From the Asian side, ancient genomes from Siberian archaeological sites — including sites on the Kamchatka Peninsula and in other parts of northeastern Asia — helped to characterize the Asian populations that were most closely related to the founding population of the Americas.

These ancient Asian genomes contributed to the demographic modeling of when and where the founding population separated from its Asian relatives and began accumulating the distinct genetic character of Native Americans.

The picture that emerged from the combined analysis was consistent with the Beringian standstill model: the founding population of the Americas separated from its closest Asian relatives approximately 25,000 to 20,000 years ago and spent an extended period in Beringia before the southward expansion began.

During this standstill period, the specific genetic character of Native Americans — the genetic changes that distinguish them from their Asian relatives — accumulated in the isolated Beringian population.