The Mal’ta Boy’s genome was sequenced in 2013, and the result was startling: he was not closely related to modern East Asians.

He was genetically more similar to modern Europeans and Western Eurasians.

This was in southern Siberia, 24,000 years ago.

His population — called Ancient North Eurasians in the subsequent literature — had contributed a significant portion of Native American ancestry.

But where did the Ancient North Eurasians get their Western Eurasian-related genetics?

The population history of this vast region in the deep Pleistocene was obscure.

The Mal’ta individual was the oldest, best-characterized example of this lineage, but his origins — the deeper history of the Ancient North Eurasians — remained uncertain.