Re: The driving force of evolution

On Aug 10, 7:13 pm, Wolf <ElLoboVi...@xxxxxxxxxx> wrote:
J.A. Legris wrote:
On Aug 10, 12:33 pm, Wolf <ElLoboVi...@xxxxxxxxxx> wrote:
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.)

You're in no position to criticise my analogies until you RTFP.

HTH

And what does the paper offer that isn't in the abstract?

I thought you'd never ask. If you send your email address to
jalegris@[Bell Canada's ISP] (I cannot see yours because Google groups
filters them) I will memorize the article to the last letter, destroy
all my copies and send you a PDF as per the terms of my access
agreement (praised be the Lord and Allah Akbar too).

--
Joe


.

Relevant Pages

  • Re: Question regarding mutation under sexual reproduction
    ... There are mutations of large phenotypic effect and mutations of small ... can easily change the populations phenotypic mean in very short time ... homozygote is balanced by mutations that produce the mutant phenotype. ... That leaves reproductive isolation to produce two species. ...
    (talk.origins)
  • Re: Non-beneficial Gaps
    ... difference in the phenotype, such as blue rather than brown eyes. ... mutations are neutral because they have no effect on reproductive ... it is true that some losses or changes in protein ... < snip rest> ...
    (talk.origins)
  • Re: Blog: The Scars of Evolution.
    ... individual's _random_ mutations is positive, ... just like most of the time a neutral allele is lost ... individual expressing that deleterious phenotype will be more likely ... Selection is *always* relative to what else is present in organisms. ...
    (talk.origins)
  • Re: Non-beneficial Gaps
    ... difference in the phenotype, such as blue rather than brown eyes. ... You can't look at a protein in isolation and determine if it ... mutations that significantly affect protein function were neutral from ... The significant majority of all mutations are essentially ...
    (talk.origins)
  • 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)