Monogamy in the genes?
Scientists believe they now know why some animals stay with their mates and others don’t: It’s all in the genes. A research team at the University of Texas at Austin identified five monogamous species, then compared them with more promiscuous close relatives: California mice vs. deer mice, mimic poison frogs vs. strawberry poison frogs, and so on. (Monogamy was defined as staying with the mate and jointly raising offspring for at least one mating season.) After analyzing the animals’ brain tissue, the researchers discovered that males that stayed loyal to their mates bore a common genetic formula: specifically, 24 genes whose activity is consistently ramped up or dialed down. It’s not yet known whether human genes behave in a similar way, and thus whether there could one day be a genetic test for human monogamy. “There are differences among individuals and a test may have to be very individualized to be effective,” lead author Rebecca Young tells The Guardian (U.K.). “Is it impossible? I’d never say that.” ■