Category Archives: Evolution

“The Selfish Gene” – review

In this classic, fascinating sociobiology text, Dawkins shows how mathematical analyses can help us understand the evolution of social behaviors in humans and other animals.

For much of the book, Dawkins uses game theory to show how differing strategies can come to coexist in populations. He does this with strategies of physical aggression (“hawk”, “dove”, “bully” etc.). He also uses this approach to explain how the sexes could have evolved and to analyze the interactions of various mating and infant-care strategies.

Dawkins also shows how mathematical models can explain the evolution of altruistic behaviors—i.e., behaviors that promote others’ survival while reducing the chances of survival of the altruistic individual. Here the analysis is based on the fundamental understanding that natural selection operates at the level of genes rather than organisms.

In the process of natural selection, random mutation creates differing alleles (versions) of genes that create different varieties of a feature (e.g. different eye colors, or different levels of aggression). The alleles that provide the organism with characteristics that best serve to reproduce that allele become increasingly common in the population. For example, an allele that confers resistance to a fatal disease will become more common because individuals who have the allele will be more likely to survive and have children who carry that allele.

By reducing the likelihood of survival, altruism reduces the likelihood of reproduction of individual organisms. However, an allele that creates an altruistic behavior could become common if that behavior preferentially benefited enough other individuals who also carried that allele: the process known as kin selection. For example, if an individual with one copy of an allele sacrificed their life to save the lives of two individuals who both carried a copy of that allele, the loss of the one copy would be compensated for by the preservation of two. Altruistic acts toward closer relatives are more likely to be of benefit to an allele because closer relatives are more likely to also have that allele.

In a similar vein, Dawkins elaborates the strategic advantages of reciprocal altruism and forgiveness using an analysis of “the prisoner’s dilemma” trust game

All of this makes for fascinating reading. However, in order to make his arguments more engaging and accessible to the general public, Dawkins takes three linguistic and logical shortcuts that can lead the reader to misunderstand the process of natural selection.

Dawkins makes the common mistake of referring to gene alleles as “genes.” Secondly, for much of the book he writes at the level of the individual organism rather than the allele. Thirdly, he writes as if genes—and animals—are thinking beings that consciously strategize with self-reproducing goals in mind.

Dawkins sometimes points out when he is taking the logical shortcuts, and they don’t compromise his mathematical analyses of specific strategies. However, he almost never restates his arguments in scientifically objective, allele-centered terms. As a result, these shortcuts can prompt the reader to misunderstand natural selection as a process in which genes direct individual organisms to engage in a dog eat dog competition for dominance.

When evolutionary theorists write of “survival of the fittest” they are referring to reproductive fitness, not the ability to win a fight. Indeed, Dawkins himself shows how non-aggressive strategies can come to stably co-exist with aggressive ones in a population.

Unfortunately, Dawkins himself seems to have succumbed to this misconception. On page 2 he writes: “I shall argue that the predominant quality to be expected in a successful gene is ruthless selfishness. This gene selfishness will usually give rise to selfish behavior.”

Gene alleles don’t have attitudes to other alleles of the same gene, they simply code for characteristics, only a fraction of which have anything to do with social behavior. Is an allele that confers disease resistance “selfish”?

The alleles that become frequent in a population are the ones that code for characteristics that enhance their reproduction. Most mutations produce alleles that reduce the viability of the organism and hence of the allele. If one wanted to attribute a quality to alleles that become common it would be “lucky,” or “effective,” not “selfish.”

That said, reading “The Selfish Gene” was a pleasurable, at times even enlightening, experience for this reviewer. I strongly recommend this book, especially if you don’t already have a background in game theory or in the theory of kin selection.

Just be careful to step around the pitfalls that Dawkins falls into.