Who are the ancestors of the Asian Indians

Migration: These Americans were once Asians

Two large genetic studies on the colonization of America are puzzling: Competing research teams found clear indications that some groups in the Amazon region are closely related to populations in Southeast Asia. However, it is completely unclear when and how the ancestors of these people came to America. However, both studies basically confirm that the continent was mainly settled by Eurasian immigrants who came from Siberia via the Bering Strait. Their descendants spread across the continent to Tierra del Fuego.

However, these people are relatively unrelated to the indigenous people examined in the Amazon region, as genetic comparisons between different groups show. Accordingly, the Suruí and Karitiana living in Amazonia are surprisingly similar to the people who live today in New Guinea, Australia or on the Andamans in the Bay of Bengal.

The larger team around Eske Willerslev from the University of Copenhagen assessed the role of this completely surprising result in the magazine "Science" rather cautiously. On the other hand, the other group around David Reich from Harvard Medical School in Boston speaks in the magazine "Nature" of indications of a second founder population in America.

Eurasian immigration via the Bering Strait

The researchers around Reich refer to it as Population Y - derived from "Ypykuera", the word for "ancestor" in the Tupi language spoken by the Suruí and Karitiana. “The question remains when and how the ancestors of Population Y reached South America,” writes the team. The authors suspect that immigration must have taken place many thousands of years ago.

The group around Willerslev, on the other hand, focuses on the process of Eurasian immigration via the Bering Strait. This took place during the height of the last glacial period a maximum of 23,000 years ago - in a single wave of migration over the former land bridge. The Eurasian immigrants may have been trapped on the Bering Strait for up to 8,000 years. They later moved along the coasts and reached southern South America no later than 14,600 years ago.

It was not until much later, about 13,000 years ago, that a group split off in North America. It penetrated towards the end of the last glacial period and the retreat of the ice masses into the interior of the continent. The Cree or Chippewyan Indians and other representatives of the Athabaskan language group are descended from them.

Similarity between Suruí and Southeast Asians

Willerslev's team also found a clear similarity between Suruí and people from Southeast Asia. However, they assume that this immigration only followed after the wave of migration from Eurasia.

Professor Johannes Krause from the Max Planck Institute for the History of Man in Jena describes the genetic similarity between Amazon residents and groups in Southeast Asia as a sensation. “At first I could hardly believe it,” says the archaeogeneticist. “The genetic signal is very strong. Neither research team offers a plausible explanation for this. "

The crucial question is which of the two groups came to America first. Further genetic studies would have to clarify this. The expert refers, among other things, to the archaeological site of Lagoa Santa in the Brazilian state of Minas Gerais. So far, more than 30 skeletons have been discovered there that are between 8,000 and 12,000 years old. Their analysis is difficult, however, because the DNA is very poorly preserved due to the hot, humid climate.