In 1947 the Norwegian explorer Thor Heyerdahl set sail from Peru on a balsa wood raft called Kon-Tiki.

As he explained a few years later in the documentary of the same name, Heyerdahl was convinced that Indigenous people from South America had used a similar craft to settle Polynesia.

One hundred one days and 4,300 nautical miles later,his raft reached French Polynesia.

The expedition didn't really prove anything other than that the feat was possible.

And most scholars agreed then and now that the Pacific islands were gradually settled from the other direction,by people traveling from East Asia.

But a new study suggests that almost 900 years ago, Polynesians and Native South Americans did make contact—and traces of that encounter live on in the genes of Polynesians today.

"Whether the people were physically standing on an island in Polynesia when they began mingling—or whether they were on the coast of South America—we can't say."Alex Ioannidis,a computational scientist and geneticist at Stanford University.

His team compared the DNA of 800 individuals from 17 Pacific islands and 15 Pacific Coast Native American groups.

And they discovered,within the genomes of modern-day Polynesians, snippets of DNA typically found in Native Americans.

"What we found is: it's actually a very similar sequence of DNA that they all share.