Sexual selection

Abstract

Competition over mates takes many forms and has far-reaching consequences for many organisms. Recent work suggests that relative reproductive rates of males and females, sperm competition and quality variation among mates affect the strength of sexual selection. Song, other display, body size, visual ornaments and material resource offerings are often sexually selected. There is much empirical evidence of mate choice, and its evolution is clarified by mathematical models. Recent advances in theory also consider costs of choice, effects of deleterious mutations, fast and slow evolution of preferences and preferred traits, and simultaneous preferences for several traits. Contests over mates are important; so is sperm competition, scrambles, endurance rivalry, and coercion. The latter mechanisms have received less attention than mate choice. Sexual selection may explain puzzling aspects of plant pollination biology.

A longitudinal analysis of women’s salivary testosterone and intrasexual competitiveness

“…Intrasexual competition refers to competition between individuals of the same sex for access to mating opportunities (Andersson, 1994). Most work on intrasexual competition in humans has focused on direct (i.e., physically aggressive) competition among men (Stockley & Campbell, 2013).…”

Sampling and assessment accuracy in mate choice: A random-walk model of information processing in mating decision

“…Mate choice is one of the main mechanisms of sexual selection and one of the main causes for the evolution of the most conspicuous and extravagant phenotypic traits observed in nature (Andersson 1994). For this reason, for over three decades, mate choice has been the object of intense theoretical and empirical investigations, but, nevertheless the effort, mate choice still remains one of the most controversial topics in evolutionary biology (Ryan et al 2007).…”

“…The descriptive approach focuses on mating preferences, that is, on the relationship between the cues that individuals of the choosing sex (active mates, thereafter females) attend to in individuals of the other sex (passive mates, thereafter males) and the underlying qualities signalled by these cues (Andersson 1994). Mating preferences are often expressed in terms of preference functions, neural algorithms that allow females to map prospective mates on a onedimensional scale of absolute (context-independent) values, according to which mating decisions are taken (Castellano and Cermelli 2006;Kirkpatrick et a.…”

“…2006). The preference functions are viewed as phenotypic traits that empiricists have tried to measure and describe under experimentally controlled conditions and that theoreticians have implicitly assumed in order to 5 investigate the co-evolutionary dynamics of mating communication systems (Andersson 1994;Arnquvist and Rowe 2005).…”

Male wing color properties predict the size of nuptial gifts given during mating in the Pipevine Swallowtail butterfly (Battus philenor)

“…Many of these ornaments are an evolutionary product of sexual selection in the context of 35 either female mate choice or male-male competition for mates (Andersson 1994). When females 36 display a preference for ornamented males, the honest-signaling or indicator hypothesis suggests 37 that there are two broad classes of benefits for females that may drive the evolution of the 38 preference (Andersson 1994). If the development of the ornament is correlated with male genetic 39 quality, females may gain indirect benefits in the form of high quality genes for their offspring.…”