Scientists are still patiently searching for the homeland of Indians - America's native population. Some think they ascend to a small group of hunting and crop-collecting people, who once migrated to the New World from Asia about 12-15 thousand years ago. Others believe that there were several stages of migration to America. The author of the most popular "three-stage migration" hypothesis Joseph Grinberg divided native Americans into three groups, according to their language differences. The Amerinds are Indians of North, Central and South America, who moved there about 11 thousand years ago. The second group is Na-dene Indians - Athapascan, Apache and Navajo, inhabiting northwest of USA, Canada and Alaska for 9 thousand years. And the third group is the Eskaleutians, i.e. Eskimo and native population of the Aleutians, who came to the US 5 thousand years ago. But archeologists and anthropologists have another point of view. They believe that Indians inhabited America much earlier - 20-33 thousand years ago. There had been a narrow isthmus instead of Bering Strait, which had helped ancient Indians to move to America from Asia.
Geneticists had also contributed to this study. They practice two techniques, which usually give a good account during such historical reconstructions: analysis of male chromosome and of a certain DNA-type, coding female line. P. Underhill has recently discovered a specific change of male chromosome in all three language groups of American Indians. This fact indicates close relationship of these three groups of American natives. The scientist thinks that mutation, which formed "American" type of male chromosome, had happened about 30 thousand years ago during either early stage of North America's colonization, or in some other place, where ancestors of Americans had dwelled.
Today scientists agree that roots of the American Indians have Asian origin. However, they can't give exact geographic location of Indians' ancient motherland. According to the data of A. Torroni, geneticist from America, DNA variety of New World native Indians includes four groups - A, B, C and D. When scientists discovered same groups in DNA of Asian Mongols, they decided that ancient Indians' motherland was situated in the east of Central Asia. At the same time scientists never considered Siberia as possible start for migration to America, until they found said groups in Altaian DNA with 57% frequency, which is higher than 48% Mongolian frequency and 46-55% Chinese frequency.
This discovery motivated geneticists from Institute of Biologic Problems of North (Magadan) to study other Siberian nations. They've studied DNA of Tuva and Buryatia population, which belong to Asian anthropological type and origin from Trans-Baikal and Eastern Mongolia. Their ancestors inhabited territories of present Tuva and Buryatia during lower and middle Paleolithic period. DNA of Tuva and Buryatia population appeared to contain all four types of "American DNA" groups - A, B, C and D. Tuva DNA has 72% frequency, Buryats - 52%. Such facts allowed scientists to suggest that people, inhabiting ancient South and East Siberia, most likely were ancestors of American Indians. American scientists, who performed an advanced research on DNAs of Altaians and Ketians from Enisey and discovered a unique male chromosome - "Siberian", which is ancestral to original "American", suggested the same hypothesis. These data prove the hypothesis of Russian scientist Yu. Rychkov about an ancient society that existed somewhere in Siberia 26 thousand years ago and gave birth to two ethnogeny branches - Siberian and American. Thus, recent genetic studies helped to find Siberian dwellings of Indian ancestors - Trans-Baikal and Baikal regions, Sayans and Altai region.
But adventures of ancient Americans are still not over. Siberia, widely known as part of Asia, is also part of Eurasia, where ancient people were free to move about. No wonder that detailed genetic analysis indicated European origin of "Siberian type" of male chromosome. Scientists from Magadan believe that first Siberian migrants appeared to be crossbred - their fathers were European men, and mothers - Mongol women. Such race-mixed nations still live in Central Siberia. This hypothesis corresponds to archeological data, describing American territories. Kennevick human skeleton, recently discovered in America and aged about 9,5 thousand years, has European anthropological type, the scientists report.