[Totally Screwed]

Is it true that the older a man gets the more the chance he has of producing a male child. And if so why is this? Please explain. Thank you!:confused:

[rockerchick26]

No that isn't true! I majored in biology in college... OK here is how it works:
Women are XX and men are XY.
A single sperm is either X or Y (your genetic material "XY" splits in half when your testes make your sperm.)
A single egg is an "X."
When they meet they:
(1)form XX (X from mom+X from dad=(girl)
or
(2) form XY (X from mom+Y from dad=(boy).
There is no way your body would be able to distinguish between the two (x or y) or shoot more Y's to conceive a boy. I hope that makes sense!

[Fr_Chuck]

No, age of man has little to dowith it.

[jem02081]

First, it is an inaccurate over simplification to simply look at the possible products of meiosis and say that the sex ratios at birth must be 1:1
A lot can happen, both before conception (primary sex ratio) and after conception (secondary sex ratio) that can alter the sex ratio. But the effects are relatively small, for example, at birth there are 105 males born for every 100 females. See the sex ratio entry in Wikipedia Sex ratio - Wikipedia, the free encyclopedia

Is there an effect of paternal age? The topic seems to be controversial. Why? It could be other things are responsible for the effect in any specific study (material age or birth order). This would result in an observed effect on paternal age but, it would be due to the paternal age being correlated to “real” reason. So, a man age might actually contribute a little to sex ratio... but not enough to "explain" the outcome of a specific pregnancy!

Biology is full of examples in animals of biased sex ratios that are the result of selection. If there are theories about natural selection acting on human sex ratios I’m not aware of them... but I bet there are some!