Ancient mitochondrial DNA provides high-resolution time scale of the peopling of the Americas

FEHREN-SCHMITZ, L.; MALLICK, S.; VALDIOSERA, C.; ROMERO, M. I. B.; JIMENEZ, L. W.; LORY, J. M.; BURGER, R. L.; WELLS, R. S.; STANDEN, V. G.; HO, S. Y. W.; LLAMAS, B.; SOUBRIER, J.; NORDENFELT, S.; ROHRLACH, A.; VALVERDE, G.; CAGIGAO, E. T.; ROHLAND, N.; RICHARDS, S. M.; REYNA, I. S. L.; ESPINOZA, I. F.; RIVERA, M. A.; MAKOWSKI, K.; REINHARD, J.; TORREZ, J. A. B.; SANTORO, C. M.; CERUTI, M. C.; REICH, D.; POLITIS, G.; HAAK, W.; SMITH, C.; COOPER, A.

Science Advances

American Association for the Advancement of Science

Lugar: NEW YORK; Año: 2016 vol. 2 p. 1 - 10

The exact timing, route, and process of the initial peopling of the Americas remains uncertain despite much research.Archaeological evidence indicates the presence of humans as far as southern Chile by 14.6 thousand years ago (ka),shortly after the Pleistocene ice sheets blocking access from eastern Beringia began to retreat. Genetic estimates ofthe timing and route of entry have been constrained by the lack of suitable calibration points and low geneticdiversity of Native Americans. We sequenced 92wholemitochondrial genomes from pre-Columbian South Americanskeletons dating from 8.6 to 0.5 ka, allowing a detailed, temporally calibrated reconstruction of the peopling of theAmericas in a Bayesian coalescent analysis. The data suggest that a small population entered the Americas via acoastal route around 16.0 ka, following previous isolation in eastern Beringia for ~2.4 to 9 thousand years afterseparation from eastern Siberian populations. Following a rapid movement throughout the Americas, limited geneflow in South America resulted in a marked phylogeographic structure of populations, which persisted through time.All of the ancient mitochondrial lineages detected in this study were absent from modern data sets, suggesting ahigh extinction rate. To investigate this further, we applied a novel principal components multiple logistic regressiontest to Bayesian serial coalescent simulations. The analysis supported a scenario in which European colonizationcaused a substantial loss of pre-Columbian lineages.