Re: Felsenstein is a liar

From: William Morse (wdmorse_at_twcny.rr.com)
Date: 02/22/05 

Date: Tue, 22 Feb 2005 01:25:19 -0500 (EST)

"Jim McGinn" <jimmcginn@yahoo.com> wrote in news:cv42e1$1ol7$1
@darwin.ediacara.org:

>
> Prediction: William Morse will not respond to this
> post. And if he does the questions I asked him at
> the end of the post will be ignored.

I think this is a piece of an earlier follow. The first prediction was a
good one, and it might still be the better part of valor for me to ignore
the challenge, but what the heck:

  
> These are the questions:
 
> 1) All other things being the same, are genes that
> are IBD different from genes that are not IBD in
> terms of their causative properties? Yes, No?

No. In fact this is a point I have been arguing in another thread on
"green beard" effects.
 
> 2) If they are different in terms of their causative
> properties what is the PROXIMATE mechanism by which
> they produce this difference in causative properties?
> I mean, do genes somehow know whether or not they are
> IBD and act accordingly? Yes, No? How do they know
> this?

I agree with you on this point.

> 3) If they are not different in terms of their
> causative properties then why even bother to
> distinguish between them?

I wish I knew the history of the term Identical By Descent. In another
thread, NAS argues the IBD a la Malecot is different from Wright's
relatedness. I have seen a discussion that includes a mathematical
derivation indicating they are the same, which I have previously posted a
reference to. But to get back to the subject at hand.

The important idea in Hamilton's inclusive fitness concept is the
probability of an individual sharing an allele with another individual.
Let us say, for a particular gene A, that there are alleles A1, A2, A3,
A4, and A5. Only version A5 results in behavior that benefits others at
the expense of the individual. Given that we know that a benefactor is
A5, what is the probability that the recipient is A5? Obviously, the more
close the relationship between the two, the more likely it is that the
recipient is A5. Now we can discuss the question of the likelihood of
sharing the allele A5 other than by descent, but that question is
irrelevant to Hamilton's rule. The reason to consider relatedness in
terms of Hamilton's rule is that it affects the likelihood of sharing a
particular allele A5.

If you are with me so far, I will try to explain why anyone bothers with
the expected prevalence of A5 alleles in a relative (i.e. the prevalence
due to IBD) vs. the expected prevalence of A5 alleles in the population
as a whole - but it isn't because of a difference in their causative
properties.

Yours,

Bill Morse

Relevant Pages

  • Re: Felsenstein is a liar
    ... >> are IBD different from genes that are not IBD in ... >> they produce this difference in causative properties? ... > probability of an individual sharing an allele with another ... > sharing the allele A5 other than by descent, ...
    (sci.bio.evolution)
  • Re: Heuristic Value
    ... Peter F - for EIMC Internetional Ptd. ... the concept of genes IBD has heuristic value ... >> they produce this difference in causative properties? ...
    (sci.bio.evolution)
  • Re: Hamiltons rule
    ... >> 1) All other things being the same, are genes that ... >> are IBD different from genes that are not IBD in ... >> they produce this difference in causative properties? ... fitness is almost completely immeasurable. ...
    (sci.bio.evolution)
  • Re: Heuristic Value
    ... the concept of genes IBD has heuristic value ... > Peter, why don't you show us how you answer these ... > they produce this difference in causative properties? ...
    (sci.bio.evolution)
  • Heuristic Value
    ... >> I think the main thrust of your discussion here is ... the concept of genes IBD has heuristic value ... they produce this difference in causative properties? ...
    (sci.bio.evolution)