This week at Nothing in Biology Makes Sense!, Sarah Hird tackles a series of studies suggesting that fruit flies may pick mates reared on similar diets because their gut microbes make them do it.
In 1989, Diane Dodd reared fruit flies (Drosophila pseudoobscura) from a common stock on two different food sources: starch and maltose. She found that after multiple generations of isolation on their separate substrates, starch-flies preferred to mate with starch-flies and maltose-flies preferred to mate with maltose-flies. The result was robust and repeatable, but the reason why and its mechanism were unknown.
To find out how the mechanism was discovered, go read the whole thing. ◼