Researchers have uncovered a previously unknown genetic history in Argentina that stretches back at least 10,000 years, offering the most detailed view yet of how ancient populations lived, mixed, and survived in the region. The findings about ancient DNA, published in Nature, help fill one of the largest gaps in South America’s human history.
One of the last regions settled by humans
The study focuses on the central Southern Cone, a vast area covering much of modern-day Argentina. Scientists consider it one of the final regions on Earth to be populated by humans, likely because of its remote location and harsh environment.
Archaeological evidence suggests people arrived more than 12,000 years ago, but their population history has remained largely unknown due to limited DNA research.
Largest ancient DNA study ever conducted in Argentina
To address that gap, a team of genetic researchers analyzed 344 bone and tooth samples from 310 individuals who lived between 10,000 and 150 years ago. They recovered full genome-wide data from 238 of them, creating one of the largest ancient DNA datasets in South America.
The results were compared with genetic data from 588 pre-European Indigenous individuals and modern Native American groups.
Discovery of a deep genetic lineage
The analysis revealed a previously unidentified genetic lineage that has existed in central Argentina for at least 8,500 years. The lineage endured long periods of environmental stress, including severe drought, and still appears in the DNA of people in Argentina today.
Researchers found two main genetic patterns within the lineage—one linked to central Andes ancestry and another tied to Middle Holocene Pampas populations.
Expansion, mixing, and long-distance links
The lineage expanded southward and mixed with neighboring populations at least 3,300 years ago. Around 800 years ago, it had become the dominant ancestry in the Pampas. Genetic ties with the central Andes appear as early as 4,600 years ago, indicating sustained contact across large geographic barriers.
Limited gene flow and a kin-based social system
Despite some mixing, the genetic record shows restricted movement between communities over long periods. Researchers say this isolation may reflect a kin-structured social system that favored marriage within the group.
Evidence of close-kin unions in northwest Argentina mirrors patterns seen in the central Andes and aligns with the ayllu system, a political and social structure based on kinship and reciprocity.
A new framework for Indigenous history in Argentina
The study provides the first long-term genetic map of Indigenous populations in the Southern Cone. The authors say the work fills a major historical gap and offers a foundation for future research.
More densely sampled regions and time periods, they note, may further explain how ancient societies in Argentina moved, interacted, and survived over thousands of years.
