This was an important finding for the interpretation of the skull morphology debate.

The morphological differences between early and later South American populations did not require a population replacement to explain.

They could be explained within a framework of overall genetic continuity, with morphological change occurring over time within an ancestral population.

Deep Ancestral Structure and the Asian Connection

The most scientifically interesting explanations for the Population Y signal involve not a separate migration from Australia but something that happened much earlier, in Asia, before anyone reached the Americas at all.

To understand this, it helps to understand the deep structure of human populations in Asia during the period when the Americas were first being settled.