This temporal overlap has led some researchers to propose that the Clovis and Western Stemmed traditions were independent — that they represent different groups of people who were in the Americas at the same time, possibly having arrived via different routes.

Under this scenario, one group moved south through the interior of the continent and developed Clovis technology, while another group — the ancestors of the Western Stemmed Tradition people — moved along the Pacific Coast and developed a different technological tradition adapted to their specific environment.

The Spirit Cave Man’s genome provides genetic evidence relevant to this debate.

His ancestry, as revealed by the DNA analysis, was most consistent with a founding population that included both the ancestors of Clovis people and the ancestors of Western Stemmed Tradition people — suggesting that the two traditions may represent different cultural expressions of the same broadly defined founding population, rather than distinct migrations.

But the question is not fully resolved.