| | Ted, you push aside Dawkin's theory of genic selection because it "creates no new models, no new equations, makes no testable predictions which differ from existing theories." Truth isn't measured by utility. And utility has a much broader base than just experiments to prove or disprove a theory. There is great intellectual utility in examining different ways of viewing a complex subject. And some views are closer to the truth than others. All of these arguments from utility are shallow don't address the truth of the concept.
The gene-centered view of biological evolution is itself a model - standing in opposition to other models. And, certainly, if it has any meaning to say, "X is the unit of selection," then those arguments would apply to whatever X stands for. You have launched attacks against one model that could also be used against any of the alternatives.
People reading your posts have come away suspecting that your objections have more to do with Dawkins, than the selfish-gene theory. I'm not the only person that noticed this aspect of your attack. You have some people you like despite their flaws, and you have some people that you hate despite their values. I value Hitchens for his fine mind despite the fact that I frequently disagree with him, despite his support for Obama, despite his colorful past as a Communist. I see you do this same rational approach with others, but not with Dawkins. And when you get like this, you make personal attacks on me or anyone else that points out how weak and strange your arguments become.
As an aside, in an earlier post you quote Jared Diamond and E. O. Wilson to establish Ernst Mayr's credentials (which in itself was a strange, convoluted argument from authority kind of thing). I would not have chosen either of them - given their epistemological/ethical/political positions. You are aware, aren't you, that Wilson believes the gene is the unit of selection - although he also believes in a multilevel form of selection that includes group selection? Diamond's blatant environmental determinism makes it hard for me to muster up much respect for him.
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"The essence of the genetical theory of natural selection is a statistical bias in the relative rates of survival of alternatives (genes, individuals, etc.). The effectiveness of such bias in producing adaptation is contingent on the maintenance of certain quantitative relationships among the operative factors. One necessary condition is that the selected entity must have a high degree of permanence and a low rate of endogenous change, relative to the degree of bias (differences in selection coefficients)." (Williams, 1966, p.22-23 - from Wikipedia)
Notice that a superficial reading of Williams' remark could support either the individual or the genes as the unit of selection. But since evolution must work over time, a period of time that exceeds the life of the individual, it has to become either the phenotypic trait or the genes responsible for that trait that is the unit of selection. A theory where a free-floating phenotypic trait is driving evolution with no reference to the cause of the trait would NOT seem like an intelligent model - not to me.
And as Williams argued, "The natural selection of phenotypes cannot in itself produce cumulative change, because phenotypes are extremely temporary manifestations." (Williams, 1966 - from Wikipedia)
Traits are not all genetic - some are learned or acquired outside of genetics and will not be transmitted to future generations and can not, therefore, be considered units of selection for evolution - no matter how they might select that individual for his individual success.
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It is not a single gene that is selected for, it is a gene-set (nor is it the entire genotype) - the genetic material that produces the trait in question. The trait that ends up shifting the balance in the relative rates of reproduction. You could say that the unit of selection is the trait, but it is the particular 'team of genes' responsible for the trait that cause it to be reproduced (developed traits don't count unless you are a Lamarkian :-). The phenotype can not be the unit of selection, because, as it has been pointed out, the individual isn't around long enough to shift the balance.
"Genes do not present themselves naked to the scrutiny of natural selection, instead they present their phenotypic effects. (...) Differences in genes give rise to difference in these phenotypic differences. Natural selection acts on the phenotypic differences and thereby on genes. Thus genes come to be represented in successive generations in proportion to the selective value of their phenotypic effects.” —Cronin, 1991, p.60 (from Wikipedia)
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"A gene can have multiple phenotypic effects, each of which may be of positive, negative or neutral value. It is the net selective value of a gene's phenotypic effect that determines the fate of the gene" (Cronin, 1991). "For instance, a gene can cause its bearer to have greater reproductive success at a young age, but also cause a greater likelihood of death at a later age. If the benefit outweighs the harm, averaged out over the individuals and environments in which the gene happens to occur, then phenotypes containing the gene will generally be positively selected and thus the abundance of that gene in the population will increase." Wikipedia
I'm aware of the complex relation between genes and phenotype and environment (including the extraordinary complexity introduced by embryology). But when you attempt to point at the individual as the unit of selection, it is like ignoring the existence of the genes which would raise the question of what gets passed forward to give any continutity to evolution.
Selection occurs at many levels. There is a chemical environment that is an agent of selection for molecular activity, there is the mechanism of embryology and the environment it works in that selects where alternatives exist at that level, the genes effect each others expression, the external environment selects against the individual traits - which can be said to be against the individual as a whole. But in the end it is the phenotypic differences that translate into differential rates of successful reproduction that are selected for - but only as a team of genes responsible for that trait, otherwise we could not explain why acquired traits don't count in the world of evolution.
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Dawkins, and others have asked, "If it makes sense to say that the adaptation is 'for the good of something,' then what is that something that is benefited?" There were those who proposed going to the chemical level and discussed molecular level and talked about units of recombination. Dawkins proposed the term "optimon" to be the unit of natural selection - that which could be said to be the beneficiary of adaptation. Independently, in a personal communication with Dawkins, E. Mayr coined the term "selecton" to serve the same purpose.
"In the rest of this chapter ['Action at a Distance', The Extended Phenotype], I hope to show that the version of 'genetic selectionism' that can be attacked as naively atomistic, and reductionistic is a straw man; that it is not the view that I am advocating; and that if genes are correctly understood as being selected for their capacity to cooperate with each other in the gene-pool, we arrive at a theory of genetic selection which Wright and Mayr will recognize as fully compatible with their own views." pg. 239. Dawkins goes on to quote Mayr and show the similarities in thought.
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“The idea that a few people have about the gene being the target of selection is completely impractical; a gene is never visible to natural selection, and in the genotype, it is always in the context with other genes, and the interaction with those other genes make a particular gene either more favorable or less favorable. In fact, Dobzhanksy, for instance, worked quite a bit on so-called lethal chromosomes which are highly successful in one combination, and lethal in another. Therefore people like Dawkins in England who still think the gene is the target of selection are evidently wrong. E. Mayr, from Wikipedia
Here are the problems with that paragraph:
- Dawkins has never spoken of the gene that narrowly - he has always spoken of the genetic material responsible for a phenotypical trait and always in the context of other genes.
- The statement that the gene is never visible to natural selection is false in the sense that the phenotypic trait is what is selected for (against it's alleles) and it is the product of the genes - it is the genes that are selected for - otherwise learned traits could be 'selected' for.
- Again, Dawkins always speaks of the genes in the context of the genome.
I don't see how anyone can say the individual is the target of selection when we are speaking of evolution. The individual dies. Does it end there? No, evolution needs so much longer than the lifespan of the individual, and it goes on because the trait or traits that made that individual more successful in ways that effect replication are passed on by gene-set - they are the target of selection, by way of the trait, by way of the individual, within the wider context of the environment.
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"If the individual were the only target of selection, this would indeed be an inevitable conclusion. However, small social groups that compete with each other, such as the groups of hunter-gatherers in our human ancestry, were as groups also targets of selection. Groups, the members of which actively cooperated with each other and showed much reciprocal helpfulness, had a higher chance for survival than groups that did not benefit from such cooperation and altruism. Any genetic tendency for altruism would therefore be selected in a species consisting of social groups. In a social group, altruism may add the to fitness. The founders of religions and philosophies erected their ethical system on this basis." Interview with E. Mayr
Here Mayr veers off into group selection and becomes reductionist with his call for a genetic basis for altruism. And further, he goes on to take altruism as an assumed value, and theorize from there that founders of religions and philosophies chose altruistic ethical systems because they aided group fitness.
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Now, there is a certain class of sophisticated modern theologian who will say something like this: "Good heavens, of course we are not so naive or simplistic as to care whether God exists. Existence is such a 19th-century preoccupation! It doesn't matter whether God exists in a scientific sense. What matters is whether he exists for you or for me. If God is real for you, who cares whether science has made him redundant? Such arrogance! Such elitism." Well, if that's what floats your canoe, you'll be paddling it up a very lonely creek. The mainstream belief of the world's peoples is very clear. They believe in God, and that means they believe he exists in objective reality, just as surely as the Rock of Gibraltar exists. If sophisticated theologians or postmodern relativists think they are rescuing God from the redundancy scrap-heap by downplaying the importance of existence, they should think again. Tell the congregation of a church or mosque that existence is too vulgar an attribute to fasten onto their God, and they will brand you an atheist. They'll be right.
