30,000-year-old human remains found in Siberia

The major problem, said Grayson, is that archaeological evidence for human dwellings in Siberia is still very sparse. Also, there is a gap of thousands of years between the 30,000-year-old Yana site and other sites in Asia and the Americas.

There was no physical barrier to going to the Americas from Asia during that period. The Bering land bridge connected the two continents until about 11,000 years ago, when a rising sea level flooded the connection and created what is now called the Bering Strait between Russia and Alaska.