The Ancient North Siberians appear to represent a population that branched from this divergence point and then moved east — establishing themselves in northeastern Siberia well before the ancestors of modern East Asians expanded into that region.

The team named them the Ancient North Siberians, abbreviated ANS.

This was not a population that anyone had ever identified before from the archaeological or genetic record.

The physical remains of the people who made the remarkable artifacts at Yana — the carved ivory, the needles, the ornaments — had not been found.

Without genetic evidence, there was no way to know that these people were genetically distinct from any other early human population in the region.

They were, in the most concrete possible sense, a lost population: people whose existence had been entirely unknown to science until two children’s milk teeth yielded up their genomes.