Just in time for summer, a group of researchers published a preprint earlier this week showing that ancient Egyptians had domesticated sweet, red-fleshed watermelon by at least 3,560 years ago. 

The team compared genomic data extracted from a leaf found in a mummy's sarcophagus to the DNA of all of the extant members of the genus Citrullus to get a more detailed picture about the watermelon's wild origin, which is surprisingly contentious. They also wondered whether the fruit was red-fleshed and sweet (which wild relatives of the watermelon are not).

They found that the DNA from the watermelon leaf from the sarcophagus had unique mutations in common with modern cultivars that are sweet and red-fleshed, and that the closest wild relative of these tasty varieties is a white-fleshed, non-bitter melon from southern Sudan. 

And these findings fit with the archaeological record. There are even wall paintings depicting ancient Egyptians eating fruits that look very much like modern watermelons!