The origin of potatoes has puzzled scientists for years, but researchers now say they've found an unlikely ancestor: tomatoes.

The evolutionary event led to the formation of the tuber, which is the swollen and edible underground root of certain plants, such as potatoes and yams. To reach these conclusions, Chinese researchers analyzed 450 genomes -- the complete set of an organism’s DNA -- from human-grown potatoes and 56 of the wild potato species.