European colonization has had a profound cultural impact on the present-day South American nations. The diversity of Indigenous languages, religions, world views, and political structures was largely replaced by European systems. “This was accompanied by a massive displacement of the Indigenous population, whose genetic diversity is still greatly reduced today,” explains Prof. Dr. Cosimo Posth from the Senckenberg Centre for Human Evolution and Palaeoenvironment at the University of Tübingen (SHEP), and he continues, “In recent years, studies of ancient genomes of Native Americans have significantly enhanced our understanding of how South America was once populated. However, one region that has been poorly studied in terms of genetics to date is the Southern Cone, the southernmost part of the continent that was colonized by humans.”

Together with the new study’s first author, SHEP doctoral student Kim-Louise Krettek, and an international research team, Posth has now been able to close important temporal and spatial gaps in the peopling of the Southern Cone using genetic data. To this end, the researchers from Tübingen collected genetic data of 52 Indigenous individuals from 31 sites in four regions of the Southern Cone. “The fossil remains we examined come from the mid- and late Holocene of the central and southern Pampas, northwest Patagonia, the Paraná and Uruguay deltas, and the eastern lowlands of Uruguay; they are between 6,000 and 150 years old,” explains Krettek.

Archaeological finds already indicated that cultural practices in the area under investigation changed significantly during the mid- and late Holocene. “However, it is still debated today whether these changes were just caused by cultural processes or they also involved human migrations,” adds Posth.

The newly obtained genetic data shows that at least three different genetic lineages were represented in the Pampas during the mid-Holocene – the period between around 8,200 and 4,200 years ago. Although contact with groups from southern Patagonia did occur, it was quite rare. Instead, the researchers discovered that a genetic lineage, whose geographical origin is still unknown, had already spread around 5,500 years ago. In the late Holocene, its proportion increased significantly. The same lineage also reached northwest Patagonia no later than around 600 years ago, where it continued to exist alongside people with a genetic profile from the southern Andes until the colonial period.

Around 1,500 years ago, the populations along the Paraná river delta and the lower reaches of the Uruguay river already differed genetically from each other. In turn, people from the eastern lowlands of Uruguay show genetic links to so-called Sambaqui groups from the southern Brazilian coast. “Our study reveals that large-scale migratory movements in southern South America during the mid- and late Holocene had a lasting impact on the genetic and cultural landscape of the Southern Cone,” emphasizes Krettek.

“In summary, we can state that genetically distinct groups spread across all the regions studied. Our finding that cultural changes were influenced by migration and intermixing for thousands of years confirms the deep roots of the Indigenous heritage,” adds Posth in conclusion.

Publication: Krettek et al., The shared genomic history of Middle- to Late-Holocene populations from the Southern Cone of South America, Current Biology (2026), https://doi.org/10.1016/j.cub.2026.03.081