Frequency-Dependent Selection

by

John A. Allen

• LAST REVIEWED: 24 November 2021
• LAST MODIFIED: 28 June 2016
• DOI: 10.1093/obo/9780199941728-0080

Introduction

Selection is frequency dependent when the fitness of a phenotype, genotype, or gene (or species) varies with its relative abundance in the population (or community) and hence can be detected only when measured at two or more frequencies. In “negative frequency-dependent selection,” fitness decreases with frequency and thus rare genotypes or, in some cases, species, could be maintained at a stable equilibrium. As a form of balancing selection, this mechanism could be one explanation for the persistence of higher than expected levels of genetic variation in natural populations, whether measured at the level of molecules, morphology or behavior. In “positive frequency-dependent selection,” fitness increases with frequency so that rare genotypes are eliminated and local genetic diversity reduced. The importance of frequency-dependent selection in the evolution of natural populations has yet to be fully substantiated, in part perhaps because of the practical difficulties in detecting it and distinguishing it from other types of selection, whether balancing or non-balancing.

General Overviews

Most evolution textbooks devote some pages to frequency-dependent selection, and Bell 2008 is particularly useful as an introduction to its role within species as well as communities. Ayala and Campbell 1974 and Clarke 1979 provide perceptive and readable reviews, updated by Clarke 2002 and Sinervo and Calsbeek 2006. Two collections of multi-authored contributions worth consulting are Clarke and Partridge 1988 and Special issue: Biological Journal of the Linnean Society 1984.

• Ayala, Francisco J., and Cathryn A. Campbell. 1974. Frequency-dependent selection. Annual Review of Ecology and Systematics 5:115–138.

  DOI: 10.1146/annurev.es.05.110174.000555

  A clearly written introduction to the subject, this comprehensive and still pertinent early review covers the theory and experimental evidence in many of the areas in which it is studied today.

• Bell, Graham. 2008. Selection: The mechanism of evolution. 2d ed. Oxford: Oxford Univ. Press.

  A tour de force covering selection in general and useful in particular for highlighting the practical difficulties in discriminating between heterozygote advantage and frequency-dependent selection as causes of observed changes in genotype frequency.

• Clarke, Bryan. 1979. Evolution of genetic diversity. Proceedings of the Royal Society B: Biological Science 205:435–479.

  DOI: 10.1098/rspb.1979.0079

  Written at the height of the “neutralist-selectionist” controversy when molecular techniques were in their infancy. The author takes an unashamed stance on frequency-dependent selection being the evolutionary cause of much of the unexpected amounts of genetic variation then being discovered in natural populations.

• Clarke, Bryan. 2002. Frequency-dependent selection. In Encyclopedia of evolution. Edited by Mark Pagel. Oxford: Oxford Univ. Press.

  A succinct summary covering the main contexts in which frequency-dependent selection operates.

• Clarke, Bryan C., and Linda Partridge, eds. 1988. Frequency-dependent selection. Philosophical Transactions of the Royal Society of London B: Biological Science 319:457–640.

  A wide-ranging collection of twelve papers presented at a Royal Society Discussion Meeting held in London, UK, 24–25 June 1987, to review the then-available evidence for frequency-dependent selection and its evolutionary implications across the biological sciences from molecular biology to ecology.

• Sinervo, Barry, and Ryan Calsbeek. 2006. The developmental, physiological, neural, and genetical causes and consequences of frequency-dependent selection in the wild. Annual Review of Ecology Evolution and Systematics 37:581–610.

  DOI: 10.1146/annurev.ecolsys.37.091305.110128

  An impressive classification of the different types of frequency-dependent selection and a major synthesis of its causes and outcomes. Emphasizes the interplay between negative and positive frequency-dependent selection, both within and among species.

• Special issue: Biological Journal of the Linnean Society. 1984. 23:102–268.

  Thirteen papers arising from the seventeenth meeting of the Population Genetics Group (UK), held in Southampton, UK, 3–6 January 1984, seven of which focus on frequency-dependent selective predation. Available online.