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Posts Tagged ‘Richard Dawkins’

The Selfish Gene

Posted by nliakos on November 3, 2018

by Richard Dawkins (Oxford Univ. Press; originally published 1976; 40th Anniversary edition ed. 2016)

This one is a Darwinian classic and has been on my list for many, many years. It is pretty dense and long but is written in a very clear way, avoiding mathematical and scientific terms (or explaining them over and over). The basic premise is that natural selection works not at the level of the organism but at the level of the gene, which replicates itself endlessly so that any gene, at any moment, is present in many (billions? trillions?) organisms. Genes are “selfish”; that is to say, their goal, if they can be said to have a goal (they can’t, really) is to survive, at the expense of (or with the cooperation of, if that works better) their fellow genes. Individual organisms such as plants, fungi, or animals, including humans, are the “vehicles” or “survival machines” which the genes build to carry themselves into the future.

Ch. 1, “Why Are People?” Dawkins introduces the book by saying it is a statement of his belief of how living things evolved. It is not about morality, and it does not describe particular animal or human behaviors in detail. The concepts of selfishness and altruism, which are central to the book, are introduced.

Ch. 2, “The Replicators” A quick and dirty explanation of DNA, chromosomes, and genes. I’ve always been confused about whether chromosomes are parts of genes or vice versa (it’s vice versa). Errors during replication (i.e., mutations) lead to natural selection.

Ch. 3, “Immortal Coils” More about the replicators, basically, adding the concepts of  nucleotides and cistrons (smaller bits than in the previous chapter, if I am not mistaken), as well as the concept of crossing over, which means swapping chromosomal bits. A gene is defined as “any portion of chromosomal material that potentially lasts for enough generations to serve as a unit of natural selection.” These two chapters are the toughest for the non-scientist reader.

Ch. 4, “The Gene Machine” Working up in size to animals, the vehicles for genetic transmission and survival. Behavior is “a trick of rapid movement”. Muscles are “gadgets to achieve rapid behavior”. Neurones (nerve cells) time movements. Communication is simply a type of behavior controlled by neurones. Astonishing fact: An axon is a long wire-like part of a nerve cell that, while microscopically tiny in width, can be as long as the neck of a giraffe!

Ch. 5, “Aggression: Stability and the Selfish Machine  The crucial concept of the Evolutionarily Stable Strategy or ESS: a strategy that, if adopted by most members of a population, proves superior to other strategies. Natural selection penalizes deviation from the ESS, which results in stable polymorphism, or an equilibrium of varied types in the gene pool. Addresses the issues of rivalry (and why animal rivals usually do not fight to the death), retaliation (behavior dependent on that of one’s opponent), and territorial defense.

Ch. 6, “Genesmanship” Reminder that a gene is not a single bit of DNA but all the replicas of that bit of DNA, wherever they are found (i.e., in whichever bodies they are “sitting”). Altruism can result from selfishness due to shared genes. (W. D. Hamilton calculated the probability of shared genes in a population.) Some altruistic behaviors, e.g., parental care, are advantageous to survival. (An animal must survive long enough to reproduce and must have lots of offspring for genes to be successful.)

Ch. 7, “Family Planning”  Bearing offspring and caring for them are separate behaviors. Most animals regulate their birthrates, and genes for the optimal number of young will eventually win out over genes for too few or too many young. In territorial animals, control of a territory can grant males “permission” to breed. Males without territories may never breed. Some attention is given to the problem of human over-population: leaders who forbid effective contraceptive methods “express a preference for ‘natural’ methods of population limitation, and a natural method is exactly what they are going to get. It is called starvation.”

Ch. 8, “Battle of the Generations”  “Parental Investment” (R. L. Trivers), or more accurately, “Altruism Investment” (Dawkins) refers to how many life resources an animal will invest in its young or other members of its family or group. Some young are better risks for a parent to invest in than others (e.g., runts). Addresses the issues of sibling rivalry (including fratricide) and parasitic bird behavior like cuckoos laying their eggs in the nests of other birds. Discusses how offspring may (unconsciously) manipulate their parents, forcing them to feed them by screaming, which attracts predators to the nest. Dawkins points out that altruism must be taught, as it does not come naturally.

Ch. 9, “Battle of the Sexes”  Mated pairs may cooperate to raise young, but they are naturally inclined to try to exploit one another. It is common for one parent to leave the other to raise the young, and whereas with animals that breed by copulating it is usually the male that runs off, leaving the female to bring up the young, with water-dwelling animals where the male fertilizes the eggs once they are released into the water, it is often the female who skips town, leaving the male to care for the young. It depends on who has the first opportunity to escape.

Animals where parents share the burden do so in response to genetic programming that has been determined to lead to a more successful outcome. In this case, females often try to spot signs that a potential mate will be faithful or not before they consent to mate. Different strategies for choosing a mate: “domestic bliss” or “he-man”. Females can be coy or fast, while males can be faithful or philanderers. Characteristics like the heavy tail of a bird of paradise or a peacock can demonstrate to a female that the male is strong enough to survive despite dragging around all that extra stuff behind him. What makes one animal male and the other female? It boils down to the gametes (sex cells): female gametes are larger (because they contain nutrition to feed the embryo) and fewer, while male gametes are tiny, more numerous, and faster. The optimal sex ratio is 50:50.

Ch. 10, “You Scratch My Back, I’ll Ride on Yours”  Interactions between different species or members of a population, including alarm calls and how they probably develop in a population of prey animals, and symbiosis, such as slave-holding, aphid-milking, and fungus-gardening ants, kamikaze bees, and grooming behaviors.

Ch. 11, “Memes: The New Replicators”  It turns out that Dawkins coined this popular term in this book. A meme is an element of human culture which can spread through a population just as a gene can. Memes can be pieces of language, music,  fashion, ways of making things, etc. God is a meme. (The musical oeuvre of Johann Sebastian Bach would constitute a “meme-complex”.) Memes replicate through imitation and are passed on in altered form, continuously mutating and blending. They can replicate much faster than genes.

Ch. 12, “Nice Guys Finish First”  Finally, the role of altruism in the success of certain genes. Dawkins uses Game Theory to explain that animals cooperate with each other because cooperation (“niceness”, “forgiveness”) leads to a more stable survival strategy. A group of strategies called Tit for Tat (only defect in retaliation for another’s defection; if the other cooperates, you cooperate as well) is the most stable of all. Dawkins has plenty of animal and also human examples of how this works, even using it to explain the cooperation between Allied and Axis troops during World War I (the famous Silent Night in the trenches being only one example).

Ch. 13, “The Long Reach of the Gene”  I suppose that this chapter was not part of the original publication, because Dawkins explains that it summarizes another book he wrote called The Extended Phenotype (1982). A phenotype is a physical manifestation of a gene, like eye color, skin color, or (I suppose) a propensity to do well in mathematics (just conjecture here). The idea is that genes can influence things beyond the body they are in; for example, a beaver is programmed by its genes to build dams, thus transforming its environment. The beautiful stone “houses” that the larvae of the caddis fly construct to protect their soft bodies are another example, as are, I suppose, the constructed landscape that humans build for themselves.

Dawkins also addresses the questions of why genes teamed up in cells, why cells teamed up in multi-cellular organisms, and most interestingly, why the lives of multi-celled animals begin and end with a single cell, a fertilized egg (a “bottle-necked” lifestyle). As Dawkins writes, “Really, I’d almost rather you stopped reading now and switched to The Extended Phenotype!”

Epilogue to Fortieth Anniversary Edition  Dawkins considers whether he would make major changes to The Selfish Gene and concludes that, except for a less inflammatory title (he suggests The Immortal Gene might have been better received and is also more poetic), he would not; current knowledge of gene structure presents no challenge to his ideas as long as his definition of gene is understood (Cf. Ch. 3).

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