An area called the central Southern Cone in South America, which consists of a large part of Argentina, is known to be one of the last global regions to become inhabited by humans.

The team’s main finding was a previously unknown deep genetic lineage that had existed in central Argentina for at least the last 8,500 years. They say this lineage has persisted over this time, and that modern Argentinians still share DNA with this group. The group had apparently persevered through millennia, despite periods of severe drought in the region.

The study authors write, “We found that the central Argentina lineage is geographically structured along two clines, one reflecting admixture with central-Andes-like ancestry and the other with Middle Holocene Pampas-like ancestry.”

This lineage coexisted with others and became the main ancestry in the Pampas after 800 years ago. The deep central Argentina lineage had expanded southward, admixing with other groups at least 3,300 years ago, according to their analysis. The team also points to genetic connectivity between the people of central Argentina and central Andes lineages as early as 4,600 years ago.