Female preference thus coevolved with the selected male trait. In other words, platyfish females harbored a preexisting bias for long swords, even though swords reveal nothing about the fitness of platyfish males. But the preference could have originated because females are more attuned to colors of a particular wavelength and then further evolved through a runaway mechanism. All these models assume that female preference is genetically determined. Recent studies indicate, however, that social factors, such as imitation, also influence mate choice.
Some guys get all the girls.
On a crowded grouse lek, for example, the top male may receive 80 percent of the mating opportunities. Using stuffed dummies to represent interested females, the researchers showed that female grouse mated preferentially with the male that appeared to have other females in his territory. Perhaps imitation teaches females what to look for in a male. In an extensive series of experiments on mate-choice copying in guppies, we determined that young females are more likely to copy the mate choice of older, more experienced females than vice versa. Further, copying may save time.