The Americas were not populated in a single generation or even a single century.

They were populated over millennia, through a process of gradual expansion and differentiation that built up the human diversity of the hemisphere layer by layer.

What Happened To The Ancient Beringians

One of the most intriguing questions raised by the USR1 discovery is what became of the Ancient Beringian lineage.

If a distinct genetic branch diverged from the main Native American founding population approximately 20,000 years ago and maintained a distinct identity long enough to be preserved in the genome of an 11,500-year-old infant in Alaska, where is that lineage in the modern genetic record?

The honest answer is that it is not clearly identifiable.