Re: Shall we get rid of our junk?
- From: "John Edser" <edser@xxxxxxxxxx>
- Date: Tue, 20 Dec 2005 11:55:53 -0500 (EST)
"g" gillawton@xxxxxxxxxxxxx wrote:-
> > "Joe Felsenstein" <joe@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote
> > Does that mean there is an individual selection explanation for the
> > retention of the "junk"? Or must we necessarily invoke species
> > selection if we explain it this way (the dying out of species if they
> > get rid of too much of their "junk" and then need a new function)?
> To take this question to another level, there seems to be an implied
>snip<
> You raise this question "... must we necessarily invoke species selection
> if
> we explain it this way..."
> (that some forms might have disposed of their transposons and, as a
> result,
> ceased to exist because they could not change to meet later necessities.
>
> But a even more provocative question is this one:
>
> How -- with so many comparably unchanged morphologies around -- can we be
> CERTAIN that the survival of those changed and complexified forms around
> today not only adapted to changes in the externalities they had to survive
> in but, also, that if they had not, they would in every case have
> perished.
>
> Does the continued existence of some forms, hardly changed at all, not
> cloud
> the assumption that evolution (change) is purely a result of necessary
> adaptation. Does the existence of these so-called "living fossils" not
> open -- by at least the tiniest crack -- the question of whether SOME
> change
> and SOME so-called *advancement* might have come about as nothing more
> than
> *alternative* successful forms, and that they replaced, or simply formed
> new
> directional paths of some within a single species. Could some
> morphological
> changes have been made NOT as a necessity, NOT as an adaptation, but just
> as
> an alternative which ALSO worked?
JE:-
The first issue is to settle what actually constitutes a valid THEORY of
group selection. Unless this is done in an entirely scientific manner what
different people mean by the same concept utterly confuses the issue. The
classical form of group selection put forward by V.C. Wynne-Edwards was and
remains monocentric (one level of selection operates) and not polycentric
(more than one level operates). Wynne-Edwards original proposition was:
selection at the organism group level always wins against selection at the
organism level allowing organism group selection to force organism fitness
altruism at the organism level. This concept only allowed the group level of
selection to actually operate, i.e. it reduces the independent organism
level to now become dependent on the group level. It should be noted that he
reversed this position in his last book which received almost zero
publicity. I have qualified each level by the use of "fertile" since an
infertile form of either level cannot pass on a heritable fitness no matter
how fitness may be coded for that level.
What fitness constitutes fitness for either level is just the reproduction
of competing entities at their own level. For the Darwinian fertile organism
level fitness is just a simple tally of the number of fertile organism
reproductions each fertile organism reproduces within one population where
each selectee must compete by necessity against every other within a
population of its own type. For classical group selection the group centric
fitness tally is the number or reproduced fertile organism _populations_
within one population of same, i.e. within a population of fertile organism
_populations_ which of course constitute an organism meta population. Again
by necessity, each fertile organism centric form must compete against every
other within the same meta population. It should be noted that only a final
fitness tally actually matters. Like a race, it does not matter if you are
winning half way through, all that matters is how you finish. In nature the
only finish possible is a tally TOTAL for each parental form within a
population of its own type. It does not matter if each competing parent does
not finish together. Once finished each form's selective result within one
population of its own kind produces a final selective result for that parent
within a population of its own type.
Regards,
John Edser
Independent Researcher
edser@xxxxxxxxxx
.
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