The owners of these genes met on the Marquesas Islands and later settled almost throughout Polynesia.
Paleogeneticists received the first full-fledged evidence that the ancestors of the Polynesians and Indians of South America had contact with each other. Scientists have found that this happened for the first time about 800 years ago in the Marquesas Islands. The description of the study was published in the scientific journal Nature.
“In the genomes of the inhabitants of several Polynesian islands at once, we found fragments of Indian DNA identical in origin. This suggests that the Polynesians inherited these segments of the genome after single contact with people from the New World. Our calculations show that this happened around 1200, at the time when the Polynesians inhabited these (Marquesas, - TASS) islands,”said Alexander Ioannidis, one of the study's authors, paleogeneticist from Stanford University (USA).
For a long time, scientists believed that the ancestors of the Indians moved to America from South Siberia and Altai about 14-15 thousand years ago during a single wave of migration. This is supported by most of the known archaeological sites in North and South America.
On the other hand, half a century ago, the Norwegian traveler Thor Heyerdahl suggested that the Indians of South America may be culturally and genetically related to the inhabitants of Oceania and Polynesia. This is also supported by the analysis of the gene pool of modern Indians from the southern regions of the New World, in which there are inclusions of Polynesian DNA, as well as the appearance and genome of the so-called Kennewick man, one of the first inhabitants of America.
By studying the genomes of contemporary residents of French Polynesia and the inhabitants of Easter Island, Ioannidis and his colleagues found out where and how such contacts took place.
Genetic history of Polynesia
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In total, scientists have deciphered and compared with each other about 800 genomes of Polynesians and Indians, who live in seventeen Pacific islands and archipelagos, as well as in 15 coastal regions of South America.
As it turned out, in the genome of the Polynesians there really were sections that they inherited from their South American ancestors. Comparing the length of the segments of "Indian" DNA and the sets of small mutations in it, Ioannidis and his colleagues found out when these mutations appeared in the genomes of the Polynesians and tracked how they spread through the population.
It turned out that the longest fragments of the Indian genome with a similar set of mutations were found among the inhabitants of the North and South Marquesas Islands. Such coincidences indicate that their ancestors were the first to meet with people from the New World. This happened, as the calculations of scientists show, around 1150-1200.
Subsequently, carriers of these genes spread across Polynesia, moving south and southeast towards Easter Island. They got there much later, in 1380. This coincides in time with the epoch of the construction of the famous idols of the island - moai.
The source of all these "Native American" genes, as shown by DNA analysis of modern South Americans, were peoples who lived on the west coast of Colombia before the Europeans got there. Paleogenetics suggest that these people reached the Marquesas before the Polynesians. This is supported by the unusually early time of their contacts.
On the other hand, scientists do not exclude that the ancient Indians and Polynesians could have met in another way. For example, the latter could reach the shores of South America, and then return back to Polynesia with a large group of Indians or descendants from mixed marriages. So it or not, scientists plan to check during the next genetic "excavation".
