Re: Hamilton's rule


"Guy Hoelzer" <hoelzer@xxxxxxx> wrote in message news:dkun5k$qrf$1@xxxxxxxxxxxxxxxxxxxxxx
> in article dkjvnh$1sna$1@xxxxxxxxxxxxxxxxxxx, Perplexed in Peoria at
> jimmenegay@xxxxxxxxxxxxx wrote on 11/5/05 8:10 PM:
>
> > "Guy Hoelzer" <hoelzer@xxxxxxx> wrote in message
> > news:dkgokl$g5l$1@xxxxxxxxxxxxxxxxxxxxxx
> >> I can't comment yet on Hamilton's "dilution effect" ...
> >
> > Read my other response first.
> >
> > I now see how to give a slightly better derivation of Hamilton's rule,
> > complete with a 'dilution factor'. The key is to use Catherine
> > Woodgold's clever trick for handling density dependent population
> > control.
> >
> > Let D be the frequency of the altruism allele in the donor.
> > Let R be the frequency of the altruism allele in the recipient.
> > Let P be the frequency of the altruism allele in the general population.
> >
> > Don't confuse 'R' with 'r' - they are different.
>
> Right. Just so we are on the same page, [D-P] can be a negative value,
> right? The same could be true of [R-P], right? If not, then maybe you mean
> that D is the frequency of the altruism allele AMONG DONORS, and R is the
> frequency AMONG RECIPIENTS. The way you wrote it above suggests to me that
> you are considering each individual separately.

You are correct that I was imprecise. And I did intend that D-P be
non-negative under normal circumstances. You are correct that I should
have described D as the allele frequency among donors as a group. And what
I should have written for R is that it is the expected allele frequency among
a sample of individuals chosen so that their average relatedness to a donor
is r.

I am discovering that I am not very good at this. I am tempted to
return to the policy I use with McGinn of referring all questions
to the textbooks.


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