Some Native American tribes have legends of migrations and other tribes have no legends of migrations and say that their ancestors have always been in the Americas and didn’t come from anywhere else. None of the tribes have stories of their ancient ancestors having come from East Asia, however, and that poses a problem for those who believe the ancestors of Native Americans once crossed the land bridge that existed between Asia and Alaska and migrated down into the Americas.
The theory of the land bridge crossing from Siberia to Alaska via the land bridge has actually been around since 1590. Since the 1930s the theory has been generally accepted but now DNA research is challenging that acceptance.
Genetic evidence show that there is NO DIRECT ANCESTRAL LINK between Native Americans and the people of ancient East Asia/Siberia. Further, based on the newest archaeological evidence humans did NOT survive the peak of the last Ice Age in Northeastern Siberia and there is NO EVIDENCE they had reached Alaska or the rest of the New World.
Evidence suggests that NE Siberia was inhabited by ancient humans during a Warm Period about 30 kya (thousand yrs ago) and that is BEFORE the last Ice Age peaked. After the peak the record goes silent and fossil evidence only returns the date of 15 kya which is AFTER the last Ice Age ended. So the million dollar question is just where did the ancestors of Native Americans go for those missing 15,000 years?
Some researchers believe they lived on the Bering Land Bridge which existed between Siberia and Alaska. It was dry land because the world’s sea levels were lower than they are today. The genetic evidence APPEARS to support this possibility.
The land bridge is thought to have been about 600 miles wide and it is believed that it was mostly shrub tundra like that found today in Arctic Alaska. There may have been a few microhabitats composed stands of spruce trees. The vegetation, it is surmised, would have supported grazing animals like woolly mammoth, woolly rhinos, camels, bison, and prehistoric horses. The shrub tundra could have also supported herds of elk, bighorn sheep, and other small mammals.
Evidence from archaeological sites in the region suggest ancient people burned animal bones for fires but a woody fire would be necessary to create the needed heat. These fires could have kept the ancient hunter-gatherers alive during the bitter Arctic winters.
Around 13 kya the sea levels began to rise and the land bridge was submerged under the waters. This was due to the melting of the massive ice sheets. As a result the entire region where the land bridge once was grew warmer and moist and the shrub tundra flourished. The steppe tundra vegetation was squeezed out as a result and that meant an end to the woolly mammoths and other large grazing mammals. Most likely it cause the ancient humans living on the land bridge to migrate into the interior of Alaska and the Yukon. Also it likely caused some to migrate south down into the Americas. There is Paleoindian evidence showing that they lived in the interior regions of Alaska around 13 kya.
Once the land bridge went under the waters it was no longer possible for people to walk across it or live on it and this resulted in an isolated human population, the Paleoindians, who became the ancestors of nearly all Native American tribes in North, Central, and South America. These would be what Native Americans call the “Ancient Ones” or “First Peoples.”
No doubt the people who lived on the land bridge came from somewhere. We know that some animals crossed the bridge from Asia into the Americas and I’m sure SOME ancient people did the same and visa versa. So basically the genetic evidence is suggesting that there is no direct ancestral link between the ancient people of East Asia/Siberia and modern Native Americans.
Getting back to what the Native Americans themselves say….at least SOME of them….they say that their ancestors were always here and didn’t come from anywhere including East Asia or Siberia. If you hold to the Multi-regional Theory of human evolution then this claim makes perfect sense as ancient humans evolved in different areas all over the planet. If you hold to the Out of Africa Theory then this would pose a problem. I personally hold to the Multi-regional Theory.