This brings me to the first point I want to make about what this book is not. I am not advocating a morality based on evolution. I am saying how things have evolved. I am not saying how we humans morally ought to behave. My own feeling is that a human society based simply on the gene’s law of universal ruthless selfishness would be a very nasty society in which to live. But unfortunately, however much we may deplore something, it does not stop it being true. Let us try to each generosity and altruism, because we are born selfish.
“Welfare” is defined as “chances of survival,” even if the effect on actual life and death prospects is so small as to seem negligible. One of the surprising consequences of the modern version of the Darwinian theory is that apparently trivial tiny influences on survival probability can have a major impact on evolution. This is because of the enormous time available for such influences to make themselves felt.
I am not trying to make a point by telling stories. Chosen examples are never serious evidence for any worthwhile generalization.
“Perpetuation of the species” is a common euphemism for reproduction, and it is undeniably a consequence of reproduction.
But are we talking about the fittest individuals, the fittest races, the fittest species, or what? For some purposes this does not greatly matter, but when we are talking about altruism it is obviously crucial. If it is species that are competing in what Darwin called the struggle for existence, the individual seems best regarded as a pawn in the game, to be sacrificed when the greater interest of the species as a whole requires it.
Perhaps one reason for the great appeal of the group selection theory is that it is thoroughly in tune with the moral and political ideals that most of us share. We may frequently behave selfishly as individuals, but in our more idealistic moments we honor and admire those who put the welfare of others first. We get a bit muddled over how widely we want to interpret the word “others,” though. Often altruism within a group goes with selfishness between groups. This is a basis of trade unionism. At another level the nation is a major beneficiary of our altruist self-sacrifice, and young men are expected to die as individuals for the greater glory of their country as a whole.
Curiously, peace-time appeals for individuals to make some small sacrifice in the rate at which they increase their standard of living seem to be less effective than war-time appeals for individuals to lay down their lives.
The feeling that members of one’s own species deserve special moral consideration as compared with members of other species is old and deep. Killing people outside of war is the most seriously-regarded crime ordinarily committed. The only thing more strongly forbidden by our culture is eating people (even if they are already dead). We enjoy eating members of other species, however. Many of us shrink from judicial execution of even the most horrible human criminals, while we cheerfully countenance the shooting without trial of fairly mild animal pests.
Lions and antelopes are both members of the class Mammalia, as are we. Should we then expect lions to refrain from killing antelopes, “for the good of the mammals”? Surely they should hunt birds or reptiles instead, in order to prevent the extinction of the class. But then, what of the need to perpetuate the whole phylum of vertebrates?
I shall argue that the fundamental unit of selection, and therefore of self-interest, is not the species, nor the group, nor even, strictly, the individual. It is the gene, the unit of heredity.
Darwin’s “survival of the fittest” is really a special case of a more general law of survival of the stable. The universe is populated by stable things. A stable thing is a collection of atoms that is permanent enough or common enough to deserve a name. It may be a unique collection of atoms, such as the Matterhorn, that lasts long enough to be worth naming. Or it may be a class of entities, such as rain drops, that come into existence at a sufficiently high rate to deserve a collective name, even if any one of them is short-lived.
The point that is relevant here is that, before the coming of life on earth, some rudimentary evolution of molecules could have occurred by ordinary processes of physics and chemistry. There is no need to think of design or purpose or directedness. If a group of atoms in the presence of energy falls into a pattern it will tend to stay that way. The earliest form of natural selection was simply a selection of stable forms and a rejection of unstable ones. There is no mystery about this. It had to happen by definition.
The answer is that although revolution may seem, in some vague sense, a “good thing”, especially since we are the product of it, nothing actually “wants” to evolve. Evolution is something that happens, willy-nilly, in spite of all the efforts of the replicators to prevent it happening.
Another curious aspect of the theory of evolution is that everybody thinks he understands it.
An octopus is nothing like a mouse, and both are quite different from an oak tree. Yet in their fundamental chemistry they are rather uniform, and, in particular, the replicators that they bear, genes, are basically the same kind of molecule in all of us — from bacteria to elephants. We are all survival machines for the same kind of replicator — molecules called DNA — bu there are many different ways of making a living in the world, and the replicators have built a vast range of machines to exploit them.
It is as though, in every room of a gigantic building, there was a book-case containing the architect’s plans for the entire building. The architect’s plans run to 46 volumes in man — the number is different in other species. The “volumes” are called chromosomes.
No matter how much knowledge and wisdom you acquire during your life, not one jot will be passed on to your children by genetic means. Each new generation starts from scratch. A body is the gene’s way of preserving the genes unaltered.
Genes have no foresight. They do not plan ahead. Genes just are, some genes more so than others, and that is all there is to it.
My definition will not be to everyone’s taste, but there is no universally agreed definition of a gene. Even if there were, there is nothing sacred about definitions. We can define a word how we like for our own purposes, provided we do so clearly and unambiguously.
Genetically speaking, individuals and groups are like clouds int he sky or dust-storm in the desert. They are temporary aggregations or federations. They are not stable through evolutionary time.
The true “purpose” of DNA is to survive, no more and no less.
Some people object to what they see as an exclusively genecentered view of evolution. After all, they argue, it is whole individuals with all their genes who actually live or die. I hope I have said enough in this chapter to show that there is really no disagreement here. Just as whole boats win or lose races, it is indeed individuals who live or die, and the immediate manifestation of natural selection is nearly always at the individual level. But the long-term consequences of non-random individual death and reproductive success are manifested in the form of changing gene frequencies in the gene pool.
Colonies of genes they may be but, in their behavior, bodies have undeniably acquired an individuality of their own. An animal moves as a coordinated whole, as a unit. Subjectively I feel like a unit, not a colony. This is to be expected. Selection has favored genes that cooperate with others.
The main way in which brains actually contribute to the success of survival machines is by controlling and coordinating the contractions of muscles. To do this they need cables leading to the muscles, and these are called motor nerves. But this leads to efficient preservation of genes only if the timing of muscle contractions bears some relation to the timing of events in the outside world. For this reason, natural selection favored animals that became equipped with sense organs, devices which translate patterns of physical events in the outside world into the pulse code of the neurones.
But to achieve more complex and indirect relationships between the timing of events in the outside world and the timing of muscular contractions, some kind of brain was needed as an intermediary. A notable advance was the evolutionary “invention” of memory. Computer memories are more reliable than human ones, but they are less capacious, and enormously less sophisticated in their techniques of information-retrieval.
There are more possible games of chess than there are atoms on the galaxy.
Genes don’t have reaction-times like that. The genes can only do their best in advance by building a fast executive computer for themselves, and programming it in advance with rules and “advice” to cope with as many eventualities as they can “anticipate.” But life, like the game of chess, offers too many different possible eventualities for all of them to be anticipated. Like the chess programmer, the genes have to “instruct” their survival machines not in specifics, but in the general strategies and tricks of the living trade.
We can carry the metaphor of gambling a little further. A gambler must think of 3 main quantities, stake, odds, and prize. If the prize is very large, a gambler is prepared to risk a big stake. A gambler who risks his all on a single throw of stands to gain a great deal. He also stands to lose a great deal, but on average high-stake gamblers are not better and no worse than other players who play for low winning with low stakes. It is often possible to picture males as high-stake, high-risk gamblers, and females as safe investors, especially in polygamous species in which males compete for females.
One way for genes to solve the problem of making predictions in rather unpredictable environments is to build in a capacity for learning. Here the program may take the form of the following instructions to the survival machine: “Here is a list of things defined as rewarding: sweet taste in the mouth, orgasm, mild temperature, smiling child. And here is a list of nasty things: various sorts of pain, nausea, empty stomach, screaming child. If you should happen to do something that is followed by one of the nasty things, don’t do it again, but on the other hand repeat anything that is followed by one of the nice things.” The advantage of this sort of programming is that it greatly cuts down the number of detailed rules that have to be built into the original program; and it is also capable of coping with changes in the environment that could not have been predicted in detail.
Through the technique of simulation, model battles can be won or lost, stimulated airliners fly or crash, economic policies lead to prosperity or to ruin. In each case the whole process goes on inside the computer in a tiny fraction of the time it would take in real life. No amount of simulation can predict exactly what will happen in reality, but a good simulation is enormously preferable to blind trial and error.
Genes are primarily policy-makers; brains are the executives. But as brains became more highly developed, they took over more and more of the actual policy decisions, using tricks like learning and simulation in doing so.
To a survival machine, another survival machine (which is not its own child or another close relative) is part of its environment, like a rock or a river or a lump of food. It is something that gets in the way, or something that can be exploited. It differs from a rock or a river in one important respect: it is inclined to hit back. Natural selection favors genes that control their survival machines in such a way that they make the best use of their environment. This includes making the best use of other survival machines, both of the same and of different species.
In a large and complex system of rivalries, removing one rival from the scene does not necessarily do any good: other rivals may be more likely to benefit from his death than oneself. This is the kind of hard lesson that has been learned by pest-control officers.
The hawk and dove story is, of course, naively simple. It is a “model”, something that does not really happen in nature, but which helps us to understand things that do happen in nature. Models can be very simple, like this one, and still be useful for understanding a point, or getting an idea. Simple models can be elaborated and gradually made more complex. If all goes well, as they get more complex they come to resemble the real world more.
The important difference between the war of attrition and a real auction sale is, after all, that in the war of attrition both contestants pay the price but only one of them gets the good. In a population of maximum bidders, therefore, a strategy of giving up at the beginning would be successful and would spread through the population.
Why the poker face rather than out-and-out lies? Once again, because lying is not stable. Suppose it happened to be the case that the majority of individuals raised their hackles only when they were truly intending to go on for a very long time in the war of attrition. The obvious counterploy would evolve: individuals would give up immediately when an opponent raised his hackles. But now, liars might start to evolve. So liar genes would spread. When liars became the majority, selection would now favor individuals who called their bluff. Therefore liars would decrease in numbers again. In the war of attrition, telling lies is no more evolutionarily stable than telling the truth. The poker face is evolutionarily stable. Surrender, when it finally comes, will be sudden and unpredictable.
A cricket that has recently won a large number of fights becomes more hawkish. A cricket that has recently had a losing streak becomes more dovish.
But such interactions between genes sitting in different bodies are only the tip of the iceberg. The vast majority of significant interactions between genes in the evolutionarily stable set — the gene pool — go on within individual bodies. These interactions are difficult to see, for they take place within cells, notably the cells of developing embryos. Well-integrated bodies exist because they are the product of an evolutionarily stable set of selfish genes.
If C is my identical twin, then I should care for him twice as much as I care for any of my children; indeed I should value his life no less than my own. But can I be sure of him? He looks like me to be sure, but it could be that we just happen to share the genes for facial features. No, I will not give up my life for him, because although it is possible that he bears 100% of my genes, I absolutely know that I contain 100% of my genes, so I am worth more to me than he is.
Indeed in a society with a high degree of marital infidelity, maternal uncles should be more altruistic than “fathers” since they have more grounds for confidence in their relatedness to the child. They know that the child’s mother is at least their half-sister. The “legal” father knows nothing.
But I wish to make a distinction between bringing new individuals into the world, on the one hand, and caring for existing individuals on the other. Depending on the ecological details of the species, various mixes of caring and bearing strategy can be evolutionarily stable. The one thing that cannot be evolutionarily stable is a pure caring strategy. If all individuals devoted themselves to caring for existing children to such an extent that they never brought any new ones into the world, the population would quickly become invaded by mutant individuals who specialized in bearing.
But from the point of view of the selfish genes there is, as we have seen, no distinction in principle between caring for a baby brother and caring for a baby son. Both infants are equally closely related to you.
Wild animals almost never die of old age: starvation, disease, or predators catch up with them long before they become really senile. Until recently this was true of man too. Most animals die in childhood, many never get beyond the egg stage.
He believes that animals who fight over territory are fighting over a token prize, rather than an actual prize like a bit of food. In many cases females refuse to mate with males who do not possess a territory. Indeed it often happens that a female whose mate is defeated and his territory conquered promptly attaches herself to the victor. Even in apparently faithful monogamous species, the female may be wedded to a male’s territory rather than to him personally.
If the population gets too big, some individuals will not get territories, and therefore will not breed. Winning a territory is therefore like winning a ticket or license to breed.
High-ranking individuals are more likely to breed than low-ranking individuals, either because they are preferred by females or because they physically prevent low-ranking males from getting near females. High social rank is another ticket of entitlement to reproduce. Instead of fighting directly over females themselves, individuals fight over social status, and then accept that if they do not end up high on the social scale they are not entitled to breed.
Individuals regulate their clutch size for reasons that are anything but altruistic. They are not practicing birth control in order to avoid over-exploiting the group’s resources. They are practicing birth control in order to maximize the number of surviving children they actually have, an aim which is the very opposite of that which we normally associate with birth control.
But the welfare state is a very unnatural thing. In nature, parents who have more children than they can support do not have many grandchildren, and their genes are not passed on to future generations. There is no need for altruistic restraint in the birth rate, because there is no welfare state in nature. Any gene for over-indulgence is promptly punished: the children containing that gene starve. Since we humans do not want to return to the old selfish ways where we let the children of too-large families starve to death, we have abolished the family as a unit of economic self-sufficiency, and substituted the state. But the privilege of guaranteed support for children should not be abused.
The welfare state is perhaps the greatest altruistic system the animal kingdom has ever known. But any altruistic system is inherently unstable, because it is open to abuse by selfish individuals, ready to exploit it. Individual humans who have more children than they are capable of rearing are probably too ignorant in most cases to be accused of conscious malevolent exploitation. Powerful institutions and leaders who deliberately encourage them to do so seem to me less free from suspicion.
But in the light of our selfish gene concept we must expect that individuals will cheat, will tell lies about how hungry they are. This will escalate, apparently rather pointlessly because it might seem that if they are all lying by screaming too loudly, this level of loudness will become the norm, and will cease, in effect, to be a lie. However, it cannot de-escalate, because any individual who takes the first step in decreasing the loudness of his scream will be penalized by being fed less, and is more likely to starve.
If one parent can get away with investing less than his or her fair share of costly resources in each child, however, he will be better off, since he will have more to spend on other children by other sexual partners, and so propagate more of his genes. Each partner can therefore be thought of as trying to exploit the other, trying to enforce the other one to invest more.
This is that the sex cells or “gametes” of males are much smaller and more numerous than the gametes of females. This is true whether we are dealing with animals or plants.
Sperms and eggs too 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.
In some respects a big isogamete would have an advantage over an average-sized one, because it would get its embryo off to a good start by giving it a large initial food supply. There might therefore have been an evolutionary trend towards larger gametes. But there was a catch. The evolution of isogametes that were larger than was strictly necessary would have opened the door to selfish exploitation. Individuals who produced smaller than average gametes could cash in, provided they could ensure that their small gametes fused with extra-big ones. This could be achieved by making the small ones more mobile, and able to seek out large one actively. The advantage to an individual of producing small, rapidly moving gametes would be that the could afford to make a larger number of gametes, and therefore could potentially have more children.
Males, then, seem to be pretty worthless fellows, and on simple “good of the species” grounds, we might expect that males would become less numerous than females. Other ways of putting this are that the male is more “expendable,” and the female more “valuable” to the species.
Since there is no shortage of males in the population, the daughters would have no trouble finding mates, and the daughter-manufacturing gene could spread. But now, think of what an enormous genetic advantage is enjoyed by those few parents who have sons. Anyone who invests in a son has a very good chance of being the grandparent of hundreds of seals.
She stands to lose more if the child dies than the father does. More to the point, she would have to invest more than the father in the future in order to bring a new substitute child to the same level of development. If she tried the tactic of leaving the father holding the baby, while she went off with another male, the father might, at relatively small cost to himself, retaliate by abandoning the baby too.
Best of all for her would be to try to deceive another male into adopting her child, “thinking” it is his own. Natural selection would severely penalize such guillibility in males and indeed would favor males who took active steps to kill any potential step-children as soon as they mated with a new wife.
Paradoxically, a reasonable policy for a female who is in danger of being deserted might be to walk out on the male before he walks out on her. This could pay her, even if she has already invested more in the child than the male has.
The point is that genes for deserting first could be favorably selected simply because genes for deserting second would not be.
We have looked at of the things that a female might do if she has been deserted by her mate. But these all have the air of making the best of a bad job. Is there anything a female can do to reduce the extent to which her mate exploits her in the first place? She has a strong card in her hand. She can refuse to copulate. She is in demand, in a seller’s market. The female is potentially in a position to drive a hard bargain before she copulates. Once she has copulated she has played her ace — her egg has been committed to the male.
The simplest version of the domestic-bliss strategy is this. The female looks the male lover, and tries to spot signs of fidelity and domesticity in advance. There is bound to be variation in the population of males in their predisposition to be faithful husbands. If females could recognize such qualities 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. Feminine coyness is in fact very common among animals, and so are prolonged courtship or engagement periods. As we have already seen, a long engagement can also benefit a male where there is a danger of his being duped into caring for another male’s child.
A business man should never say “I have already invested so much in the Concorde airliner that I cannot afford to scrap it now.” He should always ask instead whether it would pay him in the future, to cut his losses, and abandon the project now, even though he has already invested heavily in it.
Our two female strategies will be called coy and fast, and the two male strategies will be called faithful and philanderer.
Now suppose a single fast female enters the population. She does very well. She does not pay the cost of delay, because she does not indulge in prolonged courtship. Since all the males in the population are faithful, she can reckon on finding a good father for her children whomever she mates with.
If the philanderers increase so successfully that they come to dominate the male part of the population, the fast females will be in dire straits. Any coy female would have a strong advantage.
Demanding that a prospective mate should build a nest is one effective way for a female to trap him. It might be thought that almost anything that costs the male a great deal would do in theory, even if that cost is not directly paid in the form of benefit to the unborn children.
She begs from the male, using the same gestures as a young bird would use. It has been supposed that his is automatically attractive to the male, in the same way as a man finds a lips or pouting lips attractive in an adult woman.
Conversely, natural selection will tend to favor females who become good at seeing through such deception. One way they can do this is to play especially hard to get when they are courted by a new male, but in successive breeding seasons to be increasingly ready to accept quickly the advances of last year’s mate. This will automatically penalize young males embarking on their first breeding season, whether they are deceivers or not.
For simplicity, I have talked as though a male were either purely honest or thoroughly deceitful. In reality it is more probable that all males, indeed all individuals, are a little bit deceitful, in that they are programmed to take advantage of opportunities to exploit their mates. Natural selection, by sharpening up the ability of each partner to detect dishonesty in the other, has kept large-scale deceit down to a fairly low level.
The chances are that most of the females will agree with each other on which are the best males, since they all have the same information to go on. Therefore these few lucky males will do most of the copulating. This they are quite capable of doing, since all they must give to each female is some cheap sperms.
Obviously any potential mate who is courting her has proved his ability to survive at least into adulthood, but he has not necessarily proved that he can survive much longer. Quite a good policy for a female might be to go for old men. Whatever their shortcomings, they have at least proved they can survive, and she is likely to be allying her genes with genes for longevity.
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 of the most desirable qualities a male can have in the eyes of a female is, quite simply, sexual attractiveness itself. A female who mates with a super-attractive he-man is more likely to have sons who are attractive to females of the next generation.
He suggests that the tails of birds or paradise and peacocks, the huge antlers of deer, and the other sexually-selected features which have always seemed paradoxical because they appear to be handicap to their possessors evolve precisely because they are handicaps. A male bird with a long and cumbersome tail is showing off to females that he is such a strong he-man that he can survive in spite of his tail.
Usurpers do not often win fights, because if they were capable of winning they would have done so before! Any female who mates only with a harem-holder is therefore allying her genes with a male who is strong enough to beat off successive challenges from the large surplus of desperate bachelor males. With luck her sons will inherit their father’s ability to hold a harem.
It tends to be the males who go in for sexually attractive, gaudy colors, and the females who tend to be more drab. Individuals of both sexes want to avoid being eaten by predators, and there will be some evolutionary pressure on both sexes to be drably colored. Bright colors attract predators no less than they attract sexual partners.
Even if a male has a short life because his gaudy tail attracts predators, or get tangled in the bushes, he may have fathered a very large number of children before he dies. An unattractive or drab male may live even as long as a female, but he has few children, and his genes are not passed on. What shall it profit a male if he shall gain the whole world, and lose his immortal genes?
Another common sexual difference is that females are more fussy than males about whom they mate with. One of the reasons for fussiness by an individual of either sex is the need to avoid mating with a member of another species. Such hybridizations are a bad thing for a variety of reasons.
On the other hand, some human societies are promiscuous, and many are harem-based. What this astonishing variety suggests is that man’s way of life is largely determined by culture rather than by genes. However, it is still possible that males in general have a tendency towards promiscuity, and females a tendency towards monogamy, as we would predict on evolutionary grounds.
As we have seen, it is strongly to be expected on evolutionary grounds that, where the sexes differ, it should be the males that advertise and the females are drab. Most western man is undoubtedly exceptional in this respect.
The slaves are, of course, blissfully ignorant of the fact that they are unrelated to the queen and to the brood that they are tending. Unwittingly they are rearing new platoons of slave-makers.
What the aphids have to gain from the relationship is apparently protection from their natural enemies. Like our own dairy cattle they lead a sheltered life, and aphid species are much cultivated by ants have lost their normal defensive mechanisms.
Trivers goes so far as to suggest that many of our psychological characteristics — envy, guilt, gratitude, sympathy — have been shaped by natural selection for improved ability to cheat, to detect cheats, and to avoid being thought to be a cheat. Of particular interest are “subtle cheats” who appear to be reciprocating, but who consistently pay back slightly less than they receive. 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.
When you plant a fertile meme in my mind you literally parasitize my brain, turning it into a vehicle for the meme’s propagation in just the way that a virus may parasitize the genetic mechanism of a host cell. And this isn’t just a way of talking — the meme for, say, “belief in a life after death” is actually realized physically, millions of times over, as a structure in the nervous systems of individual men the world over.
It suggests that injustices in this world may be rectified in the next. The “everlasting arms” hold out a cushion against our own inadequacies which, like a doctor’s placebo, is none the less effective for being imaginary.
Fundamentally, the reason why it is good policy for us to try to explain biological phenomena in terms of gene advantage is that genes are replicators. As soon as the primeval soup provided conditions in which molecules could make copies of themselves, the replicators themselves took over. For more than 3 thousand million years, DNA has been the only replicator worth talking about in the world. Once self-copying memes had arisen, their own, much faster, kind of evolution took off. We biologists have assimilated the idea of genetic evolution so deeply that we tend to forget that it is only one of many possible kinds of evolution.
Some memes, like some genes, achieve brilliant short-term success in spreading rapidly, but do not last long in the meme pool. Popular songs and stiletto heels are examples. Others, such as the Jewish religious laws, may continue to propagate themselves for thousands of years, usually because of the great potential permanence of written records.
Mutually suitable teeth, claws, guts, and sense organs evolved in carnivore gene pools, while a different set of characteristics emerged from herbivore gene pools. Does anything analogous occur in meme pools? Perhaps we could regard an organized church, with its architecture, rituals, laws, music, art, and written tradition, as a co-adapted stable set of mutually assisting memes.
Even though a “conspiracy of doves” would be better off for every single individual than the evolutionary stable strategy, natural selection is bound to favor the ESS.
The point I am making now is that, even if we look on the dark side and assume that individual man is fundamentally selfish, our conscious foresight — our capacity to simulate the future in imagination — could save us from the worst selfish excesses of the blind replicators. We can see the long-term benefits of participating in a “conspiracy of doves,” and we can sit down together to discuss ways of making the conspiracy work. We, alone on earth, can rebel against the tyranny of the selfish replicators.
A nice strategy is defined as one that is never the first to defect. Tit for Tat is an example. It is capable of defecting, but it does so only in retaliation.
They therefore submitted nasty strategies, trying to exploit these anticipated softies!
But once again nastiness didn’t pay. Once again, Tit for Tat was the winner. And again nice strategies, in general, did better than nasty ones. All but one of the top 15 strategies were nice.
As evolutionists we are tempted to see it as the only kind of robustness that matters. Why does it matter so much? Because, in the world of Darwinism, winnings are not paid out as money; they are paid out as offspring. To a Darwinian, a successful strategy is one that has become numerous in the population of strategies. 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.
To be non-envious means to be quite happy if the other play wins just as much money as you do, so long as you both thereby win more from the banker. Tit for Tat never actually “wins” a game. Think about it and you’ll see that it cannot score more than its “opponent” in any particular game because it never defects except in retaliation. The most it can do is draw with its opponent. But it tends to achieve each draw with a high, shared score. Where Tit for Tat and other nice strategies are concerned, the very word “opponent” is inappropriate. Sadly, however, when psychologists set up games of Iterated Prisoner’s Dilemma between real humans, nearly all players succumb to envy and therefore do relatively poorly in terms of money.
Chess is zero sum, because the aim of each player is to win, and this means to make the other player lose. Prisoner’s Dilemma, however, is a nonzero sum game. There is a banker paying out money, and it is possible for the two players to link arms and laugh all the way to the bank.
Spectator sports like football are normally zero sum games for a good reason. It is more exciting for crowds to watch players striving mightily against one another than to watch them conniving amicably. But real life, both human life and plant and animal life, is not set up for the benefit of spectators. Many situation in real life are, as a matter of act, equivalent to nonzero sum games. Nature often plays the role of “banker,” and individuals can therefore benefit from one another’s success.
If I notice the banker fidget and look at his watch, I may well conjecture that the game is about to be brought to an end, and I may therefore feel tempted to defect. If I suspect that you too have notice the banker fidgeting, I may fear that you too may be contemplating defection. I will probably be anxious to get my defection in first.
They frequently ask why organisms group themselves into societies. They don’t ask — though they should — why living matter groups itself into organisms in the first place. Why isn’t the sea still a primordial battleground of free and independent replicators?
It is hard for many biologists even to see that there is a question here at all. This is because it is second nature for them to pose their questions at the level of the individual organism. Some biologists go so far as to see DNA as a device used by organisms to reproduce themselves, just as an eye is a device used by organisms to see!
When we have a cold or a cough, we normally think of the symptoms as annoying byproducts of the virus’s activities. But in some cases it seems more probable that they are deliberately engineered by the virus to help it to travel from one host to another.
The group is too wishy-washy an entity. A herd of deer, a pride of lions, or a pack of wolves has a certain rudimentary coherence and unity of purpose. But this is paltry in comparison to the coherence and unity of purpose of an individual lion, wolf, or deer.
Nowadays this cooperation between genes goes on within cells. It must have started as rudimentary cooperation between self-replicating molecules in the primeval soup. Cell walls perhaps arose as a device to keep useful chemicals together and stop them leaking away.
They can even become elephants or whales. Being big is not necessarily a good thing: most organisms are bacteria and very few are elephants. But when the ways of making a living that are open to small organisms have all been filled, there are still prosperous livings to be made by larger organisms. Large organisms can eat smaller ones, for instance, and can avoid being eaten by them.
The advantage of being in a club of cells don’t stop with size. The cells in the club can specialize, each thereby becoming more efficient at performing its particular task.
The fundamental unit, the prime mover of all life, is the replicator. A replicator is anything in the universe of which copies are made. Replicators come into existence, in the first place, by chance, by the random jostling of smaller particles. Once a replicator has come into existence it is capable of generating an indefinitely large set of copies of itself. No copying process is perfect, however, and the population of replicators comes to include varieties that differ from one another.
Replicators survive, not only by virtue of their own intrinsic properties, but by virtue of their consequences on the world. These consequences can be quite indirect. All that is necessary is that eventually the consequences, however tortuous and indirect, feed back and affect the success of the replicator at getting itself copied.