Ecological Genetics

by

Joanna Freeland

• LAST REVIEWED: 26 July 2022
• LAST MODIFIED: 26 July 2022
• DOI: 10.1093/obo/9780199941728-0091

Introduction

Ecology is the study of the relationships between organisms and their environments, whereas ecological genetics focuses more specifically on the genetics of ecologically important traits, i.e., traits that influence ecological relationships. At its inception, ecological genetics focused particularly on traits that influence fitness, such as those that affect survival and reproduction. This focus has been maintained, although ecological genetics now also investigates the ecological and evolutionary processes that influence patterns of genetic variation in natural populations. Therefore, it can also be considered a study of genetic processes associated with microevolutionary change. Although both Charles Darwin and Alfred Russel Wallace brought together ecological and genetic concepts in the nineteenth century, the term “ecological genetics” was first used by E. B. Ford in his groundbreaking book Ecological Genetics (Ford 1964, cited under General Overviews: Textbooks). The field has evolved considerably since that time and now overlaps substantially with molecular ecology, a closely related field that uses molecular genetic tools to study questions in ecology. The only real difference between molecular ecology and ecological genetics is that the latter is not limited to studies based on molecular genetics. Instead, the term “ecological genetics” can refer to any study of the genetics of natural populations, whether they are based on molecular genetics, population genetics, or quantitative genetics. However, molecular genetic techniques are increasingly accessible and increasingly informative, and they often provide a relatively fast and cost-effective way to get data. As a result, the majority of ecological genetic studies now incorporate a combination of field and molecular genetic data, and the functional line between ecological genetics and molecular ecology is increasingly blurred.

General Overviews: Textbooks

The field of ecological genetics was formally developed by E. B. Ford, whose book Ecological Genetics was first published in 1964 (Ford 1964). In a review of this book, the eminent evolutionary biologist Theodosius Dobzhansky identified it as a very important contribution to the biological theory of evolution (also known as the synthetic theory of evolution or the evolutionary synthesis), based largely on the work of a group of researchers at Oxford sometimes referred to as the “Oxford School” (Dobzhansky 1964). Ford describes the fruits of “a method which has in fact proved effective: one which combines field-work and laboratory genetics” (Ford 1964, p. 1). This was an extremely important book at the time, with Ford’s novel identification of ecological genetics as the field of study that “deals with the adjustments and adaptations of wild populations to their environments” (Ford 1964, p. 3). Ford further claimed: “it supplies the means, and the only direct means, of investigating the actual process of evolution taking place at the present time” (Ford 1964, p. 3). In 1994, several renowned biologists contributed to an updated version of Ecological Genetics (Real 1994), although copies of this book are now relatively scarce. More recent overviews include the 3rd editions of Introduction to Molecular Ecology (Rowe, et al. 2017) and Molecular Ecology (Freeland 2020). Templeton 2021 and Hamilton 2021 each provide up-to-date overviews with very strong groundings in population genetics theory, whereas Hohenlohe and Rajora 2021 and Allendorf, et al. 2022 each investigate topics in molecular ecology with particular attention to the ways in which genetics, population genetics, and genomics can be applied to problems in conservation biology and wildlife management.

• Allendorf, F. W., W. C. Funk, S. N. Aitken, M. Byrne, and G. H. Luikart. 2022. Conservation and the genomics of populations. 2d ed. Chichester, UK: Wiley-Blackwell.

  DOI: 10.1093/oso/9780198856566.001.0001

  An in-depth overview of the concepts and tools that allow researchers to apply genetic information to biological conservation. Includes a final chapter titled “Conservation Genetics in Practice” that discusses ways in which science and policy can work together in conservation genetics.

• Charmantier, A., D. Garant, and L. E. B. Kruuk. 2014. Quantitative genetics in the wild. Oxford: Oxford Univ. Press.

  DOI: 10.1093/acprof:oso/9780199674237.001.0001

  Explains ways in which the study of the genetic basis of quantitative variation in recent years has provided insight into questions of evolutionary ecology in natural populations. Topics include life history theory, behavior ecology, sexual selection, responses to climate change, and senescence in natural environments. Includes studies based on molecular genetics, laboratory studies, and long-term data sets collected in the wild.

• Dobzhansky, T. 1964. Review of Ecological Genetics. By E. B. Ford. Methuen, London; Wiley, New York, 1964. xv + 335 pp. Science 145.3629: 258–259.

  DOI: 10.1126/science.145.3629.258-a

  Review of Ford’s seminal book Ecological Genetics.

• Ford, E. B. 1964. Ecological genetics. London: Methuen.

  Includes chapter 11 on chromosome polymorphism in Drosophila (“Drosophilosophy”; p. 105), chapter 14 on industrial melanism in moths, chapter 13 on mimicry in butterflies, chapter 9 on polymorphisms in snails, chapter 10 on mating systems in primroses, and topics that include genetic drift (chapter 3), sympatric evolution (chapter 4), and isolation and adaptation (chapter 15). Ford described research by many of his Oxford colleagues who are still well respected in ecology, evolution, and genetics, including Charles S. Elton, Ronald A. Fisher, and Julian Huxley. The importance of Ford’s book is reflected in four editions that were published from 1964 to 1975.

• Freeland, J. 2020. Molecular ecology. 3d ed. Chichester, UK: Wiley-Blackwell.

  DOI: 10.1002/9780470979365

  The 3rd edition (previous editions published in 2005 and 2011) provides an updated overview of how molecular genetic information can provide insights into genetic diversity, taxonomy, gene flow, behavioral ecology, phylogeography, and conservation genetics. Recurring topics include hybridization, invasive species, landscape genomics, genome-wide data, natural selection, and environmental DNA.

• Hamilton, M. 2021. Population genetics. 2d ed. Hoboken, NJ: Wiley-Blackwell.

  A thorough and accessible overview of the key population genetics parameters that are applied to questions of ecological genetics. Includes extensive sections on genetic drift, effective population size, gene flow, mutation, adaptation, molecular evolution, and quantitative traits.

• Hohenlohe, P. A., and O. M. Rajora, eds. 2021. Population genomics: Wildlife. Cham, Switzerland: Springer.

  Provides a comprehensive overview of wildlife population genomics, with a particular focus on applications to wildlife biology, conservation and management. Includes sections on methodology (sampling, generating genomics data), adaptation of populations, genetic rescue, and taxonomy.

• Real, L. A., ed. 1994. Ecological genetics. Princeton, NJ: Princeton Univ. Press.

  Five leading experts of the time (Janis Antonovics, Michael Lynch, Montgomery Slatkin, Joseph Travis, and Sara Via) contributed overviews of topics that included gene flow, genetic differentiation, quantitative genetics, and plasticity. Many theoretical underpinnings remain valid, although the paucity of genetic data available in the late 1990s meant that the book did not receive as much attention as might be expected today.

• Rowe, G., M. Sweet, and T. Beebee. 2017. An introduction to molecular ecology. 3d ed. Oxford: Oxford Univ. Press.

  The first two editions of this book were co-authored by Beebee and Rowe in 2004 and 2008, respectively. This edition provides a very useful overview of methods that are used to characterize natural populations genetically and gain insight into processes as diverse as behavioral genetics, phylogeography, microbial ecology, and conservation.

• Templeton, A. 2021. Population genetics and microevolutionary theory. 2d ed. Hoboken, NJ: Wiley-Blackwell.

  DOI: 10.1002/9781119836070

  This second edition includes a strong underpinning in population genetics and examines ways in which these can inform our understanding of microevolutionary change. Includes thorough discussions of Hardy-Weinberg equilibrium, genetic drift, quantitative genetics, coalescence, natural selection, and relatedness and inbreeding.