http://news.nationalgeogr...ated-interbred-dna-gene/
The next time you're tempted to call some oaf a Neanderthal, you might want to take a look in the mirror.
Accordingto a new DNA study, most humans have a little Neanderthal in them—atleast 1 to 4 percent of a person's genetic makeup.
The study uncovered the first solid genetic evidence that "modern" humans—or
%$!$ sapiens—interbred with their Neanderthal neighbors, who mysteriously died out about 30,000 years ago.
What's more, the Neanderthal-modern human mating apparently took place in the Middle East, shortly after modern humans had left
Africa, not in
Europe—as has long been suspected.
"We can now say that, in all probability, there was gene flow from
Neanderthals to modern humans," lead study author Ed Green of the University of California, Santa Cruz, said in a prepared statement.
That's no surprise to anthropologist
Erik Trinkhaus, whose
skeleton-based claims of Neanderthal-modern human interbreeding—previously
contradicted with DNA evidence—appear to have been vindicated by the new gene study, to be published tomorrow in the journal
Science.
"They'vefinally seen the light ... because it's been obvious to many us thatthis happened," said Trinkaus, of Washington University in St. Louis,Missouri, who wasn't part of the new study.
Trinkhaus adds that most living humans probably have much more Neanderthal DNA than the new study suggests.
"One to 4 percent is truly a minimum," Trinkaus added. "But is it 10 percent? Twenty percent? I have no idea."
(Also see
"Neanderthals, Modern Humans Interbred, Bone Study Suggests.")
Surprising Spot for Neanderthal-Human Mating
The genetic study team reached their conclusion after comparing the genomes of five living humans—from
China,
France,
Papua New Guinea, southern Africa, and western Africa—against the available
"rough draft" of the Neanderthal genome. (
Get the basics on genetics.)
Theresults showed that Neanderthal DNA is 99.7 percent identical to modernhuman DNA, versus, for example, 98.8 percent for modern humans andchimps, according to the study. (Related:
"Neanderthals Had Same 'Language Gene' as Modern Humans.")
Inaddition, all modern ethnic groups, other than Africans, carry tracesof Neanderthal DNA in their genomes, the study says—which at firstpuzzled the scientists. Though no fossil evidence has been found forNeanderthals and modern humans coexisting in Africa, Neanderthals, likemodern humans, are thought to have arisen on the continent.
"Ifyou told an archaeologist that you'd found evidence of gene exchangebetween Neanderthals and modern humans and asked them to guess which[living] population it was found in, most would say Europeans, becausethere's well documented archaeological evidence that they lived side byside for several thousand years," said study team member David Reich.
Foranother thing, Neanderthals never lived in China or Papua New Guinea,in the Pacific region of Melanesia, according to the archaeologicalrecord. (See
"Neanderthals Ranged Much Farther East Than Thought.")
"Butthe fact is that Chinese and Melanesians are as closely related toNeanderthals" as Europeans, said Reich, a population geneticist at the Broad Institute of MIT and Harvard University.
(See pictures of a reconstructed Neanderthal and take a Neanderthals quiz.)
Neanderthal-Human One-Night Stand?
So how did modern humans with Neanderthal DNA end up in
Asia and Melanesia?
Neanderthals, the study team says, probably mixed with early %$!$ sapiens just after they'd left Africa but before %$!$ sapiens split into different ethnic groups and scattered around the globe.
Thefirst opportunity for interbreeding probably occurred about 60,000years ago in Middle Eastern regions adjacent to Africa, wherearchaeological evidence shows the two species overlapped for a time,the team says.
And it wouldn't have taken muchmating to make an impact, according to study co-author Reich. Theresults could stem from a Neanderthal-modern human one-night stand orfrom thousands of interspecies assignations, he said.
(Related:
"Neanderthals Grew Fast, but Sexual Maturity Came Late.")
More DNA Evidence for Neanderthal-Human Mating
The new study isn't alone in finding genetic hints of
%$!$ sapiens-%$!$ neanderthalensis interbreeding.
Genetic anthropologist
Jeffrey Long, who calls the
Science study"very exciting," co-authored a new, not yet published study that foundDNA evidence of interbreeding between early modern humans and an"archaic human" species, though it's not clear which. He presented histeam's findings at a meeting of the American Association of PhysicalAnthropologists in Albuquerque, New Mexico, last month.
Long'steam reached its conclusions after searching the genomes of hundreds ofmodern humans for "signatures of different evolutionary processes inDNA variation."
Like the new
Science paper,Long's study speculates that interbreeding occurred just after ourspecies had left Africa, but Long's study didn't include analysis ofthe Neanderthal genome.
"At the time we started theproject, I never imagined I'd ever see an empirical confirmation ofit," said Long, referring to the
Science team's Neanderthal-DNA evidence, "so I'm pretty happy to see it."
I'm doing some research and quite a few studies show Neanderthal DNA is not exclusive to Europeans? EXPLAIN?