Africa
Long before watermelon became a refreshing summer treat, reliefs adorning the walls of ancient Egyptian tombs suggest the fruit was a coveted delicacy. However, exactly when the species of watermelon commonly consumed today, Citrullus lanatus, became the beloved emerald-skinned fruit with white stripes and a sweet red interior is unclear. In fact, its 6,000-year-old predecessor’s pulp wasn’t very tasty and was potentially hazardous. “It actually could have killed you,” says botanist Oscar Alejandro Pérez Escobar of the Royal Botanic Gardens, Kew.
To plot the fruit’s evolutionary trajectory, Pérez Escobar’s team sequenced genomes from watermelon seeds dating to between 6,000 and 3,400 years ago excavated from graves in Libya and Sudan. They traced watermelon’s origins to a species closely related to the modern West African Citrullus mucosospermus, which has bitter, greenish-white…