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From: xia@cc.helsinki.fi
Newsgroups: bionet.population-bio
Subject: Revisiting Kin Selection
Message-ID: <3505.2727116e@cc.helsinki.fi>
Date: 25 Oct 90 16:23:10 GMT
Organization: University of Helsinki
Lines: 21

In modern behavioural ecology papers, the following text is
often found after the explanation of the so-called Hamilton's
rule:

         Therefore, a mutation that dictates its
         carrier to sacrifice one unit of its fitness
         for the increase of more than two units of
         fitness of its full sibs, or of more than four
         units of fitness of its half-sibs, will be
         favoured by natural selection.

I think this is quite misleading. When an altruistic mutant
arises in a non-altruistic population, the genetic relatedness
of this altruistic mutant to its kins has nothing to do with the
inclusive fitness of this particular altruistic gene because
this mutated gene is not identical by descent to any other genes
in the population. So the gene suffers no matter how much
benefit the altruist can bring to its relatives. (Unless its
full sibs have a probability of 0.5 to mutate into an altruist
and half-sibs have a probability of 0.25 to mutate into an
altruist).