@Eudaimonist:

There is no good evidence that gay people would choose to have fewer children than straight people. Early indications are that they would have kids at about the same rate, and what's holding them back is societal factors (can't get married, can't adopt, legal custody snafus and uncertainties, social discrimination against same-sex couples and their children, and so forth). But even in today's unwelcoming climate, about a quarter to a third of gay couples are having children.

The overpopulation problem is not an effective argument to use anyway. Too many Americans are unconvinced that it exists. It's like that anthropogenic global warming myth.

@Revy:

We get into muddy territory here. Some genes only express themselves when they are triggered by environmental signals; others are expressed constitutively, regardless of circumstances. The majority lie somewhere in between, where their normal expression rate is nonzero and can be ramped up or down as needed.

What is apparently happening with the maternal hormone levels is that they are swaying the development pathway of certain brain structures that later influence or control sexual orientation. There are lots of critical points in fetal development where tissues have to differentiate at a certain time according to chemical signals (internal or external, hormonal or otherwise); male and female fetuses share most of these critical points, but there are some obvious differences such as when the gonads have to decide to go down the ovary or the testicle route, whether you end up with a clitoris or a penis, labia or a scrotum, etc. These pathways are all the result of multiple genes working together.

I don't think you can have an example of a behavior that is triggered by environmental chemicals without have a gene associated with it. Think about it. The trigger chemical has to interact with something in the body to have any effect. Whatever that something is, it owes its existence to one or more genes. So at the deepest level of analysis, you can't escape a genetic connection.

The latest research that I've seen suggests that homosexuality isn't a genetic trait, it's determined by hormone levels in the mother during pregnancy.

Now, I'm not a geneticist, nor do I play one on TV, but wouldn't that event (maternal hormone levels) be considered a genetic trigger? We know that genes only express themselves when they are triggered by environmental signals. Do we have examples of variation in behavior that are triggered by environmental chemicals that <u> don't </u>. have a gene associated with that trigger?

I feel like if we ever get a handle on determining someone's sexuality, we should use it the opposite way and make more people gay. An easy solution to population control!

No, it doesn't. But the idea makes an excellent wedge issue.

That argument always baffled me. I mean, hetero parents raise gay kids ALL THE TIME. Parental sexual identity doesn't seem to change the kids.

Compelling arguments don't usually enter into the equation when gay adoption is discussed. All I've heard has been knee-jerk reactions from the Religious Right, coupled with a dismissal of the actual data that says these kids do quite well, thank you very much, and no, they don't turn out to be gay at any rate greater than kids raised by heterosexual parents.

I'm with you, Skippy, and I'm hetero.

But if gay people want to have babies, I am all in favor of letting them go about it any way they like. Most choose some form of adoption to fill this need. And Cthulu knows we need more people willing to adopt kids.

I'm waiting for someone to make a compelling argument (no matter WHAT their stance on homosexuality) that a kid is going to get more ruined living in a loving and stable gay household than in our crapshoot of a foster system.

I for one would rather have a beagle than a child.

Beagles are for breakfast, babies are more appropriate for lunch.

Why do these nutbars think that all Teh Gheyz are interested in children? I for one would rather have a beagle than a child.

Does anyone else here suspect that the layout of this article was intentional?

Top part of the page: GAY PEOPLE ARE PLANNING TO CLONE GAY BABIES.

Story broken up by a picture of Mahmoud Ahmadinejad.

Buried further down the page: None of this has any basis in reality. It is one paper by a law professor from Texas who was asked to "imagine technological developments that will "stress" current constitutional law."

The foundations of homosexuality probably have a necessary underlying genetic component, but I'm inclined to believe that it merely confers an inclination/possibility/predisposition. Necessary, but not sufficient. A good candidate for the triggering factor is exposure to certain prenatal hormones during a particular window in fetal development. This dovetails nicely with the fact that younger sons have a higher chance of being homosexual than their older brothers, and the chance rises with increasing birth order. Since siblings have very similar genetic makeups, this suggests an environmental influence at work (such as changes in the mother's physiological responses to the stress of repeated pregnancies).

In rat models, it's very clear. You can produce rats of any sexual orientation you like, to order, simply by varying exposure to certain hormones at certain times in utero. The mechanism in humans could turn out to be something similar.

I'm the exception to the rule. I'm the oldest child, and my younger brother was thoroughly heterosexual. He never had the slightest attraction to other men.

While there are way too many unknown to make a definitive prediction I think it is very unlikely we will find that there is some determinative mechanism, genetic or environmental, for sexual orientation. What I think will turn out is that some genetic combination makes a developing embryo more susceptible to environmental ques (such as hormone levels) that will trigger a developmental program (probably in the brain) that will result in the child being gay.

I don't mean to interrupt the discussion but @Custador - something I'd read a long time ago suggested the youngest son or two in a family with a lot of sons is/are apt to be gay - is this related? Also not sure what can be said if the mother doesn't know the sex of the fetus already. If it's a girl, how would the mother's hormone response to too many males affect a fetus that is female- make her gay or not? I'm also wondering since I thought females outnumber males anyway, what could, for instance, have affected the hormones of the mother of one of my friends - he is first-born of two and gay, while his sister was ostensibly gay but really turned out to be a man, is now a man, and from all I know of the situation, straight.

What you say makes it really hard to explain in the modern era "too many males." What would explain any gay men born during or directly after WW2, for example. I feel like I'm asking really stupid questions and hope I'm not offending anyone to "explain" why there are gay people.

The latest research that I've seen suggests that homosexuality isn't a genetic trait, it's determined by hormone levels in the mother during pregnancy. I think that it makes a good deal of sense from an evolutionary standpoint too; rather than let chance decide whether you get a gay/straight egg and sperm combination, it would let the mother's biology adapt to a situation as required - So if a population has far too many males, you would get more gay male offspring, if females vastly outnumbered males you would get more straight male offspring - all due to the mother's hormonal responses.

So there you are, bigotted men: If your son is gay, you really can bame their mother. That or the ridiculously homoerotic action figures you buy them, anyway.

They will simply reclassify homosexuality as a genetic disease.

With the advancements in sequencing technology making sequencing of the entire genome from large number of individuals feasible (not yet but probably in a few years, at the moment we can get ≈500M bp, about 16% of the human genome, off a single run for ≈$1K) identifying complex genetic traits will become possible. I think Jen is correct that what we may find is a set of genetic markers that may increase the probability of a child to be gay (similar to BRCA mutations increasing chance of breast cancer) rather then a one that will determine that a child is certain to be gay (like CFTR mutation determine you'll have CF) but I may be wrong. What strike me in the article is the moronic fear mongering of THA GAY coming for all the poor heterosexual babies and the fact that these are the same fu*ktards that keep claiming that being gay is a matter of choice and therefore they aren't being bigots when they fight against gay people having equal civil rights.

Indeed it does.

Jen's post is thoughtful, but I don't share her certainty that we will not be able to figure out the genetics of homosexuality (or any other complex trait you could name) in the next few decades. Our knowledge on the topic is increasing exponentially. Thirty years from now, I'd say it's as likely as not that embryo selection for sexual orientation will be possible.

Which opens up a huge can of worms...

Jenn McCreight has a good blog post on this topic.

The source is the WorldNutDaily so it being full of the stupid is not a surprise but apparently the author is concerned that gay couples will make sure they get gay children by embryo screening and introducing some "gay genes" when they use IVF.