The Upward Sun River infants from Alaska, dated to approximately 11,500 years and analyzed for the paper that established the Ancient Beringian concept, provided the deepest window yet into the founding diversity of the Americas: a lineage that diverged from the ancestors of all other sampled Native Americans before the main southward expansion of the founding population.

In this comparative context, the Hourglass Cave man occupies a specific niche: he is a mid-early-Holocene individual from the high-altitude Rocky Mountain interior, carrying haplogroup B, at a time and place where direct physical evidence of this kind is otherwise rare.

His position in the ancient DNA record is less about being the oldest or the most complete, and more about the specific contribution of his time, place, and haplogroup to a picture that was — and still is — incomplete.

The five founding Native American mitochondrial haplogroups — A, B, C, D, and X — are all represented in the ancient DNA record from multiple ancient individuals.