Researchers Reverse Evolution in Water Striders
The males of many species impress potential mates with brilliant plumage, massive antlers, or expensive cars. Water striders, however, don’t go in for courtship. For these smoothly gliding pond insects, mating is a wrestling match in which the male grips the female’s head and pins her down while she struggles to throw him off. Now researchers have done a bit of reverse evolution to figure out how males developed this ability in the first place.
Animals that nurture their young together choose mates that will be the best protectors or nest-builders. But as evolutionary biologist Locke Rowe of the University of Toronto in Canada explains, “In some species, males and females have competing interests.” Among water striders, for example, neither parent tends the offspring. The female’s only job is to produce eggs; the males are mere sperm donors.