Re: Hamilton's rule

in article dj1v9g$1p6k$1@xxxxxxxxxxxxxxxxxxx, Perplexed in Peoria at
jimmenegay@xxxxxxxxxxxxx wrote on 10/17/05 9:56 PM:

> "Guy Hoelzer" <hoelzer@xxxxxxx> wrote in message
> news:dj0pon$17ig$1@xxxxxxxxxxxxxxxxxxxxxx
>> in article diq3n2$1j18$1@xxxxxxxxxxxxxxxxxxx, Perplexed in Peoria at
>> jimmenegay@xxxxxxxxxxxxx wrote on 10/14/05 10:22 PM:
>>> ... And,
>>> of course 'r' is frequency independent, even though confused people
>>> like McGinn, Tyler, and Hoelzer don't seem to realize it.
>>
>> Just for the record, I never argued that "r" is frequency dependent, and
>> that is not my position. I am sure that I hold some confusion, along with
>> everybody else, but this is not one of them. I wonder what I might have
>> written to give this impression. Perhaps it relates to my argument relating
>> frequency of the altruism allele and the strength of kin selection. My
>> argument is that the strength of kin selection as a factor influencing
>> evolutionary change in a population is negatively correlated with the
>> frequency of the altruism allele. I see this as completely orthogonal to
>> the question of frequency dependence of "r".
>
> Ah! So 'r' is defined in a frequency independent way, but the validity
> of 'rb>c' depends upon frequency? If that is your position, then I
> apologize for mischaracterizing it, though I still think you are confused.

I'm afraid that you are still mischaracterizing my position. I made no
comment about validity, only about relevance. As we know from Ohta's Nearly
Neutral Theory, very weak selection pressure is virtually the same as no
selection pressure at all, leaving alternative alleles free to drift. My
contention is that the extent of kin selection pressure (the strength of kin
selection) becomes very weak as the altruism allele becomes common. In
fact, I think it would typically become negligible even at intermediate
frequencies of the altruism allele (say above 20 or 30%).

To be clear, the validity of the kin selection model is NOT dependent on
allele frequencies, however the influence of kin selection over the
evolutionary process IS dependent on allele frequencies. I am not arguing
that kin selection is an example of a frequency dependent selection model.

> Or are you saying that 'rb>c' remains valid in determining the direction
> of the evolutionary force, regardless of frequency, but that the
> magnitude of the force depends upon frequency? If that is your position
> then I apologize unconditionally.

Oops. I should have read this first. This is indeed my position.

Guy Hoelzer


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