The Selfish Gene

by Richard Dawkins Read the Original

Summary Notes

In The Selfish Gene, Richard Dawkins argues that individual selfishness and altruism can be explained by gene selfishness. He explains how genes replicate, compete, and cooperate, and how game theory and ESSs can be used to determine the most stable strategies in a population. Dawkins also looks at how males and females use different strategies, with females investing more in offspring, and how reciprocity and the Prisoner's Dilemma show cooperation is possible. He also introduces his extended phenotype theory, which suggests that genes can have effects beyond the bodies they are packaged in.

Key Learnings

• Genes can be seen as a selfish and immortal “gene complex” that survives through many individual bodies.
• Humans have the unique ability to override their genetic program, but animals make unconscious strategic moves to maximize the probability their genes will survive.
• Males and females have differing strategies due to the differences in their sex cells, with females investing more in offspring and males being more likely to abandon them.
• Reciprocal altruism is a viable evolutionary strategy, and is seen in animals such as bats and humans.
• Genes can express themselves beyond individual organisms, into other bodies and the environment.

• Summary Notes
• Key Learnings
• Explaining Selfishness and Altruism: Dawkins's Selfish Gene Theory
• The Origins of Life: From Molecules to Replicators
• Genes: The Blueprint of Life
• 46 Chromosomes and the Selfish Genes
• Genes: The Path to Immortality
• Genes: The Policymakers in Human Life
• Evolutionary Strategies for Survival
• Selfish Strategies for Gene Pool Success
• Altruism Driven by Selfish Gene and Identity Certainty
• Gene Survival: The Key to Kin Selection & Altruism
• Refuting Group-Based Altruism: Dawkins's Selfish Gene Theory
• Population Regulation and Reproduction: Dawkins' Perspective
• Sibling Rivalry: Biological Imperatives vs Human Choice
• Male & Female Parenting Strategies Differ
• Strategies for Female Monogomy in Evolutionary Perspective
• Gender Inequality: Exploring the Cost of Being Female
• Conflict & Cooperation: Exploring Gender Strategies
• Exploring Symbiotic & Altruistic Behaviors
• Memes: The Power of Cultural Transmission
• Reciprocal Altruism & The Prisoner's Dilemma
• Axelrod's Tit for Tat: Cooperation Wins Non-Zero-Sum Games
• Reciprocal Altruism: A Successful Evolutionary Strategy
• Extended Phenotype Theory: Genes Shape the World.
• The Parasitic Genes of All Bodies

Explaining Selfishness and Altruism: Dawkins's Selfish Gene Theory

Dawkins argues that genes are driven by selfishness and can sometimes show limited altruism, but this should not be interpreted as love for the species. He also notes that his book is not about any particular species, but rather about how individual selfishness and altruism can be explained by gene selfishness. He hopes to displace the misconception of group selection and show that human beings are not an exception to the selfish gene theory. "All animals are machines created by their genes, which have survived sometimes over millions of years." Genes are powerful forces, influencing the development of individual organisms over a long period of time. This highlights the idea that genes can survive beyond individual bodies, as they are immortal and capable of expressing themselves in multiple bodies and the environment.

The Origins of Life: From Molecules to Replicators

Life likely began with organic molecules in a primeval soup. These molecules eventually created replicators, which made copies of themselves, creating greater stability and diversity. These replicators are the ancestors of modern DNA molecules, the building blocks of life. “Rather, all animals are machines created by their genes, which have survived sometimes over millions of years.” Genes can be seen as a selfish entity, as they are immortal and their primary purpose is to ensure their own survival through multiple generations. This suggests that animals make unconscious strategic moves to maximize the probability of their genes surviving.

Genes: The Blueprint of Life

Genes are the instructions that create bodies, and they cooperate with one another in an organism's chromosomes. They can be passed down through generations, and in sexual reproduction, genes are shuffled. Genes are responsible for creating bodies, and can be seen as a "gene complex" that survives through many individual bodies. “The essence of life is statistical improbability on a colossal scale” Life is incredibly improbable, yet it exists and thrives on a huge scale. This speaks to the power of natural selection, which is able to take small changes and create complex life forms over time.

46 Chromosomes and the Selfish Genes

Humans have 46 chromosomes, 23 from each parent. Crossing over occurs during meiosis to create a mosaic of genes from the embryo's four grandparents. Genes are portions of chromosomes that can last for many generations and are selected for survival through natural selection. They compete for slots on chromosomes and are considered selfish. “Genes are the ultimate rationale for our existence” Genes are the primary factor that determine an organism's form and behavior, and they are the key to understanding the evolution of life on Earth. They are responsible for the diversity of life, and ultimately serve as the reason for our existence.

Genes: The Path to Immortality

Dawkins explains how genes can be relatively immortal by replicating themselves and expressing themselves in enough bodies to take up permanent residence in the gene pool. Through the process of meiosis, chromosomes are swapped and reassembled, with DNA from both mother and father, creating a patchwork of DNA from four grandparents. This ensures that a sex cell doesn't get too many chromosomes from either parent. “A gene is a portion of a chromosome and can vary in size” Genes are composed of DNA segments that can differ in length and size. This flexibility allows them to be selected for reproduction, enabling them to survive through many generations.

Genes: The Policymakers in Human Life

Dawkins explains that genes control protein synthesis, build organisms for likely environmental conditions, and give organisms general strategies for survival. Genes are the policymakers, while the brain is the executive that makes moment-to-moment decisions. Human brains have the unique ability to counteract their genetic program. “Successful genes make survival machines that are more likely to live and produce offspring” Genes that create advantageous characteristics that help an organism survive and reproduce will be more likely to be passed onto the next generation. This is a form of natural selection which shapes the gene pool of a species.

Evolutionary Strategies for Survival

Dawkins considers the body as an agent "trying" to increase the number of genes in future generations, with no consciousness. Natural selection favors organisms that make the best use of their environment, including aggression towards other organisms. John Maynard Smith's game theory introduced the idea of an evolutionarily stable strategy, a programmed behavior policy adopted by most members of a population. “Every organism contains DNA code, instructions for making its particular body.” DNA is a set of instructions that every organism follows to create its own unique body. This is a crucial part of the gene's immortality, as it allows them to be replicated in each generation.

Selfish Strategies for Gene Pool Success

Dawkins explains how genes use selfish strategies, such as helping other replicas, to increase their numbers in the gene pool. He also describes how game theory and ESSs can be used to determine the most stable strategies in a population, often resulting in a stable mixture of strategies. “A gene does not simply move from body to body; it replicates itself, sending copies of itself into sex cells so a sperm or egg can transport this blueprint into the next generation.” Genes are not simply passed down through generations, but rather they replicate themselves in each generation. This is how they achieve relative immortality by being expressed in many different bodies.

Altruism Driven by Selfish Gene and Identity Certainty

Genes recognize their replicas in close kin and can act altruistically towards them, but their behavior is ultimately in the interest of the selfish gene. Certainty of identity also plays a role in relationships, with parents having more of a reason to value and protect their offspring due to the certainty of their relationship. “The individual body is an agent ‘trying’ to increase the numbers of all its genes in future generations” A gene's primary goal is to spread and survive through multiple bodies, even if the individual body it inhabits does not. This is an example of how genes can express themselves beyond a single organism, into other bodies and the environment.

Gene Survival: The Key to Kin Selection & Altruism

Dawkins explains how genes use survival machines to determine relatedness and resources to kin, refuting the idea of parental altruism as separate from kin-selected altruism. Wild animals regulate birth rates to maximize gene survival, but rarely die of old age due to predators, starvation, and disease. “Genes must make predictions about likely environmental conditions” Genes are not only selfish in the sense that they are programmed to spread, but also in their ability to anticipate future conditions. This anticipatory quality gives them an evolutionary advantage over other species, as they can adapt and survive changing environments.

Refuting Group-Based Altruism: Dawkins's Selfish Gene Theory

Dawkins refutes Wynne-Edwards's theory of group-based altruism, arguing that all behaviors can be explained from a selfish gene perspective. He cites Lack's work on clutch size to show how natural selection determines an optimal number of offspring, and generalizes this idea to territory and hierarchy. He opposes the idea of parental altruism as a special kind of group selection, instead suggesting that animals make unconscious strategic moves to maximize the probability their genes will survive. “It is as if the genes are treating their survival machines as robots, controlled by a micro-computer program.” Genes control their survival machines like a computer program, with instructions and commands to ensure their own survival and propagation.

Population Regulation and Reproduction: Dawkins' Perspective

Dawkins argues that population regulation is not due to animals having an unspoken agreement to not reproduce, but rather due to those who are less lucky being less likely to survive and reproduce. He also argues that mothers do not have genetic favorites, but may favor some offspring over others due to their likelihood of survival and passing on her genes. Menopause is an adaptation allowing females to invest in their grandchildren. “Whether to fight and how hard should be an unconscious cost-benefit calculation.” Animals make strategic decisions about aggression, weighing the costs and benefits of fighting in order to maximize the chances their genes will survive.

Sibling Rivalry: Biological Imperatives vs Human Choice

Dawkins discusses how children may act selfishly to gain parental resources, while parents must assess the likelihood of their offspring's survival. Sibling rivalry is driven by biological imperatives, but humans have the ability to override their programming and choose to act altruistically. “In this scenario an organism acts like a dove until attacked and then retaliates.” Retaliator is a conditional strategy in which organisms use the behavior of their opponents to decide their own course of action. This strategy is an example of altruism on the gene level, which is seen in many species.

Male & Female Parenting Strategies Differ

Males and females have differing strategies due to the differences in their sex cells. Females invest more in offspring and males are more likely to abandon them. Males may use tactics such as chemical secretions or aggression to ensure their offspring are theirs, while females may deceive to get a new male to adopt her offspring. “For altruistic behavior to evolve, the net risk to the altruist must be less than the net benefit to the recipient multiplied by relatedness,” Altruism is only beneficial if the risk taken is outweighed by the benefit to the recipient, which is dependent upon the relatedness of the two.

Strategies for Female Monogomy in Evolutionary Perspective

Females can use two strategies to ensure a male doesn't desert: the domestic bliss strategy (refusing to copulate until commitment to offspring is shown) and the he-man strategy (looking for the best genes). Males tend towards promiscuity while females tend towards monogomy - a predicted result from an evolutionary perspective. “When Dawkins refers to the mathematical calculations survival machines make in determining their kinship levels or the degree to which their kin may have their genes, he means that organisms recognize that a sister shares more genes than a cousin, for example.” Organisms are programmed to recognize the degree of relatedness in order to determine how much effort should be put in to ensure the survival of the selfish genes in their family members.

Gender Inequality: Exploring the Cost of Being Female

Dawkins explores the inequality between males and females, arguing that females are more energetically expensive and invest more in their offspring, making them less free to mate with other partners. Males can have unlimited offspring, making them more likely to abandon children, while females tend to be monogamous and nurture their young. “Dawkins chides V.C. Wynne-Edwards (1906–97), a biologist who early on propagated the idea of group selection, using a theory of population regulation.” Dawkins challenges the idea of group selection, suggesting that animals regulate their birth rates at the level of the gene in order to maximize their chances of survival.

Conflict & Cooperation: Exploring Gender Strategies

Males and females often have conflicting interests and use strategies to get what they want. Altruism and reciprocal altruism are discussed, as well as how the selfish gene is related to animals living in groups. Hymenoptera (ants, bees, wasps) show females share 75% of their DNA, which makes sense for worker females to "farm" their mother to produce more sisters. “Reciprocal altruism is a viable evolutionary strategy, and is seen in animals such as bats and humans.” Altruism is not always self-sacrificial, and can actually benefit those who practice it over time. This is seen in animals like bats and humans, who are able to build relationships of trust with one another that can help them both survive.

Exploring Symbiotic & Altruistic Behaviors

Dawkins explores symbiotic relationships, such as ants and aphids, as well as reciprocal altruism, which is when favors are exchanged between individuals. He looks at the behavior of grudgers, cheaters, and suckers, and discusses the selfish gene hypothesis in the Hymenoptera, where a queen's daughters can influence her to produce more sisters than brothers. “Genes can express themselves beyond individual organisms, into other bodies and the environment.” Genes have the ability to influence more than just the individual organism they reside in. They can also have effects on other individuals and the environment, showing that they have a wider reach than previously thought.

Memes: The Power of Cultural Transmission

Dawkins proposes the idea of memes, a unit of cultural transmission. They compete in human media, and religions are a powerful meme. They can be stable like genes, but humans can also defy them and act altruistically. “Investments include food, risks, energy, and effort.” Parents invest in offspring to increase their chance of survival and reproductive success, even if it may come at the cost of other offspring.

Reciprocal Altruism & The Prisoner's Dilemma

In Chapter 12 of The Selfish Gene, Dawkins discusses reciprocal altruism and the Prisoner's Dilemma, a game used to explore altruism. In this game, players have the choice to either cooperate with each other or defect and give up their comrade. In iterated games, strategies must be developed to build trust and reciprocate. Axelrod invited experts to submit strategies, and the results showed that the best strategy was to cooperate. “For example, an undersized or otherwise unhealthy child is less likely to survive than a healthy sibling.” Natural selection dictates that parents will prioritize the healthiest offspring, as they are more likely to be successful in passing on their genes.

Axelrod's Tit for Tat: Cooperation Wins Non-Zero-Sum Games

Axelrod's Tit for Tat strategy won multiple tournaments as a "nice," "forgiving," and "robust" strategy, and is a real-life example of how cooperation can be successful in non-zero-sum games. Dawkins provides examples of this in the natural world, such as vampire bats donating food to one another. “Genes in juvenile bodies will be selected for their ability to outsmart parental bodies; genes in parental bodies will be selected for their ability to outsmart the young.” There is an evolutionary arms race between juvenile and parental bodies, in which both must adapt to outsmart the other.

Reciprocal Altruism: A Successful Evolutionary Strategy

Axelrod & Hamilton used the Prisoner's Dilemma to test people's selfish/altruistic inclinations and found that the Tit-for-Tat strategy was most successful. This shows that reciprocal altruism is a viable evolutionary strategy, and examples of it can be seen in animals such as bats, and humans. “Female exploitation begins here.” The differences between male and female sex cells create a power imbalance - females are more heavily invested in offspring than males, making them more valuable to the species.

Extended Phenotype Theory: Genes Shape the World.

Dawkins' extended phenotype theory states that genes can have effects on the world outside of an organism. These effects can include the building of beaver dams or bird nests, or even interactions between parasite and host. Natural selection favors genes that shape the world so they can propagate, and replicators survive due to their own characteristics and their consequences on the world. “Males secrete a chemical that causes pregnant females to abort if the chemical's smell is not the same as her former mate's.” Males can use strategies to avoid investing in offspring that are not their own, such as the chemical secreted by male mice to detect if the female has been with another mate.

The Parasitic Genes of All Bodies

Dawkins proposes that genes express themselves beyond individual organisms, into other bodies and the environment. He suggests that all genes are parasites belonging to one body, and that scientists should focus on the replicators rather than the bodies they are packaged in. “Males and females have differing strategies due to the differences in their sex cells, with females investing more in offspring and males being more likely to abandon them.” Males and females have different evolutionary strategies due to the different resources and roles they play in reproduction. Females focus on investing in offspring, while males are more likely to abandon them.