Human evolution: Native American contact in remote Polynesia

New evidence for prehistoric voyages between the Americas and eastern Polynesia is presented in a study in Nature this week. The analysis of genetic data from present-day and ancient individuals sheds light on the history of Polynesia and helps to resolve long-standing discussions concerning the role of Native Americans in shaping the populations of these Pacific Islands.

The possibility of prehistoric contacts between Polynesians and Native Americans is much debated, as previous genomic studies have reached contradictory conclusions. In this study, Andrés Moreno-Estrada, Alexander Ioannidis and colleagues analysed the genomes of more than 800 Polynesian and Native American individuals, and deduced that Native Americans and Polynesians must have interbred around AD 1200. A single contact event occurred in eastern Polynesia between Polynesians and a Native American group most closely related to the indigenous peoples of present-day coastal Colombia. However, Easter Island was not the first point of contact, which has been suggested in some previous studies.

Previous genomic studies have focused on contact on Easter Island, because it is the closest inhabited Polynesian island to South America. However, the new study supports the idea that first contact was on one of the archipelagos of eastern Polynesia (such as the South Marquesas), as proposed by the late Norwegian explorer, Thor Heyerdahl, who made a drift voyage from Peru to Polynesia in 1947 on a large wooden raft called the Kon-Tiki. These findings suggest that the contact event occurred earlier than was previously thought and was spread across multiple islands in Polynesia, suggesting that Native Americans had a genetic and cultural influence on Polynesia for more than five centuries before the arrival of Europeans in the region.