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New DNA Study Reveals the Prehistory of the New World Arctic

modern day canadian inuit

Image credit: Modern-day Canadian Inuit and their environment / Carsten Egevang

It is widely accepted that the barren and cold Arctic should be the last part of the Americas where modern humans came to live. However, there has been hotly debated by scientists about who the first Eskimos were and at what time they arrived there.

According to the article published in the latest edition of Science, based on new kind of genetic analysis, researchers found that the frigid area was populated in distinct waves of migration; the first group of residents stayed there for thousands of years and mysteriously disappeared 700 years ago.

By studying the tools and other artifacts, archaeologists discovered that the first residents in the North American Arctic, including Alaska, Canada and Greenland, came here nearly 6,000 years ago after crossing the Bering Strait from Siberia. The Paleo-Eskimos arrived first, and then followed by the Neo-Eskimos around 4,000 years later. The Paleo-Eskimos displayed a variety of unique cultures. The Saqqaqs used to live in tent camps and hunted caribou and seals. And then came the walrus hunters known as the Dorsets and finally the Thules, whale hunters arrived, sailing in large skin boats.

collecting remains

 In order to find out how all these different cultures are closely linked, Eske Willerslev from the University of Copenhagen and his international team collected well-preserved bone, hair and teeth samples of 169 ancient humans from Arctic Siberia, Alaska, Canada, and Greenland, and then went for analyzing their mitochondrial DNA. In addition, Eske Willerslev’s team was engaged in sequencing the genomes of seven people living in the area at present. (The picture on the right depicts a researcher looking for ancient human remains in northern Greenland.)

From their analysis, it is shown that the Paleo-Eskimos came into North America separately, followed by the migration of Inuits and Native Americans who are now living further south today.

As Willerslev said in a news release, the Paleo-Eskimos, as one single group, should be the first residents in the Arctic. After striving for survival in the isolated situation in the harsh Arctic environment for nearly 4,000 years, they went missing around 700 years ago, almost the same period at which the ancestors of present Inuit moved eastward from Alaska.

In the previous studies, scientists were not sure about whether different populations of Paleo-Eskimos (the Saqqaq and the three Dorset cultures) were originated from the same ancestral population. However, the latest research shows that all Paleo-Eskimo cultures were part of a common Siberian ancestor, but their genetic continuity had to be interrupted when a new population arrived, they were the Neo-Eskimo Thule people, ancestors of present Inuits.

The team had discovered the evidence demonstrating  gene flow between Paleo-Eskimos and the Thules, however, it possibly happened back in Siberia

inline-graphic-1rather than  in the Arctic, where the groups were largely separated.

 Willerslev said in his interview with Science, usually people might meet each other or fight each other, but normally they would have sex with each other as well. But it was not exactly the case here. Scientists are still unclear about the reason why the Paleo-Eskimo lineage vanished after the late Dorsets, it is possible that they were went to the fringes or severely smashed by some unknown diseases. Anyway, it is somehow exciting to imagine an entire people who just totally vanished.

Source: Eurekalert!

Image source: Carsten Egevang (top), Claus Andreasen (middle), M. Raghavan et al., 2014 (bottom)

Journal reference: Raghavan, Maanasa, et al. “The genetic prehistory of the New World Arctic.”Science 345.6200 (2014): 1255832.