Half a century--two human generations--is not nearly enough time for evolutionary pressures to have the sort of effect you are talking about. Least of all in a society of abundance in which the majority of members reproduce.

Instead, I'd suggest you look at the various changing environmental factors for an explanation of these phenomena: BPA in plastics (http://en.wikipedia.org/wiki/Bisphenol_A), the growing use of soy in human diets (with its attendant phyto-estrogens), and the growing quantities of synthetic human estrogen in the environment (already known to have effects on fish, see for instance http://www.seattlepi.com/local/124939_estrogen04.html).