Re: Reproductive excess model


"Malcolm" <regniztar@xxxxxxxxxxxxxx> wrote in message news:d9cud4$2c8r$1@xxxxxxxxxxxxxxxxxxxxxx
[snip]
> So clearly the maximum fixation rate is one allele per generation. However
> the human-chimpanzee split is timed at 5 million years ago. Make that ten
> million years to suppose the chimps also evolved. Given a twenty-year
> generation time, that makes a maximum of 500,000 alleles.
> Somehow ReMine gets this down to about 1,600 (obviously humans are not
> extremely r-selected) though I don't follow the details.

Some hints of Walter's argument from a previous exchange:

******
Posting of Perplexed in Peoria "Re: Haldane's Dilemma" Feb 17, 4:28 pm
******
> > JM:-
> > You frequently quote the figure 1667 as the maximum
> > number of selected substitutions in the past 10 million
> > years of human evolution. I am curious as to what
> > data goes into a calculation such as this.

WR:-
> All the key figures come from evolutionists. The core theory and
> calculations come from J.B.S. Haldane. Click here:
> http://www1.minn.net/~science/­Haldane.htm#What_is_Haldanes_D­ilemma
[snip]
> Haldane calculated that (for organisms with low reproduction rates,
> such as the higher vertebrates) the long-term average rate of
> beneficial substitution can be no faster than 1 per 300 generations
> (independent of the generation time).

JM:-
I see. And if you assume 20 years per generation, you get 1667
substitutions in 10 million years. Simple enough.


******
Posting of Walter ReMine "Re: Haldane's Dilemma" Feb 18, 5:04 pm
******
WR:-
Haldane averaged over a variety of population sizes, and dominant
versus recessive mutations, and starting frequencies. I believe his
average of 30 is on the low side, and will likely need to be
re-visited. But it's the commonly accepted figure today.

JM:-
> And how do you get from the number 30 to the number 300?

WR:-
An average cost of 30, divided by a reproductive excess of 0.1 is:
30/0.1 = 300 generations per substitution. Outside of my book,
Merrell's book, _Ecological Genetics_ does the best (or least worst)
job of explaining this.

******

My take on this is that 30 is the estimate for "selective deaths"
per substitution per member of the population, and the reciprocal
of the reproductive excess gives you the ratio of all deaths to
"selective deaths".

But if he is using such a low number for the reproductive
excess of hominids, then he apparently can't be talking about the
reproductive excess of the fittest types. That 0.1 has to be an
average for the whole population. Which suggests that he is only
modeling survival selection, and ignores fecundity selection.



.

Relevant Pages

  • Re: Reproductive excess model
    ... >>> unless there is an odd concept of reproductive excess. ... >>> selection to take place. ... selection coefficient for each allele. ... > empty nests. ...
    (sci.bio.evolution)
  • Re: ReMines reproductive excess
    ... >> Is this substitution without reproductive excess? ... >> Or is there some reproductive excess here that I do not see? ... The increase of one allele is due to mutation, ... >type A organisms had marginally more offspring than type a (A was luckier at ...
    (sci.bio.evolution)
  • Re: Reproductive excess model
    ... >>fitness of the beneficial allele. ... not necessarily because the reproductive excess is higher. ... > between the reproductive excess and the coefficient of selection ...
    (sci.bio.evolution)
  • Re: The Cost of Substitution
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  • Re: The Cost of Substitution [possible REPOST]
    ... cost of substitution and Haldane's Dilemma. ... Wilson basically supports ReMine on the 'misrepresentation' question, ... The criticisms which CB121 makes of Haldane's "Cost of Natural Selection" are ...
    (sci.bio.evolution)
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