By Jessica Crabtree
There is a growing body of evidence that Polynesian sailors reached the Americas long before the 15th century, setting up an exchange that left clues on both sides of the Pacific. The Polynesians are an optimal candidate in the search for pre-Columbian contact, because they had both the technology and the motive to reach the Americas.
The prime evidence:
Chickens: Ancient remains of chickens found on the coast of Chile predate the arrival of domesticated breeds introduced by European colonists. There were no chickens indigenous to the Americas; they are native to Southeast Asia where they were first domesticated and later brought as far east as the Pacific islands. Obviously their presence in Chile could not be explained as a simple case of migratory spread. The carbon dating of the chicken bones gave them a tentative age of 600 years, right around the peak of the Polynesian's Pacific expansion.
Sweet potatoes: As part of the Columbian Exchange, many of the New World's important native food crops—including maize, potatoes and cacao—were transported to Europe, Asia and Africa where they became fundamental commodities. One of these crops, the sweet potato, has been cultivated for more than 5,000 years by peoples in Central and South America, where it first originated. Apart from direct human introduction, it is difficult to account for sweet potato cultivation by the Polynesians dating back more than a millennia. (Sweet potatoes propagate through tubers or plant cuttings, not by seeds that can be windblown or spread by birds.) It is even more difficult to explain how they came to be called by almost identical names in both regions.
There are even deeper connections on the horizon. Many researchers point to linguistic similarities and parallels in artifacts found in the Polynesia Pacific (including Easter Island) and in America's Pacific coast cultures. Such suggestions of an information and technology exchange may be circumstantial at best. But there is considerable support rising from other fronts, not the least of which is recent DNA research confirming the exchange of much more than just trade goods.