A conceptual review of mate choice: stochastic demography, within‐sex phenotypic plasticity, and individual flexibility

• Published in: Ecology and evolution Vol. 6; no. 14; pp. 4607 - 4642
• Main Authors: Ah‐King, Malin, Gowaty, Patricia Adair
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.07.2016; John Wiley and Sons Inc
• Subjects: Adaptive flexibility; Animal behavior; choosy; Decision making; Demography; Ecological effects; Fitness; Flexibility; genetic complementarity; Health risks; indiscriminate; mate choice; Mate selection; OSR; parasite load; Phenotypic plasticity; Plastic properties; Plasticity; Predation; Review; Sex; Sex ratio; Sexual behavior; switch point theorem; Variation; genetic complementarity; switch point theorem; choosy; parasite load; indiscriminate; mate choice; Adaptive flexibility; OSR
• ISSN: 2045-7758; 2045-7758
• DOI: 10.1002/ece3.2197

Mate choice hypotheses usually focus on trait variation of chosen individuals. Recently, mate choice studies have increasingly attended to the environmental circumstances affecting variation in choosers' behavior and choosers' traits. We reviewed the literature on phenotypic plasticity in mate choice with the goal of exploring whether phenotypic plasticity can be interpreted as individual flexibility in the context of the switch point theorem, SPT (Gowaty and Hubbell ). We found >3000 studies; 198 were empirical studies of within‐sex phenotypic plasticity, and sixteen showed no evidence of mate choice plasticity. Most studies reported changes from choosy to indiscriminate behavior of subjects. Investigators attributed changes to one or more causes including operational sex ratio, adult sex ratio, potential reproductive rate, predation risk, disease risk, chooser's mating experience, chooser's age, chooser's condition, or chooser's resources. The studies together indicate that “choosiness” of potential mates is environmentally and socially labile, that is, induced – not fixed – in “the choosy sex” with results consistent with choosers' intrinsic characteristics or their ecological circumstances mattering more to mate choice than the traits of potential mates. We show that plasticity‐associated variables factor into the simpler SPT variables. We propose that it is time to complete the move from questions about within‐sex plasticity in the choosy sex to between‐ and within‐individual flexibility in reproductive decision‐making of both sexes simultaneously. Currently, unanswered empirical questions are about the force of alternative constraints and opportunities as inducers of individual flexibility in reproductive decision‐making, and the ecological, social, and developmental sources of similarities and differences between individuals. To make progress, we need studies (1) of simultaneous and symmetric attention to individual mate preferences and subsequent behavior in both sexes, (2) controlled for within‐individual variation in choice behavior as demography changes, and which (3) report effects on fitness from movement of individual's switch points. Chooser's traits and their social and ecological situations often are better predictors of chooser behavior than traits in the chosen. We argue that the first principle, fundamental demographic parameters of the switch point theorem, which predicts individual flexibility in mate choice, is theory that simplifies and unifies the dozens of variables correlated to phenotypic plasticity in the behavior of choosers. To make progress, we need studies (1) of simultaneous and symmetric attention to individuals of both sexes; (2) controlled for within‐individual – not just between‐individual – variation in choice behavior as demography changes; and (3) of the effects on relative reproductive success from switches between choosy and indiscriminate behavior.