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.

Female Guppies Agree to Differ: Phenotypic and Genetic Variation in Mate-Choice Behavior and the Consequences for Sexual Selection

“…An important difference between our study and experiments on correlated response to selection may account for that fact that our heritability estimates for most components of choice were negligible, whereas preferences have been shown to evolve in two correlated-response studies of guppies (Houde 1994;Brooks and Couldridge 1999). Our half-sibling design entailed the measurement of mate-choice components for individual females, and these measures are subject to large error (remember that repeatability is low and in many cases not significant).…”

“…The other source of indirect evidence for genetic variation in mate-choice is selection experiments in which the male trait of interest is artificially selected and the correlated response in preference is measured (Houde 1994;Wilkinson and Reillo 1994;Brooks and Couldridge 1999). Preference is expected to evolve as an indirect response to selection on ornamentation due to a genetic correlation between ornament and preference, although it may also evolve because of sexual selection or fecundity selection within lines (Gray and Cade 1999b).…”

The language of lizards: interpreting the function of visual displays of the Indian rock lizard, Psammophilus dorsalis (Agamidae)

“…Understanding the functional role of specific displays poses formidable logistical problems, however, because of the complexity of signalling. For example, a single signal might serve multiple functions, and/or a single function might be accomplished by means of multiple signals (Møller and Pomiankowski 1993;Johnstone 1995Johnstone , 1996Johnstone , 1997Brooks and Couldridge 1999). Also, the way in which a signal is expressed may vary with factors such as the age, size, signalling environment, dominance, or physiological status of the sender or the receiver (Clutton-Brock et al 1982;Tokarz 1985;Snowdown 1990;Davies 1992;Sinervo and Lively 1996;Prum 1998;Leal 1999;Castellano et al 2000;Podos 2001;Baird et al 2003;Whiting et al 2003).…”

The role of sexual preferences in intrasexual female competition

“…Empiricists have found cases of repeatable variability in genetically determined female preferences [18,19]. In such scenarios, females appear to be selecting mates based on multiple independent male traits.…”