Mate Choice

by

Michael D. Jennions, Hanna Kokko

• LAST REVIEWED: 13 January 2014
• LAST MODIFIED: 13 January 2014
• DOI: 10.1093/obo/9780199941728-0020

Introduction

Sexual selection favors characters that increase access to a limited supply of opposite-sex gametes. Some sexually selected traits are advantageous because when a male and female encounter each other they increase the likelihood of being deemed an acceptable mate. In addition, some male traits subsequently affect the way a female uses sperm. Both types of traits evolve due to mate choice arising from mating preferences. However, not all sexually selected traits require mate choice. Weaponry can confer an advantage in direct contests for mates in the absence of choosiness (although there are sometimes mating preferences for individuals with impressive weapons), as can investment into ejaculates when sperm from different males compete to fertilize eggs. Sexual selection can also favor locomotory or olfactory abilities that increase the mate encounter rate. Selection for traits that are preferred by the opposite sex (i.e., that help overcome choosiness) readily explains why seductive/attractive traits evolve. The more challenging task is to identify the benefits of choosiness. This is the focus of most theoretical studies of mate choice. If there was no cost to being choosy then mating preferences could arise as pleiotropic by-products of selection on other traits. Often, however, choice is costly. Choosiness can decrease an individual’s rate of reproduction by lowering the rate at which acceptable mates are found or by selecting for costly mate sampling behavior to ensure one is found. A lower mating rate might appear inevitable, given that choosiness implies some otherwise acceptable potential mates are rejected. Sometimes, however, mate choice is more nuanced with no outright rejection of potential mates. Instead, individuals adjust their reproductive expenditure. For example, a male (or a female) might change its investment in courtship depending on the type of female (or male) encountered, which affects the subsequent likelihood of a mating. A female, male, or even hermaphrodite might similarly adjust how many gametes are made available to a potential mate.

General Overviews

There are thousands of papers and innumerable reviews about mate choice. A sensible starting point is a handful of books that cover mate choice and allied topics. Cronin 1992 covers the long history of the field since Darwin first coined the term “sexual selection.” Valuable overviews of modern approaches to sexual selection are provided in Bradbury and Andersson 1987, Andersson 1994, and Westneat and Fox 2010, while Eberhard 1996 and Arnqvist and Rowe 2005 review more specialized topics.

• Andersson, M. B. 1994. Sexual selection. Princeton, NJ: Princeton Univ. Press.

  Remains the most comprehensive overview of all aspects of sexual selection. Theory has, reassuringly, moved forward but this book remains the best source to get up to speed on the key ideas.

• Arnqvist, G., and L. Rowe. 2005. Sexual conflict. Princeton, NJ: Princeton Univ. Press.

  The definitive argument for the claim that a difference between males and females in the extent to which they are willing to mate when they encounter each other has selected for coercive male traits and female mating resistance. The book contains lot of fun natural history facts too.

• Bradbury, J. W., and M. B. Andersson, eds. 1987. Sexual selection: Testing the alternatives: Report of the Dahlem Workshop on Sexual Selection, Berlin 1986, August 31–September 5. Life Sciences Research Report 39. New York: Wiley.

  A useful introduction to the early development of modern sexual selection theory. It anticipates many of the key debates that continue to rage up to the present.

• Cronin, H. 1992. The ant and the peacock: Altruism and sexual selection from Darwin to Today. Cambridge, UK: Cambridge Univ. Press.

  Coverage of the origins of sexual selection theory, including early debate between Darwin and Wallace about whether females have aesthetic preferences for certain male types, and the growth of interest in mate choice in the 20th century.

• Eberhard, W. G. 1996. Female control: Sexual selection by cryptic female choice. Princeton, NJ: Princeton Univ. Press.

  Extensive coverage of the many ways in which females might exert choice after mating. These include non-random use of sperm when females mate multiply and differential early investment into offspring sired by different males.

• Westneat, D. F., and C. W. Fox, eds. 2010. Evolutionary behavioral ecology. Oxford: Oxford Univ. Press.

  Section V (pp. 343–467) of this book comprises seven multi-authored chapters on recent developments in sexual selection theory, including the relationship between mate choice and parental care and the evolution of alternative male mating strategies that act to circumvent female choice.