[arketyp]

I am familiar with the gene-centered view of evolution proposed by Williams and popularized by Dawkins with the so-called selfish gene theory. Within this school of thought sexual selection by no means stands in contrast to natural selection and is not labeled an alternative to it. Instead, in fact, sexual selection is argued to be a direct consequence of natural selection as a phenomena you would expect with Darwinisitic reasoning when assuming the gene-centered view. As is made the case, the gene-centered view is the extension of Darwin's original argument, that is, Darwin's argument taken to its logical conclusion with the modern facts at hand, the DNA molecule not the least.

One of the central themes in Dawkins's The Extended Phenotype is the putting into question of the validity of traditional role of the organism in Darwinistic reasoning and why Darwin's original definition of fitness does not hold up. There is actually an entire segment on the many modern (back then) definitions of fitness and problems with each of them. I don't recall what the final conclusion is but it is certain it is not the clear-cut case you make it.

I suppose you have background in a field where your definition of fitness is more firmly established. For instance, I know biological mathematics has come a long way, and I'm not up to speed with what definitions they are using.