Talk:Heterozygote advantage
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Moved from heterozygous advantage (~700 hits) to heterozygote advantage (~9000) as it's a the common form according to Google, and also from many textbooks such as Hartl & Clark Population Genetics (1998). --Lexor|Talk 10:31, Jan 24, 2005 (UTC)
Cystic fibrosis: The high incidence of CF genes in European populations is probably not due to cholera alone, but to diarrheal infections in general. So why is it much more common in people of European descent than in other populations? Because the CF gene is associated with salty sweat. In hot climates, the advantage of protection from diarrheal infection is less than the disadvantage of dehydration. Only in colder climates does the balance tilt towards an advantage for the CF gene. See Selective Advantages of the Mutant CFTR Gene
[edit] My edits and some suggestions
The original author of the section on Kalmus's paper (1945) probably understood the concept, but did not use the scientific vocabulary correctly. I have rewritten this section.
Perhaps there should be just one section devoted to examples from human genetics. Sickle cell anemia is clearly the classic example of heterozygote advantage in humans. I didn't touch the cystic fibrosis section. I haven't done much reading on that disease, but I can see from the comments here that it is incomplete and has inaccuracies. I feel we should cut it back to a summary paragraph, and use the "main article" approach, as I have done with Tay-Sachs disease.
A good addition to this article would be a discussion of hybrid corn. Can anybody take a picture of workers detasseling corn to contribute here? I know there are other examples of hybridization in agriculture. This one is interesting because a major industry is built around it. I may be exagerating its importance worldwide, since I live in Illinois and grew up in Wisconsin (where I worked for a few weeks one summer in high school detasseling corn). Also, researchers in corn genetics now downplay the benefits due to overdominance. Many believe that dominance alone may explain the superior yields of hybrid corn.
--Metzenberg 09:43, 17 August 2006 (UTC)
- Omit Tay-Sachs. That theory really seems to be dead now. --Metzenberg 09:59, 13 May 2007 (UTC)
[edit] Estimating relative fitness, population genetics methods etc.
Assuming random mating and fitness differential is not due to fertility but chance of survival:
- Gentotype AA Aa aa
- Fitness 1-s 1 1-t
Selection in favor of the heterozygote(Aa) causes deviation from the hardy-weighberg equalibrium(p^2:2pq:q^2) and the relative geneotype freq. among adults...
- p^2(1-s) : 2pq : q^2(1-t)
- Freq. of AA = (1-s)/1
- Freq. of Aa = 1
- Freq. of aa = (1-t)/1
...Someone please expand on this and add it in.(I'm not really the person to do it). See Ridley(2004) page 126 for pop.gen. methods. Also there is lots of data on SCA (see Bodmer & Cavalli-Sforza 1976). I'll try to check back later to see if anyone has expanded on this, if not i'm going to just add what I know in a half assed fashion =) --Mike Spenard 04:08, 19 October 2006 (UTC)
