DNA Analysis Identifies New Population in Central Argentina

BUENOS AIRES, ARGENTINA—Science Magazine reports that a genetic study conducted by an international team of researchers has identified a population that lived on the plains of central Argentina for some 8,500 years, yet rarely mixed with three other groups known to have lived in the surrounding central Andes, the Amazon, and Patagonia. Scientists including David Reich and Javier Maravall-López of Harvard University and Rodrigo Nores of Argentina’s National Scientific and Technical Research Council analyzed 238 genomes of people who lived in Argentina as many as 10,000 years ago. The study indicates that only members of the lineage who lived on the edges of central Argentina mixed with the other groups, even though there were no geographic barriers to contact between the populations. “In this region you have a diversity of language and diversity of cultural changes, and you see interactions with other groups in the archaeological evidence. But the population is the same,” Nores explained. The team members also found that the oldest remains in the study belonged to a woman who was more closely related to people living in other parts of South America’s Southern Cone, rather than people who lived in Peru and Brazil to the north. “This suggests an initial period of very rapid expansion across the continent was followed by a long period of regional continuity,” Reich said. To read about hunter-gatherers in the region, go to "Letter from Patagonia: Surviving a Windswept Land."