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“It’s great,” says Jennifer Raff, a geneticist at the University of Kansas. Lawrence, exploring the American settlement. This work shows that the ancestors of the indigenous peoples of North America in Siberia were more widespread and more mobile than previously thought. Furthermore, this indirectly supports the hypothesis that the ancestors of the American Indian population were isolated from their Asian ancestors in Beringia, an ancient land bridge connecting Siberia with Alaska.
About 20,000 years ago, people from eastern Siberia began moving to Beringia. However, for a long time it was not known exactly where they lived and wandered through Siberia.
The latest study provides the oldest genetic evidence of Eurasian American Indian descent. They are much further from Beringia than anyone might think, says the study’s lead author, Johannes Krause, an archeogeneticist and director of the Max Planck Institute for Human History (MPI).
In the 1970s, Russian archaeologists excavated the Ust-Kyakhta site between the southern shores of Lake Baikal and the border with Mongolia in central and central Russia. They found thousands of bone and stone tools, pottery, deer bones and fish bones, and even part of a human tooth.
This tooth remained in the expedition’s findings drawer for a long time until RMA archaeologist Svetlana Shnaider showed it to former DNA experts at MPI. “At first, I was pretty skeptical that there might still be DNA left,” says Krause.
A fragment of a tooth that belongs to a close relative of a Native American
But Siberia’s cold and dry environment preserved DNA, and the team was able to scan its owner’s genome from the dental pulp. Based on the age of the coal scrap and bone next to the tooth using the radioactive carbon method, the researchers calculated that it should be around 14,000 years old. The genome showed that the person was a man: his genes were as unique a mixture of ancestors from East Asia and Eurasia as the current American Indians. As a result, it is the oldest known close ancestor of American Indians outside the United States, the researchers reported.
This man lived 4,500 kilometers from Beringia and almost 3,200 kilometers from a woman in Northeast Siberia, about two-thirds of whose genome matched the current American Indians. This shows that the population from which the American Indians originated occupied large areas in northeast Eurasia, Krause says.
Such impressive proportions, in turn, indicate that the direct ancestors of American Indians were genetically separated in Beringia, not Siberia, after which they traveled for thousands of years, Raff notes. Baikal’s current coastal population has virtually no genetic similarities to the ancient population, which was replaced about 10,000 years ago by migrants, mainly from Northeast Asia.
According to other findings described in the article, people living near Baikal have traveled and interacted with other groups of people for thousands of years. In two of them, buried side by side about 4,200 years ago, the bacteria that cause the plague Yersinia pestis Markers So far, they have only been found much further west, in people genetically related to the Eurasian steppes.
“But [bakterija] It traveled from the Baltic to Baikal in about 100 years, a bit surprising, “says Krause.” Now we see that the coronavirus spread around the world in 3 months, but in the Bronze Age, the world was not as globalized. “
The combination of ancient human and pathogen DNA provides a rare historical window to a critical place for understanding the genetics of American Indians, Asians, and Europeans, says Priya Moorjani, a geneticist at the University of California, Berkeley. “Each of the examples found so far in this region has helped refine our understanding of human history and development.”
Michael Price
www.sciencemag.org
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