Re: Hamilton's rule
- From: "Perplexed in Peoria" <jimmenegay@xxxxxxxxxxxxx>
- Date: Tue, 22 Nov 2005 16:40:18 -0500 (EST)
"John Edser" <edser@xxxxxxxxxx> wrote in message news:dlvnf2$mfk$1@xxxxxxxxxxxxxxxxxxxxxx
>
>
> "Perplexed in Peoria" jimmenegay@xxxxxxxxxxxxx wrote:-
>
> > > Jim McGinn wrote:-
> > > I thought all
> > > organisms recieved all their genes from their parents. Now your
> > > saying that some of them come from, "the general population." What
> > > do you mean by this, and how would you apply it, ...
>
> > A nicely asked question. Ok. A fraction 'r' of the typical recipient's
> > genes (on average) come from the common ancestors that the recipient
> > shares with the donor AND they are identical (by descent) with the
> > genes that the donor received from the same ancestors. I described this
> > using the shorthand language that these genes 'come from' the donor.
>
> JE:-
> Incorrect. You are required to be _absolutely_ correct on this most critical
> of matters within HR: A fraction 'r' of the typical recipient's genes (on
> average) come from the common ancestors that the recipient shares with the
> donor AS JUST A PROBABILITY where an average is just that, only an average.
>
> All averages and probabilities are required to be VERY CAREFULLY interpreted
> in evolutionary theory otherwise you may incorrectly use them to convert one
> level of fitness into another or even worse, entirely fail to conserve a
> critical level of fitness throughout within the mathematics.
I agree that it is important to get it right. But you have gotten it wrong.
The probability 'r' does not measure the recipient genes that come from
the common ancestor. 'r' involves the product of two probabilities -
the probability that the ancestral gene goes to the donor and the probability
that the same ancestral gene goes to the recipient.
> > The remainder (fraction (1-r)) of the recipient's genes come from
> > sources that don't provide genes to the donor.
>
> JE:-
> Who exactly are "they" and how do they "provide genes" to the recipients?
By 'they' I suppose you mean the 'other sources'. Well, for the most part
they are unshared ancestors. But they also include the shared ancestors
to the extent that they contribute one gene to the donor and a different
gene to the recipient.
> > These genes are expected
> > (on average) to have the same allele frequencies as the general
> > population.
> > I used the shorthand language of saying that these genes come from
> > the general population.
>
> JE:-
> Why are these genes "expected (on average) to have the same allele
> frequencies as the general population?"
Well, what other frequency would they have? If you followed the attempts
of Felsenstein to clear up Tim Tyler's misunderstanding of 'r', the
'general population' that I am talking about is the same as the 'base
population' that Felsenstein was talking about. That is, it is the
population a few generations back, not the current generation. Not that
this distinction makes much difference. Hamilton (and for that matter,
B.J. Williams) often mention that they are talking about gene frequencies
in the absense of selection as a way of tieing current gene frequencies
to the frequencies in the base population.
.
- References:
- Re: Hamilton's rule
- From: John Edser
- Re: Hamilton's rule
- Prev by Date: Re: Hamilton's rule
- Next by Date: Re: Hamilton's rule
- Previous by thread: Re: Hamilton's rule
- Next by thread: Re: Hamilton's rule
- Index(es):
Relevant Pages
|
