoanthropologists found evidence that these apes and hominins had been exposed to lead—sometimes in dangerous quantities—fairly often during their early years.

Tooth enamel forms in thin layers, a little like tree rings, during the first six or so years of a person’s life. The teeth in your mouth right now (and of which you are now uncomfortably aware; you’re welcome) are a chemical and physical record of your childhood health—including, perhaps, whether you liked to snack on lead paint chips. Bands of lead-tainted tooth enamel suggest that a person had a lot of lead in their bloodstream during the year that layer of enamel was forming (in this case, “a lot” means an amount measurable in parts per million).

In 71 percent of the hominin teeth that Joannes-Boyau and his colleagues sampled, dark bands of lead in the tooth enamel showed “clear signs of episodic lead exposure” during the crucial early childhood years. Those included teeth from 100,000-year-old members of our own species found in China and 250,000-year-old French Neanderthals. They also included much earlier hominins who lived between 1 and 2 million years ago in South Africa: early members of our genus Homo, along with our relatives Australopithecus africanus and Paranthropus robustus. Lead exposure, it turns out, is a very ancient problem.

Living in a dangerous world

This study isn’t the first evidence that ancient hominins dealt with lead in their environments. Two Neanderthals living 250,000 years ago in France experienced lead exposure as young children, according to a 2018 study. At the time, they were the oldest known examples of lead exposure (and they’re included in Joannes-Boyau and his colleagues’ recent study).

Until a few thousand years ago, no one was smelting silver, plumbing bathhouses, or releasing lead fumes in car exhaust. So how were our hominin ancestors exposed to the toxic element? Another study, published in 2015, showed that the Spanish caves occupied by other groups of Neanderthals contained enough heavy metals, including lead, to “meet the present-day standards of ‘contaminated soil.’”

Today, we mostly think of lead in terms of human-made pollution, so it’s easy to forget that it’s also found naturally in bedrock and soil. If that weren’t the case, archaeologists couldn’t use lead isotope ratios to tell where certain artifacts were made. And some places—and some types of rock—have higher lead concentrations than others. Several common minerals contain lead compounds, including galena or lead sulfide. And the kind of lead exposure documented in Joannes-Boyau and his colleagues’ study would have happened at an age when little hominins were very prone to putting rocks, cave dirt, and other random objects in their mouths.

Some of the fossils from the Queque cave system in China, which included a 1.8 million-year-old extinct gorilla-like ape called Gigantopithecus blacki, had lead levels higher than 50 parts per million, which Joannes-Boyau and his colleagues describe as “a substantial level of lead that could have triggered some developmental, health, and perhaps social impairments.”

Even for ancient hominins who weren’t living in caves full of lead-rich minerals, wildfires, or volcanic eruptions can also release lead particles into the air, and erosion or flooding can sweep buried lead-rich rock or sediment into water sources. If you’re an Australopithecine living upstream of a lead-rich mica outcropping, for example, erosion might sprinkle poison into your drinking water—or the drinking water of the gazelle you eat or the root system of the bush you get those tasty berries from… .

Our world is full of poisons. Modern humans may have made a habit of digging them up and pumping them into the air, but they’ve always been lying in wait for the unwary.

screenshot from the app

Cubic crystals of the lead-sulfide mineral galena.

Digging into the details

Joannes-Boyau and his colleagues sampled the teeth of several hominin species from South Africa, all unearthed from cave systems just a few kilometers apart. All of them walked the area known as Cradle of Humankind within a few hundred thousand years of each other (at most), and they would have shared a very similar environment. But they also would have had very different diets and ways of life, and that’s reflected in their wildly different exposures to lead.

A. africanus had the highest exposure levels, while P. robustus had signs of infrequent, very slight exposures (with Homo somewhere in between the two). Joannes-Boyau and his colleagues chalk the difference up to the species’ different diets and ecological niches.

“The different patterns of lead exposure could suggest that P. robustus lead bands were the result of acute exposure (e.g., wild forest fire),” Joannes-Boyau and his colleagues wrote, “while for the other two species, known to have a more varied diet, lead bands may be due to more frequent, seasonal, and higher lead concentration through bioaccumulation processes in the food chain.”

Did lead exposure affect our evolution?

Given their evidence that humans and their ancestors have regularly been exposed to lead, the team looked into whether this might have influenced human evolution. In doing so, they focused on a gene called NOVA1, which has been linked to both brain development and the response to lead exposure. The results were quite a bit short of decisive; you can think of things as remaining within the realm of a provocative hypothesis.

The NOVA1 gene encodes a protein that influences the processing of messenger RNAs, allowing it to control the production of closely related variants of a single gene. It’s notable for a number of reasons. One is its role in brain development; mice without a working copy of NOVA1 die shortly after birth due to defects in muscle control. Its activity is also altered following exposure to lead.

But perhaps its most interesting feature is that modern humans have a version of the gene that differs by a single amino acid from the version found in all other primates, including our closest relatives, the Denisovans and Neanderthals. This raises the prospect that the difference is significant from an evolutionary perspective. Altering the mouse version so that it is identical to the one found in modern humans does alter the vocal behavior of these mice.

But work with human stem cells has produced mixed results. One group, led by one of the researchers involved in this work, suggested that stem cells carrying the ancestral form of the protein behaved differently from those carrying the modern human version. But others have been unable to replicate those results.

Regardless of that bit of confusion, the researchers used the same system, culturing stem cells with the modern human and ancestral versions of the protein. These clusters of cells (called organoids) were grown in media containing two different concentrations of lead, and changes in gene activity and protein production were examined. The researchers found changes, but the significance isn’t entirely clear. There were differences between the cells with the two versions of the gene, even without any lead present. Adding lead could produce additional changes, but some of those were partially reversed if more lead was added. And none of those changes were clearly related either to a response to lead or the developmental defects it can produce.

The relevance of these changes isn’t obvious, either, as stem cell cultures tend to reflect early neural development while the lead exposure found in the fossilized remains is due to exposure during the first few years of life.

So there isn’t any clear evidence that the variant found in modern humans protects individuals who are exposed to lead, much less that it was selected by evolution for that function. And given the widespread exposure seen in this work, it seems like all of our relatives—including some we know modern humans interbred with—would also have benefited from this variant if it was protective.

Science Advances, 2025. DOI: 10.1126/sciadv.adr1524  (About DOIs).

Photo of Kiona N. Smith

Kiona is a freelance science journalist and resident archaeology nerd at Ars Technica.

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How Easter Island’s giant statues “walked” to their final platforms

anthropology, Archaeology, easter island, experimental archaeology, Physics, rapa nui, Science / /

Workers with ropes could make the moai “walk” in zig-zag motion along roads tailor-made for the purpose.

Easter Island is famous for its giant monumental statues, called moai, built some 800 years ago and typically mounted on platforms called ahu. Scholars have puzzled over the moai on Easter Island for decades, pondering their cultural significance, as well as how a Stone Age culture managed to carve and transport statues weighing as much as 92 tons. One hypothesis, championed by archaeologist Carl Lipo of Binghamton University, among others, is that the statues were transported in a vertical position, with workers using ropes to essentially “walk” the moai onto their platforms.

The oral traditions of the people of Rapa Nui certainly include references to the moai “walking” from the quarry to their platforms, such as a song that tells of an early ancestor who made the statues walk. While there have been rudimentary field tests showing it might have been possible, the hypothesis has also generated a fair amount of criticism. So Lipo has co-authored a new paper published in the Journal of Archaeological Science offering fresh experimental evidence of “walking” moai, based on 3D modeling of the physics and new field tests to recreate that motion.

The first Europeans arrived in the 17th century and found only a few thousand inhabitants on the tiny island (just 14 by 7 miles across) thousands of miles away from any other land. In order to explain the presence of so many moai, the assumption has been that the island was once home to tens of thousands of people. But Lipo thought perhaps the feat could be accomplished with fewer workers. In 2012, Lipo and his colleague, Terry Hunt of the University of Arizona, showed that you could transport a 10-foot, 5-ton moai a few hundred yards with just 18 people and three strong ropes by employing a rocking motion.

In 2018, Lipo followed up with an intriguing hypothesis for how the islanders placed red hats on top of some moai; those can weigh up to 13 tons. He suggested the inhabitants used ropes to roll the hats up a ramp. Lipo and his team later concluded (based on quantitative spatial modeling) that the islanders likely chose the statues’ locations based on the availability of fresh water sources, per a 2019 paper in PLOS One.

The 2012 experiment demonstrated proof of principle, so why is Lipo revisiting it now? “I always felt that the [original] experiment was disconnected to some degree of theory—that we didn’t have particular expectations about numbers of people, rate of transport, road slope that could be walked, and so on,” Lipo told Ars. There were also time constraints because the attempt was being filmed for a NOVA documentary.

“That experiment was basically a test to see if we could make it happen or not,” he explained. “Fortunately, we did, and our joy in doing so is pretty well represented by our hoots and hollers when it started to walk with such limited efforts. Some of the limitation of the work was driven by the nature of TV. [The film crew] just wanted us—in just a day and half—to give it a shot. It was 4: 30 on the last day when it finally worked so we really didn’t get a lot of time to explore variability. We also didn’t have any particular predictions to test.”

Example of a road moai that fell and was abandoned after an attempt to re-erect it by excavating under its base, leaving it partially buried at an angle.

Example of a road moai that fell and was abandoned after an attempt to re-erect it by excavating under its base, leaving it partially buried at an angle. Credit: Carl Lipo

This time around, “We wanted to explore a bit of the physics: to show that what we did was pretty easily predicted by the physical properties of the moai—its shape, size, height, number of people on ropes, etc.—and that our success in terms of team size and rate of walking was consistent with predictions,” said Lipo. “This enables us to address one of the central critiques that always comes up: ‘Well, you did this with a 5-ton version that was 10 feet tall, but it would never work with a 30-ft-tall version that weighs 30 tons or more.'”

All about that base

You can have ahu (platforms) without moai (statues) and moai without ahu, usually along the roads leading to ahu; they were likely being transported and never got to their destination. Lipo and Hunt have amassed a database of 962 moai across the island, compiled through field surveys and photogrammetric documentation. They were particularly interested in 62 statues located along ancient transport roads that seemed to have been abandoned where they fell.

Their analysis revealed that these road moai had significantly wider bases relative to shoulder width, compared to statues mounted on platforms. This creates a stable foundation that lowers the center of mass so that the statue is more conducive to the side-to-side motion of walking transport without toppling over. Platform statues, by contrast, have shoulders wider than the base for a more top-heavy configuration.

The road moai also have a consistent and pronounced forward lean of between 6 degrees to 15 degrees from the vertical position, which moves the center of mass close to or just beyond the base’s front edge. Lipo and Hunt think this was due to careful engineering, not coincidence. It’s not conducive to stable vertical display but it is a boon during walking transport, because the forward lean causes the statue to fall forward when tilted laterally, with the rounded front base edge serving as a crucial pivot point. So every lateral rocking motion results in a forward “step.”

Per the authors, there is strong archaeological evidence that carvers modified the statues once they arrived at their platform destinations, modifying the base to eliminate the lean by removing material from the front. This shifted the center of mass over the base area for a stable upright position. The road moai even lack the carved eye sockets designed to hold white coral eyes with obsidian or red scoria for pupils—a final post-transport step once the statues had been mounted on their platforms.

Based on 3D modeling, Lipo and his team created a precisely scaled replica of one of the road moai, weighing 4.35 metric tons with the same proportions and mass distribution of the original statue. “Of course, we’d love to build a 30-foot-tall version, but the physical impossibility of doing so makes it a challenging task, nor is it entirely necessary,” said Lipo. “Through physics, we can now predict how many people it would take and how it would be done. That is key.”

Lipo's team created 3D models of moai to determine the unique characteristics that made them able to be

Lipo’s team created 3D models of moai to determine the unique characteristics that made them able to be “walked” across Rapa Nui. Credit: Carl Lipo

The new field trials required 18 people, four on each lateral rope and 10 on a rear rope, to achieve the side-to-side walking motion, and they were efficient enough in coordinating their efforts to move the statue forward 100 meters in just 40 minutes. That’s because the method operates on basic pendulum dynamics, per the authors, which minimizes friction between the base and the ground. It’s also a technique that exploits the gradual build-up of amplitude, which “suggests a sophisticated understanding of resonance principles,” Lipo and Hunt wrote.

So the actual statues could have been moved several kilometers over the course of weeks with only modest-sized crews of between 20-50 people, i.e., roughly the size of an extended family or “small lineage group” on Easter Island. Once the crew gets the statue rocking side to side—which can require between 15 to 60 people, depending on the size and weight of the moai—the resulting oscillation only needs minimal energy input from a smaller team of rope handlers to maintain that motion. They mostly provide guidance.

Lipo was not the first to test the walking hypothesis. Earlier work includes that of Czech experimental archaeologist Pavel Pavel, who conducted similar practical experiments on Easter Island in the 1980s after being inspired by Thor Heyerdahl’s Kon Tiki. (Heyerdahl even participated in the experiments.) Pavel’s team was able to demonstrate a kind of “shuffling” motion, and he concluded that just 16 men and one leader were sufficient to transport the statues.

Per Lipo and Hunt, Pavel’s demonstration didn’t result in broad acceptance of the walking hypothesis because it still required a huge amount of effort to tilt the statue, producing more of a twisting motion rather than efficient forward movement. This would only have moved a large statue 100 meters a day under ideal conditions. The base was also likely to be damaged from friction with the ground. Lipo and Hunt maintain this is because Pavel (and others who later tried to reproduce his efforts) used the wrong form of moai for those earlier field tests: those erected on the platforms, already modified for vertical stability and permanent display, and not the road moai with shapes more conducive to vertical transport.

“Pavel deserves recognition for taking oral traditions seriously and challenging the dominant assumption of horizontal transport, a move that invited ridicule from established scholars,” Lipo and Hunt wrote. “His experiments suggested that vertical transport was feasible and consistent with cultural memory. Our contribution builds on this by showing that ancestral engineers intentionally designed statues for walking. Those statues were later modified to stand erect on ceremonial platforms, a transformation that effectively erased the morphological features essential for movement.”

The evidence of the roadways

Lipo and Hunt also analyzed the roadways, noting that these ancient roadbeds had concave cross sections that would have been problematic for moving the statues horizontally using wooden rollers or frames perpendicular to those roads. But that concave shape would help constrain rocking movement during vertical transport. And the moai roads were remarkably level with slopes of, on average, 2–3 percent. For the occasional steeper slopes, such as walking a moai up a ramp to the top of an ahu, Lipo and Hunt’s field experiments showed that these could be navigated successfully through controlled stepping.

Furthermore, the distribution pattern of the roadways is consistent with the road moai being left due to mechanical failure. “Arguments that the moai were placed ceremonially in preparation for quarrying have become more common,” said Lipo. “The algorithm there is to claim that positions are ritual, without presenting anything that is falsifiable. There is no reason why the places the statues fell due to mechanical reasons couldn’t later become ‘ritual,’ in the same way that everything on the island could be claimed to be ritual—a circular argument. But to argue that they were placed there purposefully for ritual purposes demands framing the explanation in a way that is falsifiable.”

Schematic representation of the moai transport method using coordinated rope pulling to achieve a

Schematic representation of the moai transport method using coordinated rope pulling to achieve a “walking” motion. Credit: Carl Lipo and Terry Hunt, 2025

“The only line of evidence that is presented in this way is the presence of ‘platforms’ that were found beneath the base of one moai, which is indeed intriguing,” Lipo continued. “However, those platforms can be explained in other ways, given that the moai certainly weren’t moved from the quarry to the ahu in one single event. They were paused along the way, as is clear from the fact that the roads appear to have been constructed in segments with different features. Their construction appears to be part of the overall transport process.”

Lipo’s work has received a fair share of criticism from other scholars over the years, and his and Hunt’s paper includes a substantial section rebutting the most common of those critiques. “Archaeologists tend to reject (in practice) the idea that the discipline can construct cumulative knowledge,” said Lipo. “In the case of moai transport, we’ve strived to assemble as much empirical evidence as possible and have forwarded an explanation that best accounts for what we can observe. Challenges to these ideas, however, do not come from additional studies with new data but rather just new assertions.”

“This leads the public to believe that we (as a discipline) can never really figure anything out and are always going to be a speculative enterprise, spinning yarns and arguing with each other,” Lipo continued. “With the erosion of trust in science, this is fairly catastrophic to archaeology as a whole but also the whole scientific enterprise. Summarizing the results in the way we do here is an attempt to point out that we can build falsifiable accounts and can make contributions to cumulative knowledge that have empirical consequences—even with something as remarkable as the transport of moai.”

Experimental archaeology is a relatively new field that some believe could be the future of archaeology. “I think experimental archaeology has potential when it’s tied to physics and chemistry,” said Lipo. “It’s not just recreating something and then arguing it was done in the same way in the past. Physics and chemistry are our time machines, allowing us to explain why things are the way they are in the present in terms of the events that occurred in the past. The more we can link the theory needed to explain the present, the better we can explain the past.”

DOI: Journal of Archaeological Science, 2025. 10.1016/j.jas.2025.106383  (About DOIs).

Photo of Jennifer Ouellette

Jennifer is a senior writer at Ars Technica with a particular focus on where science meets culture, covering everything from physics and related interdisciplinary topics to her favorite films and TV series. Jennifer lives in Baltimore with her spouse, physicist Sean M. Carroll, and their two cats, Ariel and Caliban.

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World-famous primatologist Jane Goodall dead at 91

anthropology, Biology, jane goodall, Obituaries, primatology, Science / /

A sculpture of Jane Goodall and David Greybeard outside the Field Museum of Natural History in Chicago

A sculpture of Jane Goodall and David Greybeard outside the Field Museum of Natural History in Chicago Credit: Geary/CC0

David Greybeard’s behavior also challenged the long-held assumption that chimpanzees were vegetarians. Goodall found that chimps would hunt and eat smaller primates like colobus monkeys as well, sometimes sharing the carcass with other troop members. She also recorded evidence of strong bonds between mothers and infants, altruism, compassion, and aggression and violence. For instance, dominant females would sometimes kill the infants of rival females, and from 1974 to 1978, there was a violent conflict between two communities of chimpanzees that became known as the Gombe Chimpanzee War.

Almost human

One of the more colorful chimps Goodall studied was named Frodo, who grew up to be an alpha male with a temperament very unlike his literary namesake. “As an infant, Frodo proved mischievous, disrupting Jane Goodall’s efforts to record data on mother-infant relationships by grabbing at her notebooks and binoculars,” anthropologist Michael Wilson of the University of Minnesota in Saint Paul recalled on his blog when Frodo died from renal failure in 2013. “As he grew older, Frodo developed a habit of throwing rocks, charging at, hitting, and knocking over human researchers and tourists.” Frodo attacked Wilson twice on Wilson’s first trip to Gombe, even beating Goodall herself in 1989, although he eventually lost his alpha status and “mellowed considerably” in his later years, per Wilson.

Goodall became so renowned around the world that she even featured in one of Gary Larson’s Far Side cartoons, in which two chimps are shown grooming when one finds a blonde hair on the other. “Conducting a little more ‘research’ with that Jane Goodall tramp?” the caption read. The JGI was not amused, sending Larson a letter (without Goodall’s knowledge) calling the cartoon an “atrocity,” but their objections were not shared by Goodall herself, who thought the cartoon was very funny when she heard of it. Goodall even wrote a preface to The Far Side Gallery 5. Larson, for his part, visited Goodall’s research facility in Tanzania in 1988, where he experienced Frodo’s alpha aggressiveness firsthand.

A young Jane Goodall in the field.

A young Jane Goodall in the field. Credit: YouTube/Jane Goodall Institute

Goodall founded the JGI in 1977 and authored more than 27 books, most notably My Friends, the Wild Chimpanzees (1967), In the Shadow of Man (1971), and Through a Window (1990). There was some initial controversy around her 2014 book Seeds of Hope, co-written with Gail Hudson, when portions were found to have been plagiarized from online sources; the publisher postponed publication so that Goodall could revise the book and add 57 pages of endnotes. (She blamed her “chaotic note-taking” for the issue.) National Geographic released a full-length documentary last year about her life’s work, drawing from over 100 hours of previously unseen archival footage.

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Is the “million-year-old” skull from China a Denisovan or something else?

anthropology, Archaeology, Denisovans, hominins, homo longi, paleoanthropology, Science, skulls / /

Homo longi by any other name

Now that we know what Denisovans looked like, they’re turning up everywhere.

This digital reconstruction makes Yunxian 2 look liess like a Homo erectus and more like a Denisovan (or Homo longi, according to the authors). Credit: Feng et al. 2025

A fossil skull from China that made headlines last week may or may not be a million years old, but it’s probably closely related to Denisovans.

The fossil skull, dubbed Yunxian 2, is one of three unearthed from a terrace alongside the Han River, in central China, in a layer of river sediment somewhere between 600,000 and 1 million years old. Archaeologists originally identified them as Homo erectus, but Hanjiang Normal University paleoanthropologist Xiaobo Feng and his colleagues’ recent digital reconstruction of Yunxian 2 suggests the skulls may actually have belonged to someone a lot more similar to us: a hominin group defined as a species called Homo longi or a Denisovan, depending on who’s doing the naming.

The recent paper adds fuel—and a new twist—to that debate. And the whole thing may hinge on a third skull from the same site, still waiting to be published.

A front and a side view of a digitally reconstructed hominin skull

This digital reconstruction makes Yunxian 2 look less like a Homo erectus and more like a Denisovan (or Homo longi, according to the authors). Credit: Feng et al. 2025

Denisovan or Homo longi?

The Yunxian skull was cracked and broken after hundreds of thousands of years under the crushing weight of all that river mud, but the authors used CT scans to digitally put the pieces back together. (They got some clues from a few intact bits of Yunxian 1, which lay buried in the same layer of mud just 3 meters away.) In the end, Feng and his colleagues found themselves looking at a familiar face; Yunxian 2 bears a striking resemblance to a 146,000-year-old Denisovan skull.

That skull, from Harbin in northeast China, made headlines in 2021 when a team of paleoanthropologists claimed it was part of an entirely new species, which they dubbed Homo longi. According to that first study, Homo longi was a distinct hominin species, separate from us, Neanderthals, and even Denisovans. That immediately became a point of contention because of features the skull shared with some other suspected Denisovan fossils.

Earlier this year, a team of researchers, which included one of the 2021 study’s authors, took samples of ancient proteins preserved in the Harbin skull; of the 95 proteins they found, three of them matched proteins only encoded in Denisovan DNA. While the June 2025 study suggested that Homo longi was a Denisovan all along, the new paper draws a different conclusion: Homo longi is a species that happens to include the population we’ve been calling Denisovans. As study coauthor Xijun Ni, of the Chinese Academy of Sciences, puts it in an email to Ars Technica, “Given their similar age range, distribution areas, and available morphological data, it is likely that Denisovans belong to the Homo longi species. However, little is known about Denisovan morphology.”

Of course, that statement—that we know little about Denisovan morphology (the shapes and features of their bones)—only applies if you don’t accept the results of the June 2025 study mentioned above, which clocked the Harbin skull as a Denisovan and therefore told us what one looks like.

And Feng and his colleagues, in fact, don’t accept those results. Instead, they consider Harbin part of some other group of Homo longi, and they question the earlier study’s methods and results. “The peptide sequences from Harbin, Penghu, and other fossils are too short and provide conflicting information,” Ni tells Ars Technica. Feng and his colleagues also question the results of another study, which used mitochondrial DNA to identify Harbin as a Denisovan.

In other words, Feng and his colleagues are pretty invested in defining Homo longi as a species and Denisovans as just one sub-group of that species. But that’s hard to square with DNA data.

Alas, poor Yunxian 2, I knew him well

Yunxian 2 has a wide face with high, flat cheekbones, a wide nasal opening, and heavy brows. Its cranium is higher and rounder than Homo erectus (and the original reconstruction, done in the 1990s), but it’s still longer and lower than is normal for our species. Overall, it could have held about 1,143 cubic centimeters of brain, which is in the ballpark of modern people. But its shape may have left less room for the frontal lobe (the area where a lot of social skills, logic, motor skills, and executive function happen) than you’d expect in a Neanderthal or a Homo sapiens skull.

Feng and his colleagues measured the distances between 533 specific points on the skull: anatomical landmarks like muscle attachment points or the joints between certain bones. They compared those measurements to ones from 26 fossil hominin skulls and several-dozen modern human skulls, using a computer program to calculate how similar each skull was to all of the others.

Yunxian 2 fits neatly into a lookalike group with the Harbin skull, along with two other skulls that paleoanthropologists have flagged as belonging to either Denisovans or Homo longi. Those two skulls are a 200,000- to 260,000-year-old skull found in Dali County in northwestern China and a 260,000-year-old skull from Jinniushi (sometimes spelled Jinniushan) Cave in China.

Those morphological differences suggest some things about how the individuals who once inhabited these skulls might have been related to each other, but that’s also where things get dicey.

front and side views of 3 skulls.

An older reconstruction of the Yunxian 2 skull gives it a flatter look. Credit: government of Wuhan

Digging into the details

Most of what we know about how we’re related to our closest extinct hominin relatives (Neanderthals and Denisovans) comes from comparing our DNA to theirs and tracking how small changes in the genetic code build up over time. Based on DNA, our species last shared a common ancestor with Neanderthals and Denisovans sometime around 750,000 years ago in Africa. One branch of the family tree led to us; the other branch split again around 600,000 years ago, leading to Neanderthals and Denisovans (or Homo longi, if you prefer).

In other words, DNA tells us that Neanderthals and Denisovans are more closely related to each other than either is to us. (Unless you’re looking at mitochondrial DNA, which suggests that we’re more closely related to Neanderthals than to Denisovans; it’s complicated, and there’s a lot we still don’t understand.)

“Ancient mtDNA and genomic data show different phylogenetic relationships among Denisovans, Neanderthals and Homo sapiens,” says Ni. So depending on which set of data you use and where your hominin tree starts, it can be possible to get different answers about who is most closely related to whom. The fact that all of these groups interbred with each other can explain this complexity, but makes building family trees challenging.

It is very clear, however, that Feng and his colleagues’ picture of the relationships between us and our late hominin cousins, based on similarities among fossil skulls in their study, looks very different from what the genomes tell us. In their model, we’re more closely related to Denisovans, and the Neanderthals are off on their own branch of the family tree. Feng and his colleagues also say those splits happened much earlier, with Neanderthals branching off on their own around 1.38 million years ago; we last shared a common ancestor with Homo longi around 1 million years ago.

That’s a big difference from DNA results, especially when it comes to timing. And the timing is likely to be the biggest controversy here. In a recent commentary on Feng and his colleagues’ study, University of Wisconsin paleoanthropologist John Hawks argues that you can’t just leave genetic evidence out of the picture.

“What this research should have done is to put the anatomical comparisons into context with the previous results from DNA, especially the genomes that enable us to understand the relationships of Denisovan, Neanderthal, and modern human groups,” Hawks writes.

(It’s worth a side note that most news stories describe Yunxian 2 as being a million years old, and so do Feng and his colleagues. But electron spin resonance dating of fossil animal bones from the same sediment layer suggests the skull could be as young as 600,000 years old or as old as 1.1 million. That still needs to be narrowed down to everyone’s satisfaction.)

What’s in a name?

Of course, DNA also tells us that even after all this branching and migrating, the three species were still similar enough to reproduce, which they did several times. Many groups of modern people still carry traces of Neanderthal and Denisovan DNA in their genomes, courtesy of those exchanges. And some ancient Neanderthal populations were carrying around even older chunks of human DNA in the same way. That arguably makes species definitions a little fuzzy at best—and maybe even irrelevant.

“I think all these groups, including Neanderthals, should be recognized within our own species, Homo sapiens,” writes Hawks. Hawks contends that the differences among these hominin groups “were the kind that evolve among the populations of a single species over time, not starkly different groups that tread the landscape in mutually unrecognizeable ways.”

But humans love to classify things (a trait we may have shared with Neanderthals and Denisovans), so those species distinctions are likely to persist even if the lines between them aren’t so solid. As long as that’s the case, names and classifications will be fodder for often heated debate. And Feng’s team is staking out a position that’s very different from Hawks’. “‘Denisovan’ is a label for genetic samples taken from the Denisova Cave. It should not be used everywhere. Homo longi is a formally named species,” says Ni.

Technically, Denisovans don’t have a formal species name, a Latinized moniker like Homo erectus that comes with a clear(ish) spot on the family tree. Homo longi would be a more formal species name, but only if scientists can agree on whether they’re actually a species.

an archaeologist kneels in front of a partially buried skull

An archaeologist comes face to face with the Yunxian 3 skull Credit: government of Wuhan

The third Yunxian skull

Paleoanthropologists unearthed a third skull from the Yunxian site in 2022. It bears a strong resemblance to the other two from the area (and is apparently in better shape than either of them), and it dates to about the same timeframe. A 2022 press release describes it as “the most complete Homo erectus skull found in Eurasia so far,” but if Feng and his colleagues are right, it may actually be a remarkably complete Homo longi (and/or Denisovan) skull. And it could hold the answers to many of the questions anthropologists like Feng and Hawks are currently debating.

“It remains pretty obvious that Yunxian 3 is going to be central to testing the relationships of this sample [of fossil hominins in Feng and colleagues’ paper],” writes Hawks.

The problem is that Yunxian 3 is still being cleaned and prepared. Preparing a fossil is a painstaking, time-consuming process that involves very carefully excavating it from the rocky matrix it’s embedded in, using everything from air-chisels to paintbrushes. And until that’s done and a scientific report on the skull is published, other paleoanthropologists don’t have access to any information about its features—which would be super useful for figuring out how to define whatever group we eventually decide it belongs to.

For the foreseeable future, the relationships between us and our extinct cousins (or at least our ideas about those relationships) will keep changing as we get more data. Eventually, we may have enough data from enough fossils and ancient DNA samples to form a clearer picture of our past. But in the meantime, if you’re drawing a hominin family tree, use a pencil.

Science, 2025.  DOI: 10.1126/science.ado9202  (About DOIs).

Photo of Kiona N. Smith

Kiona is a freelance science journalist and resident archaeology nerd at Ars Technica.

Is the “million-year-old” skull from China a Denisovan or something else? Read More »

neolithic-people-took-gruesome-trophies-from-invading-tribes

Neolithic people took gruesome trophies from invading tribes

anthropology, Archaeology, neolithic, Science / /

A local Neolithic community in northeastern France may have clashed with foreign invaders, cutting off limbs as war trophies and otherwise brutalizing their prisoners of war, according to a new paper published in the journal Science Advances. The findings challenge conventional interpretations of prehistoric violence as bring indiscriminate or committed for pragmatic reasons.

Neolithic Europe was no stranger to collective violence of many forms, such as the odd execution and massacres of small communities, as well as armed conflicts. For instance, we recently reported on an analysis of human remains from 11 individuals recovered from El Mirador Cave in Spain, showing evidence of cannibalism—likely the result of a violent episode between competing Late Neolithic herding communities about 5,700 years ago. Microscopy analysis revealed telltale slice marks, scrape marks, and chop marks, as well as evidence of cremation, peeling, fractures, and human tooth marks.

This indicates the victims were skinned, the flesh removed, the bodies disarticulated, and then cooked and eaten. Isotope analysis indicated the individuals were local and were probably eaten over the course of just a few days. There have been similar Neolithic massacres in Germany and Spain, but the El Mirador remains provide evidence of a rare systematic consumption of victims.

Per the authors of this latest study, during the late Middle Neolithic, the Upper Rhine Valley was the likely site of both armed conflict and rapid cultural upheaval, as groups from the Paris Basin infiltrated the region between 4295 and 4165 BCE. In addition to fortifications and evidence of large aggregated settlements, many skeletal remains from this period show signs of violence.

Friends or foes?

Overhead views of late Middle Neolithic violence-related human mass deposits of the Alsace region, France

Overhead views of late Middle Neolithic violence-related human mass deposits in Pit 124 of the Alsace region, France. Credit: Philippe Lefranc, INRAP

Archaeologist Teresa Fernandez-Crespo of Spain’s Valladolid University and co-authors focused their analysis on human remains excavated from two circular pits at the Achenheim and Bergheim sites in Alsace in northwestern France. Fernandez-Crespo et al. examined the bones and found that many of the remains showed signs of unhealed trauma—such as skull fractures—as well as the use of excessive violence (overkill), not to mention quite a few severed left upper limbs. Other skeletons did not show signs of trauma and appeared to have been given a traditional burial.

Neolithic people took gruesome trophies from invading tribes Read More »

incan-numerical-recordkeeping-system-may-have-been-widely-used

Incan numerical recordkeeping system may have been widely used

ancient people did stuff, anthropology, Archaeology, inca, Incan empire, indigenous americans, indigenous communities, indigenous south america, khipu, Pre-Columbian civilizations, Science, wari / /

Women in STEM: Inca Edition

In the late 1500s, a few decades after the khipu in this recent study was made, an Indigenous chronicler named Guaman Poma de Ayala described how older women used khipu to “keep track of everything” in aqllawasai: places that basically functioned as finishing schools for Inca girls. Teenage girls, chosen by local nobles, were sent away to live in seclusion at the aqllawasai to weave cloth, brew chicha, and prepare food for ritual feasts.

What happened to the girls after aqllawasai graduation was a mixed bag. Some of them were married (or given as concubines) to Inca nobles, others became priestesses, and some ended up as human sacrifices. But some of them actually got to go home again, and they probably took their knowledge of khipu with them.

“I think this is the likely way in which khipu literacy made it into the countryside and the villages,” said Hyland. “These women, who were not necessarily elite, taught it to their children, etc.” That may be where the maker of KH0631 learned their skills: either in an aqllawasai or from a graduate of one (we still don’t know this particular khipu-maker’s gender).

“Science confirming what they already knew”

The finely crafted khipu turning out to be the work of a commoner shows that numeracy was widespread and surprisingly egalitarian in the Inca empire, but it also reveals a centuries-long thread connecting the Inca and their descendants.

Modern people—the descendants of the Inca—still use khipu today in some parts of Peru and Chile. Some scholars (mostly non-Indigenous ones) have argued that these modern khipu weren’t really based on knowledge passed down for centuries but were instead just a clumsy attempt to copy the Inca technology. But if commoners were using khipu in the Inca empire, it makes sense for that knowledge to have been passed down to modern villagers.

“It points to a continuity between Inka and modern khipus,” said Hyland. “In the few modern villages with living khipu traditions, they already believe in this continuity, so it would be the case of science confirming what they already know.”

Science Advances, 2025. DOI: 10.1126/sciadv.adv1950  (About DOIs).

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Stone tools may hint at ancestors of Homo floresiensis

anthropology, Archaeology, Hobbits, hominins, homo erectus, homo floresiensis, homo luzonensis, paleoanthropology, Science, stone tools / /

Some stone tools found near a river on the Indonesian island of Sulawesi suggest that the first hominins had reached the islands by at least 1.04 million years ago. That’s around the same time that the ancestors of the infamously diminutive “Hobbits” may have reached the island of Flores.

Archaeologist Budianto Hakim of Indonesia’s National Research and Innovation Agency and his colleagues were the ones who recently unearthed the tools from a site on Sulawesi. Although a handful of stone flakes from that island don’t tell us who the ancestors of the small species were or how they reached remote islands like Flores and Luzon, the tools are one more piece in the puzzle. And this handful of stone flakes may eventually play a role in helping us understand how other hominin species conquered most of the world long before we came along. 

Crossing the ocean a million years ago

Sometimes the deep past leaves the smallest traces. At the Calio site, a sandstone outcrop in what’s now a cornfield outside the village of Ujung in southern Sulawesi, people left behind just a handful of sharp stone flakes roughly a million years ago. There are seven of them, ranging from 22 to 60 millimeters long, and they’re scratched, worn, and chipped from tumbling around at the bottom of a river. But it’s still clear that they were once shaped by skilled human—or at least human-like—hands that used hard stones as hammers to make sharp-edged chert flakes for cutting and scraping.

The oldest of these tools is likely to be between 1.04 and 1.48 million years old. Hakim and his colleagues dated teeth from a wild pig to around 1.26 million years ago. They were part of a jawbone archaeologists unearthed from a layer just above the oldest flake. Throw in some statistical modeling, and you get the range of likely dates for the stone flake buried in the deepest layer of soil.

Even the younger end of that estimate would make these tools the oldest evidence yet of hominins (of any species) in the islands of Indonesia and the Philippines. This area, sometimes called Wallacea, lies between the continents of Asia and Australia, separated from both by wide channels of deep ocean.

“But the Calio site has yet to yield any hominin fossils,” said Brumm, “so while we now know there were tool-makers on Sulawesi a million years ago, their identity remains a mystery.” But they may be related to the Hobbits, a short-statured group of hominins who lived hundreds of kilometers away on the island of Flores until around 50,000 years ago.

“The discovery of Early Pleistocene artifacts at Calio suggests that Sulawesi was populated by hominins at around the same time as Flores, if not earlier,” wrote Hakim and his colleagues in their recent paper. 

The Flores connection

The islands that now make up Indonesia and the Philippines have been a hominin hotspot for at least a million years. Our species wandered onto the scene sometime between 63,000 and 73,000 years ago, but at least one other hominin species had already been there for at least a million years. We’re just not sure exactly who they were, when they arrived, or how.

“Precisely when hominins first crossed to Sulawesi remains an open question, as does the taxonomic affinity of the colonizing population,” the authors note. 

map of Wallacean islands

This map shows the islands of Wallacea. The large one just east of Java is Sulawesi. Credit: Darren O’Connell

That’s why the handful of stone tools the team recently unearthed at Calio matter: They’re another piece of that puzzle, albeit a small one. Every slightly older date is one step closer to the first hominin tools, bones, or footprints in these islands, and another pin on the map of who was where and when.

And that map is accumulating quite a lot of pins, representing an ever-increasing number of species. Once the first hominins made it across the Makassar Strait, they found themselves in isolated groups on islands cut off from the mainland—and each other—so the hominin family tree started branching very quickly. On at least two islands, Flores and Luzon, those original hominin settlers eventually gave rise to local species, Homo floresiensis and Homo luzonensis. And University of Wollongong paleoanthropologist Richard Roberts, a co-discoverer of Homo floresiensis, thinks there are probably more isolated island hominin species.

In 2019, when Homo luzonensis was first described, Roberts told Ars, “These new fossils, and the assignation of them to a new species (Homo luzonensis), fulfills one of the predictions Mike Morwood and others (myself included) made when we first reported (15 years ago!) the discovery of Homo floresiensis: that other unknown species of hominins would be found in the islands of Southeast Asia.”

Both Homo floresiensis (the original “Hobbits”) and Homo luzonensis were short, clocking in at just over a meter tall. Their bones and teeth are different enough from each other to set them apart as a unique species, but they have enough in common that they probably share a common ancestor—one they don’t share with us. They’re more like our distant cousins, and the islands of Wallacea may have been home to many other such cousins, if Roberts and his colleagues are correct. 

Complicated family history

But who was the common ancestor of all these hominin cousins? That’s where things get complicated (as if they weren’t already). Most paleoanthropologists lean toward Homo erectus, but there’s a chance—along with some tantalizing hints, and no direct evidence—that much more ancient human relatives called Australopithecines may have made the journey a million (or two) years before Homo erectus.

Finger and toe bones from Homo luzonensis are curved, as if they spent as much of their lives climbing trees as walking. That’s more like Australopithecines than any member of our genus Homo. But their teeth are smaller and shaped more like ours. Anthropologists call this mix of features a mosaic, and it can make it tough to figure out how hominin species are related. That’s part of why the question of when the ancestors of the Hobbits arrived on their respective islands is so important.

Illusstrated chart of bones and teeth from three hominins

Compare the teeth and phalanx of Homo luzonensis to those of Homo sapiens (right) and Australopithecus afarensis (left). Credit: Tocheri 2019

We don’t know the answer yet, but we do know that someone was making stone tools on Flores by 1.02 million years ago. Those toolmakers may have been Homo erectus, Australopithecines, or something already recognizable as tiny Homo floresiensis. The Hobbits (or their ancestors) were distinctly “Hobbity” by around 700,000 years ago; fossil teeth and bones from a handful of hominins at a site called Mata Menge make that clear. The Hobbits discovered at Liang Bua Cave on Flores date to somewhere between 50,000 and 100,000 years ago.

Meanwhile, 2,800 kilometers away on the island of Luzon, the oldest stone tools, along with their obvious cut marks left behind on animal bones, date back to 700,000 years ago. That’s as old as the Mata Menge Hobbits on Flores. The oldest Homo luzonensis fossils are between 50,000 and 67,000 years old. It’s entirely possible that older evidence, of the island’s original settlers and of Homo luzonensis, may eventually be found, but until then, we’re left with a lot of blank space and a lot of questions.

And now we know that the oldest traces of hominin presence on Sulawesi is at least 1.04 million years old. But might Sulawesi have its own diminutive hominins?

So are there more Hobbits out there?

“Sulawesi is a wild card—it’s like a mini-continent in itself,” said Brumm. “If hominins were cut off on this huge and ecologically rich island for a million years, would they have undergone the same evolutionary changes as the Flores hobbits? Or would something totally different have happened?”

Reconstruction of Homo floresiensis by Atelier Elisabeth Daynes. Credit: Kinez Riza

A phenomenon called island dwarfism played a role in Homo floresiensis‘ evolution; species that live in relative isolation on small islands tend to evolve into either much larger or much smaller versions of their ancestors (which is why the Hobbits shared their island home with pygmy elephants and giant moas). But how small does an island need to be before island dwarfism kicks in? Sulawesi is about 12 times as large as Flores, for example. So what might the descendants of the Calio toolmakers have looked like by 100,000 years ago?

That’s something that we’ll only know if archaeologists on Sulawesi, like Hakim and his team, find fossil remains of those hominins.

Seafarers or tsunami survivors?

Understanding exactly when hominins first set foot on the island of Sulawesi might eventually help us figure out how they got there. These islands are thousands of kilometers from the Southeast Asian mainland and from each other, so getting there would have meant crossing vast stretches of deep, open ocean.

Archaeologists haven’t found any evidence that anyone who came before our species built boats or rafts, although those watercraft would have been made of materials that tend to decay pretty quickly, so even scraps of ancient wood and rope are extremely rare and lucky finds. But some ancient hominins did have a decent grasp of all the basic skills they’d need for at least a simple raft: woodworking and rope-making. 

Another possibility is that hominins living on the coast of mainland Southeast Asia could have been swept out to sea by a tsunami, and some of them could have been lucky enough to survive the misadventure and wash ashore someplace like Sulawesi, Flores, or Luzon (RIP to any others). But for that scenario to work, enough hominins would have had to reach each island to create a lasting population, and it probably had to happen more than once to end up with hominin groups on at least three distant islands.

Either way, it’s no small feat, even for a Hobbit with small feet.

Nature, 2025 DOI: 10.1038/s41586-025-09348-6 (About DOIs).

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Fermented meat with a side of maggots: A new look at the Neanderthal diet

anthropology, Neanderthals, Science, syndication / /

Traditionally, Indigenous peoples almost universally viewed thoroughly putrefied, maggot-infested animal foods as highly desirable fare, not starvation rations. In fact, many such peoples routinely and often intentionally allowed animal foods to decompose to the point where they were crawling with maggots, in some cases even beginning to liquefy.

This rotting food would inevitably emit a stench so overpowering that early European explorers, fur trappers, and missionaries were sickened by it. Yet Indigenous peoples viewed such foods as good to eat, even a delicacy. When asked how they could tolerate the nauseating stench, they simply responded, “We don’t eat the smell.”

Neanderthals’ cultural practices, similar to those of Indigenous peoples, might be the answer to the mystery of their high δ¹⁵N values. Ancient hominins were butchering, storing, preserving, cooking, and cultivating a variety of items. All these practices enriched their paleo menu with foods in forms that nonhominin carnivores do not consume. Research shows that δ¹⁵N values are higher for cooked foods, putrid muscle tissue from terrestrial and aquatic species, and, with our study, for fly larvae feeding on decaying tissue.

The high δ¹⁵N values of maggots associated with putrid animal foods help explain how Neanderthals could have included plenty of other nutritious foods beyond only meat while still registering δ¹⁵N values we’re used to seeing in hypercarnivores.

We suspect the high δ¹⁵N values seen in Neanderthals reflect routine consumption of fatty animal tissues and fermented stomach contents, much of it in a semi-putrid or putrid state, together with the inevitable bonus of both living and dead ¹⁵N-enriched maggots.

What still isn’t known

Fly larvae are a fat-rich, nutrient-dense, ubiquitous, and easily procured insect resource, and both Neanderthals and early Homo sapiens, much like recent foragers, would have benefited from taking full advantage of them. But we cannot say that maggots alone explain why Neanderthals have such high δ¹⁵N values in their remains.

Several questions about this ancient diet remain unanswered. How many maggots would someone need to consume to account for an increase in δ¹⁵N values above the expected values due to meat eating alone? How do the nutritional benefits of consuming maggots change the longer a food item is stored? More experimental studies on changes in δ¹⁵N values of foods processed, stored, and cooked following Indigenous traditional practices can help us better understand the dietary practices of our ancient relatives.

Melanie Beasley is assistant professor of anthropology at Purdue University.

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

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testing-ancient-paleolithic-migration-with-a-replica-canoe

Testing ancient Paleolithic migration with a replica canoe

anthropology, Archaeology, experimental archaeology, paleolithic, Science / /

(Left) GPS tracking and modeling of ocean currents toward the end of the experimental voyage. (Right) The team on the water around the time of the left image.

(Left) GPS tracking and modeling of ocean currents toward the end of the experimental voyage. (Right) The team on the water around the time of the left image. Credit: Kaifu et al., 2025/CC-By-ND

At the 30-hour mark, the captain ordered the entire crew to rest, letting the dugout drift freely for a while, which fortunately brought them closer to Yonaguni Island. At hour 40, the island’s silhouette was visible, and over the next five hours, the crew was able to navigate the strong tidal flow along the coast until they reached their landing site: Nama Beach. So the experimental voyage was a success, augmented by the numerical simulations to demonstrate that the boat could make similar voyages from different departure points across both modern and late-Pleistocene oceans.

Granted, it was not possible to recreate Paleolithic conditions perfectly on a modern ocean. The crew first spotted the island because of its artificial lights, although by that time, they were on track navigationally. They were also accompanied by escort ships to ensure the crew’s safety, supplying fresh water twice during the voyage. But the escort ships did not aid with navigation or the dugout captain’s decision-making, and the authors believe that any effects were likely minimal. The biggest difference was the paddlers’ basic modern knowledge of local geography, which helped them develop a navigation plan—an unavoidable anachronism, although the crew did not rely on compasses, GPS, or watches during the voyage.

“Scientists try to reconstruct the processes of past human migrations, but it is often difficult to examine how challenging they really were,” said Kaifu. “One important message from the whole project was that our Paleolithic ancestors were real challengers. Like us today, they had to undertake strategic challenges to advance. For example, the ancient Polynesian people had no maps, but they could travel almost the entire Pacific. There are a variety of signs on the ocean to know the right direction, such as visible land masses, heavenly bodies, swells and winds. We learned parts of such techniques ourselves along the way.”

DOI: “Traversing the Kuroshio: Paleolithic migration across one of the world’s strongest ocean currents,” Science Advances, 2025. 10.1126/sciadv.adv5508  (About DOIs).

DOI: “Palaeolithic seafaring in East Asia: an experimental test of the dugout canoe hypothesis,” Science Advances, 2025. 10.1126/sciadv.adv5507  (About DOIs).

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We’ve had a Denisovan skull since the 1930s—only nobody knew

ancient DNA, ancient proteins, anthropology, Archaeology, Denisovans, hominins, Neanderthals, paleoanthropology, paleoproteomics, proteomics, Science, skeletons and skeleton accessories, skulls / /

It’s a Denisovan? Always has been.

After years of mystery, we now know what at least one Denisovan looked like.

A 146,000-year-old skull from Harbin, China, belongs to a Denisovan, according to a recent study of proteins preserved inside the ancient bone. The paleoanthropologists who studied the Harbin skull in 2021 declared it a new (to us) species, Homo longi. But the Harbin skull still contains enough of its original proteins to tell a different story: A few of them matched specific proteins from Denisovan bones and teeth, as encoded in Denisovan DNA.

So Homo longi was a Denisovan all along, and thanks to the remarkably well-preserved skull, we finally know what the enigmatic Denisovans actually looked like.

Two early-human skulls against a black background.

Credit: Ni et al. 2021

The Harbin skull (left) and the Dali skull (right).

Unmasking Dragon Man 

Paleoanthropologist Qiang Ji, of the Chinese Academy of Sciences, and colleagues tried to sequence ancient DNA from several samples of the Harbin skull’s bone and its one remaining tooth, but they had no luck. Proteins tend to be hardier molecules than DNA, though, and in samples from the skull’s temporal bone (the ones on the sides of the head, just behind the cheekbones), the researchers struck pay dirt.

They found fragments of a total of 95 proteins. Four of these had variations that were distinct to the Denisovan lineage, and the Harbin skull matched Denisovans on three of them. That’s enough to confidently say that the Harbin skull had belonged to a Denisovan. So for the past few years, we’ve had images of an almost uncannily well-preserved Denisovan skull—which is a pretty big deal, especially when you consider its complicated history.

While the world is now aware of it, until 2021, only one person had known what the skull looked like since its discovery in the 1930s. It was unearthed in Harbin, in northeast China, during the Japanese occupation of the area. Not wanting it to be seized by the occupying government, the person who found the skull immediately hid it, and he kept it hidden for most of the rest of his life.

He eventually turned it over to scientists in 2018, who published their analysis in 2021. That analysis placed the Harbin skull, along with a number of other fossils from China, in a distinct lineage within our genus, Homo, making them our species’ closest fossil relatives. They called this alleged new species Homo longi, or “Dragon Man.”

The decision to classify Homo longi as a new species was largely due to the skull’s unique combination of features (which we’ll discuss below). But it was a controversial decision, partly because paleoanthropologists don’t entirely agree about whether we should even call Neanderthals a distinct species. If the line between Neanderthals and our species is that blurry, many in the field have questioned whether Homo longi could be considered a distinct species, when it’s even closer to us than the Neanderthals.

Meanwhile, the 2021 paper also left room for debate on whether the skull might actually have belonged to a Denisovan rather than a distinct new species. Its authors acknowledge that one of the fossils they label as Homo longi had already been identified as a Denisovan based on its protein sequences. They also point out that the Harbin skull has rather large molars, which seem to be a common feature in Denisovans.

The paper’s authors argued that their Homo longi should be a separate branch of the hominin lineage, more closely related to us than to Denisovans or Neanderthals. But if the Harbin skull looked so much like Denisovan fossils and so little like fossils from our species, the alleged relationship begins to look pretty dubious. In the end, the 2021 paper’s authors dodged the issue by saying that “new genetic material will test the relationship of these populations to each other and to the Denisovans.”

Which turned out to be exactly what happened.

A ghost lineage comes to life

Denisovans are the ghost in our family tree. For scientists, a “ghost lineage” is one that’s known mostly from genetic evidence, not fossils; like a ghost, it has a presence we can sense but no physical form we can touch. With the extremely well-preserved Harbin skull identified as a Denisovan, though, we’re finally able to look our “ghost” cousins in the face.

Paleogeneticists have recovered Denisovan DNA from tiny fragments of bone and teeth, and even from the soil of a cave floor. Genomics researchers have found segments of Denisovan DNA woven into the genomes of some modern humans, revealing just how close our two species once were. But the handful of Denisovan fossils paleoanthropologists have unearthed are mostly small fragments—a finger bone here, a tooth there, a jawbone someplace else—that don’t reveal much about how Denisovans lived or what they looked like.

We know they existed and that they were something slightly different from Homo sapiens or Neanderthals. We even know when and where they lived and a surprising amount about their genetics, and we have some very strong hints about how they interacted with our species and with Neanderthals. But we didn’t really know what they looked like, and we couldn’t hope to identify their fossils without turning to DNA or protein sequences.

Until now.

Neanderthals and Denisovans probably enjoyed the view from Denisova Cave, too. Credit: loronet / Flickr

The face of a Denisovan

So what did a Denisovan look like? Harbin 1 has a wide, flattish face with small cheekbones, big eye sockets, and a heavy brow. Its upper jaw juts forward just a little, and it had big, robust molars. The cranium itself is longer and less dome-like than ours, but it’s roomy enough for a big brain (about 1,420 millimeters).

Some of those traits, like the large molars and the long, low cranium, resemble those of earlier hominin species such as Homo erectus or Homo heidelbergensis. Others, like a relatively flat face, set beneath the cranium instead of sticking out in front of it, look more like us. (Early hominins, like Australopithecus afarensis, don’t really have foreheads because their skulls are arranged so their brains are right behind their faces instead of partly above them, like ours.)

In other words, Harbin’s features are what paleoanthropologists call a mosaic, with some traits that look like they come from older lineages and some that seem more modern. Mosaics are common in the hominin family tree.

But for all the detail it reveals about the Denisovans, Harbin is still just one skull from one individual. Imagine trying to reconstruct all the diversity of human faces from just one skull. We have to assume that Densiovans—a species that spanned a huge swath of our planet, from Siberia to Taiwan, and a wide range of environments, from high-altitude plateaus in Tibet to subtropical forests—were also a pretty diverse species.

It’s also worth remembering that the Harbin skull is exactly that: a skull. It can’t tell us much about how tall its former user was, how they were built, or how they moved or worked during their life. We can’t even say for sure whether Harbin is osteologically or genetically male or female. In other words, some of the mystery of the Denisovans still endures.

What’s next?

In the 2021 papers, the researchers noted that the Harbin skull also bears a resemblance to a 200,000- to 260,000-year-old skull found in Dali County in northwestern China, a roughly 300,000-year-old skull found in Hualong Cave in eastern China, and a 260,000-year-old skull from Jinniushi (sometimes spelled Jinniushan) Cave in China. And some fossils from Taiwan and northern China have molars that look an awful lot like those in that Tibetan jawbone.

“These hominins potentially also belong to Denisovan populations,” write Ji and colleagues. That means we might already have a better sample of Denisovan diversity than this one skull suggests.

And, like the Harbin skull, the bones and teeth of those other fossils may hold ancient DNA or proteins that could help confirm that intriguing possibility.

Science, 2023 DOI: 10.1126/science.adu9677 (About DOIs).

Photo of Kiona N. Smith

Kiona is a freelance science journalist and resident archaeology nerd at Ars Technica.

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Skull long thought to be Cleopatra’s sister’s was actually a young boy

ancient DNA, ancient egypt, anthropology, Archaeology, cleopatra, forensic archaeology, Science / /

Scientists have demonstrated that an ancient human skull excavated from a tomb at Ephesos was not that of Arsinoë IV, half-sister to Cleopatra VII. Rather, it’s the skull of a young male between the ages of 11 and 14 from Italy or Sardinia, who may have suffered from one or more developmental disorders, according to a new paper published in the journal Scientific Reports. Arsinoë IV’s remains are thus still missing.

Arsinoë IV led quite an adventurous short life. She was either the third or fourth daughter of Ptolemy XII, who left the throne to Cleopatra and his son, Ptolemy XIII, to rule together. Ptolemy XIII didn’t care for this decision and dethroned Cleopatra in a civil war—until Julius Caesar intervened to enforce their father’s original plan of co-rulership. As for Arsinoë, Caesar returned Cyprus to Egyptian rule and named her and her youngest brother (Ptolemy XIV) co-rulers. This time, it was Arsinoë who rebelled, taking command of the Egyptian army and declaring herself queen.

She was fairly successful at first in battling the Romans, conducting a siege against Alexandria and Cleopatra, until her disillusioned officers decided they’d had enough and secretly negotiated with Caesar to turn her over to him. Caesar agreed, and after a bit of public humiliation, he granted Arsinoë sanctuary in the temple of Artemis in Ephesus. She lived in relative peace for a few years, until Cleopatra and Mark Antony ordered her execution on the steps of the temple—a scandalous violation of the temple as a place of sanctuary. Historians disagree about Arsinoë’s age when she died: Estimates range from 22 to 27.

Archaeologists have been excavating the ancient city of Ephesus for more than a century. The Octagon was uncovered in 1904, and the burial chamber was opened in 1929. That’s where Joseph Keil found a skeleton in a sarcophagus filled with water, but for some reason, Keil only removed the cranium from the tomb before sealing it back up. He took the skull with him to Germany and declared it belonged to a likely female around 20 years old, although he provided no hard data to support that conclusion.

It was Hilke Thur of the Austrian Academy of Sciences who first speculated that the skull may have belonged to Arsinoë IV, despite the lack of an inscription (or even any grave goods) on the tomb where it was found. Old notes and photographs, as well as craniometry, served as the only evidence. The skull accompanied Keil to his new position at the University of Vienna, and there was one 1953 paper reporting on craniometric measurements, but after that, the skull languished in relative obscurity. Archaeologists at the University of Graz rediscovered the skull in Vienna in 2022. The rest of the skeleton remained buried until the chamber was reopened and explored further in the 1980s and 1990s, but it was no longer in the sarcophagus.

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Studies pin down exactly when humans and Neanderthals swapped DNA

ancient DNA, ancient genomics, ancient people did stuff, anthropology, Archaeology, Neanderthals, out of africa, Science / /

We may owe our tiny sliver of Neanderthal DNA to just a couple of hundred Neanderthals.

The artist’s illustration shows what the six people buried at the Ranis site, who lived between 49, 500 and 41,000 years ago, may have looked like. Two of these people are mother and daughter, and the mother is a distant cousin (or perhaps a great-great-grandparent or great-great-grandchild) to a woman whose skull was found 130 kilometers away in what’s now Czechia. Credit: Sumer et al. 2024

Two recent studies suggest that the gene flow (as the young people call it these days) between Neanderthals and our species happened during a short period sometime between 50,000 and 43,500 years ago. The studies, which share several co-authors, suggest that our torrid history with Neanderthals may have been shorter than we thought.

Pinpointing exactly when Neanderthals met H. sapiens  

Max Planck Institute of Evolutionary Anthropology scientist Leonardo Iasi and his colleagues examined the genomes of 59 people who lived in Europe between 45,000 and 2,200 years ago, plus those of 275 modern people whose ancestors hailed from all over the world. The researchers cataloged the segments of Neanderthal DNA in each person’s genome, then compared them to see where those segments appeared and how that changed over time and distance. This revealed how Neanderthal ancestry got passed around as people spread around the world and provided an estimate of when it all started.

“We tried to compare where in the genomes these [Neanderthal segments] occur and if the positions are shared among individuals or if there are many unique segments that you find [in people from different places],” said University of California Berkeley geneticist Priya Moorjani in a recent press conference. “We find the majority of the segments are shared, and that would be consistent with the fact that there was a single gene flow event.”

That event wasn’t quite a one-night stand; in this case, a “gene flow event” is a period of centuries or millennia when Neanderthals and Homo sapiens must have been in close contact (obviously very close, in some cases). Iasi and his colleagues’ results suggest that happened between 50,500 and 43,000 years ago. But it’s quite different from our history with another closely related hominin species, the now-extinct Denisovans, with whom different Homo sapiens groups met and mingled at least twice on our way to taking over the world.

In a second study, Arev Sümer (also of the Max Planck Institute) and her colleagues found something very similar in the genomes of people who lived 49,500 to 41,000 years ago in what’s now the area around Ranis, Germany. The Ranis population, based on how their genomes compare to other ancient and modern people, seem to have been part of one of the first groups to split off from the wave of humans who migrated out of Africa, through the Levant, and into Eurasia sometime around 50,000 years ago. They carried with them traces of what their ancestors had gotten up to during that journey: about 2.9 percent of their genomes were made up of segments of Neanderthal ancestry.

Based on how long the Ranis people’s segments of Neanderthal DNA were (longer chunks of Neanderthal ancestry tend to point to more recent mixing), the interspecies mingling happened about 80 generations, or about 2,300 years, before the Ranis people lived and died. That’s about 49,000 to 45,000 years ago. The dates from both studies line up well with each other and with archaeological evidence that points to when Neanderthal and Homo sapiens cultures overlapped in parts of Europe and Asia.

What’s still not clear is whether that period of contact lasted the full 5,000 to 7,000 years, or if, as Johannes Krause (also of the Max Planck Institute) suggests, it was only a few centuries—1,500 years at the most—that fell somewhere within that range of dates.

Artist’s depiction of a Neanderthal.

Natural selection worked fast on our borrowed Neanderthal DNA

Once those first Homo sapiens in Eurasia had acquired their souvenir Neanderthal genes (forget stealing a partner’s hoodie; just take some useful segments of their genome), natural selection got to work on them very quickly, discarding some and passing along others, so that by about 100 generations after the “event,” the pattern of Neanderthal DNA segments in people’s genomes looked a lot like it does today.

Iasi and his colleagues looked through their catalog of genomes for sections that contained more (or less) Neanderthal ancestry than you’d expect to find by random chance—a pattern that suggests that natural selection has been at work on those segments. Some of the segments that tended to include more Neanderthal gene variants included areas related to skin pigmentation, the immune response, and metabolism. And that makes perfect sense, according to Iasi.

“Neanderthals had lived in Europe, or outside of Africa, for thousands of years already, so they were probably adapted to their environment, climate, and pathogens,” said Iasi during the press conference. Homo sapiens were facing selective pressure to adapt to the same challenges, so genes that gave them an advantage would have been more likely to get passed along, while unhelpful ones would have been quick to get weeded out.

The most interesting questions remain unanswered

The Neanderthal DNA that many people carry today, the researchers argue, is a legacy from just 100 or 200 Neanderthals.

“The effective population size of modern humans outside Africa was about 5,000,” said Krause in the press conference. “And we have a ratio of about 50 to 1 in terms of admixture [meaning that Neanderthal segments account for about 2 percent of modern genomes in people who aren’t of African ancestry], so we have to say it was about 100 to maybe 200 Neanderthals roughly that mixed into the population.” Assuming Krause is right about that and about how long the two species stayed in contact, a Homo sapiens/Neanderthal pairing would have happened every few years.

So we know that Neanderthals and members of our species lived in close proximity and occasionally produced children for at least several centuries, but no artifacts, bones, or ancient DNA have yet revealed much of what that time, or that relationship, was actually like for either group of people.

The snippets of Neanderthal ancestry left in many modern genomes, and those of people who lived tens of thousands of years ago, don’t offer any hints about whether that handful of Neanderthal ancestors were mostly male or mostly female, which is something that could shed light on the cultural rules around such pairings. And nothing archaeologists have unearthed so far can tell us whether those pairings were consensual, whether they were long-term relationships or hasty flings, or whether they involved social relationships recognized by one (or both) groups. We may never have answers to those questions.

And where did it all happen? Archaeologists haven’t yet found a cave wall inscribed with “Og heart Grag,” but based on the timing, Neanderthals and Homo sapiens probably met and lived alongside each other for at least a few centuries, somewhere in “the Near East,” which includes parts of North Africa, the Levant, what’s now Turkey, and what was once Mesopotamia. That’s one of the key routes that people would have followed as they migrated from Africa into Europe and Asia, and the timing lines up with when we know that both Homo sapiens and Neanderthals were in the area.

“This [same] genetic admixture also appears in East Asia and Australia and the Americas and Europe,” said Krause. “If it would have happened in Europe or somewhere else, then the distribution would probably look different than what we see.”

Science, 2023 DOI: 10.1126/science.adq3010;

Nature, 2023 DOI: 10.1038/s41586-024-08420-x;

(About DOIs).

Photo of Kiona N. Smith

Kiona is a freelance science journalist and resident archaeology nerd at Ars Technica.

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