The closest known extinct relatives of modern humans were the thick-browed Neanderthals and the mysterious Denisovans. Now, a bone fragment from a Siberian cave, perhaps from a teenage girl, has revealed the first known hybrid of these groups, a new study concludes. The finding confirms interbreeding that had been only hinted at in earlier genetic studies.

A number of now-extinct human lineages not only lived alongside modern humans but even interbred with them, leaving traces of their DNA in the modern human genome. These lineages included the stocky Neanderthals, as well as the enigmatic Denisovans, known only from a few teeth and bones unearthed in Denisova Cave in the Altai Mountains. [In Images: The First Bone from a Neanderthal-Denisovan Hybrid]

Archaeological excavations have revealed that Neanderthals and Denisovans coexisted in Eurasia, with Neanderthal bones ranging from 200,000 to 40,000 years old unearthed mostly in western Eurasia and Denisovans so far only known from fossils ranging from 200,000 to 30,000 years old found in eastern Eurasia. Prior work unearthed Neanderthal remains in Denisova Cave, raising questions on how closely they interacted.

"A Neanderthal and a Denisovan were genetically more distant from each other than any two people living today are," study co-author Viviane Slon, a paleogeneticist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, said in an email to Live Science. "So we do not think that they met very often."

The scientists investigated a 1-inch-long (2.5 centimeters) bone fragment, dubbed "Denisova 11," that archaeologists found in 2012 in Denisova Cave. This shard came from a long bone, such as a shinbone or a thighbone, but scientists knew little else about it.

"You can't even tell if it's human or animal by looking at it,"study senior author Svante Pääbo, an evolutionary geneticist at the Max Planck Institute for Evolutionary Anthropology, told Live Science in a phone call.

The researchers analyzed proteins extracted from Denisova 11 and more than 2,000 other bone fragments from Denisova Cave, which revealed the fragment came from a human. The thickness of the outer part of the bone suggested that Denisova 11 belonged to a female who was at least 13 years old when she died, while radiocarbon dating suggested Denisova 11 was more than 50,000 years old.

The scientists next ground to a powder a sample from Denisova 11 and sequenced the DNA from the bone dust.

Previous genetic research suggested that the Neanderthal and Denisovan lineages diverged more than 390,000 years ago, the researchers said. Those genetic studiesalso hinted at interbreeding between Neanderthals and Denisovans, but the extent to which they interbred was unclear, Live Science previously reported.

"I never thought we would be so lucky as to find an actual offspring of the two groups," Slon said in the email.

The researchers also found that the Denisovan father of the individual Denisova 11 had at least one Neanderthal ancestor, possibly as far back as 300 to 600 generations before his lifetime. "So, from this single genome, we are able to detect multiple instances of interactions between Neandertals and Denisovans," study co-author Benjamin Vernot, a population geneticist at the Max Planck Institute for Evolutionary Anthropology, said in the statement.

In addition, the scientists found that the teenage girl's Neanderthal mother was genetically more similar to the Neanderthals of Western Europe than to a different Neanderthal that lived earlier in Denisova Cave. This find suggests that Neanderthals migrated between western and eastern Eurasia for tens of thousands of years.

So far, scientists have sequenced the genomes of only six people from Denisova Cave. That one of these had Neanderthal and Denisovan parents may suggest, from a statistical point of view, that interbreeding may have been common whenever these groups did interact, Pääbo said. "It makes you believe that when these groups met, they may have mixed freely with each other," he said.

All in all, these findings suggest that modern humans, Neanderthals and Denisovans intermingled when they encountered each another, Pääbo said. "Neanderthals and Denisovans may have disappeared just because they were absorbed into modern human populations."

The researchers are continuing to look for ancient human DNA, not just in the thousands of other bone fragments in Denisova Cave, but from the sediments that accumulated there as well.

"It's fun to think that there are probably many more discoveries to be made from remains found at the site," Slon said.

The scientists published their findings online today (Aug. 22) in the journal Nature.</s>View of the valley from above the Denisova Cave archaeological site in Siberia.

Bence Viola / Max Planck Institute for Evolutionary Anthropology</s>People’s sexual indiscretions may follow them for a very long time. Scientists say they just determined that the bone of a girl who died 50,000 years ago shows that she had a Neanderthal mother and a Denisovan father.

It’s not the first evidence of sex between humans of different subspecies, but the surprising finding indicates that different human subtypes were moving around and mixing things up very commonly in the prehistoric past.

And the ancient DNA shows evidence of even more blending, the researchers reported Wednesday in the journal Nature. The father of the girl was also part Neanderthal, they found.

“We knew from previous studies that Neanderthals and Denisovans must have occasionally had children together,” Viviane Slon, an evolutionary anthropologist at the Max Planck Institute for Evolutionary Anthropology who worked on the study, said in a statement.

“But I never thought we would be so lucky as to find an actual offspring of the two groups.”

The researchers did not have much to work with — just a fragment of bone found in a remote cave in Siberia. But they got enough DNA from the fragment to sequence it and compare it with DNA from the remains of known Neanderthals, from other bones also found in the Denisova cave, from the remains of modern humans and from chimpanzees.

The bone indicated that it had belonged to a female at least 13 years old at death. DNA inherited from the mother, called mitochondrial DNA, was clearly Neanderthal, the team found. The girl is called Denisova 11 because the bone represents the 11th distinct individual found in the cave.

“Genome-wide signatures show that the Denisova 11 individual has a Neanderthal and a Denisovan parent,” the team wrote in their report.

DNA inherited from the father was more of a mix: mostly Denisovan, but with its own sprinkling of ancient Neanderthal.

While anthropologists knew that Neanderthals and Denisovans were both alive at the same time, they also know that they must have been fairly distinct from one another. The two lines split genetically nearly 400,000 years ago.

Both subspecies were replaced by modern humans about 40,000 years ago, although many people alive today carry some Neanderthal or Denisovan DNA.

“It is striking that we find this Neanderthal/Denisovan child among the handful of ancient individuals whose genomes have been sequenced,” said Svante Pääbo, an expert on ancient DNA and director of the department of evolutionary genetics at the Max Planck Institute.

"Neanderthals and Denisovans may not have had many opportunities to meet," he said in a statement. "But when they did, they must have mated frequently — much more so than we previously thought.”

Scientists know quite a bit about Neanderthals, who were not, as commonly portrayed, shorter or stupider than modern humans. Evidence shows that they used art and made jewelry.

The Denisovans are more mysterious. There is not enough evidence from the tiny scraps of bone and tooth found so far to say what they looked like or to say anything about their behavior.

There’s just enough DNA to show that they were genetically distinct from Neanderthals and from modern humans.

It’s not clear why our particular species won the evolutionary race for survival.

It's possible that modern human ancestors killed off the others, but equally possible that a small genetic advantage simply allowed modern humans to outbreed their cousins.

There’s not even enough to say what happened to the young girl whose bone gives away so much history about interspecies impropriety.

But there’s a hint about her fate, either before or after death, left on the piece of bone that was found.

“The surface … is chemically eroded, possibly due to carnivore digestion,” the team wrote.</s>A 13-year-old girl who died over 50,000 years ago may not have had a long time alive on this planet, but she was in fact very special. Millennia later, a fragment of her skeleton reveals that she was the first-generation result of a mating between two different species of hominin.

Her mum was a Neanderthal, and her dad was a Denisovan, genome sequencing has revealed. So this tiny sliver of her remains represents direct evidence that the two species were interbreeding.

"We knew from previous studies that Neanderthals and Denisovans must have occasionally had children together," said evolutionary geneticist Viviane Slon of Max Planck Institute for Evolutionary Anthropology in Germany.

"But I never thought we would be so lucky as to find an actual offspring of the two groups."

The existence of the Denisovans wasn't uncovered until 2010, but since then we've learned more and more about them.

Neanderthals and Denisovans were probably the same group originally. But, sometime over 390,000 years ago, they separated, and evolved into two distinct, but closely related populations.

They coexisted in Eurasia for a long time. Although Denisovans are only known from bones found in one location - the Denisova Cave in Siberia (actually named after a bloke named Denis) - Neanderthal remains were also found there.

But it didn't mean they hung out there at the same time. So the discovery of this adolescent girl, named Denisova 11 (or Denny, as nicknamed by the researchers), is an astonishingly solid confirmation that the two groups knew each other, and interacted.

Denny is known only from a small fragment of bone, found in the cave in 2012 by Russian archaeologists. Based on a protein analysis, it was confirmed to be a hominin bone, so it was transferred to the Max Planck Institute for further study.

There, researchers analysed the bone and determined that it was likely part of a tibia, femur or humerus. Based on that assumption, the bone's cortical thickness indicates that Denny was at least 13 years old when she died, while radiocarbon dating put the time of her death over 50,000 years ago.

Next, they took DNA samples from the bone, and sequenced Denny's genome. They discovered her sex - and her unusual parentage. A Neanderthal mother and Denisovan father.

"An interesting aspect of this genome is that it allows us to learn things about two populations - the Neanderthals from the mother's side, and the Denisovans from the father's side," said geneticist Fabrizio Mafessoni of the Max Planck Institute for Evolutionary Anthropology.

Denny's DNA revealed that her mother was genetically closer to a population of Neanderthals who had lived in Western Europe than those who had lived in Denisova Cave in the East some 20,000 years earlier.

This indicates that the Neanderthals were migrating across Europe tens of thousands of years before they disappeared.

But Denny's mum wasn't the only one with a story to tell. Dad's DNA was interesting too. Based on what the researchers could glean from Denny's bone, he'd had at least one Neanderthal ancestor.

"So from this single genome, we are able to detect multiple instances of interactions between Neanderthals and Denisovans," said geneticist Benjamin Vernot of the Max Planck Institute for Evolutionary Anthropology.

What's interesting is that the two groups remained genetically distinct, rather than intermingling to form one species that incorporated both. This, the researchers noted in their paper, could mean that their zones of overlap were limited, both temporally and geographically.

But one more thing is really interesting. So far, only four other Denisovans have been identified via DNA analysis. Denny is the fifth.

"It is striking that we find this Neanderthal/Denisovan child among the handful of ancient individuals whose genomes have been sequenced," said evolutionary geneticist Svante Pääbo, Director of the Department of Evolutionary Genetics at the Max Planck Institute for Evolutionary Anthropology and senior author of the study.

"Neanderthals and Denisovans may not have had many opportunities to meet. But when they did, they must have mated frequently - much more so than we previously thought."

Isn't it amazing what we can learn from a single piece of ancient bone?

The team's research has been published in the journal Nature.</s>Scientists uncover remains of first known child of one Denisovan, one Neanderthal parent

Scientists have uncovered the first known child to parents of different species of ancient humans.

A small bone fragment discovered in a Siberian cave has been identified as belonging to a girl with a Neanderthal mother and Denisovan father.

The two extinct groups of humans differ far more than any two present-day groups of people but are our closest ancient human relatives. The study, published in Nature, gives a rare insight into their lives.

The team, led by palaeogeneticists Viviane Slon and Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, conducted the genome analysis on the bone fragment uncovered in the Denisova Cave in Russia.

"We knew from previous studies that Neanderthals and Denisovans must have occasionally had children together," Dr Slon told Nature.

Very few — less than 20 early human ancestors — have had their genomes sequenced.

"It is striking that we find this Neanderthal/Denisovan child among the handful of ancient individuals whose genomes have been sequenced," said Dr Pääbo.

The study also revealed that the Denisovan father had at least one Neanderthal ancestor.

"So from this single genome, we are able to detect multiple instances of interactions between Neanderthals and Denisovans," said Benjamin Vernot from the MPI-EVA, a third co-author of the study.

The Denisova cave lends its name to the Denisovans, who were first identified by a fingertip found within the cave in 2008.

The fingertip was the first of a string of notable archaeological discoveries to be found within the cave. A Denisovan tooth was found in 2010, and bone in 2013, that suggested early Europeans were more closely related to Denisovans than Neanderthals.

Scientists already knew that Neanderthals, Denisovans, and early modern humans must have interbred because mixed DNA lingers in people today, but the new study is the first to identify a first-generation child with such parents.

The two species lived until about 40,000 years ago, Neanderthals in the west and Denisovans in the east, however the cave — and the wider Altai region — are known to have been home to both groups.

The study shows that Neanderthals migrated between western and eastern Europe and Asia tens of thousands of years before they died out.</s>Scientists have for the first time discovered a first-generation individual of mixed ancestry from two distinct human groups.

Analysis of a bone discovered in a Siberian cave revealed the female, who died 90,000 years ago, had a Neanderthal mother and a Denisovan father.

The 13-year-old female, nicknamed “Denny” by scientists, is an example of interbreeding between now-extinct human groups, say scientists.

Pontus Skoglund, population geneticist at the Francis Crick Institute, said: “To find a first-generation person of mixed ancestry from these groups is absolutely extraordinary.

“It’s really great science coupled with a little bit of luck.”

The complete picture of Denny’s ancestry had been incomplete for a number of years – only her mother’s side was known after researchers discovered mitochondiral DNA in her remains came from a Neanderthal.

The most recent study set out to compare DNA variation in Denny with that of three other hominins, a Neanderthal, a Denisovan and a modern-day human (Homo Sapien) from Africa.

Palaeogeneticists Viviane Slon and Svante Paabo at Germany’s Max Planck Institute for Evolutionary Anthropology carried out genome analysis on a bone taken from the Denisova cave in the Altai Mountains of Russia.

Bone fragment (“Denisova 11”) was found in 2012 at Denisova Cave in Russia by Russian archaeologists (T. Higham/University of Oxford)

A 40% match was found with the Denisovan, as well as a 40% match for the Neanderthal, while bone density gave away the teenager’s age.

Scientists confirmed Denny came from two separate hominins – and not two hybrids – by looking at where the genomes between Neanderthals and Denisovans differ.

After comparing Denny’s DNA to genomes of a Neanderthal and a Denisovan, researchers found she had one set of chromosomes from each hominin.

Denisovans, now extinct, were a group of humans first identified from DNA analysis of a finger bone discovered in the same place a decade ago.

Neanderthals also lived in the cave.

Scientists have been aware of breeding between diffrent humant human groups, including between Denisovans and Homo Sapiens, thanks to variation among humans.

But this is the first time a first-generation offspring from the pairing has been discovered.

Scientists now think such a mix could be more common than initially thought.

“We knew from previous studies that Neandertals and Denisovans must have occasionally had children together, but I never thought we would be so lucky as to find an actual offspring of the two groups,” said Slon.

The findings were published in Nature.</s>Her mother was a Neanderthal, but her father was Denisovan, a distinct species of primitive human that also roamed the Eurasian continent 50,000 years ago, scientists reported Wednesday in the journal Nature.

Nicknamed by Oxford University scientists, Denisova 11—her official name—was at least 13 when she died, for reasons unknown.

"There was earlier evidence of interbreeding between different hominin, or early human, groups," said lead author Vivian Slon, a researcher at the Max Planck Institute for Evolutionary Anthropology.

"But this is the first time that we have found a direct, first-generation offspring," she told AFP.

Denny's surprising pedigree was unlocked from a bone fragment unearthed in 2012 by Russian archeologists at the Denisova Cave in the Altai Mountains of Siberia.

Analysis of the bone's DNA left no doubt: the chromosomes were a 50-50 mix of Neanderthal and Denisovan, two distinct species of early humans that split apart between 400,000 to 500,000 years ago.

"I initially thought that they must have screwed up in the lab," said senior author and Max Planck Institute professor Svante Paabo, who identified the first Denisovan a decade ago at the same site.

Worldwide, fewer than two dozen early human genomes from before 40,000 years ago—Neanderthal, Denisovan, Homo sapiens—have been sequenced, and the chances of stumbling on a half-and-half hybrid seemed vanishingly small.

"The very fact that we found this individual of mixed Neanderthal and Denisovan origins suggests that they interbred much more often than we thought," said Slon.

Paabo agreed: "They must have quite commonly had kids together, otherwise we wouldn't have been this lucky."

A 40,000 year-old Homo sapiens with a Neanderthal ancestor a few generations back, recently found in Romania, also bolsters this notion.

But the most compelling evidence that inter-species hanky-panky in Late Pleistocene Eurasia may not have been that rare lies in the genes of contemporary humans.

About two percent of DNA in non-Africans across the globe today originate with Neanderthals, earlier studies have shown.

Denisovan remnants are also widespread, though less evenly.

"We find traces of Denisovan DNA—less than one percent—everwhere in Asia and among native Americans," said Paabo.

"Aboriginal Australians and people in Papua New Guinea have about five percent."

Taken together, these facts support a novel answer to the hotly debated question of why Neanderthals—which had successfully spread across parts of western and central Europe—disappeared some 40,000 years ago.

Up to now, their mysterious demise has been blamed on disease, climate change, genocide at the hands of Homo sapiens, or some combination of the above.

But what if our species—arriving in waves from Africa—overwhelmed Neanderthals, and perhaps Denisovans, with affection rather than aggression?

"Part of the story of these groups is that they may simply have been absorbed by modern populations," said Paabo.

"The modern humans were more numerous, and the other species might have been incorporated."

Recent research showing that Neanderthals were not, in fact, knuckle-dragging brutes makes this scenario all the more plausible.

Our genetic cousins executed sophisticated hunting strategies in groups; made fires, tools, clothing and jewellery; and buried their dead with symbolic ornaments.

They painted animal frescos on cave walls at least 64,000 years ago, well before most Homo sapiens arrived in Europe.

Far less is known about Denisovans, but they may have suffered a similar fate.

Paabo established their existence with an incomplete finger bone and two molars dated to some 80,000 years ago.

Among their genetic legacy to some modern humans is a variant of the gene EPAS1 that makes it easier for the body to access oxygen by regulating the production of haemoglobin, according to a 2014 study.

Nearly 90 percent of Tibetans have this precious variant, compared with only nine percent of Han Chinese, the dominant—and predominantly lowland—ethnic group in China.

Neanderthals and Denisovans might have intermingled even more but for the fact that the former settled mostly in Europe, and the latter in central and East Asia, the researchers speculated.

More information: Viviane Slon et al, The genome of the offspring of a Neanderthal mother and a Denisovan father, Nature (2018). DOI: 10.1038/s41586-018-0455-x</s>One can be forgiven for thinking that the first modern humans who ventured out of Africa stumbled into a vibrant bar scene. DNA from just a single cave in Siberia revealed that it had been occupied by two archaic human groups that had interbred with the newly arrived modern humans. This included both the Neanderthals, whom we knew about previously, and the Denisovans, who we didn't even know existed and still know little about other than their DNA sequences. The DNA also revealed that one of the Denisovans had a Neanderthal ancestor a few hundred generations back in his past.

But in almost all of these cases, the ancestry seems to have come from a single exchange of chromosomes many generations prior. There was little indication that the interbreeding was frequent.

Now, the same cave has yielded a bone fragment that indicates the interbreeding may have been common. DNA sequencing revealed that the bone fragment's original owner had a mom that was Neanderthal and a father who was Denisovan. The fact that we have so few DNA samples from this time and that one is the immediate product of intermating gives us a strong hint that we should expect more examples in the future.

What is this?

The Denisova Cave sits within Russia near its borders with China, Kazakhstan, and Mongolia. It appears to have conditions that favor the preservation of ancient DNA, as bones from the site have yielded high-quality genomes from both Neanderthals and Denisovans. It does not seem to have favored the preservation of skeletons themselves, as most material has been fragmentary; all we know about the appearance of Denisovans comes from a molar and a small finger bone, though dating indicates they occupied the cave more than 30,000 years after the Neanderthal.

Because of the fragmentary nature of many of the bones, the team exploring the cave has been slowly going through them, determining which ones are human by looking at the collagen that comprises much of the bone. An ID of human caused them to focus more on a fragment called Denisova 11, which originated in a long bone (like an arm or leg bone) of an individual who was at least in their teens. Beyond that, there was nothing even distinctive enough to determine what part of the body the fragment originated in, much less which group of humans its owner belonged to, although carbon dating placed it at a time when Denisovans were known to occupy the cave.

To find out more, the researchers sequenced its mitochondrial DNA. Since this is only passed on via the egg, it tells you about an organism's mother. In this case, the mitochondrial DNA was clearly Neanderthal, which was somewhat surprising, given the date on the bone. In any case, this was enough for the researchers to decide to sequence the genome of Denisova 11. It was completed so that the average base was sequenced 2.6 times, meaning that there are still a lot of gaps and uncertainties in the genome. Still, it was enough to perform some detailed analyses.

The first thing that was clear was that Denisova 11 was a she; X-chromosome sequences showed up as often as ones from any other chromosome, suggesting she had a pair of them. The other was that the researchers' excavation techniques were very good, as contamination with the DNA from those who did the excavating couldn't account for more than 1.7 percent of the total sequences. Beyond that, most of the results were unexpected.

Because we now have several Neanderthal and Denisovan genomes, we have some sense of how they consistently differ from each other and from the genomes of modern humans. Running Denisova 11 through an analysis of these differences showed she was a nearly even mix. Instead of being mostly Neanderthal, as you would expect from the mitochondrial DNA, only 39 percent of the DNA fragments were clearly Neanderthal. Another 42 percent, by contrast, were Denisovan, meaning she was nearly an even mix of the two groups of archaic humans.

The authors checked other samples they sequenced at the same time for signs of contamination and also looked at whether there might be a software glitch, but the results held up. There are two ways to explain that. One is that she's an immediate product of a mating between these two different people. The second is that she's part of a population of hybrids, where her parents both carried mixes of Neanderthal and Denisovan DNA.

To figure out which was happening, the researchers looked at each individual site where Neanderthals and Denisovans differ. If Denisova 11 were the product of a mixed population, you'd expect a fair number of these sites to be either all Neanderthal or all Denisovan, since the genomes should be pretty randomly mixed. If she were the immediate product of a mating between individuals from distinct groups, you would expect many of these sites to have one Neanderthal and one Denisovan version. (You wouldn't expect them all to be like that, because we don't know the full diversity of either Neanderthals or Denisovans at this point.)

The results clearly favored her being a 50-50 mix. "We conclude that Denisova 11 did not originate from a population carrying equal proportions of Neanderthal and Denisovan ancestry," the researchers conclude. "Rather, she was the offspring of a Neanderthal mother, who contributed her [mitochondrial] DNA, and a Denisovan father." The differences were also spread evenly throughout her genome, as you'd expect if each half of every chromosome pair came from a different group of ancestors.

A more detailed look at her ancestry showed there were at least five small regions where both chromosomes seem to have had a Neanderthal ancestry, suggesting that Denisova 11's father came from a population that had already interbred with Neanderthals in the distant past. And her mother seems to be most closely related to a Neanderthal skeleton found in Croatia, rather than a descendent of the Neanderthals that occupied the same cave tens of thousands of years earlier.

The authors argue that, despite the indications left in modern genomes, Denisova 11 strongly suggests that interbreeding was common whenever two different groups overlapped. After all, we don't have a lot of genomes from archaic humans, and we've already found one that's the direct product of interbreeding between two groups.

So why is there the difference between this expectation and what we've seen in other genomes, which suggests the two groups seem to be largely distinct lineages? For one, we don't really know how often different populations overlapped. Based on where modern populations have higher levels of Denisovan DNA, we can infer that Denisovans inhabited East Asia, but the details on where and when simply aren't known. The full extent of Neanderthals' range is also poorly constrained.

All of which means that interbreeding could have been limited by the fact that the populations simply didn't meet up that often. "This, as well as possibly reduced fitness of individuals of mixed ancestry, may explain why Neanderthals and Denisovans remained genetically distinct," the authors conclude.

By contrast, modern humans seem to have displaced archaic ones fairly rapidly, suggesting there was a limited time window in which interbreeding could have taken place. Still, the clear signs of interbreeding and apparent past willingness to live together may indicate that the modern humans absorbed earlier populations rather than completely displacing them.

But there's also a little nugget in the paper that suggests this won't be the last time the Denisovan Cave revolutionizes our understanding of our ancestry. The only skeletons mentioned in the paper are Denisova 3 and Denisova 11, but the paper notes that there have been "over 2,000 undiagnosed bone fragments excavated in Denisova Cave." That means there are probably a lot more potential sources of DNA we still haven't looked at yet.</s>Together with their sister group the Neandertals, Denisovans are the closest extinct relatives of currently living humans. “We knew from previous studies that Neandertals and Denisovans must have occasionally had children together,” said Viviane Slon, researcher at the MPI-EVA and one of three first authors of the study. “But I never thought we would be so lucky as to find an actual offspring of the two groups.”

The ancient individual is only represented by a single small bone fragment.

“The fragment is part of a long bone, and we can estimate that this individual was at least 13 years old”, said Bence Viola of the University of Toronto. The bone fragment was found in 2012 at Denisova Cave (Russia) by Russian archaeologists. It was brought to Leipzig for genetic analyses after it was identified as a hominin bone based on its protein composition.

“An interesting aspect of this genome is that it allows us to learn things about two populations – the Neandertals from the mother’s side, and the Denisovans from the father’s side”, explained Fabrizio Mafessoni from the MPI-EVA who co-authored the study. The researchers determined that the mother was genetically closer to Neandertals who lived in western Europe than to a Neandertal individual that lived earlier in Denisova Cave. This shows that Neandertals migrated between western and eastern Eurasia tens of thousands of years before their disappearance.

Analyses of the genome also revealed that the Denisovan father had at least one Neandertal ancestor further back in his family tree.

“So from this single genome, we are able to detect multiple instances of interactions between Neandertals and Denisovans”, said Benjamin Vernot from the MPI-EVA, the third co-author of the study.

“It is striking that we find this Neandertal/Denisovan child among the handful of ancient individuals whose genomes have been sequenced”, added Svante Pääbo, Director of the Department of Evolutionary Genetics at the MPI-EVA and lead author of the study. “Neandertals and Denisovans may not have had many opportunities to meet. But when they did, they must have mated frequently – much more so than we previously thought.”</s>Analysis of a bone fragment found in a Siberian cave from a young female who died 90,000 years ago has revealed she was half Neanderthal and half Denisovan.

The girl, thought to be aged around 13, is an example of interbreeding between now-extinct human groups.

She is the first first-generation individual of mixed ancestry from two distinct human groups to be discovered.

Most modern non-African humans have traces of Neanderthal DNA and some Asian populations have Denisovan DNA, showing that Homo sapiens, Neanderthals and Denisovans interbred.

As Neanderthal populations spread eastwards they encountered Denisovans, and the girl in the cave, nicknamed Denny by researchers, is the result of mating between a Neanderthal mother and a Denisovan father.

Pontus Skoglund, population geneticist at the Francis Crick Institute, said: "To find a first-generation person of mixed ancestry from these groups is absolutely extraordinary. It's really great science coupled with a little bit of luck."

A fragment of one of Denny's long bones was found in the Siberian cave several years ago.

Previous tests had been able to establish sex and when she died.

The most recent analysis compared Denny's DNA to genomes of a Neanderthal and a Denisovan. Researchers found she had one set of chromosomes from each hominin.

Currently earliest fossils of Neanderthals in Europe are dated at 430,000 years ago and thereafter Neanderthals expanded into southwest and Central Asia.

They died out around 40,000 years ago, possibly as a result of competition following the exodus of Homo sapiens (modern humans) from Africa between 60,000 and 40,000 years ago, although DNA analysis shows interbreeding between the two species.

A now-extinct subspecies of archaic humans, Denisovans ranged from Siberia to southeast Asia.

They lived among and interbred with the ancestors of some modern humans with about 3% to 5% of the DNA of Melanesians and Aboriginal Australians and around 6% in Papuans deriving from Denisovans.
A bone fragment found in Denisova Cave, Denisova 11, is identified as that of a girl who died 50,000 years ago aged at least 13. Genome-wide signatures tell that she had a Neanderthal mother and a mostly-Denisovan father. This first find of a prehistoric first-generation mixed offspring shows that different archaic human subtypes sometimes migrated, and then mixed more frequently than previously thought.