If the Ancient North Eurasian population represented by MA-1 was located in south-central Siberia — in the Lake Baikal region, well to the south and west of the northeastern Siberian region closest to the Bering land bridge — how did ancestry related to this population end up in the founding population of the Americas?

The answer involves population movement, and the recognition that the Pleistocene world of northeastern Asia was not a static landscape with fixed populations.

People moved.

Populations expanded and contracted with the climate.

Genetic signals traveled across geographic distances as people traveled and mixed.

The most plausible scenario, based on the available ancient genomic data, is that the Ancient North Eurasian population was more broadly distributed across Siberia and northern Asia than the specific location of the Mal’ta site might suggest.

The Mal’ta and Afontova Gora sites, which provide the clearest ancient DNA evidence for the Ancient North Eurasian population, are both in the Lake Baikal region.