Wouldn't a "gay gene" have to be matrilineal? (mission)

[Endless]

Why is it in a Science vs Religion forum then?

My Church doesn't have an ex-gay group - we would welcome any gays into our church, but we would also point out that being a practising homosexual is a sin - as the Bible says. Anyway, that is just my reply to your rant.

As to the hypothetical question - a gay gene could only survive if it was recessive. It doesn't make any difference whether it was on the mother or the father in this case. That also means that there has to be a 'male female' gene which is dominant. It's only if both the father and the mother happen to have in their genes the recessive gay gene that they resulting offspring could be gay.
Should both the father and the mother be gay - then because the gay gene is recessive the offspring would have to be gay - there could be no dominate 'male female' gene in their genomes.

That is the only feasible way by which it could survive. You then have to ask the question that there has to be an evolutionary explanation for the presence of the gay gene in the first place. Since the gay gene would tend to stop reproduction with females, it is unlikely that it could have come into being on its own so to speak- because it could not get transmitted to any offspring. This then brings into question a 'bisexual gene' that is very closely related to the gay gene. Perhaps the bisexual came first then with slight mutations it becomes the 'gay gene'. This would then mean that the bisexual gene is prevailant in our population - it can be passed down through the generations. The gay gene could then be connected to that in some way.

Thinking about it in this way: gg = double recessive = Gay. bb= double recessive bisexual. MM = double dominatant male female.

If we get parents with Mb or Mg we get male female orientation because M is dominant. If we get parents with 'bg' then we get bisexual if the bisexual gene is dominant over the gay gene. Therefore the gay gene can now be passed on down through the population - via bisexuals. If we get two bisexual parents then their offspring can either be 'bb' 'bg' or 'gg' - double recessive gay gene = gay person. There's the possiblity also of Mg Mg parents - offspring can be MM, Mg (male female orientation), or gg = gay.

However all this is hypothetical - but this is the way in which it would be passed down through the generations. Science has not collaborated this and suggests it is rather a state of mind, which makes a lot more sense in my own opinion.

[Flappycat]

Okay, to clarify, what I was thinking was a gene that is only passed by the female in most cases which affects how they treat their eggs in such a way as to result in males being homosexual. No male would be directly affected by the gene or, under most circumstances, capable of passing it. I was largely wondering if there was, hypothetically, anything wrong with my reasoning. This would still leave lesbians a mystery even if it were valid, but I'm not familiar with the experiences of lesbians and wouldn't know how flexible their sexual orientation is.

Also, yes, there could be and probably are a broad assortment of reasons, among them possibly including weird interactions between normally beneficial genes or biological functions. It's anything but a perfect beast, the human.

[nutshell]

Originally Posted by standing_on_one_foot

Why precisely would a "gay gene" have to be on the X or Y chromosomes, do you know?

Exactly. Your proposal assumes the "gay gene" is on the X or Y chromosomes. There's no reason why this would have to be the case. There's other genes to choose from. Just because those are the "sex" genes doesn't mean they determine sexual orientation.

[murdocsvan]

Originally Posted by Flappycat

Rather, it might be more appropriate to say that it would be more likely to be matrilineal if there is some genetic origin.

Take siblings Xg and Yg of Mg. mDNA would only be carried by X, so the transmission of mDNA affecting Y would never be carried by Y in the first place, making the chances of Y reproducing almost irrelevant to the transmission of g because mitochondrial DNA wouldn't be affected much by the reproductive success of Y. If Xg and Xn (X normal) had equal odds of reproduction, little wonder that g was never entirely eliminated. g would only have been problematical on such occassions that an entire population had such a high Xg population that it wasn't producing a sufficient number of Yn to provide Xn and Xg with the y-chromosomes needed for reproduction.

Does this make sense? Can anyone find a flaw in my reasoning here?

Well, i don't really understand what your saying... i've only just learnt about genetics and that XX = female and XY = Male. I think one scientific theory you should take into account if you want to learn about gay people is this:

During the development of a baby in the mothers womb a stage comes up where the mother has to release a certain amount of testosterone for the baby. Most of the time its right and you come out straight, or in some cases, not enough testosterone is given off and the baby comes out "fruity". This is of course if the baby is male

For lesbians i have my own theory stemming from this:

Too much testosterone is given off and the child comes out masculine. In later life though, more of the female children with too much testosterone turn out to be bisexual so it is purely society and personel preference which decides whether the female will turn lesbian or not.

[Jaiket]

Why mitochondrial DNA, Flappycat?

If homosexuality is genetic, a recessive allele in a multiple allele, like white skin in skin colour seems like a reasonable explanation. I'm sure a quick look through the literature might provide a better explanation thought.

[ladylazarus]

Yeah, but there isn't a gay gene.

[xvnukervx]

There are psychological explainations for homosexuality. I dont beleive homosexuality is a genetic disorder as much as it is a psychological one.

[Feathers in Hair]

Originally Posted by xvnukervx

There are psychological explainations for homosexuality. I dont beleive homosexuality is a genetic disorder as much as it is a psychological one.

*confused look* Who said it was a disorder?

[Fade]

Originally Posted by Endless

My Church doesn't have an ex-gay group - we would welcome any gays into our church, but we would also point out that being a practising homosexual is a sin - as the Bible says. Anyway, that is just my reply to your rant.

Would you accept a transsexual. And if you did how would you define whether they were sinning or not depending on their choice of sexual partner.
I personally don't believe there is a gay gene and I'm inclined to agree with your earlier comment about everyone being gay to some extent. That in itself renders the bibles condemnation of the practise redundant as it is something we are born with and is thus god given.