Just in time for picnic-table trivia, a new study published in the Proceedings of the National Academy of Sciences rewrites the origins of domesticated watermelons. Using DNA from greenhouse-grown plants representing all species and hundreds of varieties of watermelon, scientists discovered that watermelons most likely came from wild crop progenitors in northeast Africa. The study corrects a 90-year-old mistake that lumped watermelons into the same category as the South African citron melon. Instead, researchers, including a first author now at Washington University in St. Louis, found that a Sudanese form with non-bitter whitish pulp, known as the Kordofan melon (C....