female:male ratio in K-3 kids
hcbio004 at DEWEY.CSUN.EDU
Mon Jan 15 16:09:00 EST 1996
On 11 Jan 1996, Terry McTigue wrote:
> Since sex is determined by the father's contribution to the genetic
> material, what could be the mechanism linking the sex ratio to the
> mother's age?
The question of sex ratio was one of the topics on my Ph.D. qualifying
exam nearly thirty years ago, and at that time, it was theorized that
repeated exposure to Y-bearing sperm stimulated an immune response, so
that older women were more likely to react against them. This hypothesis
seemed to be supported by the increase in male births at wartime, when
couples tended to marry young and conceive shortly thereafter. I do not
know whether this theory has been subjected to experiment.
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