...A Darwinian explanation of male homosexuality.
The findings suggest that the proportion of male homosexuals may signal a corresponding proportion of females with higher fecundity. Consequently, these factors always contribute, all else being equal, a positive net increase of the fecundity of the whole population, when compared to populations in which such factors are lower or absent. This increase grows as the population baseline fecundity decreases; this means that the genes influencing male homosexuality end up playing the role of a buffer effect on any external factors lowering the overall fecundity of the whole population.
Can't say I totally understand this, but it seems that the "gay gene", when it appears in women, increases their fecundity to the point where this fertility boost more than compensates for the lack of offspring fathered by gay men, and keeps the “gay” genetic factors in circulation.
Congrats, fellas! You've officially been dubbed an "evolutionary by-product".