The Elements of Evolution (46-11) Rejection


Across the animal kingdom, sex is often an emotionally rewarding experience. Rejection is hard to take.

Vinegar flies have an elaborate courtship ritual. A male may vibrate a love song on one wing, tap his intended’s abdomen with his foreleg, and touch her genitalia with his proboscis (a smell/taste sense organ).

If she is put in the mood, his attempts at copulation are not rejected. Afterward, the 2 flies part: she goes her way to lay eggs, he to court again.

If instead a female rejects a male’s advances, a male may grow despondent and drown his sorrows in the sauce (fermented fruit).

Rejection or deprivation of sex leaves male flies in a state that increases the preferential consumption of ethanol. ~ American biologist Troy Zars