Humans interbred with Neanderthals: study

Early modern humans interbred with Neanderthals when they first came to Europe, DNA analysis of a 40,000-year-old jawbone suggests.
Researchers analysed DNA from a 37,000 to 42,000-year-old human mandible from Oase Cave in Romania and found that six to nine per cent of this person's genome came from Neanderthals, more than any other human sequenced to date.
Because large segments of this individual's chromosomes are of Neanderthal origin, a Neanderthal was among his ancestors as recently as four to six generations back in his family tree.
This shows that some of the first modern humans that came to Europe mixed with the local Neanderthals.

All present-day humans who have their roots outside sub-Saharan Africa carry one to three per cent of Neanderthal DNA in their genomes.
Until now, researchers have thought it most likely that early humans coming from Africa mixed with 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.
Researchers from the Max Planck Institute for Evolutionary Anthropology in Germany, Harvard Medical School in US, and the Key Laboratory of Vertebrate Evolution and Human Origins in Beijing analysed DNA from the 40,000-year-old jawbone found in 2002, which is one of the earliest modern-human remains found in Europe.

They estimate that five to 11 per cent of the genome preserved in the bone derives from a Neanderthal ancestor, including exceptionally large segments of some chromosomes.
By estimating how lengths of DNA inherited from an ancestor shorten with each generation, the researchers estimated that the man had a Neanderthal ancestor in the previous four to six generations.
"The data from the jawbone imply that humans mixed with Neanderthals not just in the Middle East but in Europe as well," said Qiaomei Fu, one of the lead researchers of the study.
"Interestingly, the Oase individual does not seem to have any direct descendants in Europe today," said David Reich from Harvard Medical School who coordinated the population genetic analyses of the study.

"It may be that he was part of an early migration of modern humans to Europe that interacted closely with Neanderthals but eventually became extinct," Reich added.