The two main branches that constitute the vast majority of Native American ancestry are typically designated as Northern Native American (ancestral to most North American populations) and Southern Native American (ancestral to most Central and South American populations, with some North American populations also showing this ancestry).

These two branches diverged from a common ancestral founding population in Beringia or shortly after entry into the Americas, and their descendants eventually spread across the hemisphere.

The Ancient Beringians are distinct from both of these branches — not members of either, but representatives of a lineage that diverged even before the Northern-Southern split.

This is what makes the Ancient Beringian designation significant: it is not simply another variation on the Northern Native American theme, but evidence of an earlier founding lineage that was present in Beringia when the founding population was still undifferentiated.

The mitochondrial lineage of the Trail Creek child — the maternal ancestry identified through the mitochondrial genome — was consistent with a basal lineage related to haplogroup B2.