Homosexuality May Start In The Womb

[Maestro]

Homosexuality May Start in the Womb

by Elizabeth Norton on 11 December 2012, 4:45 PM

From a strictly Darwinian viewpoint, homosexuality shouldn't still be around. It isn't the best way to pass along one's genes, and to complicate the picture further, no "gay genes" have even been identified. According to a newly released hypothesis, the explanation may not lie in DNA itself. Instead, as an embryo develops, sex-related genes are turned on and off in response to fluctuating levels of hormones in the womb, produced by both mother and child. This tug of war benefits the unborn child, keeping male or female development on a steady course even amid spikes in hormones. But if these so-called epigenetic changes persist once the child is born and has children of its own, some of those offspring may be homosexual, the study proposes.

Evolutionary geneticist William Rice of the University of California, Santa Barbara, felt there had to be a reason why homosexuality didn't just fade away down the generations. Research estimates that about 8% of the population is gay, and homosexuality is known to run in families. If one of a set of identical twins is gay, there's a 20% probability that the other will be, too.

Read more: http://news.sciencem...e-w.html?ref=hp

[Maestro]

...In their study, published online today in The Quarterly Review of Biology...

The December issue of The Quarterly Review of Biology does not yet seem to be online. Somebody with an interest in it may want to keep an eye on this web page and post the link to the study once it gets online:

http://www.jstor.org...s/00335770.html

[wilcopops]

"From a strictly Darwinian viewpoint, homosexuality shouldn't still be around." this is not a very good interpretation of Darwins theories. In fact homosexuality can be demonstrtated to play a helpful part in preserving the species.

[Swiss1960]

Have not yet seen the article online, but seen a Swss-German review of it, which says (my translation from German):

Gene appendage inherited erroneously

The appendage, called epigenetic markers, regulate when and how much a gene is active. Normally, they are bound to an individual and are not inherited. According to recent studies, the marker may occasionally be transferred between generations and lead to similarities between relatives.

Some of these appendages are used in the uterus to protect the fetus against natural fluctuations of the sex hormones. This prevents male fetuses to get effeminated and vice versa. These markers can influence the forms of the genitals, sexual orientation or preference of partners.

But if these gender appendage are passed on from fathers to daughters or mothers to sons, their effect is reversed: sons get some female characteristics, such as sexual preference, daughters receive masculine qualities

While this sounds interesting, there is one HUGE danger I see in such statements: All the homophobes will come out again and say "see, we told you the are sick, homosexuality is a genetic disorder..."

[catmac]

An interesting hypotheses, but little else. I see no evidence of proof, more like a clutching of straws to overcome the fatal flaw in the genetics theory, as so plainly pointed out, if homosexuality was a purely genetic condition then in true Darwinian fashion it would have become extinct along with the Dodo.

The example given of the identical twins would hold true whatever the cause, genetic or childhood trauma or anything else, since it would likely impact on both twins equally.

Truth is, that I suppose we will never fully understand what causes some people to grow up to be gay, each of us probably has their own prefered theory.

[isanbirder]

Truth is, that I suppose we will never fully understand what causes some people to grow up to be gay, each of us probably has their own prefered theory.

I've always thought it was a natural escape valve to deal with over-population. But how that makes one person gay and the next not, I have no idea.

[Jingthing]

Truth is, that I suppose we will never fully understand what causes some people to grow up to be gay, each of us probably has their own prefered theory.

I've always thought it was a natural escape valve to deal with over-population. But how that makes one person gay and the next not, I have no idea.

I don't buy that at all. We've got war, disease, natural disasters, and limited resources to deal with that. The small percentage of people who are exclusively homosexual is very insignificant compared to other restraints on our population. Of course now that we have dominated the planet and really are absurdly overpopulated, it would be a great thing is many more people chose to not breed and/or be gay. Much more humane than the alternatives.

[JimmyTheMook]

What about the Catholic Priest / Alter Boy conversions ?

[Jingthing]

What about the Catholic Priest / Alter Boy conversions ?

What about the Catholic Priest / Alter Boy conversions ?

Being sexually molested by the same sex does not make you gay any more than being molested by the opposite sex would make you straight.

[ironbark]

I think it is all due to male pheromones.

A sweaty armpit really does it for me.

Sent from my GT-N7100

[AyG]

Starting from the point stated in the article that "If one of a set of identical twins is gay, there's a 20% probability that the other will be, too", this shows that homosexuality can not be purely genetic in origin. If it were, that probability would be 100%. There clearly must be other - environmental - factors at play.

Positing that those environmental factors are acting in utero really doesn't seem credible. Genetically identical twins come from the same uterus and are exposed to the same levels of hormones, yet there's only a 20% chance that both are gay.

In the vast majority of cases, identical twins are subject to very similar upbringings and (in my opinion) it's much more likely that post-natal environment influences sexual orientation than prenatal.

Incidentally, traditional genetics has no problem whatsoever in explaining the persistence of homosexuality across time. Putting it fairly simply, gay family members increases the chance of children in the family group surviving e.g. through nurturing support, additional food gathering capability, and reduced competition for resources given that the gay members are less likely to produce children. The related children will share many of the gay individuals' genes (including any putative genes associated with homosexuality), and will therefore be more likely to pass them on.

The classic case of genes with deleterious effect persisting is thalassaemia - a blood disorder which until modern times was invariably fatal. It was found that people carrying a single copy of the gene responsible for the disease didn't have symptoms, but also had a level of protection against malaria. (Only people with two copies of the gene were afflicted by the disease.) Thus the carriers of the defective gene were actually more likely to pass the gene on to the next generation than would otherwise be expected.

[LeCharivari]

Starting from the point stated in the article that "If one of a set of identical twins is gay, there's a 20% probability that the other will be, too", this shows that homosexuality can not be purely genetic in origin. If it were, that probability would be 100%. There clearly must be other - environmental - factors at play.

My first thought on reading the OP, too - if anything he's defeating his own argument, since there's apparently an 8% chance of their being gay anyway and similar environments pre and post natal, nurturing, upbringing, etc, should more than account for the additional 12%. It certainly doesn't support his case in any way and if anything it contradicts it.

Incidentally, traditional genetics has no problem whatsoever in explaining the persistence of homosexuality across time. Putting it fairly simply, gay family members increases the chance of children in the family group surviving e.g. through nurturing support, additional food gathering capability, and reduced competition for resources given that the gay members are less likely to produce children. The related children will share many of the gay individuals' genes (including any putative genes associated with homosexuality), and will therefore be more likely to pass them on.

Not sure I'd agree with that as cause and effect, as it demonstrates a possible benefit of having gays in the family a few millenia ago, when we were still hunter-gatherers, but it does nothing to explain why the gay gene continues genetically - if it did, having gays in the family would be so beneficial to those family groups that had them that those groups would dominate and the proportion of gays would have been increasing over time exponentially, which obviously hasn't happened. There are many better and more probable genetic and social options available, such as simple infertility of either male or female, or both.

[AyG]

Not sure I'd agree with that as cause and effect, as it demonstrates a possible benefit of having gays in the family a few millenia ago, when we were still hunter-gatherers, but it does nothing to explain why the gay gene continues genetically - if it did, having gays in the family would be so beneficial to those family groups that had them that those groups would dominate and the proportion of gays would have been increasing over time exponentially, which obviously hasn't happened. There are many better and more probable genetic and social options available, such as simple infertility of either male or female, or both.

(1) I believe the same benefits continue, both in terms of supporting family members and in having fewer offspring to compete with the offspring of related "breeders".

(2) A few millennia is but a blink in the eye in terms of genetic timescales - certainly no time for a gene to go from common (10%) to extinction.

(3) I fail to understand the comment about "simple infertility" - how is that a "more probable genetic and social option"? Perhaps you could expand?

(4) I don't think anybody with any scientific background believes in a single "gay gene" - the genetic component is almost certainly polygenetic.

[isanbirder]

Truth is, that I suppose we will never fully understand what causes some people to grow up to be gay, each of us probably has their own prefered theory.

I've always thought it was a natural escape valve to deal with over-population. But how that makes one person gay and the next not, I have no idea.

I don't buy that at all. We've got war, disease, natural disasters, and limited resources to deal with that. The small percentage of people who are exclusively homosexual is very insignificant compared to other restraints on our population. Of course now that we have dominated the planet and really are absurdly overpopulated, it would be a great thing is many more people chose to not breed and/or be gay. Much more humane than the alternatives.

I didn't claim it was exclusive! Of course there are lots of others (though war is made by man, not natural.... animals on the whole don't do anything so silly).

And yes, I think more people are choosing either not to breed at all, or to limit the number of their childrten.

Edited December 14, 2012 by isanbirder

[LeCharivari]

(1) I believe the same benefits continue, both in terms of supporting family members and in having fewer offspring to compete with the offspring of related "breeders".

Agreed - its now advantageous financially, but the same problem applies: " it does nothing to explain why the gay gene continues genetically - if it did, having gays in the family would be so beneficial to those family groups that had them that those groups would dominate and the proportion of gays would have been increasing over time exponentially, which obviously hasn't happened. "

(2) A few millennia is but a blink in the eye in terms of genetic timescales - certainly no time for a gene to go from common (10%) to extinction.

Disagree - a few millenia is a blink of an eye in terms of evolution, but in terms of genetic timescales a "gay gene" which affected 10% of the population would die out in a generation if passed down the male line and in only a few generations if passed down the female line. That's the paradox of the whole gay gene argument.

(3) I fail to understand the comment about "simple infertility" - how is that a "more probable genetic and social option"? Perhaps you could expand?

If it were such an advantage to hunter-gatherers (and now financially) to family groups to have a number of gays in those groups that the "gay gene" evolved, a "sterile gene" whereby all but the first-born male was infertile (for example) would be a far simpler genetic solution.

(4) I don't think anybody with any scientific background believes in a single "gay gene" - the genetic component is almost certainly polygenetic.

As yet (if ever) there's no scientific or empirical evidence whatsoever for either a single or multiple/polygenetic gay gene. What little evidence there is points to homosexuality starting in vitro, but so far its not known if its because of some gene (or genes) or more probably, because of the Darwinian paradox of the gene argument which is never properly addressed, because of hormonal, environmental or epigenetic changes.

[Suradit69]

Truth is, that I suppose we will never fully understand what causes some people to grow up to be gay, each of us probably has their own prefered theory.

I've always thought it was a natural escape valve to deal with over-population. But how that makes one person gay and the next not, I have no idea.

I don't buy that at all. We've got war, disease, natural disasters, and limited resources to deal with that. The small percentage of people who are exclusively homosexual is very insignificant compared to other restraints on our population. Of course now that we have dominated the planet and really are absurdly overpopulated, it would be a great thing is many more people chose to not breed and/or be gay. Much more humane than the alternatives.

"more people chose to not breed and/or be gay."

Ah, so you believe being gay is/can be a matter of choice?

Edited December 16, 2012 by Suradit69

[Jingthing]

Truth is, that I suppose we will never fully understand what causes some people to grow up to be gay, each of us probably has their own prefered theory.

I've always thought it was a natural escape valve to deal with over-population. But how that makes one person gay and the next not, I have no idea.

I don't buy that at all. We've got war, disease, natural disasters, and limited resources to deal with that. The small percentage of people who are exclusively homosexual is very insignificant compared to other restraints on our population. Of course now that we have dominated the planet and really are absurdly overpopulated, it would be a great thing is many more people chose to not breed and/or be gay. Much more humane than the alternatives.

"more people chose to not breed and/or be gay."

Ah, so you believe being gay is/can be a matter of choice?

Can of worms question. Personally, I didn't choose but knowing what I know now, I would have!

[Potosi]

Truth is, that I suppose we will never fully understand what causes some people to grow up to be gay, each of us probably has their own prefered theory.

I've always thought it was a natural escape valve to deal with over-population. But how that makes one person gay and the next not, I have no idea.

I don't buy that at all. We've got war, disease, natural disasters, and limited resources to deal with that. The small percentage of people who are exclusively homosexual is very insignificant compared to other restraints on our population. Of course now that we have dominated the planet and really are absurdly overpopulated, it would be a great thing is many more people chose to not breed and/or be gay. Much more humane than the alternatives.

Would be no problem to reverse the old ideologies, and make sex between a man and a woman immoral, because this produces offsprings, and that's bad. I'm sure there are even lots of passages in the holy books that can be interpreted this way. Some Europeans alive have seen the wildest swings during their lifetimes, faschism to communism, to democracy. No problem, one adapts.

[Thaddeus]

If homosexuality starts in the womb, and Darwin is wrong, that would explain why no men have ever developed a womb....... at least not one with a view.

[endure]

My homosexuality started round the back of the bike sheds...

[Thaddeus]

My homosexuality started round the back of the bike sheds...

There's a coincidence, that's where my heterosexuality started, before that it was Top Trumps, Click Claks, conkers and cricket...... girls.... urg..... the urg turned into ahhh.

[Jingthing]

My homosexuality started round the back of the bike sheds...

For me it was in the parking lot of a Taco Bell. I'm quite ashamed ... about the Taco Bell part.

[endure]

My homosexuality started round the back of the bike sheds...

There's a coincidence, that's where my heterosexuality started, before that it was Top Trumps, Click Claks, conkers and cricket...... girls.... urg..... the urg turned into ahhh.

What's a Clik Clak?

[Thaddeus]

My homosexuality started round the back of the bike sheds...

There's a coincidence, that's where my heterosexuality started, before that it was Top Trumps, Click Claks, conkers and cricket...... girls.... urg..... the urg turned into ahhh.

What's a Clik Clak?

The official name was "Clackers" ..... the resemblance to testicles is just coincidental, they were eventually banned because they were causing wrist damage....... hmmmmm.