Selfish Genes

by

J. Arvid Ågren, Greg Hurst

• LAST REVIEWED: 24 November 2021
• LAST MODIFIED: 25 October 2017
• DOI: 10.1093/obo/9780199941728-0094

Introduction

In its original formulation, Darwin’s theory of evolution by natural selection was based upon individual organisms. It is individuals that vary in phenotype, individuals that struggle to survive environmental pressures and compete over access to mates, and individuals that vary in fitness according to phenotype. Selfish gene theory, or the gene’s-eye view of evolution, however, offers a radically different picture of evolution by natural selection. Tracing its origins to the emergence of population genetics during the modern synthesis of the 1930s, especially to the writings of R. A. Fisher, as well as the social evolution models of W. D. Hamilton, the most ambitious form of the gene’s-eye view was spelled out in two later books: George Williams’s Adaptation and Natural Selection (1966) and Richard Dawkins’s The Selfish Gene (1976). Under this view of life, the fundamental unit of selection is the gene. Whereas individual organisms are temporary occurrences—present in one generation, gone in the next—genes are potentially immortal and their structure is passed on from generation to generation. As a consequence, the ultimate beneficiary of selection is the gene. Early on in The Selfish Gene, Dawkins relates this crucial insight as follows: “They are in you and me; they created us, body and mind; and their preservation is the ultimate rationale for our existence. They have come a long way, those replicators. Now they go by the name of genes, and we are their survival machines” (p. 21). Few phrases in science have caught the imagination of laymen and professionals alike the way “selfish genes” has done. The concept touches on several questions of interests to both biologists and philosophers, including how to articulate general principles of evolution and the units and levels of selection debate. The concept has contributed to the study of new biological phenomena, such as selfish genetic elements, greenbeard genes, and extended phenotypes. Finally, its association with selfishness and altruism has led to it being featured heavily in broader debates about morality and ethics.

Original Works

Two books stand out in the origin story of selfish gene thinking. The first of these was Williams 1966, in which “selection at the genic level” is held as a contrast to group selection explanations for traits, especially in relation to social behavior. The Selfish Gene (Dawkins 1976), published a decade later in 1976, was aimed at a broader audience and argued forcefully for genes to occupy the central role in evolutionary explanations. Both are very readable, and still offer excellent introductions to the gene’s-eye view of evolution.

• Dawkins, R. 1976. The selfish gene. Oxford: Oxford Univ. Press.

  The million-copy bestseller that coined several of the terms used in the debate, including selfish genes, replicator, survival machine, and meme.

• Williams, G. C. 1966. Adaptation and natural selection: A critique of some current evolutionary thought. Princeton, NJ: Princeton Univ. Press.

  Williams’s critique of the poor use of the concept of adaptation among contemporary biologists, especially with respect to group selection. Together with The Selfish Gene, introduced the gene’s-eye view of evolution to biology.