some anthropologists had hypothesized that the lineage’s ancestors populated the Americas in a wave of migration that was distinct from Siberians crossing the Bering land bridge some 20,000 years ...

The ice extent in late winter can vary from 700 km south of the Bering Strait in a light ice year to 1,100 km in heavy ice years. Following the regime shift, there was a clear decrease in sea ice ...

At that level, an area of "dry" land as wide as 1,000km would have stretched from Asia to North America across what is now the Bering Strait. Today, some islands — St. Lawrence Island ...