Ancient DNA Analysis Sheds Light on Early Peopling of South America; Study Provides Most Complete Genetic Evidence to Date of Complex Migration Routes in Ancient Central and South America

The first southern North American groups entered South America and spread through the Pacific coast settling the Andes (yellow arrow). At least one population split occurred soon after, branching the first groups that settled the Atlantic coast (green arrow) from the groups that gave rise to the ancient populations of Southern Cone. New Migrations may have then emerged along the Atlantic Coast, with a possible origin around Lagoa Santa, heading north toward Northeast Brazil and Panama, and south to Uruguay. Eventually, Uruguay and Panama were linked by a south-to-north migration route closer to the Atlantic coast (purple double-headed arrow). (Credit: Florida Atlantic University).

The Americas were the last continent to be inhabited by humans. An increasing body of archaeological and genomic evidence has hinted to a complex settlement process. This is especially true for South America, where unexpected ancestral signals have raised perplexing scenarios for the early migrations into different regions of the continent. Many unanswered questions still persist, such as whether the first humans migrated south along the Pacific coast or by some other route. While there is archaeological evidence for a north-to-south migration during the initial peopling of the Americas by ancient Indigenous peoples, where these ancient humans went after they arrived has remained elusive. Using DNA from two ancient human individuals unearthed in two different archaeological sites in northeast Brazil--Pedra do Tubarão and Alcobaça--and powerful algorithms and genomic analyses, Florida Atlantic University researchers in collaboration with Emory University scintists have unraveled the deep demographic history of South America at the regional level with some unexpected and surprising results.