Books

The Selfish Gene | Richard Dawkins


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Published in: 1976 / 2009

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The selfish gene theory is Darwin’s theory. But rather than focus on the individual organism, this book takes a gene’s-eye view of nature. And if you look at the way natural selection works, it seems to follow that anything that has evolved by natural selection should be selfish while we must teach generosity and altruism. This book will show how both individual selfishness and individual altruism are explained by the fundamental law called “gene selfishness”.    

THE BEGINNING. At some point a remarkable molecule was formed by accident. We call it the Replicator. It had extraordinary property of being able to create copies of itself (think of it as a mold or template). The copying process was not perfect, and mistakes happened. But erratic copying can give rise to improvement, and it was errors essential for the progressive evolution of life. DNA-molecules are modern equivalents of the first replicators.

SURVIVAL OF THE STABLE. Certain molecules, once formed, would be less likely than others to break up again. The universe is populated by stable things. A stable thing is a collection of atoms that is permanent enough or common enough. All material things – rocks, galaxies, ocean waves – are, to a greater or lesser extent, stable patterns of atoms.

COMPETITION – A NATURAL STATE. If replicator molecules of type A make copies of themselves on average once a week and type B once an hour, soon type A will be far outnumbered even if they “live” much longer. If molecules of type X and type Y last the same length of time and replicate at the same rate, but X makes a mistake on average every tenth replication while Y makes a mistake only every hundredth replication, Y will be more numerous. Any mis-copying that resulted in a new higher level of stability, or reducing the stability of rivals, was automatically preserved and multiplied. This process was cumulative. When replicators became numerous, building blocks must have been used up at such a rate that they became a scarce resource. Different replicators must have competed for them. 

SURVIVAL MACHINES IS CREATED. Replicators discovered how to protect themselves, either chemically, or by building a wall of protein around themselves (this may have been how the first living cells appeared). Replicators began to construct vehicles for their continued existence, and those that survived were the ones that built “survival machines” to live in. Survival machines got bigger and more elaborate, and the process was cumulative and progressive. They created us, the body and the mind, and their preservation is the ultimate rationale for our existence. They have come a long way, those replicators. Now they go by the name of genes, and we are their survival machines.

CLUSTERS OF GENES. All people, animals, plants, bacteria, and viruses are survival machines (for the replicator DNA). But survival machines are not just carrying one gene but many thousands. Any one chromosome in a sperm would be a patchwork of maternal genes and paternal genes. A body is a cooperative venture of such intricacy that it is almost impossible to disentangle the contribution of one gene from another. Some genes act as master genes controlling the operation of a cluster of genes. The combination of genes that is in any one individual may be short-lived, but the genes are potentially very long-lived. Their paths constantly cross and recross down the generations. The genes are not destroyed by crossing-over, they merely change partners. They are the replicators, and we are their survival machines.

A COMPLEX SURVIVAL GAME. A gene can live for a million years, but, many new genes do not even make it past their first generation. The few ones that succeed do so partly because they are lucky, but mainly because they have what it takes, and that means they are good at making survival machines. Genes are competing directly with their allies for survival, since their allies in the gene pool are rivals for their slots on the chromosomes of future generations. Any gene that behaves in such an expense of its allies will, by definition, tautologously, tend to survive.  

THE GENE MACHINE. Neurons are basically just cells, with a nucleus and chromosomes like other cells. But their cell walls are drawn out in long, thin, wire-like projections. The main way in which the brain actually contribute to the success of survival machines is by controlling and coordinating the contractions of muscles. 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 neurons.

DECISION-MAKING. Every decision that a survival machine takes is a gamble. It is the business of genes to program brains in advance so that on average they take decisions that pay off. The currency used in the casino of evolution is gene survival but for many purposes individual survival is a reasonable approximation. One way for genes to make predictions in unpredictable environments is to build in a capacity for learning. The program may take the form of instructions to the survival machine, such as rewarding (sweet taste, orgasm, mild temperature, smiling child), nasty (pain, nausea, empty stomach, screaming child). This programming greatly cuts down the number of detailed rules that have to be built into the original program, and is capable of coping with changes in the environment.

SIMULATION. No simulation can predict exactly what will happen. But a good simulation is preferable to blind trial-and-error. You imagine what would happen if you did each of the alternatives open to you. You set up a model in your head of the restricted set of entities which you think may be relevant that will be used to predict possible events. Survival machines that can simulate the future are one jump ahead of survival machines that can only learn on overt trial and error. Trial-and-error takes time and energy and is often fatal. Simulation is both safer and faster. The evolution of the capacity to simulate seems to have culminated in subjective consciousness.

OUTSOURCING RESPONSIBILITIES. Genes are the primary policy-makers, brains are the executives. But as brains became more developed, it took over more and more of the actual policy decisions, using tricks like learning and simulation. The logical conclusion to this trend, not yet reached in many 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.

EVOLUTIONARY STABLE SYSTEMS. A strategy is a pre-programmed behavioral policy. An example of a strategy is: “Attack opponent, if he flees pursue him, if he retaliates run away”. An evolutionary stabile strategy or ESS is a strategy which in most members of a population adopt it cannot be bettered by an alternative strategy. The best strategy for an individual depends on what most of the population is doing. Since the rest of the population consists of individuals, each one trying to maximize his own success, the only strategy that persists will be the one which, once evolved, cannot be bettered by any deviant individual. Following a major environmental change there may be a brief period of evolutionary instability. But once an ESS is achieved it will stay: selection will penalize deviation from it.

HUMAN ESS. The trouble with conspiracies, even those that are to everybody’s advantage in the long run, is that they are open to abuse. The conspiracy is often bound to be broken by treachery from within. An ESS is stable, not because it is particularly good for the individuals participating in it, but because it is immune to treachery from within. It is possible for humans to enter into pacts or conspiracies that are to every individual’s advantage, even if these are not stable in the ESS sense. But this is only because every individual uses conscious foresight and is able to see that it is in his own long-term interest to obey the rules of the pact.

TIT-TOR-DOUBLE TAT. A winning strategy is tit-for-tat which begins by cooperating on the first move and thereafter copies the previous move of the other player. Tit for two tats allows its opponent two defections in a row before it eventually retaliates. This might seem excessively saint, but it has won game theory tournaments. This is because it avoids runs of mutual recrimination. There are two characteristics of winning strategies: niceness and forgiveness. Tit-for-tat seems as an ESS, but it is in the stricter sense not so. To be an ESS, a strategy must not be invadable by a rare mutant strategy. Tit-for-tat cannot be invaded by any nasty strategy but another nice strategy.

MEMES: THE NEW REPLICATORS. Memes are the culture equivalent of genes, i.e. replicators. Examples of memes are tunes, ideas, catch-phrases, clothes fashion, ways of making pots or of building arches. Just as genes propagate themselves in the gene pool by leaping from body to body, so memes propagate themselves in the meme pool by leaping from brain to brain via a process which, in the broad sense, can be called imitation. If a scientist hears, or reads about, a good idea, he passes it on to his colleagues and students. It spreads from brain to brain. Imitation, in the broad sense, is how memes can replicate. But just as not all genes that can replicate do so successfully, so some memes are more successful in the meme-pool than others. This is the analogue of natural selection. Some memes, like some genes, achieve brilliant short-term success in spreading rapidly, but do not last in the meme pool.  

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