Re: Haldane's Dilemma - clarifications - and Felsenstein [LONG]

Perplexed in Peoria wrote:
Ok, I understand that you need to add the costs
of "mutational load", "substitutional load", and
whatever the "load" is called that maintains
balanced polymorphisms.

Part of my clarification of cost theory is to dump load theory (and its
terminology) as needless confusion. So, there is the cost of mutation
(the extra reproduction rate needed to cope with the abundance of
harmful mutation, and keep the population from genetically
deteriorating), and the cost of segregation (the extra reproduction
rate needed to maintain balanced polymorphisms, such as the sickle-cell
case), and the cost of random loss (the extra reproduction rate needed
to cover random losses -- such as fire, flood, famine, pestilence,
storm, selection for non-heritable traits, etcetera -- which eliminate
many of the favored organisms). Each of those three costs is large.
Indeed, the cost of mutation, and the cost of segregation have EACH
been so large that they INDIVIDUALLY may overwhelm many species.
Individually, these each have been, and substantially remain,
unresolved problems. Combined together, these cost problems all
aggravate each other, because they must all be paid from the species
finite supply of reproduction rate.

Those costs are all paid, in some sense, by
natural selection, and are additive.

A subtle correction. The costs are *never* paid by natural selection.
Cost can ONLY be paid by real (not imaginary), actual, reproduction
rate.

Also, the costs are not "incurred by natural selection" -- because that
wording would be too non-specific. Rather, the costs are incurred by a
given evolutionary scenario, and a different evolutionary scenario may
well incur different costs.

But when a neutral allele becomes fixed by
fluctuations in meiotic segregation, you say
(correctly IMO) that the excess reproduction rate
needed to accomplish this comes from a gene-level
reproductive fluctuation. Such undirected allele
fixations do not have to be paid for out of
organism-level reproductive excess.

Yes, you're showing good understanding there.

They are paid for out of an unlimited pool of
random reproductive excess at the gene level

Small correction. There is never an "unlimited" amount of reproductive
excess (random or otherwise) at any level. Reproductive excess (of any
kind) is always finite and limited. However, as discussed in my paper,
there is a great deal of stochastic reproductive excess (some at the
organism level, and some at the gene level) -- and that is combined
with special cost-reduction mechanisms (available under certain
circumstances) that make the neutral substitution rate almost always
independent of any cost-limitation. [NOTE: I say "almost always"
because we can envision odd-ball hypothetical genomes where those
mechanisms are not available, and where the neutral substitution rate
would be cost-limited.]

(which is balanced by an equal amount of
random reproductive deficit at that level).

I don't grasp your intended meaning there. It's looking garbled to me.


My problem is that I am not convinced that you are
being fair in insisting that all upward movement by slightly
advantageous alleles must be paid for out of the limited
organism-level budget, but downward movements are
credited to the unlimited gene-level budget.

When an allele decreases there is no cost, because it does not require
any extra reproduction rate. It doesn't matter what "level" we are
talking about -- a DECREASE does not require any extra reproduction
rate -- it has no cost, and there is no limit to how fast it can occur.


The cost of substitution limits the speed that things can INCREASE.

-- Walter ReMine
The Biotic Message
http://SaintPaulScience.com


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Relevant Pages

  • Re: Felsenstein and reproductive excess
    ... > some strange definition of "reproduction" that I cannot grasp. ... from their population genetics heuristic exercises: TOTALS. ... Any total cost has to be paid ... on just a relative cost of substitution which may not have to be paid ...
    (sci.bio.evolution)
  • Re: Felsenstein and reproductive excess
    ... > That scenario would REQUIRE a reproduction rate of AT LEAST ... ReMine is correctly proposing that a finite reproductive limit must ... at no time does ReMine compare this cost ... Neo Darwinists do not discriminate between fertile parents ...
    (sci.bio.evolution)
  • Re: The ultimate cause of aging
    ... There is a resource conflict between maintenance and reproduction, ... So evolution starves maintenance mechanisms and puts its resources ... It actively dislikes them - because of the cost involved ... Evolution is perfectly happy to support long lifetimes, ...
    (talk.origins)
  • Re: Death
    ... >>>Death makes continued reproduction possible without filling the world ... You're talking about senescence. ... >>>has a cost, though, and why pay that cost when you're unlikely to live ... > tooth replacement would not benefit them early in life. ...
    (talk.origins)
  • Re: ReMines secret argument
    ... > I think ReMine might agree to this. ... > Or else you have to subtract 1 from your reproduction rate. ... Implausibility suggests a spectrum of logical cost, ...
    (sci.bio.evolution)
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