Multiple Sexual Ornaments Coevolve with Multiple Mating Preferences

Abstract

In species where males have several ornaments for mate attraction, each ornament may coevolve with a different female preference. Alternatively, multiple ornaments may be sexually selected for because they stimulate the same, single, female preference. In the latter case, measures of preferences for different ornaments are essentially measures of the same phenotypic character and, thus, will be strongly pleiotropic, whereas no such expectation exists for multiple preferences. We selected directly up and down on two visual ornaments, orange and black coloration, in male guppies (Poecilia reticulata) in order to impose indirect selection on the female preference or preferences for these ornaments. Preferences for the two colors responded in a pattern similar to the response of the ornaments themselves. That female preferences for orange and for black in this guppy population are able to respond to selection more or less independently, suggests that they are probably two different characters in an evolutionary sense. Each of these preferences appears to be genetically correlated with the respective ornament.