Cooperating to build a body is as effective a survival 'strategy ' for genes as cooperating to run a town is a successful social strategy for human beings.
But society is not all cooperation; a measure of competitive free enterprise is inevitable. A gigantic experiment called communism in a laboratory called Russia proved that. The simple, beautiful suggestion that society should be organized on the principle 'from each according to his ability, to each according to his need ' proved disastrously unrealistic because each did not see why he should share the fruits of his labors with a system that gave him no reward for working harder: Enforced cooperation of the Communist kind is as vulnerable to the selfish ambitions of the individual as a free-for-all would be. Likewise, if a gene has the effect of enhancing the survival of the body it inhabits but prevents that body from breeding or is never itself transmitted through breeding, then that gene will by definition become extinct and its effect will disappear.
Finding the right balance between cooperation and competition has been the goal and bane of Western politics for centuries.
Adam Smith recognized that the economic needs of the individual are better met by unleashing the ambitions of all individuals than by planning to meet those needs in advance. But even Adam Smith could not claim that free markets produce Utopia. Even the most libertarian politician today believes in the need to regulate, oversee, and tax the efforts of ambitious individuals so as to ensure that they do not satisfy their ambitions entirely at the expense of others. In the words of Egbert Leigh, a biologist at the Smithsonian Tropical Research Institute, 'Human intelligence has yet to design
a society where free competition among the members works for the good of the whole. '' The society of genes faces exactly the same problem. Each gene is descended from a gene that unwittingly jos-tled to get into the next generation by whatever means was in its power. Cooperation between them is marked, but so is competition.
And it is that competition that led to the invention of gender.
As life emerged from the primeval soup several billion years ago, the molecules that caused themselves to be replicated at the expense of others became more numerous. Then some of those molecules discovered the virtues of cooperation and specialization, so they began to -assemble in groups called chromosomes to run machines called cells that could replicate these chromosomes efficiently. In just the same way little groups of agriculturalists joined with blacksmiths and carpenters to form cooperative units called villages. The chromosomes then discovered that several kinds of cells could merge to form a supercell, just as villages began to group together as tribes. This was the invention of the modern cell from a team of different bacteria. The cells then grouped together to make animals and plants and fungi, great big conglomerates of conglomerates of genes, just as tribes merged into countries and countries into empires.'
None of this would have been possible for society without laws to enforce the social interest over the individual, selfish drive; it was the same with genes. A gene has only one criterion by which posterity judges it: whether it becomes an ancestor of other genes.
To a large extent it must achieve that at the expense of other genes, just as a man acquires wealth largely by persuading others to part with it (legally or illegally). If the gene is on its own, all other genes are its enemies— every man for himself. If the gene is part of a coalition, then the coalition shares the same interest in defeating a rival coalition, just as employees of Hertz share the same interest in its thriving at the expense of Avis.
This broadly describes the world of viruses and bacteria.
They are disposable vehicles for simple teams of genes, each team highly competitive with other teams but with largely harmonious relations among team members. For reasons that will soon become GENETIC MUTINY AND GENDER
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apparent, this harmony breaks down when bacteria merge to become cells and cells merge to become organisms. It has to be reasserted by laws and bureaucracies.
And even at the bacterial level it does not entirely hold true. Consider the case of a new, supercharged mutant gene that appears in a bacterium. It is superior to all other genes of its type, but its fate is determined largely by the quality of its team. It is like a brilliant engineer finding himself employed by a doomed, small firm or a brilliant athlete stuck on a second-rate team: Just as the engineer or the athlete seeks a transfer, so we might expect that bacterial genes would have invented a way to transfer themselves from one bacterium to another:
They have. It is called 'conjugation, ' and it is widely agreed to be a form of sex itself. Two bacteria simply connect to each other by a narrow pipe and shunt some copies of genes across. Unlike sex, it has nothing to do with reproduction, and it is a relatively rare event. But in every other respect it is sex. It is genetic trade.
Donal Hickey of the University of Ottawa and Michael Rose of the University of California at Irvine were the first to suggest in the early 1980s that bacterial 'sex' was invented not for the bacteria but for the genes—not for the team but for the players.' It was a case of a gene achieving its selfish end at the expense of its teammates, abandoning them for a better team: Their theory is not a full explanation of why sex is so common throughout the animal and plant kingdoms; it is not a rival to the theories discussed heretofore. But it does suggest how the whole process got itself started. It suggests an origin for sex:
From the point of view of an individual gene, then, sex is a way to spread laterally as well as vertically: If a gene were able to make its owner-vehicle have sex, therefore, it would have done something to its own advantage (more properly, it would be more likely to leave descendants if it could), even if it were to the disadvantage of the individual: Just as the rabies virus makes the dog want to bite anything, thus subverting the dog to its own purpose of spreading to another dog, so a gene might make its owner have sex just to get into another lineage.
Hickey and Rose are especially intrigued by genes called transposons, or jumping genes, that seem to be able to cut themselves our of chromosomes and stitch themselves back into other chromosomes. In 1980 two teams of scientists simultaneously came to the conclusion that the transposons seemed to be examples of 'selfish ' or parasitic DNA, which spreads copies of itself at the expense of other genes: Instead of looking for some reason that transposons exist for the benefit of the individual, as scientists had done before, they simply saw it as bad for the individual and good for the transposons.' Muggers and outlaws do not exist for the benefit of society but to its detriment and for the benefit of themselves. Perhaps transposons were, in Richard Dawkins 's words,
' outlaw genes. '8 Hickey then noticed that transposons were much more common among outbreeding sexual creatures than among inbreeding or asexual ones. He ran some mathematical models which showed that parasitic genes would do well even if they had a bad effect on the individual they inhabited. He even found some cases of parasitic genes of yeast that spread quickly in sexual species and slowly in asexual ones. Such
