Fun Fact: About ripe fruits

July 21, 2022

Fun Fact: You owe the dexterity of your hands to the fact that some figs don’t change colour when they ripen.

Maybe…at least a bit. Twenty percent of figs show no color change during ripening, which poses a sensory challenge if you’re a hominid trying to find nutritious food to eat. Imagine how much longer it would take to choose an avocado at the grocery store if you couldn’t squeeze it. You would have to bite each one to know if it was edible. Store managers wouldn’t like that.

Hominids, like chimpanzees, gorillas, and humans, have uniquely dextrous hands compared to the rest of the animal kingdom. In a study lead by Dartmouth College evolutionary biologist Nathaniel Dominy, researchers found that chimpanzees’ ability to feel the ripeness of a fig conferred an advantage over rival species when selecting fruit. Monkeys (black-and-white colobus monkeys, red colobus monkeys, and red-tailed monkeys) that compete for the same food relied on colour and bite-testing. Squeezing figs supplied nearly 75 % more information about fig ripeness than colour did and it was also four times faster than plucking it, biting it, and spitting it out if it wasn’t ripe. This lead to more efficient foraging and ultimately more calories consumed by the chimps.

While the researchers couldn’t definitively say that the ability to feel if a fruit is ripe was a selective force in the evolution of more sophisticated hands, the idea is very a-peeling.

If you’re interested in further reading, you can find their paper here: https://royalsocietypublishing.org/doi/10.1098/rsfs.2016.0001