RESPECTFULLY!!:
Sorry Don, but you posted: "..Sorry Ake and Michael, but those are the facts..."

and these are your facts????...

Don: "..The ASSUMPTION is that it is genetic, because it has all of the characteristics of a genetic trait, but the specific gene or genes have not yet been isolated."

Where you DID go right was, (in your post)..

Don: "..There is one school of thought that maintains that geneticists have been looking in the wrong place, and that the mother carries the gene(s) and this effects the timing of the release of hormones when the individual is in utero,..."

Then you went awry with ...."and this determines the gender orientation of said individual."

Maybe the 'gender'..but you posted, 'orientation'...you either cut and pasted this and inserted 'orientation' or somebody's 'study' was very 'pre-biased'...you know, funded by someone to 'find' 'predetermined results'

Where you are pretty close, and as I've posted before, is that an expectant mother's 'disposition'(and that includes several things, which if you want, I'd be happy to go into(later) sets up RECEPTORS, in the nervous system, of the fetus. THAT determines the disposition of the child, and IS WHY some people say 'they were born that way'...they also don't have the knowledge to separate where or why those 'feelings' are coming to such said individual.
There was a pretty good film which goes into 'receptors' for the layman, that is pretty easy to understand..you may find it interesting. It's called 'What The Bleep Do We Know?'.

The receptors become 'geared' to receiving 'gratification' by certain emotional nerve impulses...much like a 'crack-baby', that is born already addicted...but the difference is, the crack baby is addicted to a artificial substance, as opposed to a sense of NEEDING gratification from an emotional need.
THIS IS NO FAULT OF THE CHILD...REPEAT: THIS IS NO FAULT OF THE CHILD!
....however, only .2% of babies who later claim being born homosexual from birth have that situation. The rest just jumped on the bandwagon. ..then the politicos expanded that claim...and that's where you and I have a difference. (besides the fact that you say you couldn't understand the words to "My Lady").
I'll continue later, I gotta go....

Regards Don,

GfS