The journal Nature on 5 November published a genomic study describing an indigenous lineage that inhabited central Argentina for at least 8,500 years and stayed largely isolated from neighboring populations.
An international team from CONICET, the National University of Córdoba, and Harvard University analyzed 238 ancient genomes dating back as far as 10,000 years, including 29 from Córdoba Province. Their work filled a gap in paleogenomic data for a region situated between the Andes, Amazon, and Patagonia.
The scientists uncovered a deep genetic lineage that became dominant in the Pampas about 800 years ago; its archaeogenetic signal faded around 1800 CE, yet subtle markers remain in living Argentines. DNA from 133 archaeological sites, including a woman who lived 10,000 years ago, allowed the team to trace the split between this lineage and ancestors of Andean and Brazilian coastal groups to roughly 10,000 years ago, pointing to long-term demographic isolation in the Southern Cone.
Genomic evidence revealed three migration waves: one moved northwest and mixed with Andean peoples, another reached the Gran Chaco and met forest groups, and a third stayed in the Pampas. Even after these movements, interaction along the borders was minimal, preserving a distinctive genetic profile.
“This discovery shows that the evolution of human populations in the region has been local and continuous, challenging traditional models that viewed the area as a place of population replacement,” wrote the authors in Nature.
“The depth of genetic continuity here is exceptional, and it reminds us that human history can be radically different even in neighboring areas,” said David Reich, a population geneticist at Harvard University. Reich added that an early rapid expansion across the continent was followed by a prolonged phase of regional continuity.
Despite droughts, a shift from hunting and gathering to farming, and contact with Amazonian groups, the lineage remained mostly isolated. “Given its location in the middle of these three populations, were people here a mix of these ancestries, or not?” asked Rodrigo Nores, a geneticist at the National University of Córdoba, in comments to Live Science.
The team suggested that linguistic diversity sat atop a shared genetic background, possibly maintained by the ayllu system, a social unit built on kinship, reciprocity, and endogamy, according to La Vanguardia.
“According to material culture and linguistics, it was supposed that there was a great migration from the Amazon to central Argentina about 1,300 years ago, but that is not observed in the genetic landscape,” said Ramiro Barberena, an archaeologist at CONICET.
“What we found is not a replacement of populations, but a continuous local evolution over thousands of years. This completely changes our understanding of human settlement in the Americas,” said Rodrigo Norris, an anthropologist at the Córdoba Institute and lead author of the Nature article.
Córdoba Province—home to the Sierras de Córdoba, numerous rivers and lakes, and an economy spanning industry, agriculture, and livestock—supplied much of the material for the study, linking today’s inhabitants to ancestors who first shaped the region at least 8,500 years ago.
The preparation of this article relied on a news-analysis system.