HENRY

One of the great mysteries of the Pacific is how Kumara (sweet potato) got there. We know it came from South America, but the people (the Austronesians) who settled that part of the world came from Taiwan.

Did they sail over there in waka over 8,000km of open sea and pick them up? (and leave behind other handy food crops like maize and legumes) or did kumara manage to drift across the sea? Could the seeds have been carried in sea bird bellies?

Currently the first scenario (directed voyaging) is mostly accepted – these people were excellent sailors after all, but a new simulation study possibly lends support to the kumara drifting across the sea. As reported in Nature by Brendan Borrell:

In the simulation, sweet-potato seed pods that started off in these American waters could reasonably hit seven different island groups, and had the best chance of landing on the Marquesas. “Among the three most likely targets that get hit, two are within the area where people believe the crop was introduced,” says Montenegro. But the trip took at least four months. Even coconuts can’t survive in salt water that long.

More likely, says the team, a loaded vessel was blown out to sea and landed on the islands — which could take as little as 90 days, they report in an upcoming issue of the Journal of Archaeological Science. Montenegro notes that seed pods are transported by currents alone, but a drifting vessel gains momentum from the wind.

The paper is yet to be released, but a preprint is available at Álvaro Montenegro’s webpage (PDF)

update: I do apologise about the title of this post. It was late at night, and it seemed funnier then.

Posted on May 20th, 2007 by Simon Greenhill