Polynesian navigation snow. In the mid-20th century, Thor Heyerdahl proposed a new theory of Polynesian origins (one which did not win general acceptance), arguing that the Polynesians had migrated from South America on balsa-log boats. The presence in the Cook Islands of sweet potato that is a plant native to the Americas (called "kūmara" in Māori), which have been radiocarbon-dated to 1000 CE, has been cited as evidence that Americans could have traveled to Oceania. The current thinking is that sweet potato was brought to central Polynesia circa 700 CE and spread across Polynesia from there, possibly by Polynesians who had traveled
Hanau epe explain the alleged ethnic difference between the two groups. Thor Heyerdahl popularised the view that they were a South American indigenous people, who were pale skinned with red hair. Heyerdahl's Kon-Tiki expedition was designed to show that migrants from Peru could have reached Polynesia. He believed that the Hanau epe were the earliest inhabitants of the island; they created its unique monuments, which resemble similar sculptures found in the Americas, but were eventually killed off by either the Polynesians or a later wave of migrants from the Northwest coast of America. Wilhelm and Sandoval in 1966 took the view that