Ancient genomes in South Patagonia reveal population movements associated with technological shifts and geography

Archaeological records describe several major technological shifts in South Patagonia, such as the development of marine-based economies or changes in the type of tools or raw material used to manufacture them. Several demographic scenarios have been suggested to explain those shifts along with cultural and biological differences among the ethnic groups from the region. Here we report genome-wide data from 20 ancient individuals. We find that immigration does not explain the appearance of marine adaptation. Although we document partial genetic continuity since ~6600 BP except in the western part of the region, we identify two events of gene flow that may be correlated with some technological changes: one between 4700-2000 BP incorporated an additional ancestry to primarily marine-based groups, and a later event had impact in all <2000 BP South Patagonians. Moreover, from ~2200-1200 BP, mixture between neighbors resulted in a cline correlated to geographic ordering along the coast.