Thousands of miles apart, with shared DNA—they definitely met somewhere. That's the conclusion of a new study into Indigenous Americans and Polynesians who apparently bridged the oceanic gap between them and procreated some 800 years ago, the Guardian reports. "These findings change our understanding of one of the most unknown chapters in the history of our species’ great continental expansions," says senior author Andreas Moreno-Estrada. The researchers say they analyzed DNA from over 800 Indigenous individuals in Polynesia as well as Central and South America, and found a match dating to the year 1200—when one people must have braved the Pacific Ocean and encountered the other. The question is which one did the braving.
"I favour the Polynesian theory, since we know that the Polynesians were intentionally exploring the ocean and discovering some of the most distant Pacific islands around exactly the time of contact," lead author Alexander Ioannidis tells the CBC. The study appears to settle a long-standing question about possible contact between the peoples, based partly on their shared love of the sweet potato. The Norwegian explorer Thor Heyerdahl generated public interest in the question by taking a raft from Peru to French Polynesia back in 1947. A 2014 study found a genetic link between Polynesians and South Americans prior to 1500, but the new study calls earlier research "limited" compared to the latest "genome-wide" analysis, which provides "conclusive evidence." (Read more scientific study stories.)