The Selfish Gene

Book Recommendation: The Evolution of Cooperation by Robert Axelrod Book Recommendation: The Extended Phenotype by Richard Dawkins

I have long felt that biology ought to seem as exciting as a mystery story, for a mystery story is exactly what biology is.

There is a better reason to study zoology... This reason is that we animals are the most complicated and perfectly-designed pieces of machinery in the known universe.

Chapter 1 - Why are people?

Intelligent life on a planet comes of age when it first works out the reason for its own existence.

Genes only yield cooperation under narrow circumstances and mostly focus on their survival and lead to selfish behavior in most cases. Analogy: Genes shape body like life as Chicago gangster shapes character, the ones who make it got to have certain characteristics.

Nature vs. Nurture, evolution does not dictate morale of selfishness, culture plays a role, yet, genes and their selfishness should not be forgot and factored into the picture.

Altruism towards the species is not a thing. Things that look like they are done for the survival of the species are done for the survival of the genes.

If it were true, dissenter could become more successful within species, therefore ending the altruism forever. Since that is not the case it has to be selection at a different level.

Often altruism within a group goes with selfishness between groups.

The muddle in human ethics over the level at which altruism is desirable - family, nation, race, species, or all living things - is mirrored by a parallel muddle in biology over the level at which altruism is to be expected according to the theory of evolution.

Book recommendation: Adaptation and Selection by G.C. Williams

Chapter 2 - The replicators

In the beginning was simplicity.

Darwin's idea is a special case of survival of the stable. And therefore can serve as an explanation of how things grew in complexity over time. It can therefore answer the question of where we came from to a high degree of satisfaction. That however begs a question? Is life stable? Because I would argue that it is the very opposite of stable. It is patterns that change all the time, and rising in complexity and therefore life is not stable? Also compared to a rock, or a star, life is very fragile and can go unstable in an instant and vanish. In a way then life is metastable. And that's what allows evolution to act. What allows things to grow and flourish.

Darwin's theory of evolution by natural selection is satisfying because it shows us a way in which simplicity could change into complexity, how unordered atoms could group themselves into ever more complex patterns until they ended up manufacturing people.

If a group of atoms in the presence of energy falls into a stable pattern it will tend to stay that way.

Molecules snap into place randomly until critical complexity is reached, where they can start self replicating, that's where Darwin's theory starts to take hold. As soon as a self replicator is reached it will start to copy itself through the original material. But there might be errors, variations within the replicator chemistry can arise. Those would start competing. And that's all that is necessary for evolution to be off the races. Ones that replicate faster take over, they start to improve. Furthermore and somewhat unintuitively those that replicate more accurately also have an advantage and evolution happens besides replicators trying to be 100% accurate.

Evolution is something that happens, willy-nilly in spite of all the efforts of the replicators to prevent it happening.

Human suffering has been caused because too many of us cannot grasp that words are only tools for our use.

Replicators come into competition and develop strategies to scavenge other replicators for their constituents - the first "predators" are born. Others form shells and the first cells are born.

Replicators began not merely to exist, but to construct for themselves containers, vehicles for their continued existence. The replicators that survived where the ones that built survival machines for themselves to live in.

They have come a long way, those replicators. Now they go by the name of genes and we are their survival machines.

Chapter 3 - Immortal Coils

Todays replicators are DNA and we are their survival machines. We in this case are all that we consider the biosphere to contain. DNA letterering order is the pattern that is preserved and propagated. Not us.

Now a question: In a changing environment, wouldn't it make sense for the replicator that produces the most stable replicators in the long run to win out? There could be a point of stability existing just because of change. In such a way as that all the biosphere is just one giant replicator trying to squeeze out the most replications possible. It would be looking one level below the apparent patterns within genes at the molecule DNA itself. It is not the stability over time that makes for its success but it's malleability. The forms that it can produce, in other words all of life, make it such a great replicator, such a great molecule.

DNA as a replicator, genes as pages, chromosomes as volumes, the whole is an architects plan for building a machine that can make more architects plans. Do do that, the plan has to be translated into the real world, formed into a structure - DNA codons -> amino acid sequences -> proteins -> cells -> tissues -> bodies

Genes have no foresight. They do not plan ahead.

Two different copies of genes, one from father one from mother, sometimes one copy takes precedence over another, different copies are called alleles. Set of all alleles is named gene pool. Germ line cells are formed by meiosis, half of the genome is split, from 46 to 23 chromoses in humans, two germ line cells then combine at conception to form complete human. The normal cell division is called mitosis. During meiosis, the 23 chromosomes change - the 46 are not just separated, but shuffled, part of chromosome 1a and part of 1b are exchanged to form new 1c and 1d which each go into their separate sperm/egg cells. Each egg/sperm cell therefore is unique. This is called crossover.

Any one chromosome in a sperm is a patchwork, a mosaic of maternal and paternal genes.

Cistrons are genetic material from start to end sequence of an encoding for a protein, short genetic material sequences can survive crossing over in tact and are therefore transmitted for more than 1 generation, those shorter sequences might be shared between multiple individuals. The shorter the higher the likelihood of it surviving intact and us maybe sharing the same sequence with say a dog.

Different kinds of changes to genes can happen, random point mutations + drift of whole chunks of DNA sequences + their inverting their order. Example of Butterflies mimicking two different other species of butterfly. But each individual only mimics one species. By inversion and reshuffling, cistrons can become tied to each other, so that they form a bigger genetic unit, a cluster of cistrons that then can be selected for. It is either mimic a or mimic b usually not both. Except in very rare cases where cross over splits the gene up and mixes variant a and b. Then one gets in between butterflies. So recap - a gene is a stretch of DNA that can survive for many generations untouched by crossover. The size is small, but can be bigger than multiple cistrons.

Natural Selection in its most general form means the differential survival of entities.

Individuals are not stable things, they are fleeting.

Genes have the potential to live forever, but most only stick around for one generation because they are hazardous to the survival machine. Evolution therefore is the process of increasing the length for which genes can stick around. A central property of longer lived genes is that they are selfish. They profit for their survival at the expense of other genes.

At the same time genes can cooperate to produce better results, they are part of an environment and that environment includes the presence of other genes. Only if a gene plays nicely with all other factors does it have a good chance of survival.

Aging might be caused by genes with bad effects only visible in old age but positive effects in young age accumulating. As long as an organism can reproduce early, the gene is fine and survives in the offspring. Therefore over evolutionary times those old age lethal genes accumulate and their bad effects cumulatively are what we observe as aging.

The true purpose of DNA is to survive, no more and no less.

Evolution is the process by which some genes become more numerous and others less numerous in the gene pool.

Chapter 4 - The Gene Machine

Survival machines began as passive receptacles for the genes, providing lite more than walls to protect them from the chemical warfare of their rivals and the ravages of accidental molecular bombardment.

Subjectively I feel like a unit not a colony.

Animals can behave. That is they can move fast. They have muscles to do so, the interesting question is not how they muscle can generate force, but how groups of them can be timed correctly to produce correct behavior. Answer is ofc. neurons and nervous systems.

The neuron is slower than the transistor, but it has gone much further in the direction of. 62

The main way in which brains contribute to the success of survival machines is by controlling and coordinating contractions of muscles.

One of the most striking properties of survival-machi esbehavior is its apparent purposiveness.

Brains are essentially engaged in a negative feedback loop, trying to minimize the discrepancy between a desired state and an actual state. They have sensory organs to form a picture of the actual reality and muscles to act and change things withinthat reality. When they come far away from the desired state they work harder, if very close they might even stop. This simple design leads to the likeness of purposiveness of the behavior.

Problem of control - why don't genes control action directly, but instead just setup things so that there are brains capable of controlling the situation "for" the genes? Answer: Because of a time lag. Analogy to people from other galaxy trying to conquer other worlds, who send out radio waves telling how to build effectively a trojan horse machine style computer, conquering and controlling the world if somebody builds it after having received and decoded the radio message. Genes therefore have to predict the future that their survival machines are going to be in. The genes that do this generally well have a survival advantage and are going to outcompete the others. Prediction via a reward function is more general and therefore usually better adapted, a brain doesn't come equipped with all behaviors but can learn what is good/bad because of the reward function intrinsic in it.

One of the most interesting medthos of predicting the future is simulation.

Brains run simulations of the world to come up with better decisions for gene survival. This is what we commonly call imagination.

Perhaps consciousness arises when the brain's simulation of the world becomes so complete that it must include a model of itself.

Genes can influence behaviors in direct and indirect ways. Behavior could be influenced by gene but only if certain parts of environment are there, it could also involve learning/reward/punishment stimuli to enforce/weaken certain behaviors

The genes are master programmers and they are programming for their lives.

Communication involves an element of deception, because of conflicts of interests, not just members of different species, but even children deceiving their parents and husbands their wives make sense from an evolutionary point of view.

Chapter 5 - Aggression, Stability and the Selfish machine

Survival machines compete for resources so that their genes can persist. Intra species competition is the hardest because individuals are so similar and therefore compete for the same resources. Yet killing off all rivals and eating them is not a good tactic because there are costs associated with that killing. Like one's own death or injuries. Therefore aggression follows patterns of complex cost benefit analysis.

Populations can have stable points for different competitive behaviors showing aggression (so called ESS for evolutionarily stable strategies), since the benefit of a behavior is tied to what is common in the other individuals in the species. At a certain ratio the benefits of both aggressive and non aggressive strategies balance nicely leading to an equilibrium in behavior to evolve. The perverse thing about this equilibrium is that it is worse for everybody involved if everybody were choosing a less aggressive strategy, conspiring together, their total average success would be way higher. But cheating and being aggressive anyways would be a good tactic then, leading to those mutations starting to gain weight again drifting the conspiracy back to the worse, but stable solution.

So, even in man, a species with the gift of conscious foresight, pacts or conspiracies based on long-term best interests teeter constantly on the brink of collapse due to treachery from within.

Thought: the exact same problem applies to Socialism vs. Capitism.

Models can be very simple, like this one, and still be useful for understanding a point, or getting an idea.

Strategies in attrition games are also not oscillating in the spread of the population, but instead a stable solution exists, the one where contestants choose randomly and don't give away for how long they intend to wait for the resource in question.

In more complex scenarios, where there are differences, asymmetric competitions, there might be multiple stable states that could evolve, acting as kinds of attractors to the genes in the population. Those stable configurations of fighting behaviors might even be paradoxical, but still stable, since defectors from the paradoxical strategy would still be punished hard for their behavior. Once enough of a population adopts a strategy, the whole population stays with that strategy.

Selection at the low level of the single gene can give the impression of selection at some higher level.

The gene pool is the long-term environment of the gene.

Genes in the gene pool form a stable set, most new genes introduced are worse than the stable set, occasionally a variant arises that has competitive edge in the ESS, is a new form of solution in a way, and it spreads through the pool, unsettling the ESS for a while, evolutions is happening, things change and then settle into a new ESS. Evolution therefore is like jumps in between plateaus. Higher amounts of changes in short bursts of time followed by longer periods of little to no changes happening. Examples of competing teams of rowers and of hawks and doves fighting explain how things could arise as units of bodies, but more interestingly the same thing happens on the level of genes themselves. Bodies are the result of evolution at that scale.

Well-integrated bodies exist because they are the product of an evolutionarily stable set of selfish genes.

Chapter 6 - Genesmanship

When a man throws a ball high in the air and catches I again he behaves as if he had solved a set of differential equations in predicting the trajectory of the ball. He may neither know nor care what a differential equation is, but it does not affect his skill with the ball.

Selection for genes that make the survival of other animals sharing the same genes is evolutionarily an adaptive strategy that spreads. Hence one can observe something similar to kin selection and altruism happening the world. Organisms who do these kinds of things behave as if they were calculating the weighted sum of the risks and benefits for them and the other individuals, weighted by the relatedness and other sich factors as age, reproductive capacities etc. for all their potential behaviors and then and then choosing the maximizing option. Whether they do these calculations remains in doubt, only thing clear is that if genes make their survival machine behave like that, they have higher chance of survival overall and will therefore spread.

Living bodies are machines programmed by genes that have survived.

In a world where other individuals are constant on the alert for opportunities to exploit kin-selected altruism, and use it for their end, a survival machine has to consider who it can trust, who it can be sure of.

Kin selection manifests itself in parent/child altruism, and more on the motherly side, because the certainty involved in knowing gene relatedness is greater, hence the sexual differences in child-rearin and investment into the offspring. Als certainty is hard to keep up for kin selection, when it can be exploited by other members of the species or even other species altogether, a good example are cuckoo birds here.

Chapter 7 - Family Planning

I use the word decision to mean unconscious strategic move.

There are two decisions individuals have to make, one is child caring and the other bearing. Also, the birth rate in a civilization is something that leads to a lot of people quickly, accelerating the more people there already are. Interestingly, in nature, this kind of exponential growth is not what happens most of the time. Populations are often stable so a form of birth control or family planning has to evolve... This family "planning" evolves from egoistic purposes, the amount of time and resources parents can invest in their offspring is limited, so there exists an optimum, where they have the most offspring, which is the point where they bear as many as they can care for enough to maximize the overall likelihood of having the most possible offspring. This holds offspring sizes low and makes them depend on the environment.

They 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.

Any gene for over-indulgence is immediately punished: the children containing that gene starve.

Any altruistic system is inherently unstable because it is open to abuse by selfish individuals, ready to exploit it.

The idea of this planning and predicting the future business that genes seem to be doing raises one very interesting question - what is the range of it?

Chapter 8 - Battle of the Generations

I am treating a mother as a machine programmed to do everything in its power to propagate copies of the genes which ride inside it.

Menopause can be viewed as an adaptive strategy because the likelihood of survival of grandchildren is so much higher, that it pays off enough for the decrease in relatedness. There comes a point where more genes of a female survive when she invests into grandchildren rather than her own children, at which point becoming physically incapable of rearing children is an adaptive strategy and what we see happening and call menopause. Furthermore, similar arguments can be made for selfishness among siblings. It is always about the use of resources

The sight of her child smiling, or the sound of her kitten purring, is rewarding to a mother, in the same sense as food in the stomach is rewarding to a rat in a maze.

The phrase the "child should cheat" means that genes that tend to make children cheat have an advantage in the gene pool. If there is a human moral to be drawn, it is that we must teach our children altruism, for we cannot expect kt to be part of their biological nature.

Chapter 9 - Battle of the Sexes

The strategy of producing equal numbers of sons and daughters is an evolutionarily stable strategy, in the sense that any gene for departing from it makes a net loss.

Sperms and eggs contribute equal numbers of genes, but eggs contribute far more in the way of food reserves: indeed sperms make no contribution at all and are simply concerned with transporting their genes as fast as possible to an egg. At the moment of conception, therefore, the father has invested less than his fair share of resources in the offspring. Since each sperm is so tiny, a male can afford to make many millions of them every day. This means he is potentially able to beget a very large number of children in a very short period of time, using different females. This is only possible because each new embryo is endowed with adequate food by the mother in each case. This therefore places a limit on the number of children a female can have, but the number of children a male can have is virtually unlimited. Female exploitation begins here.

A body is a machine blindly programmed by its selfish genes.

The female sex is exploited, and the fundamental evolutionary basis for the exploitation is the fact that eggs are larger than sperms.

If females could recognize such qualities [faithful mates] in advance, they could benefit themselves by choosing males possessing them. One way for a female to do this is to play hard to get for a long time, to be coy. Any male who is not patient enough to wait until the female eventually consents to copulate is not likely to be a good bet as a faithful husband. By insisting on a long engagement period, a female weeds out casual suitors, and only finally copulates with a male who has proved his qualities of fidelity and perseverance in advance. Feminine coyness is in fact very common among animals, and so are prolonged courtship or engagement periods.

Any tendency for members of either sex to deviate from their appropriate stable ratio will be penalized by a consequent change in the ratio of strategies of the other sex, which is, in turn, to the disadvantage of the original deviant.

Any male who can pass himself off as a good loyal domestic type, but who in reality is concealing a strong tendency towards desertion and unfaithfulness, could have a great advantage.

How does all of the above factor in for humans who have, besides their brilliantly set up minds which are strongly influenced by genes, things like creativity and culture? In other words - how can ideas be interwoven into this type of selection?

In a society where males compete with each other to be chosen as he-men by females, one of the best things a mother can do for her genes is to make a son who will turn out in his turn to be an attractive he-man. If she can ensure that her son is one of the fortunate few males who wins most of the copulations in the society when he grows up, she will have an enormous number of grandchildren. The result of this is that one if the most desirable qualities a male can have in they eyes of a female is, quite simply, sexual attractiveness itself. A female who mates with a superattractive he-man is more likely to have sons who are attractive to females of the next generation, and who will make lots of grandchildren for her.

Like a fashion in woman's clothes, or in American car design, the trend toward longer tails took off and gathered its own momentum. It was stopped only when tails became so grotesquely long that their manifest disadvantages started to outweigh the advantage of sexual attractiveness.

Because of a fundamental difference between the size and numbers of sperms and eggs, males are in general likely to be biased towards promiscuity and lack of paternal care.

A male on the other hand can never get enough copulations with as many different females as possible: the word excess has no meaning for a male.

Chapter Summary

There exists a fight between the sexes for sexual exploitation in the sense that each parent tries to get away with what's best for their genes. Because the size of eggs in females is bigger than that of sperm in males, females tend to be a resource that can be fought over - harem species emerge. If the offspring needs a lot of intensive care - and both parents need to participate, pair bonding species emerge. But there is a strong tendency for both genders to cheat in these populations, albeit for different reasons, and that's where sexual selection shapes behavior. Females trying to find attractive individuals which are also faithful and caring for the offspring vs. males who try to cheat and look faithful while not being so. But also females which enlist the support of less sexy males, but then cuckold them to get the sperm from more sexy ones.

Chapter 10 - You scratch my back, I'll ride on yours

Ants and bees and other such insects are weird. Sperm is stored up in the queen, but only from one male and males only have 50% of the genes of females and all of their genes come from the mother. This makes relatedness calculations a little odd, since the relatedness of mother to offspring is only 1/2 while that between sister to sister is higher - namely 3/4. There is an imbalance here that leads to different interests for the offspring that the queen has. Workers want the ratio to be 3:1 for females since that's how their genes would best replicate. Make more sisters! The queen itself wants it to be 1:1. Interestingly enough the ratio found in nature is 3:1. It seems as though the queen is machinated by the workers to do their bidding.

In raiding ant species, slaves from other colonies do all the work and here the queen can alter the sex ratio without anyone adapting to it. Since the workers don't get their genes into the next generation anyways because they came from a different colony and are unrelated to it, they don't adapt together with the queen. In these species - convincingly enough the sex ratio drifts back to 1:1 just like one would expect.

A relationship of mutual benefit between members of different species is called mutualism or symbiosis. Members of different species often have much to offer each other because they can bring different 'skills' to the partnership. This kind of fundamental asymmetry can lead to evolutionarily stable strategies of mutual cooperation.

Each one of our genes is a symbiotic unit. We are gigantic colonies or symbiotic genes.

In general, associations of mutual benefit will evolve if each partner can get more out than he puts in.

If a population arrives at an ESS that drives it extinct, then it goes extinct, and that is just too bad.

A long memory and capacity for individual recognition are well developed in man. We might therefore expect reciprocal altruism to have played an important part in human evolution. [... maybe] many of our psychological characteristics - envy, guilt, gratitude, sympathy, etc. - have been shaped by natural selection for improved ability to cheat, to detect cheats and to avoid being thought to be a cheat. [...] It is even possible that man's swollen brain, and his predisposition to reason mathematically, evolved as a mechanism of ever more devious cheating, and ever more penetrating detection of cheating in others.

Money is a formal token of delayed reciprocal altruism.

Chapter Summary:

Altruistic behavior is a little bit hard to explain for the selfish gene theory, it might seem at a first glance, however often that is not the case, because there exist evolutioary stable states for different behavioral strategies and therefore there are distinct advantages to be had, when cooperating with certain patterns. And that's what we see in most organisms today, some amount of cheating, a good amount of grudging and of mechanisms to avoid being cheated and a good amount of symbiosis and cooperation as well. One especially interesting idea from the ## Chapter is to think of the genome itself as a symbiotic relationship between different symbiotic units of single genes. Maybe we are just a different way for genes to express their symbiosis and spread, and viruses are a less symbiotic form of solving the same problem, namely that of replication. In the end, maybe humans adapted to cheating and reciprocal altruism and that's why we have such big brains.

Chapter 11: Memes - The New Replicators

Most of what is unusual about man can be summed up in one word: culture.

Language and culture evolve.

For an understanding of the evolution of modern man, we must begin by throwing out the gene as the sole basis of our ideas on evolution.

All life evolves by the differential survival of replicating entities.

Memes should be regarded as living structures, not just metaphorically but technically.

• N.K. Humphrey

Blind faith can justify anything.

Co-adapted meme-complexes evolve in the same kind of was as co-adapted gene-complexes.

Our genes may be immortal but the collection of themes that is any one of us is bound to crumble away.

A cultural traits may have evolved in the end that it has, simply because it is advantageous to itself.

Our capacity to simulate the future in imagination could save us from the worst selfish excesses of the blind replicators. We have at least the mental equipment to foster our long-term selfish interests rather than merely our short-term selfish interests.

We have the power to defy the selfish genes of our birth and, if necessary, the selfish memes of our indoctrination.

We are built as gene machines, and nurtured as meme machines, but we have the power to turn against our creators. We, alone on Earth, can rebel against the tyrannyof the selfish replicators.

Chapter Summary:

The Important part of a gene is that it is self-replicating when in the right environment -the key insight is that this applies to things other than genes as well. Dawkins calls these memes, from memetics - in other words things that imitate. Memes can exist in human brains, or any other system capable of copying information around and are simply a phenomenon of information that is good at manipulating the system to propagate and copy it. In humans - the whole of culture and language can be thought of as memes. Memes can, much like genes, form complexes that work together very well in transmitting themselves and so - much like bodies - form concrete almost physical systems, that propagate themselves very nicely. Religions and all the Ritual and stuff attached to it, are one example for such memeplexes. In the end though, even though there exists memes and genes that are programming and nurturing and controlling us for their selfish purposes, we have the power to break lose from these constraints and invent things that are truly not-selfish and truly altruistic.

Chapter 12 - Nice Guys Finish First

Iterative vs. Non Iterative Prisoners Dillema Games are very different. In nature we find a lot more cooperation, because trust in interactions can be built up over time, because animals play an iterative Prisoners dilemma game. The strategies that evolve in such a context are known as reciprocal altruism (with vengeance and retaliation as well). There was a competition for ongoing prisoners dilemma games to send in computer programs (by a cool guy named Axelrod) and one of the most effective strategies is simply - tit for tat, always copy the last move of opponent and start by cooperating. The strategies can be grouped into "nice", "nasty", "forgiving" etc. depending on whether they defect in the game or not.

Two characteristics of winning strategies: niceness and forgivingness.

Success for a strategy depends upon which other strategies happen to be submitted.

Strategies are robust if they do well against a variety of other strategies. But the harder, more important point is that there is a "climate" of strategies, and that climate is changing all the time in the real world, depending on the success of the strategies themselves. What becomes important now is that a strategy, that gains a certain threshold of the total population will become stable, by becoming the best possible strategy in that climate, increasing itself and spreading through the population.

For a strategy to remain successful, it must do well specifically when it is numerous, that is in a climate dominated by copies of itself.

Tit for Tat doesn't have that stability, because other "nice" strategies can invade the population because they will be the same as tit for tat if the whole gene pool is filled with tit for tats cooperating all the time. Only problem is, after some time this dissolving of the tit for tat strategy to other "nice" strategies, opens up the room for nasty strategies exploiting those nice strategies at the expense of tit for tat. So the tit for tat equilibrium can be broken by a mix of two or more strategies, arising together at the same time. This is the main idea behind a Collectively Stable Strategy.

Systems like this can have multiple points of attraction in their phase spaces. Meaning that multiple collectively stable strategies exist. Always defect can be stable, so can tit for tat.

This whole idea becomes even more crazy, when thinking about gradual gradients of density of individuals with certain strategies, because they are physically separated and therefore closer to other Tit For Tat players than they would be if they were randomly mixed. Now waves of "crystallization" can happen in this pool, because the stable point of attraction can be locally overcome by cooperative strategies, which then propagate outwards from the origin, slowly transforming the whole population to one that is cooperating with a tit for tat strategy.

Envy in prisoners dilemma style games is leading to worse outcomes overall.

Zero vs. non-zero sum games, we should prefer to stick with non-zero sum games, because these are what rewards cooperation and altruism.

Many situations in real life are, as a matter of fact, equivalent to nonzero sum games.

The estimated length of a prisoners dilemma style game, forces different strategies to "win". When the rest of the game is assumed to be short, the value of defecting goes up and if the game is expected to continue for a long time then the value of cooperation and altruism go up.

Prisoners dilemma is characterized by the order or ranking of outcomes in how desirable they are. Defection, while the other cooperates should be worth the most, then should come mutual cooperation, then should come both players defecting.

Nice strategies of cooperation arise in nature of the circumstances are right - i.e. when the circumstances are similar to a prisoners dilemma game, unfolding over long periods of time, we see evolution coming up with "nice" behavioral strategies.

Chapter Summary:

Nice Guys can finish first was the title and the leading idea in the whole ## Chapter is that "niceness" as a strategy of cooperation can pay off in a certain type of game - namely non-zero-sum long running prisoners dilemma. It then went on to explain multiple examples of where such strategies might be found in nature. The ## Chapter ends on a high note - even in a world where evolution favors and creates utterly selfish genes, under the right circumstances - it pays to be cooperative and invent strategies of reciprocal altruism. And so in nature in a sense nice guys can finish first under some circumstances.

The Long Reach of The Gene

The body looks and behaves like a pretty impressive agent in its own right.

Natural selection favors some genes rather than others not because of the nature of the genes themselves, but because of their consequences - their phenotypic effects.

What about genes which are bad for the body but good at spreading themselves? Maybe something like a meiotic drive - a gene that can insert itself into the offspring with a higher likelyhood, by influencing the processes going on during meiosis and thereby improving its own "odds" of transmission? Those genes exist and they are called segregation distorters.

Genes can cheat other genes with which they share a body.

If the effects of these cheating genes are bad to the body, but still effective at getting spread, mutations like them can drive whole populations extinct.

Why do organisms exist? Why does living matter group itself into nice units of organization that works together as an organism?

Phenotypic effects are normally seen as all the effects that a gene has on the body in which it sits. But the phenotypic effects of a gene need to be thought of as all the effects that it has on the world.

That an artefact in the real world is due to behavior or due to the "body" being that way doesn't interest the selfish gene theory because of this idea of the extended phenotype. A body can be thought of in just the same way as a particular type of behavior of that body. It's just a change produced in the world, by the gene, that is good for the survival of the gene. No matter if it's the shell of a lobster or the built dam of a beaver or the net of a spider. Genes that create these types of artefacts have a higher chance of spreading and surviving.

This means that there are "genes" meaning reproductive units of DNA - that directly translate to instructions on - which wood a beaver should use to build it's dam, or genes controlling the size and shapes of stones that a caddis fly uses to build it's protective house.

The main idea this shows is that the influences of a gene are always indirect, because genes only affect protein synthesis and only from there do we go to body growth and to nervous system changes and to behavior.

Stone hardness is an extended phenotypic effect of the caddis's genes.

Furthermore:

Genes in one organism can have extended phenotypic effects on the body of another organism.

Certain parasitic worms can increase the thickness of a snails shell. Normally snails want to have shells of the right size, because shells are expensive and the energy is better spent on offspring. But the worm has a different agenda and therefore wants to have a longer living snail with a bigger Shell, because that is what is good for the worms genes in the end. So the worms genes effectively control the environment, which happens to be another animal to their advantage. But this is not different than the snails genes manipulating their environment into building a snail in the first place.

Genes reach outside their "own" body to influence phenotypes in other bodies.

If parasite genes happen to be spread through the same mechanism as the hosts bodies genes happen to be spread, closer and closer cooperation starts to develop until the parasite "merges" with the body of the host and the two become so closely linked that we start to think of them as only one body. There is a multitude of stages of symbiosis and cooperation between a hostile parasite and a completely merged "single" body.

A parasite whose genes aspire to the same destiny as the genes of its host shares all the interests of its host and will eventually cease to act parasitically.

We can take this argument to its logical conclusion and apply it to normal, "own" genes. our genes cooperate with one another, not because they are our but because they share the same outlet - sperm or egg - into the future.

Some types of DNA such as plasmids, might opt out of this shared reproductive step and just float around through cells randomly slicing open fragments of DNA and inserting itself, starting to multiply and then hitching another ride in another cell. What we describe here - is a way of how viruses could form from "normal" living things. It's just genes that found a different way to manipulate their environment into cloning them.

Beaver lakes are extended phenotypic effects of beaver genes, and they can extend over several hundreds of yards.

Cuckoo genes control the minds of their host birds into feeding them, almost like a drug addict seeing their drug, has to take it, a cuckoo presents a superstimulus to the feeding parent, that has no choice but to give the cuckoo the food destined for its own brood.

Life/Dinner Principle - Rabbit runs faster than the fox. Built in asymmetry in evolutionary arms races such as the cuckoo vs. its hosts.

Cuckoo genes have extended phenotypic effects on host behavior.

Parasitic insects such as ants are even wilder. Ants decapitating the original queen of a colony and then silently replacing it and even worse, another species, chemically inducing the own daughters of the queen to kill her.

In the world of the extended phenotype, ask not how an animals behaviour benefits it's genes, ask instead whose genes it is benefiting.

*An animal's behaviour tends to maximize the survival of the genes "for" that behaviour, whether or not those genes happen to be in the body of the particular animal performing it.

Idea of replicators and vehicles. Replicators is what Darwinian selection and therefore evolution can act on. DNA is a replicator. Vehicles are just the maifestations of those replicators in the real world, with only one purpose, to replicate the replicators. Bodies, however complicated, are vehicles...

Vehicles can combine together, if the means of reproduction (how the replicators leave the vehicles), the goals of the underlying replicators creating the initial vehicles, are the same. That's when parasites stop being distinct organisms but fuse into one with their hosts.

"Single" individual organisms such as ourselves are the ultimate embodiment of many such mergers.

A vehicle needs an exit for its replicators. That's what makes it a vehicle.

The main question remains though - why are vehicles so crazy complicated as our bodies are?

3 questions arise from it: Why do genes form cells? Why do cells do multicellular life? And why do vehicles have a "bottlenecked" life cycle - i.e. why is there only one exit for the genes?

The complexity necessary to use certain chemical pathways is quite big - it needs the coordination of quite a lot of proteins - otherwise they can't be accessed. Genes that form alliances to produce these protein cascades have a big survival advantage because their vehicles - by means of their increased complexity - can use sources of energy other genes can not. This is the basic idea why cells become a necessity at some point the chemical pathways get so intricate and connected that one thing that also needs to be there is a special environment, distinct from the surrounding and a barrier to protect that "internal" environment and there will be genes providing that. A first cell is born.

At some point the available pathways becomes closer to 0 because all the different single celled organisms found out what they could to exploit the chemistry of their environment to replicate. But there is still opportunity for improvement - namely by increasing the complexity even more, and accessing yet more complicated replication strategies, like eating other single celled organisms. Some of those need more size and specialized tools - like a "mouth". That's how groups of cells might start banding together into multicellular organisms and exploit those more complicated pathways to replicate themselves. Also now that multiple cells cooperate each single cell can start to specialize and gain new functionality for the whole vehicle that it otherwise couldn't have. Tissues and organs are born and the complexity skyrockets even more, while selection over time finds more and more complicated ways to replicate.

Third question - why the single cell intermidate stage at reproduction? Why not have a vehicle clone separate parts if itself kind of all at once? Growth and replication are different things. But why? The main reason might be that improvements to an already grown thing by mutation is not possible, whereas the rebuilding from a single cell allows single gene mutations to influence the freshly build body, globally and widely. Therefore the replicators which do go through a single cell stage can better adapt and transform in a changing environment and are therefore selected more! Another thing that happens because of these clear cut distinctions between growth and reproduction is that there can exist something like a "schedule" - for the cells to know when to do what. Which can lead to even higher specialization of tissues and thereby higher complexity and yet different routes of reproduction for the replicators.

Another thing to keep in mind is the relatedness of the cells. In an organism where this distinction between growth and replication and the bottleneck doesn't exist, new mutations would constantly divide the cells of the "same" organism further and further apart, until eventually the cooperation might start to break down, because the different mutations cause the different replicators to "want" different things. To them building different outlets for their vehicles essentially.

Natural selection will choose among cells rather than organisms.

The essentia, defining feature of an individual organism is that it is a unit that begins and ends with a single-celled bottleneck.

The whole world is criss-crossed with causal arrows joining genes to phenotypic effects, far and near.

Chapter Summary:

1. Read "The Extended Phenotype" ;) There are two distinct concepts - vehicles and replicators. Replicators construct vehicles that help them replicate. Our genes are replicators, while our bodies are vehicles. The reach of replicators goes beyond their vehicles - in a sense the whole environment can be manipulated into helping the reproduction of the replicator. This includes the vehicles that other replicators built themselves, as is the case in parasites such as cuckoos, but also inanimate matter like stones and sticks as is the case for caddis flies and beavers. The only reason to call something a "body" / a vehicle for a certain replicator - belonging to that replicator - is that it has an exit for the replicator - i.e. it has to have a mechanism to make more of the replicator and then release that more into the environment in some form (for example another vehicle/body). Therefore vehicles from different replicators can become entangled and merge, when they start sharing the same exit for their respective replicators. That is when parasites and host become indistinguishable from another and merge into one, which happened a lot in evolutionary history. In a way our cells are collections of mergers like that. One question remained to be answered and that is - why built complicated bodies in the first place? The question is split into three parts - why do cells exist, why do cells form tissues and multicelled organisms and why do bodies go through a single celled bottleneck in their development? The answer to all of them is very similar - it increases the adaptation of the replicators to the environment. Cells - i.e. collections of replicators working together in a complex allow for different sources of chemical pathways to be used for replication. The same is true for the step up to multicelled vehicles. The bottleneck now becomes important because multicelled life still needs to have the same exit for the replicators, otherwise mutations couldn't accumulate in the whole organism because they would never spread and so slowly the complex cooperation necessary for organs and tissues to work properly would slowly break down (that's what we call cancer btw.) Finally it allows bodies to coordinate even more effectively to grow highly specialized tissues and organs, because there is a clear phase of when things happens that can coordinate the efforts of the replicating complex. So the answer is this - complexity allows harvesting of otherwise unattainable energy sources. Hence replicators, in a struggle to survive and replicate as much as possible, create ever more ingenuous and more complex ways to do so. Bodies tend to become more complex over time.

Epilogue

The Selfish Gene is quite likely a valid account of life on other planets even if the genes on those other planets have no connection with DNA.

The definition of relatedness, "cousins", etc. Is different depending on the vantage point one choses. If looked at from a genes perspective a closer cousin might be the B bloodtype gene of an ape compared to the A gene of another fellow human. Even though to the body the closest common ancestor between the humans would be a lot closer. Genes have only one parent and therefore they stay related to each other over vast distances in time. Their "relatedness" doesn't explode exponentially if looking back in time.

This allows the idea of a coalescence point - the common ancestor of the same gene on two different persons.

The pattern of coalescences among pairs of genes in the genome of a single individual gives us enough information to reconstruct demographic Details about datable moments in the prehistory of an entire species.

A sufficiently knowledgeable geneticist should be able to read out, from the genome of an animal, the environments in which its ancestors survived.