There’s a new report out on ancient DNA results from Alaska.
It seems that the individual they studied (from about 11k years ago) is from a group of Beringians that never migrated south of the glaciers. Willerslev says: ” It’s basically a relict population of an ancestral group which was common to all Native Americans”.
The kid was equally related to the two main groups of Amerindians, north and south. Some tribes in North America, like the Algonquins, are in the northern groups, while some North American Amerindians and all those in Central and South America fall into the southern group
You may be wondering about Aleuts, Eskimos, and Athabascans/Na-Dene speakers, particularly if you just read Carl Zimmer’s article in the NYTimes. Don’t. They’re from later migrations -a separate story. Let’s keep it as simple as possible.
Here’s Willerslev’s model:
From their data and analysis, the researchers think that the northern and southern branches of the Amerindians split around 15k years ago in a region south of eastern Beringia – already past the ice.
One very important point, naturally mentioned in none of the press accounts, is what they didn’t see: the Alaskan kid didn’t have any of the Australo-Melanesian, Andamanese-like component that exists in Amazonian Indians today. The Clovis-complex Anzick-1 skeleton from Montana, about 12.6k years old, was a member of the southern Amerindian branch – but it didn’t have any Andamanese-like component either.
So we’re saying that a Beringian population, pretty close to the common ancestors of the Northern and Southern Amerindians branches, didn’t have the Andaman-like admixture.
The Northern branch doesn’t seem to have it today.
Only some members of the Southern branch have it today: the earliest known sample from the southern population doesn’t have it.
Therefore the Southern branch (some of them) very likely picked it up after they left Beringia, also after they split with the northern branch. Which means it was already there before the Amerindians came down from Beringia. Probably in Brazil.