This was the first and most fundamental result, and it established that whatever else the analysis would show about the child’s specific ancestry, she was unambiguously part of the founding population of the Americas — the population that had migrated from northeastern Asia during the Ice Age and eventually gave rise to all of the Indigenous peoples of the Western Hemisphere.

This was important to establish clearly, because the morphological diversity of early American populations — the variation in skull shape that had led some researchers to propose multiple founding migrations — had created a scientific and sometimes politically charged context in which any finding that placed an early American outside the mainstream of later Native American populations could be misinterpreted or misused.

USR1’s relationship to Native American populations was unambiguous: she was more closely related to Native Americans than to any non-American population.

But the analysis also showed that within the broad category of Native American-related populations, USR1 occupied a specific and unusual position.