The new study, published online Wednesday in the journal Nature, represents the oldest genome of a modern human ever fully sequenced.
Modern-day Native Americans share from 14 to 38 percent of their DNA with the Siberian hunter-gatherers — who are not closely related to East Asians — with the remainder coming from East Asian ancestors. Most scientists have thought that the first Americans came only from the East Asian populations.
“If you read about the origins of Native Americans, it will say East Asians somehow crossed the Bering Sea,” said study author and evolutionary biologist Eske Willerslev at Copenhagen University. “This is definitely not the case — it’s more complex than that.”
It isn’t known where or when the meeting of the two peoples happened, but a likely location could be Beringia, the region surrounding the current gap between Alaska and Siberia. Although presently occupied by the Bering Strait and its surrounding waters, the glaciers of roughly 20,000 years ago locked up much of the earth’s water, exposing a land bridge between the two continents.
