Homo sapiens, Neanderthals and Denisovans… did they interbreed? | Think, Learn & Live Think, Learn & Live Search for: Homo sapiens, Neanderthals and Denisovans… did they interbreed? Recent discoveries in DNA have shed light on the relationship of Homo sapiens and extinct hominids, Homo neanderthalensis and Denisova hominins. There is evidence to suggest that all three lived around the same time, and possibly in the same area (Krause et al., 2010)(Meyer et al., 2012). If these three groups lived close together, it should be possible to detect whether or not theyinterbred. If H. sapiens interbred with H. neanderthalensis and D. hominins, we should be able to find genetic evidence of this interbreeding in modern H. sapiens genomes. Using modern genetic examination (Gibbons, 2010), scientists have determined that H. sapiens did interbreed with both H.

neanderthalensis (Green et al, 2010)(Hawks, 2013)(Meyer et al, 2012) and with D. hominins (Hawks, 2013)(Meyer et al, 2012). Homo neanderthalensis fossils were first discovered in 1856 in Germany, and ever since, scientists have been exploring the relationship of Neanderthals to modern humans. (Gibbons, 2012) The first “draft sequence of the Neanderthal genome” was published in 2010 (Green, et al), and that has given us insight into the relationship of Neanderthal DNA to the DNA of modern humans. Using data obtained by the Human Genome Project (Intl Human Genome Sequencing Consortium, 2001), scientists can compare human and Neanderthal DNA in order to discover the genetic relationship between the two. The evidence suggests that Neanderthals lived in both Europe and Asia before going extinct around 30,000 years ago (Green et al, 2010). However, many of the Neanderthals interbred with H.

sapiens before going extinct. According to Green and colleagues (2010) andHawks (2013), modern humans living outside of Africa represent between 1% and 4% of ancestry from Neanderthal populations. It is possible, with modern genomic technology, for the average person to send a sample of her own DNA to a lab (ex: ‘23andMe’) and get results showing her ancestry. If she has European ancestry, it is possible that she will also have some small percentage of Neanderthal ancestry (Gibbons, 2012). These sorts of results would only be possible had the Neanderthals interbred with direct ancestors of modern humans. Not all of the evidence suggests that Neanderthals interbred with the ancestors of modern humans, however. A study showed that there were no contributions from Neanderthal mtDNA to modern human mtDNA from a specimen recovered from Mezmaiskaya Cave in the northern Caucasus. (Ovchinnikov, 2000) This is not necessarily contradictory data from the other studies; it shows that not all Neanderthal populations interbred with modern human populations.

The Denisova hominins, when compared to the Neanderthals, have been studied in much less detail. This is partially due to the minimal amount of evidence scientists have regarding the Denisovans; nothing more than the DNA from two teeth and a finger found in a cave in Siberia, aging from between 74,000 – 82,000 years ago (Harmon, 2012). The DNA that scientists do have, however, allows a fairly substantial analysis of possible interbreeding with the ancestors of modern humans. Analysis shows that approximately 6% of modern Papuans’ DNA came from the Denisovans (Harmon, 2012). Research also shows that modern Australian and Melanesian people derive up to 5% of their ancestry from the Denisovan population (Hawks, 2013) An analysis of mtDNA shows that the Denisovans, Neanderthals and modern humans diverged approximately one million years ago, but the Denisovans themselves lived from around 30,000 to 50,000 years ago (Krausse, 2010).

This data conflicts with the data from Harmon, showing that mtDNA sequencing and DNA sequencing indicate different time periods in which the Denisovans lived. The DNA evidence does suggest that ancestors of modern humans interbred with the Denisovans, but when they lived together isn’t known with much certainty. Cooper and colleagues (2013) confirm a date at more than 50,000 years ago and show that Denisovan and modern human ancestors interbred in remote Island Southeast Asia. Scientists may not know exactly when the interbreeding happened and we have reason to believe that it wasn’t extremely common, but the data presented in the wide variety of research clearly shows that the direct ancestors of Homo sapiens interbred with both Homo neanderthalensis and Denisova hominins. By understanding the relationships between all three groups, this information will lead to a better understanding of human history. By gaining a better understanding of modern human ancestry, we can determine the differences that may have caused the rise of H. sapiens and the decline (and ultimate extinction) of H. neanderthalensis and D. hominins. ——————————— Cooper, A. & C. B. Stringer.

(2013) “Did the Denisovans Cross Wallace’s Line? Science. Green, Richard E., et al. 2010. A Draft Sequence of the Neanderthal Genome. Science. Gibbons, Ann. 2010. “Tiny Time Machines Revisit Ancient Life” Science Gibbons, Ann. 2012. “The Neanderthal in My Family Tree; New genetic evidence shows our ancestors interbred with now-extinct species.” The Big Questions – What Makes Humans Human. Harmon, K. 2012. “New DNA Analysis Shows Ancient Humans Interbred with Denisovans”. Nature News. Hawks, John. 2013. “Significance of Neandertal and Denisovan Genomes in Human Evolution” Annual Review of Anthropology. International Human Genome Sequencing Consortium. 2001. “Initial Sequencing and Analysis of the Human Genome”. Nature. Krause, J., et al. 2010. “The complete mitochondrial DNA genome of an unknown hominin from southern Siberia”. Nature. Meyer, M. A., et al. 2012. “High Coverage Genome Sequence from an Archaic Denisovan Individual”.

Science ————– This paper was originally a small research project for my Science Writing (bio389) class at SUNY at Buffalo State College Share this: Human ancestors interbred with related species : Nature News Published online 5 September 2011 | Nature | doi:10.1038/news.2011.518 News Human ancestors interbred with related species Analysis suggests genetic mixing occurred in Africa around 35,000 years ago. Matt Kaplan Native African genomes still contain signs of ancient mixing with other species.Giacomo Pirozzi/PANOS Our ancestors bred with other species in the Homo genus, according to a study published today in the Proceedings of the National Academy of Sciences 1 . The authors say that up to 2% of the genomes of some modern African populations may originally come from a closely related species. Palaeontologists have long wondered whether modern humans came from a single, genetically isolated population of hominins or whether we are a genetic mix of various hominin species. Last year, an analysis comparing the Neanderthal genome sequence to that of modern H.

sapiens showed that some interbreeding did take place between the two species in Europe some time between 80 and 30,000 years ago and that, to a certain extent, Neanderthals 'live on' in the genes of modern humans 2 . It has been a mystery whether similar genetic mixing took place among Homo species even earlier, before the populations that became modern humans left Africa. To find out, evolutionary biologist Michael Hammer at the University of Arizona in Tucson and his colleagues studied DNA from two African hunter-gatherer groups, the Biaka Pygmies and the San, as well as from a West African agricultural population known as the Mandenka. Each of these groups is descended from populations that are thought to have remained in Africa, meaning they would have avoided the genetic bottleneck effect that usually occurs with migration. This means the groups show particularly high genetic diversity, which makes their genomes more likely to have retained evidence of ancient genetic mixing. “We need to modify the standard model of human origins.” Michael Hammer University of Arizona, Tucson To find signs of infiltration from other Homo species, the researchers looked at 61 non-coding DNA regions in all three groups.

Because direct comparison to archaic specimens wasn't possible, the authors used computer models to simulate how infiltration from different populations might have affected patterns of variation within modern genomes. Then they looked for such patterns of variation in the DNA of the three African populations. On chromosomes 4, 13 and 18, the researchers found genetic regions that were more divergent on average than known modern sequences at the same locations, hinting at a different origin. Mixing things up Hammer and his colleagues argue that roughly 2% of the genetic material found in these modern African populations was inserted into the human genome some 35,000 years ago. They say these sequences must have come from a now-extinct member of the Homo genus that broke away from the modern human lineage around 700,000 years ago. Hammer says this disproves the conventional view that we are descended from a single population that arose in Africa and replaced all other Homo species without interbreeding. "We need to modify the standard model of human origins," he says. Geneticist Sarah Tishkoff, who studies population genetics and human evolution at the University of Pennsylvania in Philadelphia, is more cautious.

"This raises the possibility that there may have been ancient admixture with archaic populations," she says. ADVERTISEMENT But some researchers will require yet more convincing. "The authors model differences in very small parameters, such as the difference between no admixture and 1-2% admixture with an archaic population," says anthropologist Brenna Henn, a graduate student at Stanford University in Palo Alto, California. "The ability to discern complex models of demographic history with such a small data set, when many of the basic features of African genomes and history remain unknown, concerns me." Tishkoff would also like to see further work. "Analyses of whole genome sequences of these populations will be necessary to more definitively test this hypothesis," she says.

References New DNA Analysis Shows Ancient Humans Interbred with Denisovans - Scientific American Scientific American Evolution New DNA Analysis Shows Ancient Humans Interbred with Denisovans A new high-coverage DNA sequencing method reconstructs the full genome of Denisovans--relatives to both Neandertals and humans--from genetic fragments in a single finger bone By Katherine Harmon on August 30, 2012 Credit: Image courtesy of Max Planck Institute for Evolutionary Anthropology Advertisement | Report Ad Tens of thousands of years ago modern humans crossed paths with the group of hominins known as the Neandertals. Researchers now think they also met another, less-known group called the Denisovans. The only trace that we have found, however, is a single finger bone and two teeth, but those fragments have been enough to cradle wisps of Denisovan DNA across thousands of years inside a Siberian cave. Now a team of scientists has been able to reconstruct their entire genome from these meager fragments. The analysis adds new twists to prevailing notions about archaic human history. "Denisova is a big surprise," says John Hawks , a biological anthropologist at the University of Wisconsin–Madison who was not involved in the new research.

On its own, a simple finger bone in a cave would have been assumed to belong to a human, Neandertal or other hominin. But when researchers first sequenced a small section of DNA in 2010 —a section that covered about 1.9 percent of the genome—they were able to tell that the specimen was neither. "It was the first time a new group of distinct humans was discovered" via genetic analysis rather than by anatomical description, said Svante Pääbo, a researcher at the Max Planck Institute (M.P.I.) for Evolutionary Anthropology in Germany, in a conference call with reporters. Now Pääbo and his colleagues have devised a new method of genetic analysis that allowed them to reconstruct the entire Denisovan genome with nearly all of the genome sequenced approximately 30 times over akin to what we can do for modern humans. Within this genome, researchers have found clues into not only this group of mysterious hominins, but also our own evolutionary past. Denisovans appear to have been more closely related to Neandertals than to humans, but the evidence also suggests that Denisovans and humans interbred.

The new analysis also suggests new ways that early humans may have spread across the globe. The findings were published online August 30 in Science. Who were the Denisovans? Unfortunately, the Denisovan genome doesn't provide many more clues about what this hominin looked like than a pinky bone does. The researchers will only conclude that Denisovans likely had dark skin. They also note that there are alleles "consistent" with those known to call for brown hair and brown eyes. Other than that, they cannot say. Yet the new genetic analysis does support the hypothesis that Neandertals and Denisovans were more closely related to one another than either was to modern humans. The analysis suggests that the modern human line diverged from what would become the Denisovan line as long as 700,000 years ago—but possibly as recently as 170,000 years ago. Denisovans also interbred with ancient modern humans, according to Pääbo and his team. Even though the sole fossil specimen was found in the mountains of Siberia, contemporary humans from Melanesia (a region in the South Pacific) seem to be the most likely to harbor Denisovan DNA.

The researchers estimate that some 6 percent of contemporary Papuans' genomes come from Denisovans. Australian aborigines and those from Southeast Asian islands also have traces of Denisovan DNA. This suggests that the two groups might have crossed paths in central Asia and then the modern humans continued on to colonize the islands of Oceania. Yet contemporary residents of mainland Asia do not seem to posses Denisovian traces in their DNA, a "very curious" fact, Hawks says. "We're looking at a very interesting population scenario"—one that does not jibe entirely with what we thought we knew about how waves modern human populations migrated into and through Asia and out to Oceania's islands. This new genetic evidence might indicate that perhaps an early wave of humans moved through Asia, mixed with Denisovans and then relocated to the islands—to be replaced in Asia by later waves of human migrants from Africa. "It's not totally obvious that that works really well with what we know about the diversity of Asians and Australians," Hawks says. But further genetic analysis and study should help to clarify these early migrations. Just as with modern Homo sapiens, the genome of a single individual cannot tell us exactly what genes and traits are specific to all Denisovans.

Yet, just one genome can reveal the genetic diversity of an entire population. Each of our genomes contains information about generations far beyond those of our parents and grandparents, said David Reich, a researcher at the Massachusetts Institute of Technology–Harvard University Broad Institute and a co-author on the paper. Scientists can compare and contrast the set of genes on each chromosome—passed down from each parent—and extrapolate this process back through the generations. "You contain a multitude of ancestors within you," Reich said, borrowing from Walt Whitman. The new research reveals that the Denisovans had low genetic diversity—just 26 to 33 percent of the genetic diversity of contemporary European or Asian populations. And for the Denisovans, the population on the whole seems to have been very small for hundreds of thousands of years, with relatively little genetic diversity throughout their history. Curiously, the researchers noted in their paper, the Denisovan population shows "a drastic decline in size at the time when the modern human population began to expand." Why were modern humans so successful whereas Denisovans (and Neandertals) went extinct? Pääbo and his co-authors could not resist looking into the genetic factors that might be at work.

Some of the key differences, they note, center around brain development and synaptic connectivity. "It makes sense that what pops up is connectivity in the brain," Pääbo noted. Neandertals had a similar brain size–to-body ratio as we do, so rather than cranial capacity, it might have been underlying neurological differences that could explain why we flourished while they died out, he said. Hawks counters that it might be a little early to begin drawing conclusions about human brain evolution from genetic comparisons with archaic relatives. Decoding the genetic map of the brain and cognition from a genome is still a long way off, he notes—unraveling skin color is still difficult enough given our current technologies and knowledge. New sequencing for old DNA The Denisovan results rely on a new method of genetic analysis developed by paper co-author Matthias Meyer, also of M.P.I. The procedure allows the researchers to sequence the full genome by using single strands of genetic material rather than the typical double strands required. The technique, which they are calling a single-stranded library preparation, involves stripping the genetic material down to individual strands to copy and avoids a purification step, which can lose precious genetic material.

The finger bone—just one disklike phalanx—is so small that it does not contain enough usable carbon for dating, the researchers note. But by counting the number of genetic mutations in a genome and comparing them with other living relatives, such as modern humans and chimpanzees, given assumed rates of mutations since breaking with a last common ancestor, "for the first time you can try to estimate this number into a date and provide molecular dating of the fossil," Meyer said. With the new resolution, the researchers estimate the age of the bone to 74,000 to 82,000 years ago. But that is a wide window, and previous archaeological estimates for the bone are a bit younger, ranging from 30,000 to 50,000 years old. These genetic estimations are also still in limbo because of ongoing debate about the average rate of genetic mutations over time, which could skew the age. "Nevertheless," the researchers noted in their paper, "the results suggest that in the future it will be possible to determine dates of fossils based on genome sequences." This new sequencing approach can be used for any DNA that is too fragmented to be read well through more traditional methods.

Meyer noted that it could come in handy for analysis of both ancient DNA and contemporary forensic evidence, which also often contains only fragments of genetic material. Hawks is excited about the new sequencing technology. It is also helpful to have a technology developed specifically for the evolutionary field, he notes. "We're always using the new techniques from other fields, and this is a case where the new technique is developed just for this." Hawks himself has heard from the researchers that have worked with the Denisovan samples that "the Denisovan pinky is just extraordinary" in terms of the amount of DNA preserved in it. Most bone fragments would be expected to contain less than 5 percent of the individual's endogenous DNA, but this fortuitous finger had a surprising 70 percent, the researchers noted in the study. And many Neandertal fragments have been preserved in vastly different states—many are far worse off than this Denisovan finger bone. The new sequencing approach could also improve our understanding of known specimens and the evolutionary landscape as a whole. "It's going to increase the yield from other fossils," Hawks notes. Many of the Neandertal specimens, for example, have only a small fraction of their genome sequenced.

"If we can go from 2 percent to the whole genome, that opens up a lot more," Hawks says. "Going back further in time will be exciting," he notes, and this new technique should allow us to do that. "There's a huge race on—it's exciting." The Denisovans might be the first non-Neandertal archaic human to be sequenced, but they are likely not going to be the last. The researchers behind this new study are already at work using the new single-strand sequencing technique to reexamine older specimens. (Meyer said they were working on reassessing old samples but would not specify which specimens they were studying—the mysterious "hobbit" H. floresiensis would be a worthy candidate.) Pääbo suggests Asia as a particularly promising location to look for other Denisovan-like groups. "I would be surprised if there were not other groups to be found there in the future," he said. Taking this technique to specimens from Africa is also likely to yield some exciting results, Hawks says. Africa, with its rich human evolutionary history, holds the greatest genetic diversity.

The genomes of contemporary pygmy and hunter–gatherer tribes in Africa, for example, have roughly as many differences as do those of European modern humans and Neandertals. So "any ancient specimen that we find in Africa might be as different from us as Neandertals," Hawks says. "Anything we find from the right place might be another Denisovan." Neanderthals may have been wiped out due to INTERBREEDING and not because of a lack of intelligence | Daily Mail Online Neanderthals may have been wiped out due to INTERBREEDING and not because of a lack of intelligence Two researchers have suggested that Neanderthals never went extinct Instead, they say they vanished because they mated with early humans They also say Neanderthals were not as dumb as we believed them to be Their lack of intelligence is often cited as the reason they disappeared They thrived in Eurasia for 300,000 years but vanished 40,000 years ago comments They are often depicted as dim-witted evolutionary losers, but Neanderthals were not driven to extinction by their lack of brains, a new study suggests.

Instead, it is more likely that they disappeared 40,000 years ago because of interbreeding and assimilation with our early modern human ancestors, scientists believe. An analysis of archaeological evidence dating back 200,000 years strips away some of the myths surrounding Neanderthals and reveals they were more advanced and sophisticated than has widely been thought. Why did Neanderthals go extinct? It's often thought their lack of intelligent ultimately led to their demise, but new research suggests it may instead have been due to interbreeding and assimilation with our early modern human ancestors The differences between the two human sub-species are not enough on their own to account for the demise of the Neanderthals, say the two US and Dutch researchers. Dr Paola Villa, from the University of Colorado Museum, and Professor Wil Roebroeks, from Leiden University, wrote in the online journal Public Library of Science ONE: 'Genetic studies now suggest that the debate on the demise of the Neanderthals needs to be reframed in terms of some degree of interbreeding. 'In that sense, Neanderthals did not go extinct, even though their distinctive morphology did disappear.

RELATED ARTICLES Share 'We conclude that all the "archaeology-based" explanations for the demise of the Neanderthals... are flawed.' Neanderthals thrived in Eurasia for 300,000 years but vanished around 40,000 years ago as early modern humans began to settle in Europe. In the past, experts have theorised that Neanderthals died out because they were mentally, technologically and culturally inferior to the newcomers and unable to compete for limited resources. But more recent evidence has shown that Neanderthals made effective tools and weapons, wore ornaments such as eagle claws, used ochre and pitch, ate plants and fish as well as big game and created organised living spaces in their caves. In many cases this was happening before the arrival of modern humans, so the behaviours could not have been copied from them. Reviewing the evidence, the scientists pointed out that 200,000 years ago Neanderthals were using fire to produce pitch from tree bark. Experiments showed that the process required high temperatures and an oxygen-free environment such as an enclosed pot, suggesting a high level of technical knowledge.

Evidence of the Neanderthals and early humans mixing can be seen in the fossil record. Some human-like characteristics have been found in late Neanderthal fossils, and conversely, Neanderthal features have been seen in early specimens of modern humans in Europe Neanderthal DNA, which was sequenced in 2010, shows clear evidence of interbreeding, the researchers add. Neanderthals and early modern humans are most likely to have interbred in Europe and the Middle East around 50,000 years ago. Today Neanderthal inheritance is estimated to make up between 1% and 4% of the DNA of people outside Africa. Interbreeding could be one reason why Neanderthals vanished, according to the scientists. They were not so much driven to extinction as assimilated. Evidence of the two mixing can be seen in the fossil record. Some human-like characteristics have been found in late Neanderthal fossils, and conversely, Neanderthal features have been seen in early specimens of modern humans in Europe. Neanderthals were more robust and much stronger than modern humans, with a backward sloping chin and forehead.

It is possible that interbreeding with Neanderthals may have helped our ancestors survive outside Africa, say the scientists. On the other hand some Neanderthal genes may have contributed to sterility, which is why so few remain. The researchers wrote: 'The Neanderthal demise appears to have resulted from a complex and protracted process including multiple dynamic factors such as low population density, interbreeding with some cultural contact, possible male hybrid sterility and contraction in geographic distribution followed by genetic swamping and assimilation by the increasing numbers of modern immigrants.' EUROPEANS MORE CLOSELY RELATED TO NEANDERTHALS THAN AFRICANS Europeans may be closer to their Neanderthal cousins than previously thought, new research suggests. Breeding with Neanderthals has long been known to have left its traces in the DNA of modern Europeans. Scientists in Edinburgh have now confirmed that the genetic similarity between the two must have arisen after interbreeding in Europe and Asia, before our ancestors spread across the globe. Previous research speculated that modern Europeans and Asians are related to Neanderthals because they originated from a similar sub-population in Africa. Both groups evolved from a common ancestor in Africa before spreading to other parts of the world.

The two groups emerged at different times with Neanderthals leaving the African continent more than 200,000 years before humans did. Now scientists at the University of Edinburgh and Wageningen University found the species mated in Europe and Asia thousands of years ago. The research involved dividing up the genetic code of each sub-species to calculate the statistical likelihood of distant or recent interbreeding. They traced the biological ties that exist between humans and the ancient species which are believed to have died out around 30,000 years ago. The research found that the two per cent of neanderthal DNA which exists in people today came from the mating outside of Africa. Did Interbreeding with humans give dwindling Neanderthals new lease on life? | Genetic Literacy Project Did Interbreeding with humans give dwindling Neanderthals new lease on life? Printer Friendly What happened to the Neanderthals? It’s a question many in the sciences have tried to answer for over a century. The last five years have seen a number of new insights due to major leaps forward in our ability to process ancient DNA.

We now know that modern humans interbred with our bulkier cousins in Europe and Asia—enough so that a small fraction of the genomes of some modern humans contain Neanderthal remnants. Some have even suggested that certain behaviors and conditions like drug abuse and depression are from gene variants we got from this ancient ‘ co-mingling ‘. Yet, the discovery that humans and Neanderthals interbred only complicates the initial question of what happened to them. Much of the debate surrounding their extinction has focused on the arrival of the “invasive” modern human species to the Neanderthal’s turf. But new evidence suggests that early human immigrants to the European continent may have actually helped Neanderthals stave off extinction—at least for several thousands years. Neanderthals, like humans, trace their evolutionary origin to Africa. But starting about 400,000 years ago most left and begun to populate what today is Europe and Western Asia. Some scientists suggest that at their peak in numbers—before the arrival of humans—Neanderthals may have totaled around 70,000 .

A long held belief has been that Neanderthals were unable to adapt to the changing colder climate of this period, but that’s now thought to be mistaken. Neanderthals appear to be particularly well adapted to colder climes because of their short torsos and limbs that helped conserve heat and their large noses that humidified and warmed dry, cold air. It is hard to pin down exactly when humans first interacted with Neanderthals. The first Homo sapiens are believed to have appeared around 200,000 years ago, also in Africa. It had long been accepted that modern humans began settling in Europe about 45,000-60,000 years ago—probably in more than one migration event. However, newly uncovered fossils, as well as DNA evidence, suggests early humans may have encountered Neanderthals 40,000-50,000 years earlier than that. No matter when the first meeting happened, Neanderthals were completely extinct by about 30,000-40,000 years ago. There are a number of theories as to why.

Although there is no evidence of direct human-Neanderthal combat, many people still believe in the popular notion that humans “wiped them out.” We may have done this indirectly by out-competing them for space and resources, perhaps because of our superior intellect and technology. There’s another mistaken belief that because their DNA can be found in modern human genomes Neanderthals never actually went extinct. A recent popular theory backed by some evidence was that humans (particularly when engaging in sexual intercourse with Neanderthals) may have spread infectious diseases— herpes, tapeworms, and tuberculosis —that the Neanderthals immune system was ill equipped to deal with. Whatever the reasons for their demise, the arrival of modern humans in Eurasia appears to be the prelude to the permanent departure of the Neanderthals. But Neanderthals didn’t drop from 70,000 strong to nothing quickly. They were already a dwindling species by the time Homo sapiens began making places other than Africa their home.

While it is difficult—if not impossible—to say with complete accuracy the global Neanderthal population, estimates suggest that their global numbers could have been as low as 1,500 reproductive-aged females around 70,000 years ago—which coincides with about the time of the largest Homo sapien migration out of Africa. Also during this time, evidence suggests Neanderthals were living in small geographically isolated communities . This means when humans arrived in Europe and Asia, Neanderthals were likely very few in numbers and living in isolated populations with little contact amongst each other. Anyone who works in the field of species extinction will tell you that this is a very bad combination for long term survival. The fact they existed in small, isolated populations also suggests that Neanderthals likely were inbreeding, which can lead to (often recessive) deleterious traits becoming more and more abundant in the overall population, making them even more vulnerable to disease. (It’s a process that modern humans would see play out often among royal families ; e.g. hemophilia in 19 and 20th century Europe).

How inbreeding increases frequency of deleterious traits Their geographic isolation would have likely compounded this and made it increasingly more difficult for natural selection to “weed out as bad mutations” as paleoanthropologist John Hawks of the University of Wisconsin at Madison has put it. A recent analysis has also found that the Neanderthal genome was full of genes that reduced their overall fitness— some 40 percent compared to Homo sapiens. Neanderthals were likely a species on the brink when humans suddenly appeared. Mating and exchanging DNA with these ‘invaders’ quite possibly served as a ‘short in the arm,’ helping to restore their genetic diversity, quite possibly extending their species tens of thousands of years—until some stronger forces, perhaps disease, wiped them out. One species saving another through interbreeding to rebuild genetic diversity is actually not unheard of. The U.S. Fish and Wildlife Service credits an interbreeding program between the endangered Florida panther and Texas pumas as a driving factor in staving off the former’s extinction. Similar programs have been implemented in conservation efforts for the greater prairie chicken. Humans may or may not have dealt Neanderthals their final blow; further evidence may reveal an answer or we may never know.

But our initial arrival probably did their survival (and gene pool) a lot of good. Nicholas Staropoli is the associate director of GLP and director of the Epigenetics Literacy Project. He has an M.A. in biology from DePaul University and a B.S. in biomedical sciences from Marist College. Follow him on twitter @NickfrmBoston . Mystery humans spiced up ancients’ sex lives : Nature News & Comment Sharing Mystery humans spiced up ancients’ sex lives Genome analysis suggests there was interbreeding between modern humans, Neanderthals, Denisovans and an unknown archaic population. RIA NOVOSTI/SPL An excavation in Denisova cave in Siberia, Russia, where remains of Denisovan hominins were first discovered. Updated genome sequences from two extinct relatives of modern humans suggest that these ‘archaic’ groups bred with humans and with each other more extensively than was previously known. The ancient genomes, one from a Neanderthal and one from a member of an archaic human group called the Denisovans, were presented on 18 November at a meeting on ancient DNA at the Royal Society in London.

The results suggest that interbreeding went on between the members of several ancient human-like groups in Europe and Asia more than 30,000 years ago, including an as-yet-unknown human ancestor from Asia. “What it begins to suggest is that we’re looking at a Lord of the Rings-type world — that there were many hominid populations,” says Mark Thomas, an evolutionary geneticist at University College London who was at the meeting but was not involved in the work. The first published Neanderthal 1 and Denisovan 2 genome sequences revolutionized the study of ancient human history, not least because they showed that these groups bred with anatomically modern humans, contributing to the genetic diversity of many people alive today. Mixed heritage All modern humans whose ancestry originates outside of Africa owe about 2% of their genome to Neanderthals. Certain populations living in Oceania, such as Papua New Guineans and Australian Aboriginals, share about 4% of their DNA with Denisovans, members of a group named after a cave in the Altai Mountains in Siberia, Russia, where they were discovered. The cave contains remains deposited between 30,000 and 50,000 years ago.

At the meeting, however, David Reich, an evolutionary geneticist at Harvard Medical School in Boston, Massachusetts, who worked on those studies, said that the conclusions were based on low-quality genome sequences, riddled with errors and full of gaps. His team, along with collaborator Svante Pääbo at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, has now produced much more complete versions of the Denisovan and Neanderthal genomes — matching the quality of contemporary human genomes. These high-quality Denisovan and Neanderthal sequences are both based on bones from the Denisova Cave. The Denisovan genome indicates that the population got around: Reich said at the meeting that as well as interbreeding with the ancestors of Oceanians, they also bred with Neanderthals and the ancestors of modern humans in China and other parts of East Asia. Most surprisingly, Reich said, the genomes indicate that Denisovans interbred with yet another extinct population of archaic humans that lived in Asia more than 30,000 years ago — one that is neither human nor Neanderthal. The meeting was abuzz with conjecture about the identity of this unknown population of humans.

“We don’t have the faintest idea,” says Chris Stringer, a paleoanthropologist at the Natural History Museum in London, who was not involved in the work. He speculates that the population could be related to Homo heidelbergensis, a species that left Africa around half a million years ago and later gave rise to Neanderthals in Europe. “Perhaps it lived on in Asia as well,” says Stringer. Journal name: Author details Ewen Callaway Ewen joined Nature in August 2010, after 2 years at New Scientist as Boston-based biomedical reporter. He attended the science-writing programme at the University of California, Santa Cruz, and earned a master’s degree in microbiology at the University of Washington. He spends his free time learning… Evolution of Modern Humans: Early Modern Homo sapiens Neandertal modern Homo sapiens The first fossils of early modern humans to be identified were found in 1868 at the 27,000-23,000 year old Cro-Magnon rock shelter site near the village of Les Eyzies in southwestern France. They were subsequently named the Cro-Magnon people. They were very similar in appearance to modern Europeans.

Males were 5 feet 4 inches to 6 feet tall (1.6-1.8 m.) That was 4-12 inches (10-31 cm.) taller than Neandertals. Their skeletons and musculature generally were less massive than the Neandertals. The Cro-Magnon had broad, small faces with pointed chins and high foreheads. Their cranial capacities were up to 1590 cm3, which is relatively large even for people today. Origins of Modern Humans Current data suggest that modern humans evolved from archaic humans primarily in East Africa. A 195,000 year old fossil from the Omo 1 site in Ethiopia shows the beginnings of the skull changes that we associate with modern people, including a rounded skull case and possibly a projecting chin. A 160,000 year old skull from the Herto site in the Middle Awash area of Ethiopia also seems to be at the early stages of this transition. It had the rounded skull case but retained the large brow ridges of archaic humans.

Somewhat more advanced transitional forms have been found at Laetoli in Tanzania dating to about 120,000 years ago. By 115,000 years ago, early modern humans had expanded their range to South Africa and into Southwest Asia (Israel) shortly after 100,000 years ago. There is no reliable evidence of modern humans elsewhere in the Old World until 60,000-40,000 years ago, during a short temperate period in the midst of the last ice age. Important Early Modern Homo sapiens Sites Date of Fossil Cro-Magnon (France) 27,000-23,000 Note: Artifactual evidence indicates that modern humans were in Europe by at least 40,000 and possibly as early as 46,000 years ago. Dating of the earliest modern human fossils in Asia is less secure, but it is likely that they were present there by at least 60,000 years ago and possibly 100,000 years ago.

It would seem from these dates that the location of initial modern Homo sapiens evolution and the direction of their dispersion from that area is obvious. That is not the case. Since the early 1980's, there have been two leading contradictory models that attempt to explain modern human evolution--the replacement model and the regional continuity model. The replacement model of Christopher Stringer and Peter Andrews proposes that modern humans evolved from archaic humans 200,000-150,000 years ago only in Africa and then some of them migrated into the rest of the Old World replacing all of the Neandertals and other late archaic humans beginning around 60,000-40,000 years ago or somewhat earlier. If this interpretation of the fossil record is correct, all people today share a relatively modern African ancestry. All other lines of humans that had descended from Homo erectus presumably became extinct. From this view, the regional anatomical differences that we now see among humans are recent developments--evolving mostly in the last 40,000 years. This hypothesis is also referred to as the "out of Africa", "Noah's ark", and "African replacement" model.

The regional continuity model (or multiregional evolution model) advocated by Milford Wolpoff proposes that modern humans evolved more or less simultaneously in all major regions of the Old World from local archaic humans. For example, modern Chinese are seen as having evolved from Chinese archaic humans and ultimately from Chinese Homo erectus. This would mean that the Chinese and some other peoples in the Old World have great antiquity in place. Supporters of this model believe that the ultimate common ancestor of all modern people was an early Homo erectus in Africa who lived at least 1.8 million years ago. It is further suggested that since then there was sufficient gene flow between Europe, Africa, and Asia to prevent long-term reproductive isolation and the subsequent evolution of distinct regional species. It is argued that intermittent contact between people of these distant areas would have kept the human line a single species at any one time. However, regional varieties, or subspecies, of humans are expected to have existed. Replacement Model Arguments There are two sources of evidence supporting the replacement model--the fossil record and DNA. So far, the earliest finds of modern Homo sapiens skeletons come from Africa. They date to nearly 200,000 years ago on that continent.

They appear in Southwest Asia around 100,000 years ago and elsewhere in the Old World by 60,000-40,000 years ago. Unless modern human remains dating to 200,000 years ago or earlier are found in Europe or East Asia, it would seem that the replacement model better explains the fossil data for those regions. However, the DNA data supporting a replacement are more problematical. Beginning in the 1980's, Rebecca Cann, at the University of California, argued that the geographic region in which modern people have lived the longest should have the greatest amount of genetic diversity today. Through comparisons of mitochondrial DNA sequences from living people throughout the world, she concluded that Africa has the greatest genetic diversity and, therefore, must be the homeland of all modern humans. Assuming a specific, constant rate of mutation, she further concluded that the common ancestor of modern people was a woman living about 200,000 years ago in Africa. This supposed predecessor was dubbed "mitochondrial Eve" . More recent genetic research at the University of Chicago and Yale University lends support to the replacement model.

It has shown that variations in the DNA of the Y chromosome and chromosome 12 also have the greatest diversity among Africans today. John Relethford and other critics of the replacement model have pointed out that Africa could have had the greatest diversity in DNA simply because there were more people living there during the last several hundred thousand years. This would leave open the possibility that Africa was not necessarily the only homeland of modern humans. Critics of the genetic argument for the replacement model also point out that the rate of mutation used for the "molecular clock" is not necessarily constant, which makes the 200,000 year date for "mitochondrial Eve" unreliable. The rate of inheritable mutations for a species or a population can vary due to a number of factors including generation time, the efficiency of DNA repair within cells, ambient temperature, and varying amounts of natural environmental mutagens. In addition, some kinds of DNA molecules are known to be more subject to mutation than others, resulting in faster mutation rates. This seems to be the case with the Y chromosome in human males. Further criticism of the genetic argument for the replacement model has come from geneticists at Oxford University.

They found that the human betaglobin gene is widely distributed in Asia but not in Africa. Since this gene is thought to have originated more than 200,000 years ago, it undercuts the claim that an African population of modern Homo sapiens replaced East Asian archaic humans less than 60,000 years ago. Regional Continuity Model Arguments Fossil evidence also is used to support the regional continuity model. Its advocates claim that there has been a continuity of some anatomical traits from archaic humans to modern humans in Europe and Asia. In other words, the Asian and European physical characteristics have antiquity in these regions going back over 100,000 years. They point to the fact that many Europeans have relatively heavy brow ridges and a high angle of their noses reminiscent of Neandertals. Similarly, it is claimed that some Chinese facial characteristics can be seen in an Asian archaic human fossil from Jinniushan dating to 200,000 years ago. Like Homo erectus, East Asians today commonly have shovel-shaped incisors while Africans and Europeans rarely do. This supports the contention of direct genetic links between Asian Homo erectus and modern Asians.

Alan Thorne of the Australian National University believes that Australian aborigines share key skeletal and dental traits with pre-modern people who inhabited Indonesia at least 100,000 years ago. The implication is that there was no replacement by modern humans from Africa 60,000-40,000 years ago. However, the evidence does not rule out gene flow from African populations to Europe and Asia at that time and before. David Frayer, of the University of Kansas, believes that a number of European fossils from the last 50,000 years have characteristics that are the result of archaic and modern humans interbreeding. Assimilation Model It is apparent that both the complete replacement and the regional continuity models have difficulty accounting for all of the fossil and genetic data. What has emerged is a new hypothesis known as the assimilation (or partial replacement) model. It takes a middle ground and incorporates both of the old models. Gunter Brauer, of the University of Hamburg in Germany, proposes that the first modern humans did evolve in Africa, but when they migrated into other regions they did not simply replace existing human populations.

Rather, they interbred to a limited degree with late archaic humans resulting in hybrid populations. In Europe, for instance, the first modern humans appear in the archaeological record rather suddenly around 45-40,000 years ago. The abruptness of the appearance of these Cro-Magnon people could be explained by their migrating into the region from Africa via an eastern Mediterranean coastal route. They apparently shared Europe with Neandertals for another 12,000 years or more. During this long time period, it is argued that interbreeding occurred and that the partially hybridized predominantly Cro-Magnon population ultimately became modern Europeans. In 2003, a discovery was made in a Romanian cave named Peştera cu Oase that supports this hypothesis. It was a partial skeleton of a 15-16 year old male Homo sapiens who lived about 30,000 years ago or a bit earlier. He had a mix of old and new anatomical features. The skull had characteristics of both modern and archaic humans. This could be explained as the result of interbreeding with Neandertals according to Erik Trinkaus of Washington University in St. Louis.

Alan Templeton, also of Washington University, reported that a computer-based analysis of 10 different human DNA sequences indicates that there has been interbreeding between people living in Asia, Europe, and Africa for at least 600,000 years. This is consistent with the hypothesis that humans expanded again and again out of Africa and that these emigrants interbred with existing populations in Asia and Europe. It is also possible that migrations were not only in one direction--people could have migrated into Africa as well. If interbreeding occurred, it may have been a rare event. This is supported by the fact that most skeletons of Neandertals and Cro-Magnon people do not show hybrid characteristics. relationship between Neandertals and modern humans. This link takes you to another web page. To return here, you must click the "back" button on your browser program. (length = 17 mins, 2 secs) It would be a mistake to assume that from the time modern Homo sapiens began migrating out of Africa that all people in that continent were modern humans. The video below presents evidence of pockets of archaic humans surviving in West Africa until at least 13,000 years ago. human skull from Nigeria.

This link takes you to a BBC website. Select the video at the top of the article. To return here, you must click the "back" button on your browser program. (length = 1 min, 45 secs) Expansion Out of the Old World Homo sapiens began migrating into the lower latitudes of East Asia by at least 70,000 years ago. Along the way, some of them interbred with archaic humans, including both Neandertals and Denisovans. Genetic markers from these archaic human populations are found in the gene pool of some Southern Chinese, New Guinean, and other Micronesian Island populations today. Homo sapiens from Southeast Asia travelled to Australia by 46,000 years ago and possibly as early as 60,000 years ago. Because Australia was not connected to Southeast Asia by land, it is probable that these first Australian Aborigines arrived by simple boats or rafts. Modern humans reached the Japanese Islands by 30,000 years ago or somewhat earlier. Around 35,000-30,000 years ago, Homo sapiens big game hunters moved into Northeastern Siberia.

Some of them migrated into North America via the Bering Plain, or Beringia , by 20,000-15,000 years ago. Some Homo sapiens may have reached the Americas a bit earlier than this, but the evidence is still considered questionable by most paleoanthropologists. The Bering Plain intercontinental land connection appeared between Siberia and Alaska as a result of sea levels dropping up to 450 feet (137 m.) during the final major cold period of the last ice age. Until that time, all human evolution had occurred in the Old World. A consequence of human migrations into new regions of the world has been the extinction of many animal species indigenous to those areas. By 11,000 years ago, human hunters in the New World apparently had played a part in the extermination of 135 species of mammals, including 3/4 of the larger ones (mammoths, mastodons, giant sloths, etc.). Most of these extinctions apparently occurred within a few hundred years. It is likely that the rapidly changing climate at the end of the last ice age was a contributing factor.

However, the addition of human hunters with spears to the existing top predators (mostly saber-toothed cats, lions, and dire-wolves) very likely disrupted the equilibrium between large herbivores and their predators. As a consequence there was a major ecosystem disruption resulting in the rapid decline of both non-human carnivores and their prey. Humans were very likely the trigger that set off this "trophic cascade". Unlike most other major predators, people survived by switching their food quest to smaller animals and plants. Following the arrival of aboriginal people in Australia and Polynesians in New Zealand there were similar dramatic animal extinctions. In both of these cases humans apparently were directly responsible for wiping out easily hunted species. Large vulnerable marsupials were the main victims in Australia. Within 5,000 years following the arrival of humans, approximately 90% of the marsupial species larger than a domesticated cat had become extinct there. In New Zealand, it was mostly large flightless birds that were driven to extinction by human hunters following their arrival in the 10th-13th centuries A.D. It is sobering to realize that the rate of animal and plant extinction has once again accelerated dramatically.

During the last century and a half, the explosion in our global human population and our rapid technological development has allowed us to move into and over-exploit most areas of our planet including the oceans. That exploitation has usually involved cutting down forests, changing the courses of rivers, pushing wild animals and plants out of farm and urban areas, polluting wetlands with pesticides and other man-made chemicals, and industrial-scale hunting of large land animals, whales, and fish. During the early 19th century, there were at least 40,000,000 bison roaming the Great Plains of North America. By the end of that century, there were only a few hundred remaining. They had been hunted to near extinction with guns. The same fate came to the African elephant and rhinoceros during the 20th century. Likewise, commercial fishermen have depleted one species of fish after another during the last half century. Governments have had to step in to try to stem the tide of these human population effects on other species. However, they have been only marginally successful.

The World Conservation Union conservatively estimates that 7,266 animal species and 8,323 plant and lichen species are now at risk of extinction primarily due to human caused habitat degradation. The endangered list includes 1/3 of all amphibian species, nearly 1/2 of the turtles and tortoises, 1/4 of the mammals, 1/5 of the sharks and rays, and 1/8 of the birds. This list does not include the many millions of species that are still unknown to science. It is likely that most of them will become extinct before they can be described and studied. People Today Are we genetically different from our Homo sapiens ancestors who lived 10-20,000 years ago? The answer is almost certainly yes. In fact, it is very likely that the rate of evolution for our species has continuously accelerated since the end of the last ice age, roughly 10,000 years ago. This is mostly due to the fact that our human population has explosively grown and moved into new kinds of environments, including cities, where we have been subject to new natural selection pressures.

For instance, our larger and denser populations have made it far easier for contagious diseases, such as tuberculosis, small pox, the plague, and influenza to rapidly spread through communities and wreak havoc. This has exerted strong selection for individuals who were fortunate to have immune systems that allowed them to survive. There also has been a marked change in diet for most people since the end of the last ice age. It is now less varied and predominantly vegetarian around the globe with a heavy dependence on foods made from cereal grains. It is likely that the human species has been able to adapt to these and other new environmental pressures because it has acquired a steadily greater genetic diversity. A larger population naturally has more mutations adding variation to its gene pool simply because there are more people. This happens even if the mutation rate per person remains the same. However, the mutation rate may have actually increased because we have been exposed to new kinds of man-made environmental pollution that can cause additional mutations. It is not clear what all of the consequences of the environmental and behavioral changes for humans have been.

However, it does appear that the average human body size has become somewhat shorter over the last 10,000 years, and we have acquired widespread immunity to the more severe effects of some diseases such as measles and influenza. Finally, can we say what direction human evolution will take in the future? This is a fascinating question to consider but impossible to answer because of innumerable unknown factors. Though, it is certain that we will continue to evolve until we reach the point of extinction. NEWS: Maanasa Raghavan et al. reported on November 20, 2013 ( and ) that a 24,000 year old child skeleton from Mal�ta near Lake Baikal in eastern Siberia shared major DNA markers with Western Europeans and 1/4 of living Native American. A 17,000 year old adult skeleton from Siberia also had genetic markers indicating European origin. This indicates that ice age Homo sapiens from Europe migrated much farther beyond that continent than commonly believed. It also implies that the New World native populations owe their ancestry not only to East Asians but to Europeans as well.

Neanderthals interbred for longer with East Asian humans, DNA reveals | Daily Mail Online Neanderthals interbred for longer with East Asian humans, DNA reveals Scientists say Neanderthals and humans may have interbred multiple times People in East Asia carry 15 to 30% more Neanderthal DNA than Europeans They say Europeans appear to have interbred on just one occasion But the ancestors of East Asians may have interbred for a second time It suggests Neanderthals spread far further east than originally thought Their remains are concentrated in Europe and as far east as central Asia Experts say Neanderthals in the East may have outlived those in Europe Neanderthals And Europeans Had Sex, Scientists Confirm Using Human Genome Study - International Science Times Neanderthals And Europeans Had Sex, Scientists Confirm Using Human Genome Study By Ben Wolford on April 8, 2014 11:12 AM EDT This is the skull of a Neanderthal who lived about 30,000-50,000 years ago in Europe, on display at the American Museum of Natural History.

(Photo: Wikimedia Commons) Geneticists in Europe say they've confirmed beyond doubt what mounting evidence already suggests: that early European humans had children with Neanderthals. Their study, to be published this week in GENETICS , "allows us to conclusively reject" an alternate theory that humans and Neanderthals evolved from the same subpopulation, they said. Their genome analysis also indicates that modern Europeans and Asians inherited more Neanderthal DNA than previously thought. Like Us on Facebook "Our approach can distinguish between two subtly different scenarios that could explain the genetic similarities shared by Neandertals and modern humans from Europe and Asia," Konrad Lohse, a population geneticist at the University of Edinburgh, said in a statement Tuesday. Lohse wrote the paper along with Laurent A. F. Frantz, of the Wageningen University in The Netherlands. Scientists began reimagining human origins when, in December, geneticists sequenced the most complete Neanderthal genome yet. In a related paper published in Nature, the researchers argued that modern non-African humans share between 1.5 and 2.1 percent of their DNA.

Neanderthals are genetically distinct enough from modern humans to earn them their own species designation, Homo neanderthalensis. They lived among Homo sapiens in Europe, the Middle East, and central Asia as recently as 28,000 years ago before either going extinct or being incorporated into the modern human species. Already, scientists knew that Neanderthals probably behaved similarly to humans. According to the Smithsonian Institution , they used "tools, controlled fire, lived in shelters, made and wore clothing, were skilled hunters of large animals and also ate plant foods, and occasionally made symbolic or ornamental objects." They may have even buried their dead and placed flowers on their graves. Another study of a special bone needed for complex speech bolstered the idea that Neanderthals could talk like humans. Recently, even more research has emerged linking the two species. Some humans may have inherited extra fat from Neanderthals. And scientists have pinpointed several genetic traits (and problems like Crohn's disease) that may have been passed down from the Neanderthal version of those DNA. But even as this genetic evidence grew, there was an alternate explanation for it that wouldn't require inter-species sex.

After the first humans migrated out of Africa, proponents of this theory said the same genetic traits could have been inherited in modern humans from a common ancestor to both humans and Neanderthals. In other words, Neanderthals and humans could simply be two branches of the same stem. This new research attempted to close that gap by using a different kind of genetic testing they had previously developed with rare species of European insects and Southeast Asian pigs. They compared the genome of a Neanderthal, a European human, an African human, and a chimpanzee. "The method makes maximum use of the information contained in individual genomes," Lohse said. In their paper, the authors wrote: "Our analysis allows us to conclusively reject a model of ancestral structure in Africa and instead reveals strong support for Neandertal admixture in Eurasia at a higher rate (3.4 percent-7.3 percent) than suggested previously." Mark Johnston, the editor of the journal GENETICS, said, "This work is important because it closes a hole in the argument about whether Neandertals interbred with humans.

And the method can be applied to understanding the evolutionary history of other organisms, including endangered species." © 2012 iScience Times All rights reserved. Do not reproduce without permission. Neanderthal-Human Hybrid Reveals that Two Species Interbred Relatively Recently : Nature & Environment : Science World Report Neanderthal-Human Hybrid Reveals that Two Species Interbred Relatively Recently Catherine Griffin First Posted: Jun 22, 2015 01:16 PM EDT It turns out that at least one early European had a close Neanderthal ancestor. Scientists have analyzed the DNA from a 37,000 to 42,000-year-old human mandible and have found that six to nine percent of this person's genome came from Neanderthals. Present-day humans who have their roots outside sub-Saharan Africa carry one to three percent of Neanderthal DNA in their genomes. Until now, though, researchers have thought it more likely that early humans coming from Africa mixed with the Neanderthals in the Middle East around 50,000 to 60,000 years ago, before spreading into Asia, Europe and the rest of the world.

However, radiocarbon dating of remains from sites across Europe suggests that modern humans and Neanderthals both lived in Europe for up to 5,000 years and that they may have interbred there too. In this case, the researchers examined a 40,000-year-old jawbone that was uncovered in Romania. The researchers analyzed DNA from the fossil, which is one of the earliest modern-human remains found in Europe. "The data from the jawbone imply that human mixed with Neanderthals not just in the Middle East but in Europe as well," said Qiaomei Fu, one of the lead researchers of the new study, in a news release. With that said, it doesn't seem as if this person has any direct descendants in Europe today. It could be that he was part of an early migration of modern humans to Europe that interacted closely with Neanderthals and eventually became extinct. The researchers hope to continue making discoveries in order to reconstruct the interactions between Neanderthals and modern humans in more detail. This, in turn, may tell scientists a bit more about the migration and evolution of humans. The findings are published in the journal Nature. Related Stories

Question: What species interbred with humans in Europe and Asia before going extinct around 30,000 B.C.?
Answer: Neanderthal