One interpretation was that the earliest Americans had come from a different population than the one that gave rise to most historical Native American peoples — that there had been more than one founding migration, with an earlier, morphologically distinct group being followed by later waves of people who eventually became numerically dominant and whose distinctive skull shapes replaced the earlier pattern.

This interpretation — sometimes called the two-migration or two-population model — had implications that extended well beyond academic debate.

It could be used to suggest that the historical Native peoples of the Americas were not the direct descendants of the very first Americans, which in turn could complicate — or in some political and legal contexts, was used to complicate — arguments about the depth and exclusivity of Indigenous claims to the Americas.

Naia’s skull showed the same unusual pattern.