Abstract

The details of the early human settlement of the Americas such as the dispersal time, number of migrations, and migration routes remain subject to debate. With many Native populations now extinct, the Pre-Columbian genetic make-up has been partly lost or blurred by recent admixture. The present study examines the mitochondrial genetic diversity of extinct Fuegian populations in order to illuminate the population history of South America. The Fuegians lived on the islands of Tierra del Fuego in the Southern Cone of South America in isolation from other Native Americans until their extinction at the beginning of the 20th century, likely maintaining their original genetic signature without recent admixture. Based on the Fuegian robust cranial morphology, a few controversial studies have suggested that Fuegians might be descendants of a putative earlier migration wave preceding the arrival of the other Native Americans. Using target enrichment and next-generation sequencing, we obtained complete mitochondrial genomes from skeletal remains of 37 Fuegians and 19 individuals from adjacent Patagonia. Comparing them to published sequences of other Native Americans, we estimated the divergence times and past population dynamics in the Southern Cone and we assessed the question of population continuity in the region. The coalescent ages of deep Fuegian-specific clades suggest early human settlement in Tierra del Fuego, probably associated with the initial peopling of the continent. The early arrival of Fuegians to the Southern Cone is consistent with the generally accepted scenario of rapid coastal dispersal throughout the Americas, which is further supported by the presence of Monte Verde, the oldest known South American pre-Clovis archaeological site, in Chilean Patagonia. In this presentation, alternative views on Fuegian origins and their genetic affinities with other Native Americans are considered in the context of the evolutionary history of South American populations.