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Author Topic: Why doesn't homosexuality evolve out of existance?  (Read 7271 times)

Offline John Chapman

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There are a number of theories about why people become homosexual. Genetic links have been found. Birth order and conditions within the womb have also been cited as have various social influences. For the purposes of this question the reasons are probably irrelevant and for each possible cause there are plenty of both gay and straight people. My question is about the susceptibility of some people to be affected by those causes, whatever they may be.


So, whatever the cause there is natural variation within populations that mean some people become gay. As these individuals produce fewer offspring than heterosexual ones their particular variation should evolve out of the population and less people in the next generation should be influenced by that cause. So why isn't homosexuality bred out of existence.



 

Offline Make it Lady

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Why doesn't homosexuality evolve out of existance?
« Reply #1 on: 20/02/2009 18:12:13 »
Well, if we are looking at the conditions in the womb, it is nothing to do with genetics. It is more to do with hormones. This means it would not be bread out of existance. If we are talking about the influence of say a dominant mother, well this is not a genetic cause either. I guess we would have to say that homosexuality is more complex than mere genetics.
 

Offline John Chapman

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Why doesn't homosexuality evolve out of existance?
« Reply #2 on: 20/02/2009 18:53:29 »
Hi Make it Lady

When you say dominant mother I assume you are talking about personality. Why would personality traits, which are influenced so severely by biochemistry, not be inheritable? And the same with anatomy of the womb? Even if these things skipped a generation or were gender linked, with no next generation they would disappear.
 

Offline John Chapman

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Why doesn't homosexuality evolve out of existance?
« Reply #3 on: 20/02/2009 18:59:04 »
Oh and another thing. It's the susceptibility to these conditions making you gay that is less likely to be passed on by gay people. Many people have dominant mothers and most are not homosexual. Those who are most likely to develop homosexuality because of it are least likely to pass that characteristic onto the next generation. Ipso facto it should die out!
« Last Edit: 20/02/2009 21:25:10 by John Chapman »
 

Offline neilep

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Why doesn't homosexuality evolve out of existance?
« Reply #4 on: 20/02/2009 19:00:31 »
Ewe may as well cite so many other things that could well be bred out of existence.

People are either born gay, have gay proclivities (gay-curious, bi-curious etc)...or can be ' turned ' gay.....(whilst in captivity etc)

I personally think we're all gay .

People wont admit it but I believe there are times when even the straightest of people have wondered what it might be like to be gay...even for a fleeting moment.

Within the rest of the animal kingdom too........ ewe will find many examples of gay behaviour. Surely something as base as ' instinct' would have evolved to preclude that kind of behaviourthen ?
 

Offline John Chapman

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Why doesn't homosexuality evolve out of existance?
« Reply #5 on: 20/02/2009 19:13:00 »
Yes I think that has an element of truth.

But the fact remains that those who are homosexual enough to form long term relationships are least likely tp pass the trait on.
 

Offline Chemistry4me

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Why doesn't homosexuality evolve out of existance?
« Reply #6 on: 20/02/2009 22:34:36 »
But the fact remains that those who are homosexual enough to form long term relationships are least likely tp pass the trait on.
True.
Why doesn't heterosexuality evolve out of existence? :)
 

Offline John Chapman

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Why doesn't homosexuality evolve out of existance?
« Reply #7 on: 20/02/2009 22:38:23 »
Sorry Chem. I don't know what you mean.
 

Offline Chemistry4me

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Why doesn't homosexuality evolve out of existance?
« Reply #8 on: 20/02/2009 22:40:30 »
Don't worry, it was a rhetorical.
 

Offline rosy

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Why doesn't homosexuality evolve out of existance?
« Reply #9 on: 21/02/2009 00:21:02 »
Even assuming that sexuality were entirely genetically determined, which is unlikely, it will certainly be determined by the cumulative effects of several genes. As any homosexual person is likely to have siblings, who will share with them a subset of those genes, either (a) having a breadwinning uncle with no wife/children of their own to support may well increase the likelihood of those nephews and neices surviving to breed succesfully and pass those genes on to future generations or (b) their siblings might share with them fewer genes for homosexuality which might make them better parents*.

There is a second effect, which is that actually a significant proportion of people who are wholly homosexual by preference are nevertheless capable of going through the motions a few times and producing children. This is less common in modern Britain, but in more homophobic cultures is actually quite common- there was an article on the World Service last night about Indian MSM's (men who sleep with men) as they're called there.

* I'm not sure I buy this, but there's lots of other examples of recessive single genes where having one non-standard copy gives a reproductive advantage but two prevents reproduction entirely or in part (I'm thinking of sickle cell anaemia, but there are others).

... so there are lots of reasons why homosexuality doesn't evolve out. And that's without really discussing the extent to which lots of people are really bisexual but settle down to be just  hetero- or homosexual because ieven in civilised societies where gay-bashing is frowned upon being bi can be a bit hard work socially (and many people end up in long-term monogamous relationships, which are inevitably either hetero-or homosexual).
 

Offline Make it Lady

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Why doesn't homosexuality evolve out of existance?
« Reply #10 on: 21/02/2009 01:20:11 »
I settled down with a blokey because it was so hard to meet other lesbians where I lived. I also wanted children so this meant a long term girl on girl relationship was less attractive. I agree with Neil that everyone could be gay if they didn't ignore same sex attraction as crushes (I was told that my attraction to my best friend was a crush.) I think bisexuality is like a sexual torrettes, in that you can't sit on your impulse to shag people of the same sex.
 

Offline neilep

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Why doesn't homosexuality evolve out of existance?
« Reply #11 on: 21/02/2009 02:15:47 »
I settled down with a blokey because it was so hard to meet other lesbians where I lived. I also wanted children so this meant a long term girl on girl relationship was less attractive. I agree with Neil that everyone could be gay if they didn't ignore same sex attraction as crushes (I was told that my attraction to my best friend was a crush.) I think bisexuality is like a sexual torrettes, in that you can't sit on your impulse to shag people of the same sex.

May I ask ewe a question ?....

(Sheepy assumes ' yes' )


If girlies could produce babies without blokes intervention or contribution ie: without male ' input' at all....Would you rather be with a girlie than a boi ?

(hope it's not too indelicate a question )
 

Offline John Chapman

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Why doesn't homosexuality evolve out of existance?
« Reply #12 on: 21/02/2009 09:12:16 »
Hi Rosy

Thanks for that well considered responce. Yes, I understand the basic Mendelian model of genetics in that if two people carried a recessive 'gay gene' in their genotype then the next generation would typically include 25% who have the double recessive gene which would show as a gay phenotype, 25% who do not carry the 'gay gene' at all and 50% who would, like the parents, carry the recessive gene but not show it. That would explain how homosexuality bucks the trend of genetics to wipe out those with a trait who don't reproduce. This of course is also the situation with many lethal genetic diseases where those who show the trait die while siblings may be silent carriers.

I appreciate that this is a vast over simplification and that a single gay gene has not been found, although I understand some are implicated by correlation. And it may be that genetics play a small part in sexuality.

That was a good point you raised about homosexual people conforming to society's norms by having children, particularly throughout our less enlightened history.



Thanks for your insight Make it Lady. No doubt you are very happy with Mr Make it Lady but do you still find both genders attractive? Or was that crush on your best friend a one-off? How old were you?

I remember when I first reached puberty I found the idea of nakedness and sex exciting but is was not gender specific. It wasn't that I was turned on by both genders - it would be more accurate to say I was turned on by neither. It was the situation/sex/flesh-on-flesh stuff that got me going. My sexual fantasies slowly developed to concentrate more and more on the female form and I developed heterosexually. But I have always wondered if, at the stage before my desires specialised to include just girls, could I have been influenced to develop the other way. I was certainly like a sexual sponge and would have been very open to influence. My feeling is that my heterosexual desires are so Strong that, whatever I might have experimented with had my influences been different, I would always have ultimately developed heterosexually.
 

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Why doesn't homosexuality evolve out of existance?
« Reply #12 on: 21/02/2009 09:12:16 »

 

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