Re: Hamilton's rule

in article dl58qa$p8l$1@xxxxxxxxxxxxxxxxxxx, Catherine Woodgold at
an588@xxxxxxxxxxxxxxxxxxx wrote on 11/12/05 9:29 AM:

> Guy Hoelzer (hoelzer@xxxxxxx) writes:
>> My confusion is rearing its ugly head again. If the axes of the graph are
>> "frequency in focal individual (Y axis) vs frequency in population (X
>> axis)", then I don't see how dominance/recessiveness can influence the lines
>> at all. What am I missing?
>
> One of the lines is labelled "donor". The only individuals
> who act out the "donor" phenotype are the ones which have
> the set of genes that code for altruism. If altruism is
> a recessive trait, then all of the "donors" must have
> two copies of the altruism gene. Therefore the frequency
> in the "donor" focal individual is always 1 if altruism
> is a recessive trait.
>
> But if the altruism gene
> is dominant, then the set of "donors" includes some
> individuals with one copy of the gene and some individuals
> with two copies of the gene. If an individual is
> observed to carry out an altruistic act, or if it
> finds itself experiencing an overwhelming urge to
> carry out an altruistic act, then an observer
> (or the organism itself) can conclude that the
> individual has one or two copies of the altruism gene.
> The expected frequency in this individual can thus be
> predicted to lie between 0.5 and 1 (closer to 1 if
> the altruism gene is very common in the population).

Maybe I should have said more. All of this was apparent to me. In the
artificially restricted world of modeling perfect dominance/recessiveness
the starting point of the donor line would be 0.5 (pure recessiveness) or
1.0 (pure dominance). In either case, however, there is a simple linear
relationship on the frequency/frequency graph that converges on the point
(1,1). The comment you quoted above came from a discussion where I thought
it was implied that the shape of the relationship (e.g., linearity) was said
to depend on dominance/recessiveness. I may have been reading too much into
Jim's comments, which I still think reached way outside the scope of the
simple frequency/frequency graph.

Guy


.

Relevant Pages

  • Re: Hamiltons rule
    ... One of the lines is labelled "donor". ... the set of genes that code for altruism. ... two copies of the altruism gene. ... observed to carry out an altruistic act, ...
    (sci.bio.evolution)
  • Re: Hamiltons rule
    ... >> to the frequency of the altruism allele. ... The second graph for a relative is also a straight line, ... If the donor is heterozygous (altruism is dominant) ...
    (sci.bio.evolution)
  • Re: Logic of kin selection
    ... > passiveness of the recipient is irrelevant - the only question is whether ... > the benefit to the recipient outweighs the cost to the donor. ... > elicited altruism follow Hamilton's rule. ... There the incidence of altruism depended on ...
    (sci.bio.evolution)
  • Re: Hamiltons rule
    ... >> - If the altruism locus is purely dominant, ... That doesn't matter as long as the donor D line never drops ... >> or of how many loci are involved, it remains the case that the recipient ... > favor the altruism allele. ...
    (sci.bio.evolution)
  • Re: Hamiltons rule
    ... >> the set of genes that code for altruism. ... >> two copies of the altruism gene. ... - If the altruism locus is purely dominant, the graph of allele frequency ... it is possible that the donor line may be something other ...
    (sci.bio.evolution)