What happened in the interval from 31,000 to 10,000 years ago — the roughly twenty thousand years during which the ANS population either persisted in some form, dwindled, or was absorbed into other populations — is not documented in the ancient genetic record because no ancient human individuals from northeastern Siberia during this interval have yet been successfully sequenced.

This gap is partly a reflection of the difficulty of finding and sampling human remains from this period and region.

The Last Glacial Maximum, which fell in the middle of this interval at approximately 20,000 years ago, was a period of extreme climate that may have dramatically reduced or even temporarily eliminated human populations from the far north of Siberia.

If the ANS population was concentrated in the far Arctic — above the Arctic Circle, in the zone most severely affected by the glacial maximum — it may have experienced a dramatic population crash during the coldest period.