Originally Posted by EL72
The first part of your statement is true but not the conclusion. Genes cannot self-perpetuate; they need to be passed on to your offspring for the traits they activate to remain in the population. In other words, if every tenth gay uncle never has any kids, irrespective of the adaptive value of having gay uncles, they have no one to pass their genes to and will become extinct.
An interesting corollary of this discussion is that if gay people today are increasingly open with their homosexuality and stop reproducing (i.e. they don't marry and have kids for show and remain closet homos as they used to) and there seems to be evidence of this, then they will remove themselves from the gene pool within a few generations - assuming of course that there is indeed a gay gene.
Assuming for the sake of discussion that there were such a thing as a "gay gene", I'm not sure your conclusion would follow. With the reduction of societal prejudices against gay people, and with the increase in medical sophistication, gay couples are now much more able to start families with babies who carry their genes -- through the use of surrogates, in vitro fertilization, whatever.
But there's a more fundmental problem that runs through this discussion. Concepts like "fitness" and genetic "advantages" can sometimes
be deduced retrospectively, although even that is a complicated endeavor. Given the variety of factors (only some of them understood) at play and the time scales involved in evolution and Darwinian "selection", trying to make such judgments or predictions prospectively is, for a variety of reasons, generally a fool's errand.