The Selfish Gene: 30th Anniversary Edition by Richard Dawkins
In wanting to deepen my knowledge of evolutionary biology, the writings of Richard Dawkins would necessarily ring out loudly calling for my attention. I’ve gone back to the beginning with Stephen Jay Gould (and am slowly grinding forward) and now I’m also going back to the beginning with Dawkins’ The Selfish Gene, published in 1976 and updated in 1989. He cites “four heroes” whose work makes up the foundations of the books thesis: W. D. Hamilton, Robert Trivers, John Maynard Smith, and George Williams.
In regards to genes themselves, when discussing how “good” genes are those that spread throughout the gene pool, he remarks “This is not a theory; it is not even an observed fact: it is a tautology.” I think this expression is rather significant, as in any given population those genes that confer some advantage to their host in the endgame of reproduction will increase their frequency in the world over those that don’t. Genes don’t “want” to replicate, they have no consciousness or drive: they either replicate or they don’t. Those that don’t replicate only last as long as it takes for the universe to tear their molecular substrates apart. Those that do successfully replicate spread.
This is fairly obvious: genes that confer an advantage will, all things being equal, spread. What makes life so fascinating is that things are not always equal, in that genes compete. Apparently The Selfish Gene, when it was published, was a refutation of sorts of group selection which was in vogue. Group selection says that the actions of individual organisms are selected for in terms of what effect they have on the species. Examples like altruism seemed to support this (why would an individual expend energy and decrease its survival chances helping out others when it could just be maximally selfish and hoard energy?). Dawkins’ goal is to dispel this notion: Genes act only in their self interest, and any forms of altruism must be accounted for by this view.
From my reading, The Selfish Gene could have been called Game Theory in Biology, as discussions of things like evolutionary stable strategies and the Prisoner’s Dilemma occupy much of the word count of the book. Genes have no foresight; they do what they do and are either selected for or against. Whereas game theory has not lived up to its utopian promise in describing the actions of humans (where issues like pride and fairness muck up the clean mathematics), it seems to have great success in the selfish gene theory. An example, not from the book, would be the height of trees: It would be best if all trees remained small since they wouldn’t have to expend a lot of energy on building and maintaining large trunks. Every individual tree could get its share of sunlight and conserve resources for reproduction. But the rewards for cheating are great: if this tree grows it captures more sunlight that might have gone to its neighbors. Cheaters gain an energetic or reproductive advantage, and the genes that cause this cheating tendency spread throughout the gene pool, muscling out cooperative genes. It’s a one-off Prisoner’s Dilemma, where all the trees are worse off than if they had all cooperated but the strategy for any individual tree is to cheat.
Altruism also arises this way: in an iterated Prisoner’s Dilemma game where you play over and over, Tit-for-Tat strategies (copy whatever your opponent does, but if you go first then cooperate) tend to prevail over more vicious strategies. We see this in vampire bats, where some days some members of a group go hungry and are given surplus by other bats, but if they don’t reciprocate at a later date they are punished. The small decrease in survival chance of one sharing bat is offset by the spread of the sharing gene which decreases the chance of you starving on a bad day.
Other subjects are broached, like the relation between parents and children and among siblings and cousins, the dichotomy of males and females, and the behavior of the social insects like ants and bees (and naked mole rats). The now common idea of a “meme” or cultural unit of replication is introduced, though Dawkins’ aims were more modest than later claims in that he just wanted to introduce the idea that you could have evolution without specifically relying on DNA. Finally, there’s a chapter that summarizes his later book The Extended Phenotype, where the effects of genes upon the world is not limited to the shell of its host organism’s body (think of a beaver dam).
I think of The Selfish Gene as a philosophy of biology book, where the main takeaway is a different way of thinking about evolutionary systems. It would be extremely difficult to answer the question “What effect would this new mutated gene have?” since the world is complex and chaotic. Many different species have occupied different niches and adopted different strategies contingent both on their physical environment and what other organisms occupy that space. Biology then, is highly contingent on external factors, and the selfish gene theory is concerned with answering the question “Given this external environment (both physical and biological), why was this strategy adopted or rather selected for?” Dawkins argues that we should couch our explanations from a genetic rather than an individual (let alone a group) perspective.