The apparent rapidity of the initial human spread is consistent with, though does not prove, this scenario.

The study also confirmed and refined the picture of two major branches within the Native American founding lineage — a northern branch and a southern branch — that had diverged at some point after the initial entry from Beringia but before the spread across most of the hemisphere.

The Spirit Cave Man’s genome showed him to be genetically related to the northern branch, consistent with his geographic position in the Great Basin.

And the study directly addressed — and effectively refuted — the suggestion that the Spirit Cave Man represented a distinct, separate founding lineage unrelated to modern Native Americans.