Crossing From Asia, the First Americans Rushed Into the Unknown
Nearly 11,000 years ago, a man died in what is now Nevada. Wrapped in a rabbit-skin blanket and reed mats, he was buried in a place called Spirit Cave. Now scientists have recovered and analyzed his DNA, along with that of 70 other ancient people whose remains were discovered throughout the Americas. The findings lend astonishing detail to a story once lost to prehistory: how and when humans spread across the Western Hemisphere.
The earliest known arrivals from Asia were already splitting into recognizably distinct groups, the research suggests. Some of these populations thrived, becoming the ancestors of indigenous peoples throughout the hemisphere.
The Ancient Beringians separated from the ancestors of living indigenous people in the Americas about 20,000 years ago. The new findings suggest they endured for several thousand years. Then they disappeared, leaving no known genetic trace in living people. But another wave of migrants from Siberia did not stop in Alaska. They kept moving, eventually arriving south of the ice age glaciers. Then they split into two branches.
One group turned and headed north, following the retreating glaciers into Canada and back to Alaska. The other branch took a remarkable journey south. The genetic data suggest that this group spread swiftly across much of North America and South America about 14,000 years ago. The expansion may have taken only centuries.
https://www.nytimes.com/2018/11/08/science/prehistoric-migration-americas.html?action=click&module=Discovery&pgtype=Homepage
