Genetic evidence suggests the tubers were in the South Pacific more than 100,000 years ago
Sweet potatoes were domesticated thousands of years ago in the Americas. So 18th century European explorers were surprised to find Polynesians had been growing the crop for centuries. Anthropologists have since hypothesized that Polynesian seafarers had brought the tuber back from expeditions to South America — a journey of over 7,500 kilometers.
New genetic evidence instead suggests that wild precursors to sweet potatoes reached Polynesia at least 100,000 years ago — long before humans inhabited the South Pacific islands, researchers report April 12 in Current Biology. If true, it could also challenge the idea that Polynesian seafarers reached the Americas around the 12th century.
For the new study, the researchers analyzed the DNA of 199 specimens taken from sweet potatoes (Ipomoea batatas) and 38 species of its wild relatives. The goal, says plant