An international team of genetic researchers has found conclusive evidence for a single contact between Polynesian individuals and a Native American group most closely related to the indigenous inhabitants of present-day Colombia around 1200 CE.
Tahitian warrior dugouts from ‘Le Costume Ancien et Moderne’ by Giulio Ferrario, Milan, between 1816 and 1827.
“The possibility of voyaging contact between prehistoric Polynesian and Native American populations has long intrigued researchers,” said lead author Dr. Alexander Ioannidis, a scientist in the Institute for Computational and Mathematical Engineering at Stanford University and Mexico’s National Laboratory of Genomics for Biodiversity and his colleagues from Chile, Mexico, Norway, the United Kingdom and the United States.
“Proponents have pointed to the existence of New World crops, such as the sweet potato and the bottle gourd, in the Polynesian archaeological record, but nowhere else outside the pre-Columbian Americas.”
“The Norwegian explorer Thor Heyerdahl controversially suggested that prehistoric South American populations had an important role in the settlement of east Polynesia and particularly of Easter Island.”
“Several genetic studies have reached opposing conclusions, and the possibility continues to be as hotly contested today as it was when first suggested.”
For the study, the researchers collected saliva samples from 807 individuals on 17 Polynesian islands and 15 Native American groups along the Pacific coast of the Americas from Mexico to Chile.
They then conducted genetic analyses to look for snippets of DNA that are characteristic of each population and for segments that are identical by descent, meaning they are inherited from the same ancestor many generations ago.
“We found identical-by-descent segments of Native American ancestry across several Polynesian islands,” Dr. Ioannidis said.
“It was conclusive evidence that there was a single shared contact event.”
In other words, Polynesians and Native Americans met at one point in history, and during that time people from the two cultures produced children with both Native American and Polynesian DNA.
“Statistical analyses confirmed the event occurred around 1200 CE, which is around the time that these islands were originally being settled by native Polynesians,” Dr. Ioannidis said.
Using computational methods, the authors then localized the source of the Native American DNA to modern-day Colombia.
“If you think about how history is told for this time period, it’s almost always a story of European conquest, and you never really hear about everybody else,” Dr. Ioannidis said.
“I think this work helps piece together those untold stories — and the fact that it can be brought to light through genetics is very exciting to me.”
A paper on the findings was published June 8, 2020 in the journal Nature.
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A.G. Ioannidis et al. Native American gene flow into Polynesia predating Easter Island settlement. Nature, published online June 8, 2020; doi: 10.1038/s41586-020-2487-2
