This implication has sometimes been used in politically motivated arguments about Indigenous land rights — the suggestion that if the “first Americans” were replaced by a different group before European contact, then the land rights of contemporary Native Americans are somehow less firmly grounded.

This implication is both historically wrong and ethically incoherent.

The historical relationships between contemporary Indigenous peoples and the specific ancient peoples whose DNA is being studied are complex and cannot be simply read off from genetic signals, and the rights of contemporary Indigenous peoples do not depend on proving that no group preceded them.

Third, the “who got here first” framing misses what is scientifically most interesting about the Population Y signal.

The most interesting question is not which of two competing groups arrived first but rather what the deep structure of the ancestral population was — what the internal diversity of the founding Native American population looked like before and during the American settlement, and how that internal diversity was distributed across the continent as the settlement proceeded.