Both of these approaches are scientifically defensible on the current evidence.

The challenge is that they make somewhat different predictions about what future ancient DNA data should show, and testing those predictions requires data that is not yet available.

The Ancient DNA from Brazil, Uruguay, and Panama

The broader dataset of ancient South American genomes — not just Lagoa Santa but other early sites across the continent — has contributed important additional evidence to the Population Y debate, with results that are revealing in their pattern of consistency and inconsistency.

Ancient genomes from the Atacama Desert of Chile, where the extreme dryness of the environment has allowed remarkable preservation of organic material, have been analyzed and show the expected Native American ancestry without clear evidence of the Population Y signal at the intensity seen in some Amazonian populations.