Fruit

Wild peaches were only 25mm long with a flesh-to-pit ratio of just 3:2—essentially an almond with a thin layer of flesh. Peaches and almonds are very closely related species, and if you look closely at a peach pit, you can see it resembles an almond.

Most red grapefruit today descend from mutations born of gamma ray exposure. In a 1950s "Atoms for Peace" experiment, radioactive material was placed in a garden with plants around it. Those at the right distance mutated from pink into today's red, sweeter variety.