This structural position in the family tree is what makes USR1 so important as a data point for modeling the founding of the Americas.

She provides information about the state of the founding population before the main diversification events that produced the north-south distinction, giving researchers a reference point for the deep ancestry that all Native Americans share.

The north-south split, and the Ancient Beringian divergence that preceded it, together sketch a picture of the founding of the Americas as a multi-stage process: first, a period of isolation in Beringia that produced the founding population and began the process of differentiation; then, a divergence between the Ancient Beringian lineage and the ancestors of other Native Americans; then, a divergence within the main Native American ancestral population that produced the northern and southern branches; then, the geographic expansion of those branches through the hemisphere.

Each stage of this process took time — time measured in thousands of years — and each stage was shaped by the specific geography, ecology, and demographic history of the populations involved.