Native Americans’ ancestors ‘spent 10,000 years on Ice Age land bridge’

Ice Age ancestors of native Americans lived on land linking Siberia and Alaska, say scientists

PUBLISHED : Friday, 28 February, 2014, 9:52pm
UPDATED : Friday, 28 February, 2014, 9:54pm

When it comes to camp-outs, this one was epic.

On the way from Asia into the Americas, the ancestors of native Americans hunkered down for about 10,000 years during a particularly frigid period of the Ice Age in territory called the Bering Land Bridge that once linked Siberia with Alaska.

That's the argument advanced by scientists who said that fossil evidence showing that shrubby lowlands there could have supported human habitation fits nicely with DNA data about the ancestors of today's native American population.

Perhaps several thousand people lived in the territory, now submerged under the Bering and Chukchi Seas, from about 25,000 years ago to 15,000 years ago before crossing into Alaska and dispersing throughout North and South America, they said.

"It's staggering when you think about people living in temporary shelters - probably something like a tent - in the Arctic, especially in winter," said palaeoecologist Scott Elias, of Royal Holloway, University of London.

"These are extremely rugged people. I'm sure they were very well adapted to living in the cold in terms of their physique, their physiology, their ability to withstand temperatures that would make most of us be absolutely miserable or die," he said.

Previous DNA research indicated that the ancestors of native Americans became isolated from rest of the human race long enough to acquire their own distinctive genetic blueprint.

Elias and two colleagues, archaeologist John Hoffecker, of the University of Colorado, and anthropologist Dennis O'Rourke, of the University of Utah, wrote in the journal Science that evidence suggested this isolation took place on the land bridge. People trekking onto the land bridge were blocked from entering North America by huge ice sheets covering large parts of the continent during one of the coldest periods on earth.

As the planet warmed, ice sheets retreated, opening up routes into North America. The land bridge disappeared amid rising sea levels caused by surging global temperatures.

Some experts have felt conditions on the land bridge would have been too harsh to sustain people. But Elias said the central part of the land bridge may have provided a proper refuge.