And if you want Science, let's bust off the Natural Selection theory and go a step further with it.
If you don't procreate, you die. Pretty simple concept. In fact, the only Genus to not exhibit that to some degree is: HUMANS
Every OTHER species is self-correcting in that area.
And the only Humans that don't truly advance life by making it is: Gays
Natural Selection is just like Confucious, it say, "Hey, sword-fighting make no babies, therefore, no more sword-fighting". And the species continues ALBEIT with some lateral changes here and there in breeding. But, in a MINORITY there will ALWAYS be deviation from the norm. Simple NUMBERS!
So, to keep going with it, if you add in the supposed "environment" and other excuses, you will ACTUALLY find that it is CULTURAL bullshit.
Let's go on down the line and do this: In the old days, you were gay, you got killed (some will still happily do so). In some OLD cultures, bi-sexualism was considered OK, but ONLY in wealthy societies that could support said "gayness" and generally even then only in the hierarchies themselves, never really trickling down into the substrate of everyday society UNTIL........drum roll please......NOW.
This means the empires that said bi-sexualism was OK were actually a FEW people (minority) saying it was OK, NOT THE MAJORITY OF THE POPULATION!!!! (Rulers always make the rules remember?)
So the "untold millions" is actually "untold bullshit".
Specifically, the last 30 years or so in OUR American society. Because of the so-called "sexual freedom" we have NOW, you see MUCH more gayness, and etc.
But if things changed back, and there were tighter societal and cultural rules with less leeway towards aberrant sexual behaviour (like the churches having more power), you would NOT be gay anymore than you would have been Jewish during WW2. But I can guarantee it was a CHOICE you would have died for THEN, not now.
Debate is open, let's keep it going. Why wait on overpaid Geneticists when all they will say tomorrow is, "Oops, butter IS better than margarine, sorry about that". Hopefully, next week they will tell me that gengineered corn is ok on MY genetics..........