Re: The driving force of evolution

J.A. Legris wrote:
[...]
Nei argues that before selection can act on phenotypes, the underlying
genetic mutations must occur, most of which have insignificant effects
on the phenotype, as indicated by the large amount of neutral genetic
variation within species. The mutations that are significant drive the
phenotype down developmental pathways that are unpredictable and
tightly restrictive on subsequent viable mutations.

This (interpreted with a great dollop of charity) is merely paraphrase of what Dawkins and others have said explicitly, and what was implicit in Darwin's claim that natural selection acts upon the "variations" in organisms.

And as a matter of fact, it's not clear just what effect most mutations have on the phenotype, since we have almost no statistics on failed development of the zygote. That is, we just don't know how many fertilisations of eggs, for example, fail to develop at all, never mind what percentage develop in more or less abnormal ways. The few data I'm familiar with suggest that roughly 2/3rds of mutations in humans prevent development, period. BTW, at any given moment in your life, a large percentage of your cells contain mutations. You are, molecularly, not the man you used to be.

Natural selection
is the final arbiter of which mutations persist, but the mutations
themselves are setting the agenda.

Mutations just happen, is all. To say they set the agenda implies some sort of agency on their part. IOW, a metaphor, and a stupid one IMO, though not nearly as stupid as taking it literally.

As I see it, an analogy is that of
a highly creative artist producing new works that are released into
the market. The artist must update his materials and techniques to
follow popular trends, but the selectivity of the market is secondary
to his creative output.
[...]

The selectivity of the market is secondary? That's like saying that digestion is secondary to eating (since you like analogies.)


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  • Re: The driving force of evolution
    ... most of which have insignificant effects ... on the phenotype, as indicated by the large amount of neutral genetic ... variation within species. ... The mutations that are significant drive the ...
    (comp.ai.philosophy)
  • Re: The driving force of evolution
    ... most of which have insignificant effects ... on the phenotype, as indicated by the large amount of neutral genetic ... variation within species. ... The mutations that are significant drive the ...
    (comp.ai.philosophy)