Huuu, social darwinism at it's worst.
First, I want to say that I find that Miriam story disgusting, as Clements has already pointed it out.
Alpha, and RC gamer, if I understand well, your argumentation is backed up by the assumption that perpetuating life at the personnal scale is good, and that anything that pervents you of transmitting your DNA is bad (mostly, he). Did you ever thought that life is rather pointless... The life on earth will most probably cease to exist some day, anyway...
The main goal of everyone on earth is to try to be happy, not to perpetuate life. Most sexual perversions don't harm anybody anybody, anyway.
About normality:
If you consider that that majority == normality, then blonde people with blue eyes are definitely not normal at an internationnal scale...
If you think that what's natural is good, and that human should take example on the animals, then please turn off your computer immediately, I don't know of any animal besides man that would be able to use a computer the way you do. The natural/artificial distinction is very pretentious. Man is an animal. Humanity is a part of the nature. Every human behaviour is therefore natural.
About straight sex as an instinctive behaviour... You should assist to some fertility consultations at the local hospital, you'd be surprised. Couples who try very hard to make babies either by putting the dick in the ass or the umbilic do exist
The medical point of view:
Psychology and neurology are immensely complex, and it won't be fully understood anytime soon. I wouldn't build any ethic theory based on this. It's not because there is no gay gene that genes don't have any impact. There are lots of stuff that rely on polygenic phenomenons.
A few more biological oddities:
- If you make a testosterone injection to a straight female, you will raise her sexual appetite... for men!! (the fact that men think about sex more often than women is related to the amount of testosterone in the blood

)
- There are people with only one X and no Y, it's a disease called Turner Syndrome. They are sterile woman with stripped ovaries, who never enter puberty unless they are given estrogens.
- Long, but interresting: The androgen insensitivity syndrome (AIS). These are people whith an XY genotype and a knocked out androgen receptor. They have working testes that produce tons of testosterone (more than in normal males, because there is a negative feedback loop that implies the same receptor) They look like females (with no uterus), because the expression of the male phenotype during embryogenesis depends on cell response to androgens secreted by the testes during foetal life. Their testes remain inside the abdomen. The testes become quiet during childhood, then awaken at the puberty. They produce, once again tons of testosterone, which is partially turned into estrogens by periferal tissues. The estrogen concentration is similar to what a girl would have, and as a consequence, they have a feminie puberty, except two things: a) they never have periods, since they don't have an uterus. b) they don't have any pubic or axilary hair, sice these depend on androgene sensitivity of hair cells. Jamie Lee Curtis is alleged to suffer from AIS.
- There are XX males as well, although not fertile ..
It's way too easy to medicalise a problem and claim boo, they are not normal doctors say so.. It's not because it homosexuality has been traeted as a disease that it is a disease.
About homosexuality:
Homosexuality is a fact. The problem is not homosexuality in itself, but the way the society, ie most people look at homosexuals. In ancient Greece, it was a perfectly tolerated phenomenon. It isn't the case nowadays in most places in the world, mainly due to the strong influence of the Bible on our culture.
It's not a boolean phenomenon. Some people are "100%" straight, some are 100% homosexual, some are 100% bisexual (no preference, about both sex and love) and some are in between these extremes. This could explain the partial results of the psychotherapy.
Homosexualtiy is not only about sex, it's also about love, and social life. I know a guy who never fell in love for a girl in his whole life. He does fall with boys though. He's human, he longs for couple life and this kind of things. But this is badly judged by a large part of the people.
Homosexualtiy has been medicalised, there have been attempts for decades to "cure" it with little results.
Maybe someday there will come an effective way to turn every single gay/lesbian into a straight. Meanwhile what do you do?
Since they are in no way a threat to the society, I don't understand why they would be to blame...
About transexuals.
Provided that transexuals are people with a real sexual identity problem, I think that someone who is surgically transgendered has toi be considered as a sterile person of it's new physical sex.
I don't like ambiguous people, though...