Are all Bengali Indians

Ancient baby DNA provides clues to American colonization

A new study supports the theory that there was only one wave of immigration from Siberia to America. And it proves the existence of a previously unknown, now extinct Alaskan population.

Two babies, who died and buried around 11,500 years ago in what is now Alaska, are further tangible evidence for researchers that the American continent was only settled in one wave of immigration from East Asia. Detailed genetic analyzes of the bones of the older girl, who was only six weeks old at most, have shown that she is very closely related to today's American Indians. However, the girl is not one of their ancestors, but belongs to a population group now extinct, which the discoverers of the bones call Old Beringians.

The migration started 36,000 years ago

In the oldest human DNA ever found in Alaska, the international team of researchers, led by Eske Willerslev from the University of Copenhagen, was able to find further clues about the migration of humans tens of thousands of years ago. As a result, people from East Asia crossed the Bering Strait, which was still exposed at the time, to America a good 36,000 years ago. This agrees with previous genetic as well as archaeological studies.

Up until about 25,000 years ago, there were still encounters, including genetic exchanges, between the groups moving eastwards and those who stayed behind. The visits then had to be stopped, presumably because of the increasingly harsh climate in the region.

Separation of the original Indians

Around 20,000 years ago, emigrants from East Asia split into two groups: One became the now extinct Old Beringians. The others are the ancestors of all of today's Indians. Both groups lived in Alaska. But only the descendants of the second then colonized the American continent. 15,000 to 17,000 years ago, the indigenous Indians split up - presumably they were already living south of the great North American ice sheet at that time - into the ancestors of today's North and South American Indian tribes.

According to the new study, the Indians living in the far north today are descended from people who later moved back up north from more southern areas of North America. The researchers have not yet been able to clarify whether the Athabascan living near the place where the two baby skeletons from the Pleistocene were found still bear genetic traces of the ancient Beringians, as the modern tribesmen do not allow genetic tests.

Stopover in Bering Land

The Danish-American team is convinced that, according to the genetic data, there were no further, later waves of immigration to America. However, it is unclear where exactly on their way from Siberia to Alaska the Old Beringians and the ancestors of today's Indians separated. According to the authors and other research groups, however, it is certain that there was a longer, i.e. several thousand year long, stopover on the Bering land mass off the American continent. A mighty ice sheet made the onward journey impossible.