Early human dispersals within the Americas

Abstract

Studies of the peopling of the Americas have focused on the timing and number of initial migrations. Less attention has been paid to the subsequent spread of people within the Americas. We sequenced 15 ancient human genomes spanning Alaska to Patagonia; six are ≥10,000 years old (up to ~18x coverage). All are most closely related to Native Americans, including an Ancient Beringian individual, and two morphologically distinct "Paleoamericans." We find evidence of rapid dispersal and early diversification, including previously unknown groups, as people moved south. This resulted in multiple independent, geographically uneven migrations, including one that provides clues of a Late Pleistocene Australasian genetic signal, and a later Mesoamerican-related expansion. These led to complex and dynamic population histories from North to South America.