Is Homosexuality Genetic? and even if it is...

Homosexuality has become a hot topic as of late, and this question has been burning in my mind for years, so here goes. I hope this doesn’t start a personal attack, or sound like one. I’m trying to speak as objectivly as possible and avoid any judgement whatsoever. Logic only responces please.

Is homosexuality genetic? Meaning is it a trait that is passed on from one’s parents, or if not passed on through chromosones, is it perhaps a naturally occuring genetic development. The point being, that it is a genetic condition, independent from the environment. I hear gay men and women use this argument quite often. (A gay man says: “I can’t help it, I was born a woman”)

But if you make that argument, shouldn’t you then acknowledge that an evolutionary trait that occurs in a person which prevents them from procreating will eventually be, well, bred out (not to put too fine a point on it).

When I try to debate this with gay friends, some say it’s only partly genetic. That it depends on your environment too. That would mean homosexuality is only becoming prevelant now because of increased exposure allowed by our interconnected world. Then if homosexuality becomes socially accepted everywhere, it won’t be partly genetic anymore (since there is no geneticlly homosexual person who doesn’t become homosexual because of a lack of the proper envrionment), and will, with a wave of a darwinian wand, vanish when the homosexuals don’t create children.

But maybe I’m crazy.
-Phil from FSU

p.s. I also heard a strange argument that homosexuality may be a kind of evolutionary responce to overpopulation. There are amphibians who change sex in a single sex environment, so biology can be affected by society. Since we’re a bit more complicated internally, maybe changing the object of our affections is enough. Don’t subscribe to it myself, but life has a funny way of working things out.

I just asked this about a week ago. Here is the link. The nice dopers provided plenty of links to follow up on.

Hope this helps.

I don’t think the jury is in on this yet.

First of all, you’re apparently conflating homosexuals with transsexuals (“one gay man says: ‘I can’t help it, I was born a woman’”). They’re two entirely different things.

Second of all, have you ever heard of recessive genes? While Kalhoun is correct that the jury is still out on what causes homosexuality, the genetic explanation IS possible, because of recessive traits and also because of gene complexes.

I have a friend who is born gay. It was visible since he was not much older then a baby.

In case you think this is something that only happens to humans and can be caused by external factors, I disagree.
I have two dogs (different race) I should mark as being gay because they clearly are. I breed with one of these races, but that particular male shall not contribute to that on a natural way although he is healthy and “normal” enough.

Salaam. A

This has been debated many times. Search for the older threads to find more info. The present thinking seems to be that the hormonal environment in utero is the biggest contributing factor.

If that was true, wouldn’t it have happened already? No. You’re thinking too small- the fact that a gay person’s genes won’t be passed on doesn’t mean that he won’t contribute to the survival of the species as a whole.

It’s not a catching disease - you don’t ‘get gay’ by being exposed to gay people. The fact that something is environmental (or partly environmental) doesn’t mean it’s acquired.

In less complex animals, yes, biology seems to be affected by society. If you buy the idea that humans are overpopulated, you’d have to explain that homosexuality in humans is not a recent development.

The alternative to saying homosexuality is biological is that it’s a choice, which seems patently ridiculous. Homosexual behavior has been documented in hundreds of animal species, including apes closely related to us (like bonobos).

When I’m off work, I’ll search for some of the old threads. Whenever this topic comes up I end up using info posted by annaplurabelle, which is where I got the in utero thing. Try searching for ‘prenatal wash.’

A trait or characteristic that is “genetic” in nature is not necessarily independent of the environment.

One of my favorite examples, *** Himalayan mutation *** involving the expression of hair pigmentation genes.

A snippit from here:

A possible evolutionary advantage of this mutation…the colder regions of the animal, furthest from the heart and body core (toes, tips of ears and tail) are dark in contrast to the rest of the body that is white or pale. The darker color of these areas helps to absorb warmth from whatever sun is around and decreases the chances of tissue damage due to extreme cold.

There are plenty of other examples of an organism’s environment influencing it’s genetic expression, such as the previous comment regarding the environment in utero.

I’ve always been interested in this theory, and I’ve posted about it on previous threads.

My best guess, as a gay person with a biology background, is that being gay is probably due to a suite of factors (such as those debated on these boards) with certain factors being more influential than others, depending on the individual.