The Selfish Gene

Genetic research has come so far since Dawkins wrote The Selfish Gene that one might think he would need to revise the whole book. But he’s convinced that he doesn’t need to do that, because of the special way he’s defining “gene.” He uses the definition of “gene” created by Williams (also used by Maynard Smith and Hamilton). Williams defines the gene as “any portion of chromosomal material that potentially lasts for enough generations to serve as a unit of natural selection.” Dawkins jokes that technically, a more accurate title for this book would be “the slightly selfish little bit of chromosome and the even more selfish little bit of chromosome.” 

Embryologists are concerned with how genes affect phenotypes based on what they’re made of. However, like Darwin, Dawkins is only concerned with how something become numerous in a population. He reiterates that this “something” can’t be organisms, because they don’t become numerous: each organism is unique. The phenotypic effects of genes determine how numerous they become. Successful genes exist in many bodies over time. Genes help bodies survive “long enough to reproduce in the environment.” “Environment” includes things that are outside the body (such as predators and the weather), but also things that are inside the body (especially other genes).

 It makes sense that natural selection favors genes that “flourish in the company of other genes in the population.” Genes are “selfish,” but they are also “cooperative” with genes in the same body and in other bodies. Organisms that reproduce sexually are effectively “a cartel of mutually compatible cooperating genes.” These genes don’t cooperate because they’re selected as a group. Rather, they’re selected individually, and they tend to survive if they also happen to cooperate. Dawkins could easily call his book The Cooperating Gene and the content wouldn’t change.

Dawkins could have also called his book The Immortal Gene and the content would still be the same. He speculates that “immortal” might have been a better word, because it captures an important claim in his argument. Evolution is possible because of the “high fidelity” of DNA copying. DNA molecules mostly copy themselves accurately. This means that successful genes can live on for millions of years in the form of exact copies of themselves. Bill Hamilton calculated genetic relatedness by thinking about how much more related one is to kin than to the base population, which is another claim that Dawkins endorses.

Dawkins says that “genes” (as Williams defines them) are “things you can count as the generations go by.” He means that The Selfish Gene is probably “a valid account of life on other planets even if the genes on those other planets have no connection with DNA.” 

Dawkins wonders how related he is to Queen Elizabeth II. Apparently, he’s her “15th cousin twice removed.” His point is that humans are all “cousins” to each other, in some way or another, by virtue of our shared ancestors. We’re part of the “background population” in which our relatedness is nearly (but not quite) zero.  Dawkins finds calculating exactly what level of cousin one is to someone else to be kind of pointless. It makes more sense to think about how related people are from the “point of view of the gene.” For example, “what relation is my blue eyed gene to the postman’s blue eyed gene?”

Unlike organisms (which tend to have two parents, four grandparents, and so on), genes only have one parent. That means any two people can trace every one of their genes back to a common ancestor. The “coalescence point” is the point at which one person’s gene and the other person’s gene “peeled off” from their common ancestor. Dawkins thinks “the gene’s eye view” of evolution can extend into much deeper territory than “altruism.”

Dawkins believes that one can derive information about the entire “prehistory” of an entire species from genes. He tried this on a television show once by having the genes in one of his cells decoded. He discovered that a lot of genes coalesced 60,000 years ago, but a few coalesced 300,000 years ago. This means that the population was larger 300,000 years ago than 60,000 years ago. Likely, there was some sort of catastrophe between the two dates that drastically shrunk the population. The “gene’s eye view of life” thus “illuminates the deep past.” Dawkins discusses this idea more in The Ancestor’s Tale (co-authored with Yan Wong).

According to Dawkins, “the gene pool of a species is a mutually supportive cartel of genes that have survived in particular environments of the past, both distant and recent.” A geneticist could learn about all the environments in which a gene survived from its genetic code. Dawkins speculates that one can learn about ancient deserts from the genes of camels and one can learn about ancient oceans from the genes of dolphins.

Genomes even contain information about prehistorical eras, such as times when dinosaurs were alive, and even earlier when humans’ ancestors were fish. Dawkins would like to write a book about this someday, called “The Genetic Book of the Dead.” He thinks such a project would provide him with fresh insights to add, when future editions of The Selfish Gene are released.