The Selfish Gene

“Like successful Chicago gangsters, our genes have survived, in some cases for millions of years, in a highly competitive world. This entitles us to expect certain qualities in our genes. I shall argue that a predominant quality to be expected in a successful gene is ruthless selfishness.”

Dawkins argues for the selfish gene as the primary locus of evolution. To survive, genes have to have certain characteristics. Dawkins examines these characteristics throughout the book. Dawkins often utilizes similes and metaphors to help readers visualize his ideas.

“At some point a particularly remarkable molecule was formed by accident. We will call it the Replicator. It may not necessarily have been the biggest or the most complex molecule around, but it had the extraordinary property of being able to create copies of itself.” 

Dawkins describes the origins of replicators. Replicators became genes, and genes continue to evolve today in organisms. Replicators formed complex machines to protect themselves, and these machines became plants, animals, and humans. Essentially, humans contain large collections of replicators.

“Evolutionary trends toward these three kinds of stability took place in the following sense: if you had sampled the soup at two different times, the later sample would have contained a higher proportion of varieties with high longevity/fecundity/copying-fidelity. This is essentially what a biologist means by evolution when he is speaking of living creatures, and the mechanism is the same-natural selection.” 

Replicators that copy themselves effectively become more common. This forms the basis of evolutionary theory. As replicators evolve, their hosts eventually die. But as the diversity in a gene pool increases, the prevalent varieties—"survival machines” (22)—also evolve. While they began as protective barriers, these machines changed over time to become complex forms, e.g., humans.

“They are in you and in 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.” 

Dawkins inverts the common view of genes as merely parts of organisms. Instead, genes are the primary replicators, while humans and other organisms are merely their robot servants.

“A monkey is a machine that preserves genes up trees, a fish is a machine that preserves genes in the water; there is even a small worm that preserves genes in German beer mats. DNA works in mysterious ways.” 

Animals, and other organisms such as plants, form different types of machines. Each machine assists its genes to survive in various environments. Dawkins incorporates examples of various animals, insects, and plants to illustrate the principal points of his theory.

“A gene is defined as any portion of chromosomal material that potentially lasts for enough generations to serve as a unit of natural selection. In the words of the previous chapter, a gene is a replicator with high copying-fidelity.” 

Dawkins defines a gene such that it matches the properties necessary for evolution. Replicators have the same characteristics, so Dawkins links the two. “Copying-fidelity” refers to the gene’s ability to maintain an accurate copy, or reproduction. 

“Can we think of any universal qualities that we would expect to find in all good (i.e. long-lived) genes? Conversely, what are the properties that instantly mark a gene out as a 'bad', short-lived one? There might be several such universal properties, but there is one that is particularly relevant to this book: at the gene level, altruism must be bad and selfishness good.”

“Selfish” genes copy themselves effectively, surviving better. This gives shape to the entire book. Evolution occurs through the differential survival of selfish genes. Dawkins also considers genes as “good” and “bad,” signifying that “good” genes persist. However, within this context, the concepts of “altruism” and “selfishness” are inversed: altruism is bad, and selfishness is good. The latter ensures survival of the gene.

“This easy life came to an end when the organic food in the soup, which had been slowly built up under the energetic influence of centuries of sunlight, was all used up. A major branch of survival machines, now called plants, started to use sunlight directly themselves to build up complex molecules from simple ones, re-enacting at much higher speed the synthetic processes of the original soup. Another branch, now known as animals, 'discovered' how to exploit the chemical labours of the plants, either by eating them, or by eating other animals. Both main branches of survival machines evolved more and more ingenious tricks to increase their efficiency in their various ways of life, and new ways of life were continually being opened up.”

Replicators gradually built up their “survival machines” into increasingly complex organisms. The life forms that we see today descend from the original replicators. Dawkins personifies survival machines in the process of evolution to help explain how the machines developed “tricks” to increase their survival and form complex organisms—plants, animals, and humans.

“Genes work by controlling protein synthesis. This is a powerful way of manipulating the world, but it is slow. It takes months of patiently pulling protein strings to build an embryo. The whole point about behaviour, on the other hand, is that it is fast. It works on a time-scale not of months but of seconds and fractions of seconds. Something happens in the world, an owl flashes overhead, a rustle in the long grass betrays prey, and in milliseconds nervous systems crackle into action, muscles leap, and someone's life is saved—or lost. Genes don't have reaction-times like that.”

Dawkins treats animals as survival machines, comparable to man-made machines. Brains are information-processing machines like computers. Over time, survival machines take over ever more of the roles of genes and could eventually overthrow them.

“The logical policy for a survival machine might therefore seem to be to murder its rivals, and then, preferably, to eat them. Although murder and cannibalism do occur in nature, they are not as common as a naive interpretation of the selfish gene theory might predict.” 

The selfish gene can produce selfish or altruistic individuals. Conflicts of interest, especially among closely interacting individuals, result in competition. Competition breeds an arms race of aggression.

“Since the rest of the population consists of individuals, each one trying to maximize his own success, the only strategy that persists will be one which, once evolved, cannot be bettered by any deviant individual.” 

An evolutionarily stable strategy fixes in a population competing for resources. Dawkins relies on this mathematical device heavily. It explains aggression, parenting, romance, genes, and more.

“A gene might be able to assist replicas of itself that are sitting in other bodies. If so, this would appear as individual altruism but it would be brought about by gene selfishness.” 

Genes can cause bodies to act in their environments so as to assist their copies elsewhere, producing the illusion of altruism. This explains kin altruism, in which organisms assist closely related organisms sharing genes.

“The species with which we are most familiar-mammals and birds-tend to be great carers. A decision to bear a new child is usually followed by a decision to care for it. It is because bearing and caring so often go together in practice that people have muddled the two things up. But from the point of view of the selfish genes there is, as we have seen, no distinction in principle between caring for a baby brother and caring for a baby son.”

Dawkins applies evolutionarily stable strategies to understand family size. The debate between group selection and gene selection then prevalent had addressed population explosions. Selfish genes show how parents select the number of offspring and the amount of nurturing.

“Parental Investment (P.I.) is defined as 'any investment by the parent in an individual offspring that increases the offspring's chance of surviving (and hence reproductive success) at the cost of the parent's ability to invest in other offspring.' The beauty of Trivers's parental investment is that it is measured in units very close to the units that really matter. When a child uses up some of its mother's milk, the amount of milk consumed is measured not in pints, not in calories, but in units of detriment to other children of the same mother.” 

The parental investment theory explains the calculations involved in how parents and offspring interact. This enables understanding of family dynamics.

“If there is conflict of interest between parents and children, who share 50 per cent of each others' genes, how much more severe must be the conflict between mates, who are not related to each other? All that they have in common is a 50 per cent genetic shareholding in the same children.” 

Sexual organisms mate to reproduce. Dawkins often demystifies topics by mathematical analysis. Using this scientific approach, Dawkins explores how genes can explain sexual behaviors.

“The obvious way to achieve this desirable state of affairs is to induce your sexual partner to invest more than his or her fair share of resources in each child, leaving you free to have other children with other partners.” 

Mating produces counter-intuitive incentives. Both parents have incentives to copy their genes as much as possible. This implies mating with numerous partners, and then getting them to raise the offspring.

“Bird alarm calls have been held up so many times as 'awkward' for the Darwinian theory that it has become a kind of sport to dream up explanations for them. As a result, we now have so many good explanations that it is hard to remember what all the fuss was about. Obviously, if there is a chance that the flock contains some close relatives, a gene for giving an alarm call can prosper in the gene pool because it has a good chance of being in the bodies of some of the individuals saved.” 

Animals often live in groups and take risks for each other. These apparently altruistic acts can be seen as preserving the selfish gene. In this way, Dawkins illustrates how an act of altruism is, in fact, a selfish directive.

“Finally and most importantly, the analogy extends to reproduction. The majority of individuals in a social insect colony are sterile workers. The 'germ line'—the line of immortal gene continuity—flows through the bodies of a minority of individuals, the reproductives. These are the analogues of our own reproductive cells in our testes and ovaries. The sterile workers are the analogy of our liver, muscle, and nerve cells. Kamikaze behaviour and other forms of altruism and cooperation by workers are not astonishing once we accept the fact that they are sterile.” 

Insects have different reproductive systems than mammals. As a result, insect colonies often appear altruistic. However, scientifically, they still behave according to the selfish gene. In insect colonies, such as demonstrated with ants and bees, the “sterile workers” will apparently sacrifice themselves for the Queens. However, they inherently do so in order to help their species’ propagation. 

“Cultural transmission is analogous to genetic transmission in that, although basically conservative, it can give rise to a form of evolution.” 

Dawkins develops the idea of a “meme,” a unit of cultural evolution. Culture evolves in human brains, as genes evolve in their environments. He describes memes as fundamental units of culture, likening them to genes. Memes—like genes—spread for their own selfish interests.

“So, we have identified two characteristics of winning strategies: niceness and forgivingness. This almost utopian-sounding conclusion—that niceness and forgivingness pay—came as a surprise to many of the experts, who had tried to be too cunning by submitting subtly nasty strategies.” 

 In a mathematical game theory tournament, computer programs compete to see which strategy works best. Cooperative strategies can arise even from competitive circumstances. Dawkins emphasizes how “nasty strategies,” which researchers anticipated would win out, failed in comparison to “nice strategies.” However, Dawkins makes the point that even these “nice” and “forgiving” tactics evolve from selfish genes. When it is beneficial for survival to be cooperative, genes will choose this recourse over “defecting” (157).

“A body doesn't look like the product of a loose and temporary federation of warring genetic agents who hardly have time to get acquainted before embarking in sperm or egg for the next leg of the great genetic diaspora.” 

Genes collaborate in bodies. Each gene struggles for itself. Yet, the combination produces the impression of a single unit. Dawkins highlights that genes struggled to become the complex organisms they comprise today.

“Natural selection favours some genes rather than others not because of the nature of the genes themselves, but because of their consequences—their phenotypic effects.” 

Genes do not act directly on themselves, but through the environment. Dawkins writes about the “extended phenotype” (175), including the organism as well as other parts of the environment. The extended phenotype refers to a gene’s ability to exert effects outside of its body, i.e., on the environment. For example, a spider has the capability of creating the gossamer thread used to build its web. 

“The geneticist should recognize genes 'for' house shape in precisely the same sense as there are genes for, say, leg shape.” 

 Genes produce behaviors, and behaviors produce artifacts. Therefore, Dawkins considers houses (of humans or other animals) part of the phenotype. Genes, by nature, shape more than just our physical being. They also intrinsically shape how we affect our environments. Dawkins uses the example of a house to illustrate this.