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
Marquesan Dog and is visible today at the site of Iʻipona. Only one of the dog carving is discernible now; the other one has weathered away. In 1956, Norwegian adventurer and ethnographer Thor Heyerdahl later claimed the reliefs on Tiki Makiʻi Tauʻa Pepe were llamas or pumas instead to bolster his theory that Polynesia was settled from South America. Later unidentified writers and rumors have insinuated that Heyerdahl deliberately altered and defaced the images in his process of restoring them. The modern consensus is that the carvings represent the extinct dog; they do not represent llamas, pumas or rats. In 1956, Robert