phillip smith wrote:
> in article buh2gr$1k08$1{at}darwin.ediacara.org, Anon. at
> bob.ohara{at}SPAMMERS.SOD.OFF.helsinki.fi wrote on 20/1/04 6:01 AM:
> 
> 
>>Fisher 1930?  Or do you want something readable?
>>
>>[moderator's note: Hey! I think Fisher 1930 is perfectly readable,
>>and since it's available in a Dover paperback edition, it's really
>>cheap, too -- certainly worth tackling. Besides, if _I_ had to wade
>>through it, YOU should too. - JAH]
>>
>>You should try a good textbook on quantitative genetics.  Either
>>Falconer & McKay or Lynch & Walsh would be a good start
(L&W is big, though)
>>
> 
> Thanks for those pointers. I have on many occasion tried to wade through
> Crow and Kimura  and CC Li
> 
>>>I can think of three confounding factors for such as argument.
>>>1) Epistatic interactions between the rest of the genome on the
coefficent
>>>of selection are unknown and perhaps unknowable
>>
>>This is a only problem if there is also linkage disequilibrium.
>>
>>Also note that for a lot of the genome, the genes are not polymorphic
>>(=no variation), and most of the rest of the genome probably have
>>negligible epistatic effects.
> 
> Jus checking for data on the web I found some data on heterozygosity in
> natural populations Medfly about 8% with estimates of heterozygosity
> fluctuating substantially around that in a few studies I could find. WE
> probably wont have decent figure till population genomics becomes
> technically possible. But certainly figures above 1 % would not be
> supprising. I think the human genome is supposed to be around 20,000 genes
> so around so we might say you have to ignore epistatic interations of  200
> genes on the locus you are investigating. That sounds like a lot tome.
> Especially since you are already ignoring all the non coding DNA ad any
> epignetic effects
> 
>>So, at least the problem is smaller.  :-)
> 
> Or perhaps just underestimated
> 
>>>2) selection events are insufficiently  uniform. I.e every
individuals death
>>>is a unique event
>>
>>But that brings you back to drift.  With an infinite number of
>>individual deaths, the other effects average out.  With a finite number,
>>the difference is drift.
> 
> 
> Fair enough. What if no two deaths are the same? I.e same stage of
> development, same cause, same genome.
> 
Well, that can only happen in a finite population.  :-)

In one sense, no two deaths are the same, as every individual is unique. 
  What is important is the way that an organism's genes affect the 
probabilities of the different deaths (and othe events, of course), so 
you can average over them (or, for calculating fitness, take the 
expectation).

Bob

-- 
Bob O'Hara

Dept. of Mathematics and Statistics
P.O. Box 4 (Yliopistonkatu 5)
FIN-00014 University of Helsinki
Finland
Telephone: +358-9-191 23743
Mobile: +358 50 599 0540
Fax:  +358-9-191 22 779
WWW:  http://www.RNI.Helsinki.FI/~boh/
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