First analysis of ancient mtDNA genetic diversity in Northern coast of Argentinean Patagonia

In the past decades, archaeological research advances in different Patagonian sectors have contributed to the knowledge of lifestyle and evolution of pre-Columbian populations in these regions. The San Matías Gulf archaeological record (Río Negro province, Northern Patagonia, Argentina) shows that humans occupied the area from Middle Holocene to contact period, where palaeodietary and technological changes are evident from around 1700 14C BP. Nevertheless, few studies have been done on biological origin and evolution of these populations. For this reason and in order to investigate mitochondrial genetic variability in comparison with other ancient and contemporary Patagonian populations, we analyzed ancient DNA on human skeletal remains belonging to different chronologies of this area. We found a prevalence of founding lineages C1, D1 (D1g and D1j subclades) and D4h3a, low frequency of A2 and absence of B2. This supports the hypothesis of genetic drift acting on populations of the Southern Cone of South America. Individuals analyzed present similar haplotypes, indicating a possible temporal and regional continuity or a common population origin. Those lineages are also present in Tehuelche and Mapuche contemporary populations. However, B2 is highly represented in these extant groups possibly as a consequence of recent migrations related with Araucanization process.