it's certainly possible that the polynesians had the sweet potato since they went to south america, but many plants have spread over long ocean distances by e.g. birds, or just floating, so it could be that as well. The linguistic evidence could just be chance; without some rigorous statistical argument it's hard to give it much credit. anyways my point was just don't convey conviction or certitude when there is and should be none. and sorry for being snippy about it. there is just a ton of misinformation in this thread, but you aren't one of the main offenders.