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INTERBREEDING BETWEEN NEANDERTHALS AND MODERN HUMANS
In May 2010, the team lead by Svante Paabo of the Max Planck Institute reported that, in the process of sequencing the Neanderthal genome, it found that between 1 percent and 4 percent of the genes that people from Europe and Asia possess can be traced back to Neanderthals. This means that humans and Neanderthals mated.
The discovery was reportedly in the journal Science in article authored by Paabo, Richard Green of the University of California, Santa Cruz, and David Reich of Harvard Medical School. It was determined by analyzing genetic material collected from bones of three Neanderthals and five modern humans. Their research showed a relationship between Neanderthal and modern humans outside of Africa, with the interbreeding likely taking place in the Middle East.
Before the discovery some anthropologists argued that modern men wiped out the Neanderthals. Others theorized the two species intermingled and Neanderthals were absorbed into the more numerous modern humans. Paabo told the Times of London, “It’s cool to think that some of us have a little Neanderthal DNA in us, but for me the opportunity to search for evidence of positive selection that happened shortly after the species separated is probably the most fascinating aspect of this project.”
Bones have been unearthed of individuals that have both Neanderthal and human qualities. In December 1998 Portuguese archaeologists João Maurício and Pedo Souto João Zilhão discovered a 24,500-year-old skeleton of a four-year-old boy near Fatima in Portugal that had chin, jaw and arm bones resembled those of “Homo sapiens” and a stocky torso and short legs like those of a Neanderthal. A 40,000-year-old skull of a teenager found in a Romania also showed traits of both Neanderthals and modern humans. Mostly it had traits associated with modern humans but its exceptionally large molars and relatively flat head are traits usually associated with Neanderthals.
Neanderthal expert Erik Trinkaus of Washington University told Time, Neanderthals may have been just another tribe. "They may have heavier brows or broader noses or stockier builds, but behaviorally, socially and reproductively they were all just people." He told National Geographic, “There were few people on the landscape, and you need to find a mate and reproduce, Why not? Humans are not known to be choosy. Sex happens.” He told Discover he believed that inbreeding was probably widespread: "This is not just two individuals who happened to meet in the bushes.”
The DNA evidence is far from a slam dunk or a smoking gun. Studies of DNA taken from the rib of a 30,000-year-old Neanderthal found in Germany in1856 indicate that Neanderthal's left no genetic legacy in today's people. Mitochondrial DNA studies suggest that Neanderthals and modern humans had a common ancestor 100,000 to 500,000 years but never mixed.
Neanderthals and Humans Appear to Have Had Sex and Interbred in Israel
After modern humans migrated out of Africa, researchers believe they encountered and interbred with Neanderthals in the Middle East around 60,000 years ago. Archeologists believe that Neanderthal and modern humans lived side by side in the Nahal Mea'rot (Cave River) nature reserve in a coastal mountain range of modern-day Israel. None of the bones uncovered at Nahal Me'arot - a World Heritage site - had lethal wounds which suggested prehistoric men lived in peace with each other 80,000 years ago. [Source: Daily Mail, 29 September 2012]
Neanderthals and humans lived side by side and appear to had sex and interbred with them. Stone axes and sharp flint arrowheads of both Neanderthals and modern humans have been discovered in limestone caves in northern Israel. The fact that modern mans carry some Neanderthal (suggests the two species had to have had sex. Genetic studies have indicated that modern Europeans got between 1 and four per cent of their genes from Neanderthals. The genes are thought to have spread through modern humans when small groups of pioneers who left Africa met and had sex with Neanderthals already long at home in Eurasia. Oldest genome sequence of a modern human suggests Homo sapiens first bred with Neanderthals 50,000-60,000 years ago |=|
Archeologist Daniel Kaufman told James Hilder of The Times that he believed peaceful cross-breeding between Neanderthals and modern humans was more likely the result of a consensual encounter than a rape attack. Kaufman said: 'If that interbreeding did take place, it must have been here.”
Skull Found Israel Helps Pin Down Place Where Humans and Neanderthal First Had Sex
omo sapien on the right, Neanderthal on the left
A modern human skull found in a northern Israeli cave in western Galilee, thought to be from 55,000-year-old female, matches up where scientists believe interbreeding with Neanderthals took place as modern humans migrated from Africa to Europe. Ian Sample wrote in The Guardian: The partial skull belonged to an individual, probably a woman, who lived and died in the region about 55,000 years ago, placing modern humans there and then for the first time ever. Homo sapiens walked out of Africa at least 60,000 years ago, but the harsh climate in parts of Europe at the time hampered their spread across much of the continent until about 45,000 years ago. The skull reveals that modern humans reached the Levant where the population may have given rise to those who later colonised Europe when the frozen climate abated and the territory became more habitable. [Source: Ian Sample, The Guardian, January 28, 2015 |=|]
“Israel Hershkovitz at Tel Aviv University said the skull, though missing its face and jaws, was an extraordinary find. Distinctly modern in its anatomy, the braincase resembles the European Cro-Magnons (robustly built early modern humans), but retains some African features too. “It’s amazing. This is the first specimen we have that connects Africa to Europe,” Hershkovitz told the Guardian. |=|
“Palaeontologists spotted the skull on a rocky shelf in the side chamber of the enormous Manot cave that was discovered by chance when a bulldozer broke through the roof while cutting a sewer trench for a nearby village. When scientists abseiled through the hole torn in the ceiling, they found the cave opened up more than 20 metres deep, 50 metres wide and 100 metres long. The original entrance to the cave had collapsed about 30,000 years ago, sealing off the contents. “We couldn’t believe our eyes. We immediately realised it was a prehistoric cave and that it had been inhabited for a very long time. Because the entrance had collapsed so long ago, it had been frozen in time. Nobody had been inside for 30,000 years,” said Hershkovitz. There is a huge central cave and several beautiful side chambers. In one side chamber, the skull was lying there on top of a rocky shelf. It was there waiting for us. We just had to pick it up,” he added. |=|
“Excavations at the site have yielded an impressive haul of modern human and antelope bones, but the partial skull is the oldest of the human remains recovered from the cave. How it came to be perched on a shelf in a side chamber of the cave is a mystery: it may have come to rest there after being washed in by floodwater. Or perhaps it was placed there intentionally by another individual living in the cave.” |=|
Manot Cave
Ian Sample, wrote in The Guardian: “Writing in the journal Nature, the scientists explain how dating the skull to 55,000 years ago reveals that modern humans arrived in the region when it was already well populated with Neanderthals. Skeletons of Neanderthals from the same time have been recovered from Amud cave 24 miles (40km) to the east of Manot cave, and from Kebara cave 30 miles to the south. [Source: Ian Sample, The Guardian, January 28, 2015 |=|]
“That modern humans and Neanderthals shared the land around Manot cave 50,000 to 60,000 years ago means that the rolling hills of what is now Galilee may have provided the romantic backdrop to the spell of interbreeding that left non-Africans with a smidgen of Neanderthal DNA. Genetic studies suggest that humans and Neanderthals mixed in the same 50,000 to 60,000-year-old period, most probably in western Asia. “Manot is the best candidate for the interbreeding of modern humans with Neanderthals and there is really no other candidate,” Hershkovitz said. “The people at Manot cave are the only population we know of that shared the same geographical region for a very long period of time,” he added. Without DNA from the skull, it is impossible to know if the Manot cave individual was a product of such couplings. |=|
“Chris Stringer, head of human origins at the Natural History Museum, said the region was certainly a contender for the main interbreeding that happened 50 millennia ago, though further north than modern day Israel was possible. “At about 55,000 years old, this is the first modern human from western Asia which is well dated to the estimated timeframe of interbreeding between early modern humans and Neanderthals,” he said. “Manot might represent some of the elusive first migrants in the hypothesised out-of-Africa event about 60,000 years ago, a population whose descendants ultimately spread right across Asia, and also into Europe. Its discovery raises hopes of more complete specimens from this critical region and time period,” he added. |=|
Human Femur Helps Pin Down Time Where Humans and Neanderthal First Had Sex
An ancient leg bone found by chance on the bank of a Siberian river has helped scientists work out when early humans interbred with our extinct cousins, the Neanderthals. Ian Sample wrote in The Guardian: “A local ivory carver spotted the bone sticking out of sediments while fossil hunting in 2008 along the Irtysh river near the settlement of Ust’-Ishim in western Siberia. The bone was later identified as a human femur, but researchers have learned little else about the remains until now. The importance of the find became clear when a team led by Svante Pääbo and Janet Kelso at the Max Planck Institute for Evolutionary Anthropology in Leipzig ran a series of tests on the fragile material. [Source: Ian Sample, The Guardian, October 22, 2014]
“Radiocarbon dating of pieces of the leg bone put the remains at around 45,000 years old. The team went on to extract DNA from the bone, which allowed them to reconstruct the oldest modern human genome ever. The genetic material showed that the thigh bone belonged to a man who carried about 2 percent Neanderthal DNA, a similar amount to people from Europe and Asia today. The presence of Neanderthal DNA meant that interbreeding between them and modern humans must have taken place at least 45,000 years ago. |=|
“But amid the DNA were more clues to when humans and Neanderthals reproduced. Strands of Neanderthal DNA found in modern humans can act like a biological clock, because they are fragmented more and more with each generation since interbreeding happened. The strands of Neanderthal DNA in the Siberian man were on average three times longer than those seen in people alive today. Working backwards, the scientists calculate that Neanderthals contributed to the man’s genetic ancestry somewhere between 7,000 and 13,000 years before he lived. |=|
“The findings, published in the journal Nature, suggest that humans and Neanderthals had reproductive sex around 50,000 to 60,000 years ago, though other couplings might well have happened later. Until now, estimates for interbreeding have varied enormously, ranging from 37,000 to 86,000 years ago. |“What we think may be the case is that the ancestors of the Ust’-Ishim man met and interbred with Neanderthals during the initial early admixture event that is shared by all non-Africans at between 50,000 and 60,000 years ago, and perhaps somewhere in the middle East,” Kelso told the Guardian. |=|
“But a small number of fragments of Neanderthal DNA in the man’s genome were longer than expected given how many generations had passed. Those might be evidence of his ancestors breeding with Neanderthals closer to the time he was born. “Everyone outside Africa has about same amount of Neanderthal DNA. It seems to be something early on where one really mixed with Neanderthals in a serious way,” said Pääbo. “Since that happened I wouldn’t be surprised if, now and again, one did it here and there later on too.” Prior to the latest study, the oldest modern human genome came from the 24,000-year-old remains of a boy buried at Mal’ta near Lake Baikal in easterbn Siberia. |=|
Homo sapiens Neanderthal comparison
“Chris Stringer, head of human origins at the Natural History Museum in London, said the ancient DNA from the Siberian man sheds fresh light on the story of early human migrations out of Africa. In the 1920s and 30s, researchers found 100,000-year-old skeletons of modern humans in caves in what is now Israel. The remains may have belonged to a group of humans that left Africa and ultimately went on to colonise southern Asia, Australia and New Guinea. But an alternative explanation is that they were from a migration that failed to go much further. According to that view, the more successful dispersal of humans out of Africa happened much later, around 60,000 years ago. |=|
“The latest findings suggest that the ancestors of modern Australians, who carry a similar amount of Neanderthal DNA to Europeans and Asians, are unlikely to have picked up their own Neanderthal DNA before 60,000 years ago. “The ancestors of Australasians must have been part of a late, rather than early, dispersal through Neanderthal territory,” Stringer said. |=| “While it is still possible that modern humans did traverse southern Asia before 60,000 years ago, those groups could not have made a significant contribution to the surviving modern populations outside of Africa, which contain evidence of interbreeding with Neanderthals,” he added.” |=|
Human- Neanderthal Love Child Found Italy?
The skeletal remains of an individual found in northern Italy, dated to 40,000-30,000 years ago, are believed to be that of a human-Neanderthal hybrid, according to a paper in PLoS ONE. Jennifer Viegas wrote in Discovery News: “If further analysis proves the theory correct, the remains belonged to the first known such hybrid, providing direct evidence that humans and Neanderthals interbred. Prior genetic research determined the DNA of people with European and Asian ancestry is 1 to 4 percent Neanderthal. [Source: Jennifer Viegas, Discovery News, March 28, 2013 =]
“The present study focuses on the individual’s jaw, which was unearthed at a rock-shelter called Riparo di Mezzena in the Monti Lessini region of Italy. Both Neanderthals and modern humans inhabited Europe at the time. “From the morphology of the lower jaw, the face of the Mezzena individual would have looked somehow intermediate between classic Neanderthals, who had a rather receding lower jaw (no chin), and the modern humans, who present a projecting lower jaw with a strongly developed chin,” co-author Silvana Condemi, an anthropologist, told Discovery News. =
“Condemi is the CNRS research director at the University of Ai-Marseille. She and her colleagues studied the remains via DNA analysis and 3D imaging. They then compared those results with the same features from Homo sapiens. The genetic analysis shows that the individual’s mitochondrial DNA is Neanderthal. Since this DNA is transmitted from a mother to her child, the researchers conclude that it was a “female Neanderthal who mated with male Homo sapiens.” =
“By the time modern humans arrived in the area, the Neanderthals had already established their own culture, Mousterian, which lasted some 200,000 years. Numerous flint tools, such as axes and spear points, have been associated with the Mousterian. The artifacts are typically found in rock shelters, such as the Riparo di Mezzena, and caves throughout Europe. =
“The researchers found that, although the hybridization between the two hominin species likely took place, the Neanderthals continued to uphold their own cultural traditions. That's an intriguing clue, because it suggests that the two populations did not simply meet, mate and merge into a single group. As Condemi and her colleagues wrote, the mandible supports the theory of "a slow process of replacement of Neanderthals by the invading modern human populations, as well as additional evidence of the upholding of the Neanderthals' cultural identity.” =
“Prior fossil finds indicate that modern humans were living in a southern Italy cave as early as 45,000 years ago. Modern humans and Neanderthals therefore lived in roughly the same regions for thousands of years, but the new human arrivals, from the Neanderthal perspective, might not have been welcome, and for good reason. The research team hints that the modern humans may have raped female Neanderthals, bringing to mind modern cases of "ethnic cleansing." Ian Tattersall is one of the world’s leading experts on Neanderthals and the human fossil record. He is a paleoanthropologist and a curator emeritus at the American Museum of Natural History. Tattersall told Discovery News that the hypothesis, presented in the new paper, “is very intriguing and one that invites more research.” =
Did Human Women Contribute to Neanderthal Genomes over 200,000 Years Ago?
A Neanderthal mitochondrial genome published in 2017 from a femur that was excavated in 1937 from the Hohlenstein-Stadel (HST) cave site in southwestern Germany supports the hypothesis that interbreeding occurred among African hominins 200,000 years ago. Jennifer Raff wrote in The Guardian: “Reconstructing past population history accurately requires temporal and geographic diversity in sampling. It’s tremendously important. Someday we will have so many archaic genomes sequenced that a new one isn’t a big deal and doesn’t add very much to the panoply. But that day isn’t here yet, and so the recovery of genetic data from each new individual has the potential to make a huge difference in how we understand evolutionary history. This is the case with the new HST Neanderthal mitochondrial genome, which is strikingly different to all others sequenced thus far – so much so that it nearly doubles the known genetic diversity of Neanderthal populations. [Source: Jennifer Raff, The Guardian, July 18, 2017. Raff is a geneticist who specialises in the study of human variation among contemporary and ancient populations |=|
“The HST genome may resolve a longstanding point of confusion regarding the evolutionary relationships between modern humans, Neanderthals, and Denisovans. We actually get different histories for the three groups depending on whether we analyze their mitochondrial (maternally inherited) or nuclear (bi-parentally inherited) genomes. Nuclear DNA indicates that Neanderthals and Denisovans were more closely related to one another than to humans, and that the three groups last shared a common ancestor sometime between 765-550,000 years ago. Neanderthals and Denisovans diverged later (probably by 430,000 years ago) into genetically and geographically distinct groups. |=|
“However, mitochondrial DNA (inherited exclusively maternally) shows a different pattern: humans and Neanderthals appear to be more closely related to each other, and the Denisovans are a more distant cousin group. The nuclear DNA story is most likely the correct one, as nuclear genomes give us a much more robust glimpse into the past by allowing us to look at the independent histories of thousands of genetic markers. But why does the mitochondrial DNA disagree? |=|
“One explanation for these results is that Neanderthal mitochondrial genomes may actually derive from gene flow with another group of hominins from Africa, ancestral or closely related to modern humans, whose maternal lineages effectively replaced the older Denisovan-like lineages. Indeed, the 430,000 year old hominins from the Sima de los Huesos site in Spain, who physically resemble the ancestors of Neanderthals, have early Neanderthal-like nuclear genomes but more Denisovan-like mitochondrial genomes, suggesting that the early Neanderthal populations had maternal lineages very unlike those found in later populations. If there was gene flow into Neanderthal population from female hominins from Africa, it’s possible that there could have been a complete replacement of the maternal lineages in this population without obscuring the histories reflected in the nuclear genome. |=|
“The HST genome has now provided a good chance to test this hypothesis, because it is quite old – about 124,000 years, according to an estimate based on the molecular clock (in contrast to most other published Neanderthal genomes, which are much more recent). HST’s mitochondrial lineage is distinct from all other Neanderthal mitochondrial genomes sequenced thus far, and is basal (very ancient) relative to them. Using this new mitochondrial genome in their analyses, researchers found it was indeed plausible that some hominins may have migrated out of Africa and interbred with Neanderthals sometime between 413,000 and 270,000 years ago, perhaps in the Middle East. This event would have significantly predated the major Out-of-Africa human migration, which is currently thought to have occurred around 75,000 years ago. There is other evidence to suggest that early human populations were much more mobile than we had previously thought, such as the recent classification of hominin fossils in Morocco dating to 300,000 years ago as early “pre-modern” H. sapiens. These data may give indirect support for early small-scale migrations before the major spread of human populations out of Africa.
“The HST mitochondrial genome adds more important details to our ever-expanding understanding of hominin evolution and allows us to be a bit more confident in one model that resolves seemingly contradictory genetic results. While nuclear DNA from the HST fossil would tell us even more, unfortunately the endogenous Neanderthal DNA in the fossil is not well preserved. Of the ~240,000 unique sequence reads recovered from the femur, only about 1,110 were from the Neanderthal. The rest were from other organisms such as soil bacteria and modern humans. These high contamination and low endogenous DNA levels mean that it will be difficult to obtain a nuclear genome from this bone. |=|
“I feel like every time I write about ancient DNA it’s an exercise in expectation lowering, since so few remains ever yield their genetic secrets. So here I want to emphasize that what we have learned about our histories from this single fossil really is remarkable. The brand new editions of textbooks that many of us are planning on using for our courses next term are already completely out of date, and I’m hopeful there are even more surprises to come in the near future. I’m sure I speak for the whole biological anthropology community when I say that we couldn’t be happier about the pace of discoveries these days, even if it does feel overwhelming.” |=|
Why Neanderthals, Humans Likely Produced Few Kids
Humans carry around a significant amount of Neanderthal DNA by why don’t they carry more? Charles Q. Choi of Live Science wrote: “Turns out, the Y chromosome may have been key in keeping the two lineages apart by creating conditions that might often have led to miscarriages if or when the two got together, researchers now say. [Source: Charles Q. Choi, LiveScience.com, April 11, 2016 +++]
“The last major component of the Neanderthal genome that scientists had not analyzed was the Y chromosome. In modern humans and Neanderthals, the Y chromosome determines if someone is male in sex. Now researchers have completed the first in-depth analysis of a Neanderthal Y chromosome. They focused on a Neanderthal male found in El Sidrón, Spain. Overall, the differences between the Neanderthal and modern human Y chromosomes suggest these lineages diverged almost 590,000 years ago, consistent with previous research. +++
“The Neanderthal Y chromosome was genetically distinct from any seen in modern humans. This suggests that this El Sidrón male's lineage is extinct, without any living carriers in modern humans. It remains uncertain how much other Neanderthal Y chromosomes resembled or differed from this one. Further analysis revealed that genetic mutations might explain why this Neanderthal Y chromosome was lost in modern humans. Three mutations seen on this chromosome generate molecules that can trigger immune responses from women during pregnancy that can lead to miscarriages, and two of these three mutations are unique to Neanderthals. +++
“The researchers suggest that such genetic incompatibilities between Neanderthals and modern humans may have helped drive these lineages apart by discouraging interbreeding between them. "We should pay attention to the potential role of immune incompatibilities in population isolation," study lead author Fernando Mendez, a population geneticist at Stanford University, told Live Science. +++
“In future research, scientists could analyze more Y chromosomes from a variety of male Neanderthals, Mendez said. Lab experiments could then determine the effect of these newfound Neanderthal mutations on interactions between male cells and female immune cells. The result might also confirm the idea that these mutations helped keep Neanderthals and modern humans apart, he added. Mendez and his colleaguesdetailed their findings in the April 7, 2016 issue of the American Journal of Human Genetics.” +++
Humans and Neanderthals Broke Up After Humans Discovered Eurasia
It appears the relationship between Neanderthals and modern humans was a short one. The limited amount of data related to the issue seems to suggest the two species interbred the first time and the last time around the time modern humans with advanced stone tools expanded out of Africa in to Europe and Asia. The last sex between Neanderthals and modern humans likely occurred as recently as 47,000 years ago, researchers say. [Source: Charles Q. Choi, Live Science, October 4, 2012 ^-^]
In 2010, scientists completed the first sequence of the Neanderthal genome using DNA extracted from fossils. Charles Q. Choi wrote in Live Science: “The Neanderthal genome revealed that people outside Africa share more genetic variants with Neanderthals than Africans do. One possible explanation is that modern humans mixed with Neanderthals after the modern lineage began appearing outside Africa at least 100,000 years ago. Another, more complex scenario is that an African group ancestral to both Neanderthals and certain modern human populations genetically diverged from other Africans beginning about 230,000 years ago. This group then stayed genetically distinct until it eventually left Africa. ^-^
“To shed light on why Neanderthals appear most closely related to people outside Africa, researchers looked at similar DNA chunks in European and Neanderthal genomes. When sperm and egg cells are created, the strands of DNA within them break and rejoin to form new combinations of genetic material. This "recombination" decreases the length of the chunks in each generation. By comparing lengths, "we can estimate when the two populations last shared genes," explained researcher Sriram Sankararaman, a statistical geneticist at Harvard Medical School. ^-^
The research team estimates modern humans and Neanderthals last exchanged genes between 37,000 and 86,000 years ago, and most likely 47,000 to 65,000 years ago. This is well after modern humans began expanding outside Africa, but potentially before they started spreading across Eurasia. These findings suggest modern humans last shared ancestors with Neanderthals during the period known as the Upper Paleolithic. Back then, modern humans had begun using relatively advanced stone tools, such as knife blades, spear points, and engraving and drilling implements. "I think we will be able to get new insights on how modern humans adapted as they occupied new regions," Sankararaman told LiveScience. "It shows the power of genetic data to learn about historical events." ^-^
“Future research will explore other prehistoric interbreeding events, such as the apparent mixing between ancestors of modern Papuans and the recently unearthed extinct human lineage known as the Denisovans. "There are technical challenges here," Sankararaman said. "Papuans have had gene flow from Neanderthals and from Denisovans. That makes it challenging to tease their contributions apart." The scientists detailed their findings online Oct. 4 in the journal PLoS Genetics.”
DNA from Neanderthal Toe Reveals Interbreeding with Humans and Denisovans
A 50,000-year-old toe bone from a Neanderthal, discovered in Denisova Cave in Siberia, gave up DNA indicating interbreeding between Neanderthals, modern humans and Denisovans scientists reported in the journal Nature. DNA from the Neanderthal toe fossil was compared to the genomes of 25 present-day human and a group of Denisovans. According to their analysis, Neanderthals contributed roughly 2 percent of their DNA to modern people outside Africa and half a percent to Denisovans, who contributed 0.2 percent of their DNA to Asian and Native American people.[Source: Monte Morin, Los Angeles Times, December 18, 2013 \=]
Monte Morin wrote in the Los Angeles Time: “The biggest surprise, though, was the finding that a fourth hominin contributed roughly 6 percent of the DNA in the Denisovan genome. The identity of this DNA donor remains a mystery. “It is possible that this unknown hominin was what is known from the fossil record as Homo erectus,” said lead study author Kay Prufer, a geneticist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. “Further studies are necessary to support or reject this possibility.” \=\
“Geneticists and anthropologists said the inch-long bone and resulting analysis have greatly illuminated a period of time roughly 12,000 to 126,000 years ago. It does seem that Eurasia during the Late Pleistocene was an interesting place to be a hominin, with individuals of at least four quite diverged groups living, meeting and occasionally having sex,” biologist Ewan Birney of the European Bioinformatics Institute and Stanford geneticist Jonathan Pritchard wrote in a commentary that accompanied the study. \=\
“The toe bone was discovered in an ancient natural shelter called Denisova Cave, in Siberia’s Altai Mountains. It was in the same cave that archaeologists discovered evidence of the Denisovans, who were recognized as a distinct group in 2010. Based on DNA taken from the toe bone, researchers were able to determine that it belonged to a female Neanderthal. They could also tell that her parents were very closely related, and “were either half siblings who had a mother in common, double first cousins, an uncle and a niece, an aunt and a nephew, a grandfather and a granddaughter, or a grandmother and a grandson,” they wrote in the study.
“Such inbreeding might have been necessary because the Neanderthal population was very small, perhaps already well on the road toward extinction, the study authors suggested. “The data are consistent with the population being small enough that breeding among relatives was reasonably common,” said UC Berkeley biologist Montgomery Slatkin, a member of the research team. DNA analysis of additional Neanderthal remains would be needed to confirm that hunch, Slatkin said.
“The study authors estimated that the ancestors of Neanderthals and Denisovans split from the lineage that led to modern humans roughly 600,000 years ago, and then split between each other roughly 400,000 years ago. Based on the genomes of each group, researchers concluded that all of their populations were in decline at least 1 million years ago. Sometime after that, our ancestors began to grow in number while the Neanderthal and Denisovan populations continued to shrink. Researchers estimate that Homo sapiens became the planet’s sole surviving humans roughly 30,000 years ago.
While the study’s conclusions were sure to fire the imagination of the general public, at least one outside expert said the anthropological sleuthing had just begun. John Hawks, a paleoanthropologist at the University of Wisconsin, Madison, said it was very difficult to pin down the timing and number of groups involved in genetic mixing. We could really be looking at mixture from multiple different populations with different histories,” Hawks said.
Study authors hope that by mapping the Neanderthal genome they might gain insights into the evolution of modern humans. The list of DNA sequences that distinguish us from Neanderthals is relatively short, according to the study’s senior author, Svante Paabo, director of the Max Planck Institute’s department of genetics. It’s a catalog of the genetic features that sets all modern humans apart from all other organisms living or extinct,” Paabo wrote in a statement released by the institute. “I believe that in it hide some of the things that made the enormous expansion of human populations and human culture and technology in the last 100,000 years possible.”
Denny, the Neanderthal-Denisovan Love Child
Denny was an inter-species love child, with a Neanderthal mother and a Denisovan father, scientists reported 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. [Source: Marlowe Hood, AFP, August 23, 2018 \=/]
Marlowe Hood of AFP wrote: “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. "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. \=/
“Or not. "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...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.” \=/
Image Sources: Wikimedia Commons
Text Sources: National Geographic, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Nature, Scientific American. Live Science, Discover magazine, Discovery News, Ancient Foods ancientfoods.wordpress.com ; Times of London, Natural History magazine, Archaeology magazine, The New Yorker, Time, Newsweek, BBC, The Guardian, Reuters, AP, AFP, Lonely Planet Guides, “World Religions” edited by Geoffrey Parrinder (Facts on File Publications, New York); “History of Warfare” by John Keegan (Vintage Books); “History of Art” by H.W. Janson (Prentice Hall, Englewood Cliffs, N.J.), Compton’s Encyclopedia and various books and other publications.
Last updated April 2024