Book SummaryThe Selfish Gene, by Richard Dawkins

1-Page Summary1-Page Book Summary of The Selfish Gene

The Selfish Gene shows that all forms of life on Earth begin with genes, and that the purpose of life is to make sure those genes survive. While many biologists would say that the purpose of life is to survive and reproduce at the organismal level, Dawkins argues that there are things that the organismal approach can’t explain, such as the prevalence of sexual reproduction when it leads to offspring that are substantially different from the parents. Therefore, it makes more sense to look at life from the perspective of a selfish gene doing anything it can to reproduce itself because, outside of random mutations, genes pass from one generation to the next unchanged.

Any form of life anywhere in the universe must begin with some type of replicating molecule. That molecule first arises by chance, as atoms randomly bump into each other in some primordial soup. Once formed, however, that replicator quickly copies itself and spreads throughout its environment. Copying itself is that molecule’s only purpose.

Sooner or later, the environment runs out of freely available resources, and then the molecules will have to compete. Those that can’t effectively replicate themselves will be squeezed out of the population, while those that can undergo various mutations during the copying process. Some of those mutations, by pure chance, are helpful, and the molecules carrying them replicate more effectively than others. New mutations build on top of old ones to create ever-more effective and elaborate vehicles to carry those replicators. On Earth, those replicators became DNA and evolution led to the complex organisms we have today.

Genes are like a blueprint for the bodies they create and inhabit. Genes can’t control their bodies directly, so they create structures like the brain and muscles to coordinate and execute all of the many processes required for life.

However, for all of the complex structures and systems they give rise to, genes are still replicator molecules doing whatever they can to keep replicating and survive through the generations. This is the meaning of “selfish gene,” and the reason all biology should be considered from the perspective of genes, not individuals.

Altruistic and Selfish Behaviors

While the driving force behind biology may be genes attempting to replicate, in modern times many must do so through the behaviors of their hosts. Behavior is how scientists describe specific actions that creatures take. A behavior is something quick and definite, so only animals can really be said to have them—some plants do move, but not in a fast or purposeful way.

Selfish behaviors in nature are easy to explain: Animals would naturally be expected to behave in ways that benefit themselves at the expense of others, given that the purpose of life is to survive and reproduce. However, altruistic behavior—helping others at cost to oneself—seems counterintuitive.

Group Selection

One possible explanation for altruistic behavior is group selection: the idea that natural selection acts on groups of creatures, rather than on the individual level. While the commonly accepted theory today is that individuals compete for the ability to reproduce, group selection says that animals will instinctively act for the good of their local population, or even their entire species. If true, it would make altruistic behavior very easy to explain; risking oneself to help others of one’s species would then be the default, not the exception.

However, group selection is a fatally flawed theory. There are many ways to rebut it, but the simplest is to recognize that a population of altruistic individuals can be easily exploited by a selfish one. The selfish individual will accept all the help that other members of the population offer, while taking on no risks or costs to itself. Therefore, a selfish individual in an altruistic population will inevitably be more successful than the average creature in that population.

That selfish creature would quickly spread its genes—and therefore its selfishness—until a large portion of the population turns selfish. In other words, the individual will succeed at the expense of the group, and therefore group selection can’t be true.

Gene Selection

The other explanation for altruistic behavior is gene selection. The key to understanding gene selection is recognizing that close relatives, by definition, share many of the same genes. For example, in a typical mammal that reproduces sexually, an individual’s offspring and siblings will both have 50% of its genes. However, there’s no way for a gene to actively recognize itself in another organism, so it has to play the odds. If another organism carries 50% of the same genes, then there’s a 50% chance that it carries a copy of the gene in question.

Therefore, from the perspective of a selfish gene, siblings and offspring should be considered 50% as valuable as the organism that gene happens to be in. So, to give an extreme example, if an organism could save more than two of its siblings or children by sacrificing its own life, selfish gene theory dictates that it should do so. Genes don’t need one particular organism to survive, as long as organisms likely to be carrying them are able to keep reproducing.

Nature Seeks Stability

Since genes themselves aren’t living organisms, it may be confusing to talk about their “survival”; substituting the word “stability” might help to clarify the matter. By definition, something that’s unstable—whether it’s a single molecule or a population of animals—will keep changing until it finds a stable form. For primordial molecules, this happens by chance; atoms randomly bump into each other until they happen to land in a form that sticks.

In animal populations, it’s a lot more complex. As we’ve discussed, a population of altruistic animals could be easily overtaken by selfish individuals, and therefore can’t be...

The Selfish Gene Summary Chapters 1-2: The Purpose of Life

The Selfish Gene is a long essay arguing that biology should be considered from the perspective of individual genes, not entire organisms. Dawkins points out flaws in the organism-centric biology of his day and proposes that many of the apparent paradoxes in nature could be explained by genes, rather than creatures, trying to replicate themselves.

One major paradox is the prevalence of sexual reproduction in nature. If, as Dawkins argues, the main purpose of life is to replicate itself, then sexual reproduction doesn’t make much sense. The offspring produced by sexual reproduction will be inherently different from their parents, so it’s not really a form of replication at all. This apparent contradiction is explored in Chapter 3.

Most of the essay, but especially Chapters 5, 8, and 9, explore competition in nature and how it leads to evolution. Genes that survive at the expense of others will naturally reproduce more effectively and come to outnumber the less successful ones. In Chapters 5 and 12, we’ll also dip into game theory, the mathematical study of decision-making, to help explain some of the more complex behaviors that animals exhibit.

The Selfish Gene ends...

The Selfish Gene Summary Chapter 3: What Are Genes?

(Shortform note: As you read, it’s worth keeping in mind that evolution, genes, and so forth aren’t conscious entities and therefore can’t “seek” or “want” anything. A gene doesn’t want to replicate itself, nor does it actively look for the most efficient way to do so. Replicating is just what genes do.)

In this chapter, we’ll explore what genes are, how they’re formed, how they reproduce, and why all of that has such an impact on how organisms behave.

Genes: The Basics

To start at a basic level, the replicator that all complex life forms host is DNA. DNA is a nucleic acid, a polymer made up of many molecules called nucleotides. There are only four types of nucleotides in DNA: adenine (A), cytosine (C), guanine (G) and thymine (T). Those nucleotides are identical no matter what kind of creature has them: You’ve got the same four nucleotides as your pet cat, or the birds outside. The only difference between different species is how those nucleotides are arranged. To a much lesser extent, they are also arranged differently between different people (except for identical twins).

Those nucleotides are then organized into genes. The genes are like blueprints for...

The Selfish Gene Summary Chapter 4: How Genes Lead to Behaviors

In this chapter, we'll discuss how both our genes and our consciousness affect our behavior. First, we’ll explore how genes prompt the behaviors that are the most likely to lead to an animal’s survival. Then, we’ll look at how animals, most notably humans, have developed the ability to work against some of these genetically programmed behaviors and pursue our own desires.

Evolution is ultimately driven by need. For example, when the “food” molecules of the early primordial soup were used up, the things inhabiting it needed new energy sources in order to survive.

Some organisms were able to use the energy from sunlight to build the molecules they needed to survive. These would become plants. Other types, which would become animals, were able to get energy from eating the plants or other animals.

As the environment became more competitive, survival mechanisms became more complex by necessity. Therefore, genes that allowed cooperation and centralized control within the body would have been favored over those that allowed mechanisms to work independently. **In modern organisms the systems work so well together that they’re seen as a single being, rather than a collection of...

The Selfish Gene Summary Chapter 5: Aggression and Selfishness

In this chapter, we’ll explore different behavioral styles in animals. It seems logical that strong, aggressive animals will have an advantage in nature, and therefore all animals should selfishly try to take as many resources as they can for themselves. However, that isn’t always true.

A population of animals actually needs a particular balance of aggression and pacifism in order to be stable—too many aggressive (selfish) individuals will constantly fight each other, and too many peaceful individuals will be easily overpowered and exploited by a few aggressive ones. A stable population is the best situation for selfish genes trying to survive through as many generations as possible, without being overwhelmed by other types of animals.

Animals will naturally compete with one another—there are only so many resources to go around, so only a limited number of genes’ hosts can reproduce. Members of different species may compete for various things—for instance, blackbirds and moles might compete for earthworms—but members of the same species will be in much more direct competition. This is because they tend to live in the same environment and need the same things,...

The Selfish Gene Summary Chapter 6: Why Animals Help Their Relatives

Now we’ll explore how and why animals show altruistic behaviors, especially toward their family members. Genes don’t just act to protect the individual they’re inside of. We know this because animals frequently help their offspring and relatives, even at risk to themselves. This makes sense if we consider a “selfish gene” to be all copies of that gene across the entire population. Then we can assume that individuals will act to protect other individuals who are likely to have the same gene.

This perceived likelihood could come from a physical characteristic that the gene gives. For example, if there were a gene for purple hair, you might expect one purple-haired person to act altruistically toward another. However, the odds of a single gene providing both “purple hair” and “altruism toward purple hair” characteristics are astronomical—remember that genes aren’t conscious, and can’t choose what effects they have on their hosts. Granted, it’s possible that those two genes might tend to be inherited together, as they provide a mutually beneficial environment.

However, a much easier way for genes to “recognize” themselves in others is through family relations. By...

The Selfish Gene Summary Chapter 7: Animal Reproduction: Bearing vs. Caring

How, when, and why do animals choose to reproduce? All of those decisions are designed to maximize their offsprings’ chance of survival. There are two competing theories for how animal populations control their reproduction: an altruistic theory put forth by group-selection theorists, and a selfish theory that Dawkins believes is true.

Animals often have to choose between reproducing and taking care of children that have already been born (bearing vs. caring). There are advantages and disadvantages to each choice, from the perspective of a selfish gene. Bearing more children creates more opportunities for genes to be passed on and survive, but often involves a great deal of risk and resource spending. Caring for already-living family members is less resource-intensive than bearing new ones, but doesn’t create more vessels for genes to inhabit.

Reaching an ESS usually (though not always) involves some balance of both—in fact, the only strategy that can never be an ESS is a pure caring strategy. This is because a population of pure carers, who rarely or never have offspring of their own, would quickly be invaded by another species turning the carers’ altruism to their own...

The Selfish Gene Summary Chapters 8-9: Limited Resources and Conflicts of Interest

Because Earth is a finite world with finite resources, there’s a natural struggle between the creatures who inhabit it to get those resources. In this chapter we discuss various ways that family members compete with each other—their own selfish interests conflict with their shared desires to have their offspring and siblings survive. We’ll also explore the natural conflict between mates, each of whom would benefit from the other contributing more resources to their offspring.

Finally, we examine the role of sexual attractiveness, especially among species where the male doesn’t engage in this conflict between mates, but simply leaves to find another female to impregnate. Sexual attraction is especially important for such species, because there’s no chance that the mate will stick around to contribute to raising the offspring. In that case, all that matters is finding the best, most fit mates through which animals can pass on their genes.

The Universal Struggle for Resources

Every animal has a limited amount of resources to invest in furthering its genes. This limit represents the total amount of food that animal can gather or make, as well as the total energy...

The Selfish Gene Summary Chapter 10-11: Populations and Culture

In these chapters, we explore why many animals live in groups. We also explore some unexpected outcomes of group living, including various shared behaviors, and even what one might call culture. Strangely, culture spreads much like genes do: Ideas act as non-physical replicator “molecules,” and reproduce themselves in individuals’ minds.

Many types of animals move, or even live, together in groups. Some advantages of this are obvious. For instance, prey animals gain some protection from predators. Meanwhile, predators like hyenas can bring down much larger prey by working together, so it benefits them all even though they have to share the food afterward. Birds fly in formation and switch leaders frequently to reduce turbulence and make travel less tiring. There are countless other examples in nature.

In Chapter 1, we discussed birds who give alarm calls to warn of predators, at some risk to themselves. However, this act of altruism may ultimately be an act of selfishness—in fact, considering the selfish gene theory, it must be. By the simple fact of natural selection, we can infer that giving that alarm call is more beneficial to the individual’s genes than not...

Shortform Exercise: Think About the Impact of Memes

Memes (in the sense that Dawkins uses the word, a self-replicating idea) have enormous impact on our day-to-day lives.

Think about your day. Identify one meme that had an impact on it. (For example, a song that got stuck in your head, or an idea that you couldn’t stop thinking about.)

The Selfish Gene Summary Chapter 12: The Prisoner’s Dilemma

This chapter is about another way to use game theory to explain behaviors, especially at the population level. By using game theory, scientists can determine effective behavioral strategies. They can also find—or at least approximate—an ESS for a population made up of such behaviors.

The Prisoner’s Dilemma is a logistical riddle closely tied to game theory. In the Prisoner’s Dilemma there are two players, each with two options: Cooperate and Betray. Neither player knows which option the other has chosen, and they are not allowed to influence the other’s choice in any way.

If both players choose Cooperate, they each get a significant payout—but a smaller one than in the next situation. If one player Cooperates and the other Betrays, the betrayer gets a large payout while the cooperative player suffers a large penalty. If both players Betray, they each suffer a small penalty. Cooperation and betrayal are altruistic and selfish actions, respectively. Therefore, everything we know about the Dilemma could be compared to nature.

In any single instance of the game, the logical choice is to simply pick Betray. If your opponent chose Cooperate, you’ll get a larger payout than...

The Selfish Gene Summary Chapter 13: The Far-Reaching Effects of Genes

This chapter is a bit of a smorgasbord—it talks briefly about several different topics that didn’t fit anywhere else in The Selfish Gene. First, it discusses the impact that genes have not only on the creatures they inhabit, but also on the world around them. Then it discusses a strange quirk of reproduction: How most organisms begin as single cells, and why that fact is important—possibly necessary—for stability and evolution.

So far we have discussed biology and behavior in terms of genes; but, of course, there is a difference between a gene and an organism. Most biologists make the mistake of focusing their questions and their studies on the organismal level: They ask why an organism does something, or behaves a certain way.

In fact, it’s quite common for biologists to say that DNA and RNA are tools organisms use to replicate themselves—which, in light of what we’ve discussed so far, is the exact opposite of the truth. Organisms don’t replicate themselves at all (except in the relatively rare case of asexual reproduction). Given that the “purpose” of life is replication, it seems clear that organisms are tools that genes use to replicate themselves.

Starting...

Shortform Exercise: Identify Extended Phenotypes

The effects of extended phenotypes—things created or influenced by living organisms—are all around you. Take a look out the nearest window.

What can you identify that an animal created? Remember that humans are animals too!