A seemingly definitive declaration is made "The prevailing view is that sexual orientation is biological in nature, determined by a complex interplay of genetic factors and the early uterine environment. Sexual orientation is therefore not a choice. That is, individuals do not choose to be homosexual, heterosexual, bisexual, or asexual."
is if this has been proven, then the very same wiki article goes on to say:
Current scientific investigation seeks to find biological explanations for the adoption of a particular sexual orientation. As yet there are no replicated scientific studies supporting any specific biological etiology for human sexual orientation although scientific studies have found a number of statistical biological differences between gay people and heterosexuals, which may result from the same underlying cause as sexual orientation itself.
That isn't exactly being honest, totally forthcoming with the facts, and upfront. What it is seems more like when people have a preconception and try to fit the data into confirming that preconception. Sometimes saying, "I don't know" is best. And in the case of the origins of sexual orientation, we honestly can only at this point say, "we don't know."
Again, according to wiki: http://en.wikipedia.org/wiki/Biology_and_sexual_orientation
Various studies point to different, even conflicting positions, such as a combination of genetic, hormonal, and environmental influences, with biological factors involving a complex interplay of genetic factors and the early uterine environment, or no genetic influence.
It would seem most reasonable to conclude at this point that humans have a predisposition towards sexuality and that there is a "trigger" or there are "triggers" of some sort that we have yet to be able to positively identify, that funnels individuals towards a particular sexual orientation.
The control of the direction of an individual's conscious erotic desire
(which is basically how sexual orientation is defined), has NOT proven to be something individuals can influence or change by any scientific means. My issue is not with the idea stated above. What I take issue with is sexually identifying individuals based on this factor moreso than identifying individuals based on the sexual behavior that they exhibit in the shared reality that we know as the real world. If makes very little practical sense to weight orientation above actual sexuality.
In addition, I've lost my train of thought.............will continue in a minute.