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task this apparently surplus DNA is doing. But from the point of view of the selfish genes themselves, there is no paradox. The true ‘purpose’ of DNA is to survive, no more and no less. The simplest way to explain the surplus DNA is to suppose that it is a parasite, or at best a harmless but useless passenger, hitching a ride in the survival machines created by the other DNA.*
Interesting!
notable advance was the evolutionary ‘invention’ of memory. By this device, the timing of muscle contractions could be influenced not only by events in the immediate past, but by events in the distant past as well.
There are more possible games of chess than there are atoms in the galaxy.
All we have to believe is that those individuals whose genes build brains in such a way that they tend to gamble correctly are as a direct result more likely to survive, and therefore to propagate those same genes.
but on average high-stake gamblers are no better and no worse off than other players who play for low winnings with low stakes.
The possibilities of saccharine and masturbation are not anticipated according to this example; nor are the dangers of over-eating sugar in our environment where it exists in unnatural plenty.
Survival machines that can simulate the future are one jump ahead of survival machines who can only learn on the basis of overt trial and error.
The evolution of the capacity to simulate seems to have culminated in subjective consciousness.
Perhaps consciousness arises when the brain’s simulation of the world becomes so complete that it must include a model of itself.*
What has all this to do with altruism and selfishness? I am trying to build up the idea that animal behaviour, altruistic or selfish, is under the control of genes in only an indirect, but still very powerful, sense.
By dictating the way survival machines and their nervous systems are built, genes exert ultimate power over behaviour. But the moment-to-moment decisions about what to do next are taken by the nervous system.
Genes are the primary policy-makers; brains are...
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The logical conclusion to this trend, not yet reached in any species, would be for the genes to give the survival machine a single overall policy instruction: do whatever you think best to keep us alive.
This last group uncapped the wax cells of diseased grubs, but they did not follow through and throw out the larvae.
Secondly it illustrates the fact that genes ‘cooperate’ in their effects on the behaviour of the communal survival machine. The throwing-out gene is useless unless it is accompanied by the uncapping gene and vice versa. Yet the genetic experiments show equally clearly that the two genes are in principle quite separable in their journey through the generations.
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.
Why is it that animals do not go all out to kill rival members of their species at every possible opportunity?
The moral of this simple hypothetical example is that there is no obvious merit in indiscriminately trying to kill rivals.
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. You have a serious agricultural pest, you discover a good way to exterminate it and you gleefully do so, only to find that another pest benefits from the extermination even more than ...
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An evolutionarily stable strategy or ESS is defined as a strategy which, if most members of a population adopt it, cannot be bettered by an alternative strategy.*
Following a major environmental change there may be a brief period of evolutionary instability, perhaps even oscillation in the population. But once an ESS is achieved it will stay: selection will penalize deviation from it.
Now is much less than the average pay-off for a dove in a population of doves (15). If only everybody would agree to be a dove, every single individual would benefit. By simple group selection, any group in which all individuals mutually agree to be doves would be far more successful than a rival group sitting at the ESS ratio. (As a matter of fact, a conspiracy of nothing but doves is not quite the most successful possible group. In a group consisting of hawks and doves, the average pay-off per contest is . This is the most successful possible conspiracy,
in conspiracies of doves, a single hawk does so extremely well that nothing could stop the evolution of hawks.
An ESS is stable, not because it is particularly good for the individuals participating in it, but simply because it is immune to treachery from within.
In a population of maximum bidders, therefore, a strategy of giving up at the beginning would be successful and would spread through the population.
The point is that even if there were no general reason to suppose that residents have an advantage over intruders, an ESS depending on the asymmetry itself would be likely to evolve. A simple analogy is to humans who settle a dispute quickly and without fuss by tossing a coin.
The reason it can be stable is this. In a population consisting entirely of paradoxical strategists, nobody ever gets hurt. This is because in every contest one of the participants, the larger, always runs away.
For instance a lion wants to eat an antelope’s body, but the antelope has very different plans for its body. This is not normally regarded as competition for a resource, but logically it is hard to see why not.
We are still so used to thinking in terms of the ‘good of the species’ view of evolution that we often forget to ask perfectly reasonable questions like: Why don’t lions hunt other lions? Another good question of a type which is seldom asked is: Why do antelopes run away from lions instead of hitting back?
What makes a gene good? As a first approximation I said that what makes a gene good is the ability to build efficient survival machines—bodies. We must now amend that statement. The gene pool will become an evolutionarily stable set of genes, defined as a gene pool that cannot be invaded by any new gene. Most new genes that arise, either by mutation or reassortment or immigration, are quickly penalized by natural selection: the evolutionarily stable set is restored. Occasionally a new gene does succeed in invading the set: it succeeds in spreading through the gene pool. There is a transitional
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Genes are selected on ‘merit’. But merit is judged on the basis of performance against the background of the evolutionarily stable set which is the current gene pool.
But now we are emphasizing that ‘it’ is a distributed agency, existing in many different individuals at once.
The key point of this chapter is that a gene might be able to assist replicas of itself that are sitting in other bodies. If so, this would appear as individual altruism but it would be brought about by gene selfishness.
Gene selfishness!
If the albino gene could make one of its bodies save the lives of ten albino bodies, then even the death of the altruist is amply compensated by the increased numbers of albino genes in the gene pool.
The possessor of an altruistic gene might be recognized simply by the fact that he does altruistic acts. A gene could prosper in the gene pool if it ‘said’ the equivalent of: ‘Body, if A is drowning as a result of trying to save someone else from drowning, jump in and rescue A.’
If an individual dies in order to save ten close relatives, one copy of the kin-altruism gene may be lost, but a larger number of copies of the same gene is saved.
The relatedness between parent and child is always exactly .
Refer: The Gene
Genetically speaking, your first cousin is equivalent to a great-grandchild. Similarly, you are just as likely to ‘take after’ your uncle () as after your grandfather
Genetically speaking, parental care and brother/sister altruism evolve for exactly the same reason: in both cases there is a good chance that the altruistic gene is present in the body of the beneficiary.
If conditions change radically, survival machines will tend to make erroneous decisions, and their genes will pay the penalty. Just so; human decisions based on outdated information tend to be wrong.
Conceivably, racial prejudice could be interpreted as an irrational generalization of a kin-selected tendency to identify with individuals physically resembling oneself, and to be nasty to individuals different in appearance.
In most cases we should probably regard adoption, however touching it may seem, as a misfiring of a built-in rule.
We may suppose that a proportion of cuckoo eggs and chicks are ‘found out’, and those that are not found out are the ones who live to lay the next generation of cuckoo eggs. So genes for more effective deception spread through the cuckoo gene pool.
So we conclude that the ‘true’ relatedness may be less important in the evolution of altruism than the best estimate of relatedness that animals can get.
the gene for individual selfishness has the enormous advantage of certainty of individual identity. The rival kin-altruistic gene runs the risk of making mistakes of identity, either genuinely accidental or deliberately engineered by cheats and parasites. We therefore must expect individual selfishness in nature, to an extent greater than would be predicted by considerations of genetic relatedness alone.
Maternal grandfathers are just as sure of their grandchildren as paternal grandmothers are, since both can reckon on one generation of certainty and one generation of uncertainty.
Similarly, uncles on the mother’s side should be more interested in the welfare of nephews and nieces than uncles on the father’s side, and in general should be just as altruistic as aunts are.
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.
Incidentally, a thing that is sometimes not realized even by people who worry about population problems is that population growth depends on when people have children, as well as on how many they have. Since populations tend to increase by a certain proportion per generation, it follows that if you space the generations out more, the population will grow at a slower rate per year. Banners that read ‘Stop at Two’ could equally well be changed to ‘Start at Thirty’! But in any case, accelerating population growth spells serious trouble.
