Europeans were not the first to the Americas, Stanford study finds

Stanford graduate students published a paper on July 8 detailing a study claiming that Polynesians made contact with Native Americans hundreds of years before the arrival of Europeans. 

By conducting deep genetic analyses on 807 living participants from South America, Polynesia and Mexico, the research team discovered common genetic signatures.

“Through this research, we wanted to reconstruct the ancestral roots that have shaped the diversity of these populations and answer deep, long-standing questions about the potential contact between Native Americans and Pacific Islanders, connecting two of the most understudied regions of the world," Andres Moreno-Estrada, professor and head of genomic services at the National Laboratory of Genomics for Biodiversity in Mexico, told Stanford Medicine. 

A debate among academics about contact between Oceania and the Americas has been going on for decades, but the paper authored by Stanford graduate student Javier Blanco-Portillo and Moreno-Estrada provides scientific evidence that there was contact as early as A.D. 1200 between Polynesians and Native Americans living in the area of modern-day Colombia. The genetic nature of the evidence means that Polynesians and Native Americans would have produced children during their meeting. 

“Our laboratory in Mexico has been very interested in understanding the genetic diversity of populations throughout Latin America and, more generally, of underrepresented populations in genomic research,” Moreno-Estrada told Stanford Medicine.

In the past, most of the research done in this area of genomics has been centered on European contact with the Americas, but there were still hints of contact between Polynesia and the Americas in the form of the sweet potato.

“The sweet potato is native to the Americas, yet it’s also found on islands thousands of miles away,” Alexander Ioannidis, Ph.D. and postdoctoral scholar at Stanford, told Stanford Medicine. “On top of that, the word for sweet potato in Polynesian languages appears to be related to the word used in Indigenous American languages in the Andes.”

Genetic studies of sweet potatoes from Polynesia and South America were unable to prove similar origins. Prior to this recent genomic study, genetic data was taken from the bones of deceased Native Americans and Polynesians but ancient samples are often degraded and the evidence was inconclusive. 

Ioannidis and his research team used big data to analyze 807 people from 15 different Native American groups and participants from 17 different Polynesian Islands to sift for conclusive genetic evidence of contact. Ioannidis and his team found what they were looking for—snippets of DNA that prove common ancestor.

“We found identical-by-descent segments of Native American ancestry across several Polynesian islands,” Ioannidis told Stanford Medicine. “It was conclusive evidence that there was a single shared contact event.”

You can find more information on this topic by visiting the Stanford Institute for Computational & Mathematical Engineering website.