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
Thor Heyerdahl their speech. Heyerdahl claimed that in Incan legend there was a sun-god named Con-Tici Viracocha who was the supreme head of the mythical fair-skinned people in Peru. The original name for Viracocha was "Kon-Tiki" or "Illa-Tiki", which means "Sun-Tiki" or "Fire-Tiki". Kon-Tiki was high priest and sun-king of these legendary "white men" who left enormous ruins on the shores of Lake Titicaca. The legend continues with the mysterious bearded white men being attacked by a chief named Cari, who came from the Coquimbo Valley. They had a battle on an island in Lake Titicaca, and the fair race was massacred.