But populations don’t respect the boundaries of their most productive archaeological sites.

The people related to the Mal’ta population may have ranged widely across Siberia, including into the northeastern regions where mixing with East Asian-ancestry populations was possible.

Alternatively, the mixing between Ancient North Eurasian and East Asian-ancestry populations may have occurred partly as a result of population movements — the Ancient North Eurasian people expanding into northeastern Asia, or the East Asian-ancestry people expanding westward, or both, with mixing occurring in zones of contact.

The specific geography of the mixing event is still being worked out by researchers analyzing additional ancient genomes from across northern Asia.