Originally posted by Adam_PoE
No, we do not. It is presumed that heterosexuality is caused by biological and genetic factors, despite no biological or genetic indicators of heterosexuality having been identified. That is the entire point.
Yet, somehow, there can be derived specific evolutionary traits about sex and reproduction of the human species such as the over development of females breasts and male's penises being larger "around" than most mammals. (On a proportions level, of course...lol)
What about androgens and their receptors?
*reads your next point* aahhh, I see where you were/are going with this.
Originally posted by Adam_PoE
Sexually reproducing organisms are not biologically-driven to reproduce, but to copulate. The result of copulation may be reproduction in some cases, but it is the urge to copulate, not to reproduce which causes them to have sex in the first place.
That is a perspective that is reaching a little bit, imo. Yes, they are programed to copulate...but why were they programmed to copulate...to further the species. In other words, they were programmed to copulate to further the species...therefore, they were programmed, genetically, to further the species via copulation.
I hope I didn't offend you by saying homosexuality is not normal. I don't mean that from a psychological perspective but a biological one.
Also,
While experiments are being done to unlock reasons for homosexuality, heterosexual causes are discovered as well. To me, studying the "causes" of homosexuality is also a way to discover the "causes" of heterosexuality. It would be easier to go that route because genetic and other biological differences will be easier to test for. (Without going on and on why this is so...basically, a difference between two heterosexual tests subjects may not indicate the cause of their heterosexuality, however, a difference between one homosexual and one heterosexual test subject may indicate a cause for both their respective sexual orientations.)