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MindMap Gallery The Selfish Gene [English] Richard Dawkins
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The Selfish Gene [English] Richard Dawkins
In this book, Dawkins introduces in detail the main topics in social theory one by one, such as the concepts of altruistic and self-interested behavior, the definition of selfishness in genetics, the theory of kinship (including parent-child relationships and the evolution of social insects), The theory of sexual ratios, reciprocal altruism, deceptive behavior, and natural selection of sexual differences. At the same time, based on the progress of biological research and his own understanding, Dawkins determined the unit or level of biological evolution in genes, and through the use of ethical language, he explained that the basic characteristic of genes is "selfishness."
Edited at 2023-03-28 16:27:03
- cáncer de pulmón
El cáncer de pulmón es un tumor maligno que se origina en la mucosa bronquial o las glándulas de los pulmones. Es uno de los tumores malignos con mayor morbilidad y mortalidad y mayor amenaza para la salud y la vida humana.
- diabetes
La diabetes es una enfermedad crónica con hiperglucemia como signo principal. Es causada principalmente por una disminución en la secreción de insulina causada por una disfunción de las células de los islotes pancreáticos, o porque el cuerpo es insensible a la acción de la insulina (es decir, resistencia a la insulina), o ambas cosas. la glucosa en la sangre es ineficaz para ser utilizada y almacenada.
- sistema digestivo
El sistema digestivo es uno de los nueve sistemas principales del cuerpo humano y es el principal responsable de la ingesta, digestión, absorción y excreción de los alimentos. Consta de dos partes principales: el tracto digestivo y las glándulas digestivas.
The Selfish Gene [English] Richard Dawkins
- cáncer de pulmón
El cáncer de pulmón es un tumor maligno que se origina en la mucosa bronquial o las glándulas de los pulmones. Es uno de los tumores malignos con mayor morbilidad y mortalidad y mayor amenaza para la salud y la vida humana.
- diabetes
La diabetes es una enfermedad crónica con hiperglucemia como signo principal. Es causada principalmente por una disminución en la secreción de insulina causada por una disfunción de las células de los islotes pancreáticos, o porque el cuerpo es insensible a la acción de la insulina (es decir, resistencia a la insulina), o ambas cosas. la glucosa en la sangre es ineficaz para ser utilizada y almacenada.
- sistema digestivo
El sistema digestivo es uno de los nueve sistemas principales del cuerpo humano y es el principal responsable de la ingesta, digestión, absorción y excreción de los alimentos. Consta de dos partes principales: el tracto digestivo y las glándulas digestivas.
- Recommended to you
- Outline
selfish gene
Chapter 1 Why is there someone?
Wrong definition of "biological" altruism - organisms evolve to "benefit their species" or "benefit their group"
Interest - what we call "interest" means "opportunity to survive",
The “wrong” theory of evolution
Wynne Edwards' theory of "group selection" - the world is likely to be occupied by groups of individuals with a spirit of self-sacrifice
"Individual selection" theorists - a selfish rebel can exploit the altruism of other members and thus be more likely to survive and reproduce than other members.
"I" theory
"Gene selection" - using "gene selfishness" to explain "individual selfishness" and "individual altruism"
Purpose - To study the biological significance of selfish behavior and altruistic behavior.
Argument - We and all other animals are machines created by our genes. (In some special circumstances, a kind of limited altruism can also be fostered)
Definition - only concerns the effect of the action, whether it reduces or increases the likelihood of survival of the putative altruist, and the likelihood of survival of the putative beneficiary.
"I" do not "argument"
1. I do not advocate an evolution-based morality
2. Positional issues in the debate over "nature or upbringing" as the decisive factor in human characteristics
3. No detailed description of the behavior of humans or some other animal.
Chapter 2 Replication Factors
The first part of the argument - "evolution"
It briefly explains Darwin's "evolutionary theory" - "survival of the fittest", that is, "survival of the stable" → countless stable substances "aggregates of atoms" move and combine over and over again to form various molecules.
Briefly describe the "origin of life" - organic matter energy → larger organic molecules (primordial soup) → replicators (the first modern replicator DNA) → conditions for evolution
"Evolution" is made possible by the "errors" made by the original replicator during its replication process
"Three" conditions for stable development
"Long-lived" replicators will "evolve"
Replicating factors that replicate quickly will "evolve"
Replicating factors with high replication accuracy will "evolve"
Are replication errors and high-precision replicators both conditions for evolution? How to mediate their contradictions?
Evolution seems to be a "good thing" in some vague sense, especially since humans are the product of evolution. evolution happens by chance
The second part of the argument – “Competition”
The limited resources (components) caused a competition among "replicating factors" → "replicating factors that constructed a survival machine for themselves to live in" survived.
Chapter 3 The Immortal Double Helix
The "species" on the earth are all survival machines of "replicating factor DNA", but their survival methods are different - there are creatures that live in water, and there are creatures that live in the air; there are creatures that reproduce asexually, and there are also creatures that reproduce asexually. sexually reproducing organisms
A brief description of the DNA molecule
1) The "nucleotide building blocks" in all animals and plants are the same, which can be abbreviated as A, T, C and G, but the sequences they are constructed are not the same (not only between humans and animals, but also between individuals) are all different)
A, T, C and G are the "bases", and the bases make up the DNA molecule. Only a small part of it is genetic
2) Two things the DNA molecule does
self-replicate
Indirectly oversees the manufacture of different types of molecules - proteins
3) Genes control embryonic development
Genes control the production of the human body, and their influence is unidirectional. Acquired characteristics cannot be inherited.
Natural selection favors genes that skillfully control embryonic development
4) Characteristics of modern replication factors (modern DNA)
It is highly social - genes cooperate with each other
The gene itself can survive for a long time
However, the emergence of sexual reproduction has made the survival time of each individual gene combination short-lived. That is to say, the survival time of the "gene combination" is short-lived, but a single "gene" can survive - through inheritance
Discuss the persistence of individual genes
The author defines a gene as - any part of chromosomal material capable of acting as a unit of natural selection for several successive generations. That is, the replication factor for highly accurate replication
Sexual activity mixes genes (23 chromosomes in sperm 23 chromosomes in ovaries)
The lifespan of a chromosome is one generation, and the genetic unit is "small enough" that it may be a complete copy of the "original" genetic unit
The shorter the genetic unit, the longer it lives → a cistron is likely to be much shorter than 1% of a chromosome, and even a group of adjacent cistrons can live for many generations before breaking down for exchange. (A cistron can probably be called a gene, but units larger than a cistron should also be considered genes)
way of new genetic units
Preexisting subunits come together by chance by exchange (general approach)
Point mutations (rare; the longer the genetic unit, the more likely it is that it has been changed by a mutation at some point)
Inversion (rare; usually catastrophic, but may be closely linked to "good genetic material" to form new genetic units; the best example is "mimicry")
Genes approach the paradigm of indivisible particles to a considerable extent; but they are not indivisible, but they rarely separate; and they do not age
Conditions for perpetuation of a single gene
Only "good" genes can be "eternal"
In the gene pool, the "good" genes are the winners after competing with alleles. So, at the genetic level, altruistic behavior must be bad, and selfish behavior must be good.
(How to call it "good" genes? - "Suitable" genes. For example, carnivores need sharp incisors to survive well, intestines suitable for digesting meat, etc.; while herbivores need flat grinding teeth. , and a much longer intestine.
The role a gene plays depends on its environment, which includes other genes
Genes are immortal, while the lifespan of individuals and other higher-order units is short-this assumption is based on the following two facts
Sexual reproduction and chromosome exchange
Sexual Reproduction and Chromosome Exchange – What Are the Benefits of Sex? →Genes are "selfish" →If sexual reproduction, as opposed to asexual reproduction, is beneficial to the genes responsible for sexual reproduction, this is a sufficient reason for the existence of sexual reproduction.
The reason why we can think of this small genetic unit or gene as closest to a basic and independent evolutionary factor is the result of sex and chromosome exchange.
death of the individual
Another common property of successful genes is that they usually postpone the death of their survival machines until at least after reproduction (ancestors do not die young)
Late-acting lethal genes in the gene pool are much more stable than early-acting lethal genes
Chapter 4 Gene Machine
Main content: Discussing behavior—the kind of rapid movements that are widely used by branches of animals
Gene reservoir→survival machine
Plants use sunlight to build complex molecules from simple molecules
animals - eating plants or other animals
The kind of rapid movements widely exploited by branches of animals
The part used in animal evolution to perform fast movements is muscles
The basic unit of a biological computer is the nerve cell or so-called neuron
How we control the timing and speed of muscle contractions
Motor nerves are responsible for controlling and coordinating muscle contractions
The development of memory has allowed the timing of muscle contractions to be influenced by events not only in the recent but also in the long past.
The behavior of survival machines has one of the most prominent features, which is its obvious purpose
(1) Help animals’ genes survive
(2) A certain kind of "purposeful behavior" that is more similar to human purposeful behavior
(At least one of the modern survival machines has gone through the process of evolution, so that this purpose has gradually acquired the characteristic we call "consciousness")
In order to achieve "certain purpose", genes need to control the "survival machine". However, due to the "time lag", genes cannot directly control the "survival machine". Instead, they control the synthesis of proteins.
Since the survival machine needs "timely response" to survive in the face of "countless" "encounters", and genes do not have such a fast response time, it can only do its best to deploy everything in advance so that it can gain enough future Laws of all "possibilities" that will occur, and "advice" for them.
How genes predict the future
Give the survival machine a learning ability in advance (for example: do things that make you feel "positive" and avoid things that make you feel "negative")
Simulation - Good simulation is far better than blind trial and error → The evolution of simulation capabilities seems to eventually lead to the emergence of subjective consciousness (thus, survival machines are finally liberated from their masters, genes, and become capable of execution decision makers)
Altruistic and selfish behaviors are both under genetic control
For an altruistic behavior to survive, the gene for that behavior must be more likely to survive than the genes for other behaviors.
Every "behavior" operation has its own "gene" ("uncovering" and "throwing" in the bee experiment). Their union makes the whole action meaningful, so from this perspective they can be regarded as a single cooperative unit, but as replicators, they are two free and independent actors.
A way to promote genetic survival through superficial altruistic behavior - contact
The gradual improvement of communication signals benefits both the sender and the receiver.
Whenever a communication system develops, there is always a risk that some organism will exploit the system for its own benefit (all animal communication involves some element of fraud)
Chapter 5 Aggression: Stability and Selfish Machines
Main content: The concept of "aggression" is largely misunderstood
Natural selection favors genes that control their survival machinery and make the most of their environment
A strategy that allows survival machines to persist - Evolutionary Stability Strategy or ESS
(Once established, the ESS becomes stable: deviations from the ESS will be punished by natural selection.)
When the two sides are "symmetrical" (the conditions for the participants in the competition are equal in all aspects except fighting strategies)
Most of the ESS used by each individual is a "responsibility strategy" (a mixture of counterattack strategy, exploratory counterattack strategy and pigeon strategy)
Calm facial expressions are an evolutionarily stable strategy
When both sides enter an "asymmetric" competition
There seem to be three main categories of asymmetries
Category 1 - Individuals may differ in size or fighting equipment (different species & same species)
Category 2 - Individuals may differ based on the number of fruits of victory
Category III - purely arbitrarily assumed and apparently unrelated asymmetries
The ESS strategies formed by these three categories respectively
The first category - reasonable strategists (picking small battles), paradoxical strategists (picking big battles)
Category 2 - Dominant order (winner always wins)
The third category - territorial behavior (residents and intruders, they generally have conditional strategies: "For those who stay, attack; for all intruders, retreat.")
Stable genomes are best able to survive in the gene pool
Chapter 6 Genetic Race
Main content: Genes may help duplicates that exist in some other individuals
The purpose of genes—trying to expand their ranks in the gene pool
The method used is to help the "individuals" it inhabits program themselves to survive and reproduce.
Raise the question - Why does "individual" altruism to "close relatives" exist?
Solve the problem - the apparent altruistic behavior of "individuals" is actually the "selfish gene"
Argument question
1. Most close relatives share the same genes, and the gene that controls an individual's altruistic behavior toward relatives may lose one copy, but a large number of copies of the same gene are preserved.
2. How to make up for the individual's "self-sacrifice" to obtain equal or greater benefits - Calculated on average: one altruistic gene prepared for self-sacrifice = saving more than two siblings (children or parents) = more than 4 aliens Half-siblings (or uncles, aunts, nephews, nieces, grandparents, grandchildren) = 8 or more first-generation cousins
3. Why parental love is greater than biological relationship——
1) Certainty index: Genetically speaking, the relationship between parents and children is not closer than the relationship between brothers and sisters, but it is much more certain. (Under normal circumstances, it is not as easy to determine who is your brother as it is to determine who is your child)
2) Life expectancy: As far as the average life span in the equation is concerned, genes that control parents’ altruistic behavior are in a relatively advantageous position.
Chapter 7 Family Planning
Main content: How an individual survival machine should make decisions about whether to give birth to new individuals.
Knowledge points
The individual survival machine must make two completely different kinds of decisions - decisions to raise and decisions to reproduce.
The most evolutionarily stable strategies—mixed strategies of rearing and reproduction
How animals regulate “birth rates” – two divergent arguments
1. Animal birth control is altruistic, and birth control is done for the overall benefit of the group.
1) Animals that have a "territory" and win in the "male competition" have a better chance of breeding, and losers exit the "breeding" stage.
2) For the welfare of the group, the task of stray animals is to act as substitutes, ready to take over the position of the territory occupier who dies on the stage of group reproduction.
3) Animals will engage in "showy behavior" to understand the overall number of animals, and family planning
Summary: Individuals limit the number of children they have for the overall benefit of the group (proposed by Wynn-Edwards)
2. Animal birth control is selfish and is done for the benefit of the individuals who reproduce.
1) Draw conclusions based on the observation of "number of eggs in wild bird nests"
A. Each selfish individual’s choice of the number of hatching eggs in each clutch is based on the number that it can raise to the maximum extent.
B. They control their fertility in order to maximize the number of surviving children they have
2) Refutation of Wynn Edwards’ “altruism” argument
A. Animals that do not own a territory are physiologically capable of reproduction.
B. Wandering animals spend less energy and wait for territorial animals to die.
C. "Family planning" is to prevent "famine" caused by excessive population
Summary: Parental individuals practice family planning in order to keep their birth rate at an optimal value.
Chapter 8 The war between generations
Ask a question: Should mothers treat their children equally, without favoring one over another?
1. Concept
Parental investment is defined as: “Any form of investment by a parent in an individual offspring that increases that individual’s chances of survival (and therefore successful reproduction) at the expense of the parent’s ability to invest in other individuals of the offspring. "
Disadvantages: Parental investment is not a perfect calculation method because it overemphasizes the importance of parents and relatively devalues other genetic relationships.
Altruistic investment: We say that individual A invests in individual B, which means that individual A increases the survival chances of individual B, but at the expense of individual A's ability to invest in other individuals, including himself. All costs need to be weighted according to the appropriate kinship index.
Disadvantages: This method is too cumbersome and cannot solve practical problems.
2. Demonstrate whether parents should not treat everyone equally
(1) Mother’s point of view
1) In terms of relatedness, a mother's "relatedness index" to herself is twice the closeness she has to any of her children, other conditions remaining unchanged. This means that she deserves to selfishly keep most of her resources to herself.
2) However, genes that are willing to spend part of their resources on their children, which encourages investment in individuals who are more in need rather than in themselves, can gain an advantage in the gene pool.
3) Genetically, the relatedness index between mother and each child is the same, which is ½. But in reality, some individuals are more ideal life insurance insureds than others.
A. If the uneven distribution of resources means that one of the parties is going to die, the one who is saved is often the older one because the parental investment in him or her is greater.
B. If the decision does not directly involve a matter of life or death, then more resources will tend to be allocated to the younger child. Because older children are "more capable"
In different scenarios, parents’ choice of “parental investment” has different emphasis
(2) Children’s perspective
1) In terms of kinship, he is twice as close to himself than to any of his siblings. The closeness between him and any of his brothers or sisters is exactly the same as the closeness between his mother and her children, and the relatedness index is ½
2) Genetically speaking, he and his mother both want to work for the benefit of his siblings, and they hold that desire to an equal degree.
3) The older person will behave "humbly" so that the younger person can obtain the resources they "need more".
4) Competition among "mates of the same generation" or "nest" may become more intense for the possibility of survival.
Summary: If other conditions remain unchanged, he will hope that his mother will invest more in him.
The final outcome: often a compromise between the ideal conditions sought by the offspring and the ideal conditions sought by the parents.
selfish gene
Chapter 9 The War of the Sexes
Dive Deeper: The Fundamental Nature of Maleness and Femaleness
1. The basic definition of male and female - Gender has a basic characteristic by which all animals and plants can be designated as male and female. This is because male sex cells, or "gametes," are much smaller and more numerous than female "gametes."
(Volume: egg > sperm; quantity: sperm > egg)
2. The difference between sperm & egg:
1) The egg provides food storage, but the sperm does not provide it and is only responsible for transferring genes to the egg (therefore, the father's investment in the offspring is less than his share of resources (50%))
2) Sperm can produce a large number of embryos, so it has the potential to breed more babies.
*Natural selection favors the creation of sex cells that are small but can proactively find and fuse with larger ones.
3. Different evolutions of sexual “strategies”:
1) Heavy investment or “honest” strategy – Egg
2) Small investments, exploitative or “sneaky” strategies – sperm
4. Knowledge of the mechanisms that determine gender
1. The strategy of producing an equal number of children is an evolutionarily stable strategy (genes that deviate from this strategy will suffer a net loss)
1) Explain based on the theory of parental investment
(1) The usual situation is that the amount of investment in each son is roughly equal to the amount of investment in each daughter, and the sex ratio is generally 1:1 in terms of quantity.
(2) Assume that every individual is a selfish machine and does its best to maintain all its genes. The optimal strategy for such a selfish machine is often completely different depending on its gender.
(3) Reducing one’s own investment in “raising” children in order to obtain more reproductive opportunities is a strategy that both genders yearn for.
(4) Often, a female’s physiological structure requires her to pay more for “raising” than a male. (Female individuals are exploited, and the main evolutionary basis for this exploitation is that eggs are larger than sperm)
(5) Then, for females, the following actions can be taken to make males pay more "nurturing" investment than themselves:
a. Trick another male into adopting her baby, "thinking" it is his own baby - Disadvantages: The male may kill the potential stepson or stepdaughter (Bruce effect) or discover that the female is pregnant. When a pregnant female rat smells this chemical, she abandons her (*Bruce effect): Male rats secrete a chemical that causes them to abort themselves.
b. The female will abort the fetus and find a new mate as soon as possible
c. Raise the child in an attempt to get something in return or because the child also has half of the male's genes, she can vent her resentment on the child and abandon the child.
d. For a female who is in danger of being abandoned, the appropriate strategy is to leave the male before he abandons her.
F. The best strategy a female can use to mitigate the losses caused by her mate exploiting her in the first place is to refuse to mate.
2) In natural selection, beneficial strategies for female and male selection
(1) The strategy of male individuals - to mate with as many females as possible to obtain more offspring.
(2) Strategies of female individuals
A. the domestic-bliss strategy
*The simplest form is: the female individual first looks at the male individual, trying to detect signs of his loyalty and attachment to family life in advance
Strategies you can use to spot loyal males
(The word "strategy" refers to a blind, unconscious behavioral program):
a. Putting on airs and coyness for a long time (the patient male wins)
b. Wait until the male builds her nest before agreeing to mate with her, or the male must feed the female a considerable amount of food
c. According to different females and different male individuals, there are two strategies:
The two female strategies are called coy and fast
The two strategies of males are called faithful and philanderer.
When a slutty female enters this group → slutty female ⬆ → callous male gene ⬆ → slutty female ⬇ shy and shy female ⬆ → loyal male ⬆ (completes a cycle)
*But for the "strategy" to really work, an important assumption is required - that most individuals of the female population are willing to adopt the same approach. (If a "loose" female appears, the male will choose to abandon the "coy" female)
B. The he-man strategy.
*Species that adopt this strategy no longer care about the father of their children. Rather, they are “selective” genes. That is to select male individuals that you think are "high quality" enough.
In this regard, their criteria for selecting "male" are:
a.Signs of survivability
b. Perhaps it represents strong muscles that can capture food, or it may represent long legs that can escape predators.
Individuals of both sexes "want" to maximize their total reproductive success during their lifetime; the resulting conflict of interests results in an "evolutionarily stable strategy" that is better for both parties in the relationship.
Chapter 10 You tickle me, and I’ll ride on your head
Main content: social animals
1. Why animals put themselves in more "dangerous" situations in order to "save" the group (explain with various examples)
1) The bird makes a warning sound to notify its companions of approaching danger, but its sound also increases its own danger.
(1) Kelvey's theory - if the companion's voice is too noisy, the location will be easily exposed. By issuing a warning sound, the companion will not reveal himself.
(2) "Never leave the team" theory - leaving the team is more dangerous than issuing a warning sound
2) The jumping behavior of gazelles - in order to prove that they are "powerful" so that "predators" will not target them.
3) Suicidal behavior of social insects such as bees - workers are sterile (workers use their mothers to produce copies of their own genes at the expense of protecting or sacrificing themselves)
2. Mutually beneficial relationship/mutually beneficial symbiosis
1) Ants & aphids, lichens & fungi and green seaweed - this basic asymmetry can lead to evolutionarily stable strategies for mutual cooperation.
2) Each of our genes is a symbiotic unit. We ourselves are a huge group of symbiotic genes
Chapter 11 Memes: New Replicating Factors
Main content: Discuss the uniqueness of human beings
1. What makes us unique as humans can be summed up in one word – culture (transmitted through language)
2. The author believes that the principle that is universally applicable to all forms of life may be the law that all life evolves through the differential survival of replicating entities. (Gene is one of them)
3. The author believes that a new type of replicating factor has appeared on our planet - culture, which he calls "memes" (melody, concept, punchline, fashion, way of making pots or building arcades are all memes) )
4. Analogy between memes and genes
1) Broadly speaking, memes reproduce themselves through imitation. By analogy with genes, not all genes are good at replicating themselves, and the same goes for memes.
2) The characteristics that contribute to the survival value of memes are the same as those of replicators: longevity, fecundity, and the ability to replicate accurately.
3) But regarding "accurate copying ability": Far from the granular, all-or-nothing genetic properties of gene transmission, meme transmission is affected by successive mutations and intermixing (e.g. : All those who firmly believe in Darwin's theory do not completely copy Darwin's own words, but interpret his theory in their own way)
4) Analogy with genes’ “purposeless” and “unconscious” “selfless” and meme:
(1) Wherever sexual reproduction exists, each gene competes with its alleles, which are its rivals for the same position on the chromosome.
(2) Memes do not seem to have anything equivalent to chromosomes, nor do they have anything equivalent to alleles. But he may have some type of competition. (For example: conflicts between different cultures, different people choose the communication of different cultures)
5) Memes and genes often support and reinforce each other, but they sometimes conflict.
*Such as celibacy. Genetically, celibacy is not heritable (except in very special circumstances, such as in populations of social insects), but memes that promote celibacy in individuals can succeed in the meme library.
There are two things we can leave to our descendants after we die: genes and memes. But genes will gradually die out from generation to generation, but memes are eternal (your various "cultural outputs")
Chapter 12 Good people will eventually be rewarded
Main content: Discussing "good people will be rewarded"
1. Understand the conclusion of "good people are rewarded" through games:
1) "Prisoner's Game"
(1) The order of benefits obtained from the "Prisoner's Dilemma" in the game: the temptation to betray > the reward for mutual cooperation > the punishment for mutual betrayal > the price of failure.
(2) In a simple game, we can foresee that "defection" is the only rational strategy; however, in repeated games, we can obtain more other strategies, not just "defection".
(3) Among various strategies, researchers found that strategies distributed under the categories of "kindness" and "tolerance" can achieve more wins.
(4) However, these "successful strategies" also depend on your "opponent's strategies"
(5) The "Tit for Tat" strategy with categories of "kindness", "tolerance" and "non-jealousy" (the strategy you make depends on your opponent). If you want to defeat the "Always Betrayal" strategy, you need to make yourself a "dominant one" "Party" - the most obvious way is to be brought together by genetic ties - kinship
(6) Although the "Always Betrayal" strategy is an "evolutionary stable strategy", it cannot help each other to achieve group prosperity, and will also make their respective living environments worse; therefore, in "repeated games", "tit for tat" will eventually Gather enough numbers to cross the decisive point, and their numbers will eventually rebound.
2) How to transform "zero-sum game" into "non-zero-sum game"
Most situations in real life are non-zero-sum games, where society plays the role of "banker" and individuals benefit from the success of the other party. Cooperation and mutual assistance also promote social prosperity and development
(1) It can only happen when the game is repeated. Players must understand that this is not the last game between them.
(2) Theoretically, the length of the game is not important. What is important is that both parties in the game must not know when the game will end.
(3) In general: Natural advantage requires setting up a prisoner's dilemma with a long shadow in the future, and it is a non-zero-sum game.
Chapter 13 The Extension of Genes
In-depth discussion: How to resolve the contradiction between "life carrier" and "gene", two different ways of thinking about life
1. When the "gene's phenotype" is beneficial to the "overall gene", the theoretical contradiction is easily resolved, and what is beneficial to the gene is also beneficial to the entire living organism. (For example, the "speed" of an individual can enable the individual to succeed, avoid harm, and benefit all genes)
2. When the phenotype of a gene is only beneficial to it, but harmful to other genes and the entire body? (Isolated disguised factors do not manifest themselves as a "phenotype" but instead extensively replace their alleles to enter the sperm/egg)
1) If both good and bad effects occur in an organism at the same time, the result still helps the entire body.
2) If there are only adverse effects on the body, but genes only have benefits, the result will be disastrous for the organism.
3. Gene extension
1) Genes not only affect the own individual, but can also have an extended phenotypic impact on another organism (trematodes and snails)
2) Genes may leave the body of an individual and affect the phenotype of other individuals. ("parasitic castration")
3) The central dogma of "extended phenotypes": Animal behavior tends to maximize the survival of the genes that direct that behavior, regardless of whether those genes are present in the animal that performs the behavior. (cuckoo)
4. The contradictory relationship between individual organisms and genes competing for the central position in natural selection - one way to solve this problem is to use "replicating factors" and "vectors"
1) The replicator is the basic unit of natural selection, the fundamental individual of life and death, and connects replicating bloodlines that are essentially the same or randomly mutated from generation to generation.
2) DNA molecules are replication factors, and they are usually linked together to form a larger public gene storage machine - a "carrier" (for example: our body)
3) Genes and individual organisms play different roles as replication factors and carriers respectively, complementing each other and being equally important.
4) Why do genes need to be chosen to form large vectors? (Broken into three questions)
(1) Why do genes make up cells? ——Similar to the "extension of genes", genes must achieve symbiosis through cooperation, and this cooperation does not stop at cell biochemistry. Cells come together to form multicellular organisms
(For example: Each protease was selected as a separate, selfish gene, but it could only thrive in the presence of other genes in its group.)
(2) Why do cells form multicellular organisms? ——The combination of these cells can exert their unique expertise, and each component can be more efficient in handling its specific tasks.
(3) Why do organisms adopt a "bottleneck" life cycle? ——Bottleneck" The historical tendency of life makes organisms evolve into independent and unified carriers. The three supporting reasons for this theory can be called "back to the drawing board", "punctual time cycle" and "cell unity" respectively.
Chapter 14 Genetic Determinism and Genetic Selection Theory
Main content: Debunking the myth of genetic determinism
1. What do we mean when we say that one thing determines another? Philosophers think more about cause and effect, while for professional biologists, cause and effect is just a simple statistical concept.
2. All genetic factors must be in a certain environment when they work.
3. Genes may change the effects of other genes and may change the role of the environment. Internal and external environmental events may alter the effects of genes, as well as the effects of other environmental events.
4. Theoretically speaking, there is no difference between genetic causes and environmental causes. Some of the effects caused by both are difficult to reverse, while other effects are easy to reverse. Some effects may often be difficult to reverse, but can become easy with the right approach.
5. Genes do not directly control behavior by intervening in the implementation process of the behavior. The only control comes from programming the machine before the behavior is performed.
6. Whether you happen to agree that genes are causal factors or environmental determinants, it will not have any positive or negative impact on the discussion of determinism and free will.
7. Are there genes that make some people “smarter” than others? In this regard, the following arguments cannot be denied:
(1) At a certain point in time, our ancestors were not as brainy as we are;
(2) There must have been an increase in "brainfulness" in all our ancestors' lineages;
(3) This growth is achieved through evolution, possibly driven by natural selection;
(4) Whether driven by natural selection or not, at least some of the evolutionary changes in phenotype reflect deep-seated genetic changes—allelic replacement has occurred, resulting in an increase in the average level of mental ability across generations;
(5) Human groups must have had significant genetic changes in their "braininess", at least in ancient times. At that time, some people were genetically smarter than their contemporaries, while others were genetically dumber.
Chapter 15 Constraints on Perfection
Main content: Constraints of perfection - all living things are the result of "adaptation"
1. Make a list and categorize the constraints to perfection, and 2. List the main reasons why students should proceed with caution as they learn to adapt.
1. Constraints of perfection
(1) Time lag - the animals we see today are most likely "obsolete" and the genes that affected their establishment were selected at an earlier period in response to conditions different from today's . (Changes in the environment may change the nature of the phenotypic trait we want to explain)
(2) Historical constraints—theoretically may enhance the likelihood that a lineage will achieve optimal design. True natural selection is an anti-perfection mechanism due to its lack of foresight.
(3) Available genetic changes - the "genes" animals receive are not the most perfectly designed. It is the product of a series of historical changes, and each change represents, at best, the option that happened to be better at the time.
(4) Cost and material constraints - the best design is the solution that meets the index requirements at the lowest cost ("satisfies the minimum demand").
(5) Imperfections at one level due to selection at another level—what one individual selectionist sees as adaptive may be seen as imperfect by another group selectionist
(6) Errors caused by the unpredictability or "maliciousness" of the environment - No matter how well an animal adapts to its environment, these environmental conditions must be regarded as a statistical average. It is often impossible to cover every conceivable contingency in detail.