Multiple populations with distinct genetic characters coexisted, came into contact, and mixed across the vast geographic range of northern Asia.

The founding population of the Americas was one product of this mixing — the population that happened to move into Beringia and eventually across into the Americas, carrying both East Asian and Ancient North Eurasian ancestry.

Later research has also addressed the genetic diversity within the founding population of the Americas itself.

Ancient genomes from early Americans in both North and South America have been analyzed in increasing numbers, revealing that the founding population was not genetically homogeneous but included distinct subgroups with somewhat different ancestry profiles.

The detailed reconstruction of how this diversity developed — which subgroups entered the Americas first, how they spread and diversified, and how later waves of migration modified the initial picture — is an active area of ongoing research.