Talk:Haldane's rule

From Wikipedia, the free encyclopedia

	This article is within the scope of WikiProject Medicine. Please visit the project page for details or ask questions at the doctor's mess.
Stub	rated as stub-Class on the assessment scale
???	This article has not yet received an importance rating on the assessment scale.

[edit] "homozygous chromosome"

Apparently this expression needs to be disambiguated in a slightly entended description. Is there a biologist ready to help?--Wetman 20:03, 6 December 2006 (UTC)

[edit] I don't follow

I don't really understand this paragraph. One possible rationalisation of the rule is that in two subspecies, a gene necessary for fertility or viability may be absent from the homozygous chromosome of one of the subspecies, and so not be transmitted to some hybrids with the heterozygous sex. As speciation progresses, this is likely to start with a reduction in fertility, and then of viability, of one of the sexes of hybrids, at which point the rule can be seen; if it then affects both sexes then the two subspecies stop being able to interbreed and become different species.

A gene necessary for fertility absent from one subspecies. What does that mean? If it is really valid, please rephrase and reinsert it. thanks. --Seb951 15:26, 17 February 2007 (UTC)