The solemn, steadfast moai dot the landscape, seemingly guarding the secrets of Easter Island. The enormous, unique stone carvings of human-like head-and-torso known as moai number 900 and are attributed to the handiwork of the Rapa Nui, the ancient inhabitants of the isolated Pacific island from about 1200 to the early 1600s.

To date, scientists have generally believed that the Rapa Nui were completely isolated, considering that their island is surrounded by the Pacific ocean at its location some 2,300 miles west of South America and roughly 1,100 miles from the closest neighboring land mass.

A study published on Thursday in the journal Current Biology offers evidence that, in fact, the Rapa Nui made contact with Native populations on the South American continent hundreds of years before Westerners arrived on Easter Island in 1722, over a century after the culture began to falter.

Genetic sequence analyses on 27 Ester Island natives suggests that interbreeding between the Rapa Nui and native South Americans took place between 1300 and 1500.

“We found evidence of gene flow between this population and Native American populations, suggesting an ancient ocean migration route between Polynesia and the Americas,” said geneticist Anna-Sapfo Malaspinas of the Center for GeoGenetics at the University of Copenhagen, who led the study.

It is not clear whether the Rapa Nui reached South America or that the South Americans arrived on Easter Island. However, the researchers reason that odds favor the idea that the Rapa Nui made the round-trip ocean trek to South America and took some natives back with them on the return trip. The distance they traveled, presumably by wooden outrigger watercraft, is staggering.

A second study which was also published on Thursday in Current Biology documents a separate visit to South America by the Rapa Nui. Two ancient skulls belonging to Brazil’s Botocudo people were found to be Polynesian, not Botocudo, in their genetic makeup. No detectable Native American ancestry was found.

“How the two Polynesian individuals belonging to the Botocudos came into Brazil is the million-dollar question,” said University of Copenhagen geneticist Eske Willerslev of the Center for GeoGenetics, who led the second study. “[I]t is an amazing story.”