But a controversial new study questions that assumption, using the most extensive genetic analysis yet to suggest that the sweet potato was widespread on Earth long before humans came into the picture.
Researchers at the University of Oxford say their findings show that sweet potatoes (Ipomoea batatas) originated in South America some 800,000 years ago, and that the plant likely made its way to the Pacific island simply by seeds traveling on the wind.
"We show there is no need to invoke human-mediated transport," co-author Tom Carruthers, a PhD student at the University of Oxford, told AFP.
"Sweet potato evolved before humans so the origin of sweet potato hasn't got anything to do with humans."
However, some experts questioned the findings, saying they ignore an ample amount of archeological and linguistic evidence that suggests early Polynesian marine navigators traveled to South America and brought the sweet potato back with them as early as 1000-1100 AD.