AI interpretationAI-generated
Ancient DNA reveals an 8,000-year continuous lineage in central Argentina.
This study analyzed 238 ancient genomes from Argentina and neighboring regions, spanning 10,000 years. It identifies a previously unknown deep lineage in Central Argentina that persisted for millennia without interregional migration. The oldest individual, from the Pampas at 10,000 BP, already showed distinct genetic affinity. Later, this Central Argentina ancestry mixed into the Pampas, Northwest Argentina, and Gran Chaco. The findings highlight long-term genetic continuity and complex interactions among ancient South American populations.
- A previously unsampled deep lineage in Central Argentina dates back to at least 8,500 BP and persisted for thousands of years with no evidence of interregional migration.
- Central Argentina ancestry contributed to three distinct gene flows: into the Pampas by 3,300 BP (becoming dominant after 800 BP), into Northwest Argentina with Central Andes ancestry, and into Gran Chaco with Tropical/Subtropical Forest ancestry.
- Close kin unions increased in Northwest Argentina by 1,000 BP, mirroring patterns in the Central Andes; a 400 BP individual from the Paraná River with Guaraní archaeological association clusters with Brazilian groups.
Sample interpretation
The site includes 223 ancient individuals, with 116 resolved Y-chromosome lineages. Y-haplogroups are dominated by Q-M848 (49) and Q-M3 (36), typical of Native American paternal lineages. Mitochondrial DNA shows high frequencies of C1b (54), A2 (37), B2 (29), and D1 (21), reflecting common maternal lineages in South America. These genetic markers confirm deep indigenous roots and regional continuity.
For genealogy enthusiasts
For ancestry enthusiasts, this study shows that some Argentine regions have deep local genetic continuity stretching back thousands of years, rather than being solely shaped by recent migrations. It also underscores the complexity of ancient population interactions and the value of ancient DNA in filling gaps in South American prehistory.
Abstract
The central Southern Cone of South America was one of the last regions of the globe to be peopled, yet remains underrepresented in ancient DNA. We generated new genome-wide data from 238 ancient individuals spanning ten millennia. The oldest, from the Pampas region and dating to 10000 years before present (BP), had distinct genetic affinity with Middle Holocene Southern Cone individuals, showing that differentiation from the Central Andes and Central East Brazil had begun by this time. Individuals dating to 4600-150BP primarily descended from a hitherto-unsampled deep lineage whose earliest representative is an individual dating to around 8500BP. This Central Argentina lineage co-existed with two other lineages during the Mid-Holocene, and within Central Argentina, this ancestry persisted for thousands of years with no evidence of interregional migration. Central Argentina ancestry was involved in three distinct gene flows: it mixed into the Pampas by 3300BP and became the main component there after 800BP; with Central Andes ancestry in Northwest Argentina; and with Tropical and Subtropical Forest ancestry in the Gran Chaco. In Northwest Argentina, there was an increased rate of close kin unions by 1000BP, paralleling the pattern in the Central Andes. In the Paraná River region, a 400BP individual with a Guaraní archaeological association clusters with Brazilian groups, consistent with Guaraní presence by this time.