Some regions of the Americas show evidence of a second wave of migration from Asia — the ancestors of the Na-Dene-speaking peoples of the Pacific Northwest and interior regions of North America are believed to have arrived in a separate migration event following the initial peopling.

The population history of the Arctic, settled by the Thule and earlier Arctic peoples, involved additional migration events from Siberia and Beringia.

Within South America, the ancient genomic evidence has revealed population movements and replacements that complicate the simple picture of a single founding event followed by geographic diversification.

The complex population histories of Amazonian and Andean peoples, in particular, have been the subject of active research.

All of this complexity sits downstream of the MA-1 finding.