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
Torgeir Sæverud Higraff Easter Island after 43 days at sea, becoming the first rafts to have sailed to Easter Island in modern times. The return journey proved more difficult due to unusual weather patterns and the expedition was terminated halfway between Easter Island and South America. Torgeir Sæverud Higraff Torgeir Sæverud Higraff is an explorer, teacher and author with special interest in prehistoric transoceanic contact. Like Thor Heyerdahl, Higraff combines history, anthropology and traditional knowledge with expeditions. In 2002, the year Heyerdahl died, Higraff decided to recreate the Kon-Tiki expedition, and in 2006 the Tangaroa Expedition sailed from Peru to Raiatea in eastern