Homosexuality and Genetics

Adims:I seemed to have dragged the Morality and God thread a bit off topic. Mammuthus suggested starting a new thread, so that’s what I guess I’ll do. I’m not sure what to call itperhaps something as simple as Genetics and Homosexuality’, but I’m a bit worried that too many people would avoid the topic because they a have, like myself, a rather limited knowledge of genetics.
Anyway, I guess I’ll start things off by replying to Mammuthus from the Morality postMammuthus, in the other thread you wrote:I completely agree with this, but it’s not a two way street. By that I mean that those individuals that do not have the gene will not exhibit the trait, regardless of any environmental factors to which they are exposed (if you do not have the genes to be six feet tall, then you will not be six feet tall). This is not the same as saying that %100 of those that have the gene will express the trait. The environment will/could make the difference. But still, they first have to have the gene(s). It is in this sense that I made my comment the genes are the root cause to all behaviors. So with homosexuality, individuals much first posses the correct genetic sequenceagreed?
Also, there is no reason to assume that the environment will have an effect on all behaviors. As such, I still have a hard time believing that the environment will have an affect on this particular behavior. What possible environmental factor(s) could there be that would result in an individual becoming gay? What is the common link that results in rich gays, poor gays, Jewish gays, Christian gays, male gays, female gays, white gays, black gays, European, gays, American gays? I just can’t imagine that there is one (or many). This is a tough one for me to explain. There has to be a genetic difference between those that are homosexual and those that are not. So someone that does not have the genetic sequence for homosexuality will not, no matter the environment to which they are exposed (internal or external), be gay. However, those that do posses this sequence will be gay if, at the right time during their development, they are exposed to some magical environmental condition? I don’t buy it. How can this be? It would mean that every homosexual person on the planet somehow was exposed to the same environmental condition(s) that triggered the gay gene sequence to be expressed.
And what about homosexual behavior in other animalswhat causes that? Do they also need some sort of environmental condition to be met before they express homosexual behaviors? Would it be the same for every species?

Thread moved here from the Proposed New Topics forum.

Differences, presumable genetic at least in part, in the brain seems to do it in sheep:
Biology behind homosexuality in sheep, study | EurekAlert!
News articles and features | New ScientistThe New Scientist link has its own links to some other studies, as well.

What I'd like someone to explain to me is why/how I've never had any interest in girls at all. I've dated more girls than I could count in the past, but I've never once had the desire to do anything more than to hold hands. They've always scared me for some reason.So, in my case it's not just my natural attraction toward other guys. It's also my natural repulsion toward girls.Might I also add that I grew up in an ultra-conservative catholic family.

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He's not dead. He's electroencephalographically challenged.

Hello Again Lam: I’m not sure if you are agreeing with me or asking me attempt to answer you questions. I am of the belief that homosexuality is genetic and I fail to see how the environment could have an effect. I guess I am of the notion that someone is indeed born gay.
Also, as I said in another post (I’m not sure if you read it), I hope you realize I was joking around when I gave you those three morality strikes and told you to go set on the bench. I knew you were gay (you mentioned somewhere) don’t care, and have absolutely no moral objection to homosexual behavior. Which is of no surprise to me because I think it makes no difference.

FliesOnly,Given your name, I figure you should be made aware of the fruitless mutation in fruit flies: I believe in this first study, the fruitless males preferentially tried to mate with other males. I think more mutations have been made in the fruitless gene, and some have been decribed as causing bisexuality.I'm not sure about the current knowledge of the mechanisms of fruitless function, but I believe it's been shown to modify female physiology as well...

Coragyps: I looked over those papers (but have not gone to any of the links yet) and they seem to say it certainly involves genetics (we all new that) but do not mention anything about environment. So it seems to me, at least, that so far we seem to agree that homosexuality has genetic components to it. At the same time, some argue that the environment plays a role in ultimately deciding if the behavior will be expressed. I am arguing from the position that it (the environment) has no effect.
I’m not a geneticists, I’m not a behaviorist, and I’m not involved in any ongoing research of any kind, so what I am saying comes solely from my educational background. With that in mind, couldn’t polygenic inheritance be the major factor in homosexuality?

there is another aspect of environmental factors, and that involves the supression of development.for instance if testosterone is not produced (genetic fault) the default development is female - the person grows up looking to all intents and purposes like a female (breasts, higher voice, bone structure, etcetera), yet will be sterile due to internal organs being male and not female.there may be a genetic predisposition to having the environmental aspects of development take different paths.there could also be several genes that control sexuality and sexual behavior, such that {male develoment} and {attraction to female} do not always appear on the same genes (imperfect sequence copying or other replication errors).I don't believe it is a matter of choice for a number of reasons, but I also do not believe that there will be a strict "gay gene" ever found. I do believe that it is bound up in the develpment of the person, and the big question is how long the process takes and how much of it happens after birth (brain still developing in many ways).I also believe it is as natural to be gay as to be hetero because, obviously, there are gay animals (see bonobos et al).

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we are limited in our ability to understand
by our ability to understand RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

FliesOnly,When you use the broad term 'environment', what exactly do you mean?The 'environment' could be psychological/sociological (culture and upbringing); or it could be biological (hormonal exposure in utero or during postnatal development, for example).

Pink Sasquatch:Just so ya know, my name refers to one of my hobbies....fly fishing. If ya ain't using a fly rod...ya ain't really fishin!!Anyway, in reading the abstract, I again come to the same conclusion....it's all in the genes. I'm not pretending to say I know the answer one way or the other in regards to if the environment may influence gene expression as it relates to homosexuality. I'm simply asking those that think the environment does play a role, how? In what manner?
Lam grew up in an ultra-conservative catholic family and stated that he has always felt a repulsion towards girls. I would guess that other gay males feel the same way towards females, but it is highly unlikely that they shared many identical environmental factors with Lam. So all am I asking is if you think the environment plays a role, why are there homosexuals present in almost any grouping (race, religion, income level, ethnic background, etc) used to "classify" humans, since these groups probably have very few shared environmental factors. (Wow...what a crappy sentence ).

Pink Sasquatch: I'm not the one claiming the environment has an affect (I'm also not saying that you are) so I guess I'll leave the answer to this question up to whom ever wants to claim either a sociological explanation or a biological explanation. This is true. I personally would argue that the psychological/sociological environment would have no effect on homosexuality but that obviously the biological environment could have an effect. But again, I guess to even more narrowly define my argument, I think that once an individual is born, their sexuality is set.But I would further argue that even if someone wants to claim that it's the biological environment, then they would also have to demonstrate how this would result in homosexuality. What biologicl environmental factor was Lam and all other homosexuals exposed to that I and all other heterosexuals were not?This message has been edited by FliesOnly, 10-22-2004 03:56 PM

I don't disagree.This might sound odd, but I think some people are so indoctrinated that they don't even know (subconsciously) that homosexuality is an option.As an example, sort of:I have a friend who hasn't come out to his parents yet. Yet he hasn't really tried to hide it, either. Most strikingly, he brings his boyfriend to family functions and holidays (over the course of years), and they even share a bed when they stay at his parents house.However, his parents don't have a clue that he is a homosexual - his reading is that they can't even consider someone they know as a potential homosexual - not because they think it is wrong, but rather they just don't consider it.A fairly odd situation, but it speaks to how someone's learned outlook on life could be strong enough to suppress notions of homosexuality. If someone with an outlook like my friend's parents was a homosexual themself, I'm not sure what the outcome might be.However, this wouldn't neccessarily change the fact that the person is a homosexual, just that they might live their life as a heterosexual despite that fact.Don't know how elucidating that was...

RAZD:Just so we're clear here, I never claimed that there is a "gay gene". I have only claimed that (or at least my intent was to only claim) an individual’s sexual preference is completely determined by the genes they have when they are born. I won't argue that certain factors very, very early during in utero development may alter their subsequent DNA sequences but I have no idea what those factors may be. Still, I would have a hard time accepting even this, without seeing some strong evidence first.
As I think about this more, I do start to come up with some possible scenarios. Maybe a developmental biologist out there can answer these questions. Do chromosomal mutations occur to a fetus early on that may have an effect on subsequent development? I guess that I have always assumed the mutations occurred in the parental gametes prior to zygote formation. Could it be that genes for homosexual behavior are linked with other genes that do mutate more regularly (not as random) than other genes? I don’t knowI’m asking for help. Remember, I said at the start of this thread that I know very little about genetics and now I think I may be digging myself into a hole so deep that soon I'll have no chance of extricating myself.

everytime you have duplication of a cell going on you have opportunities for replication errors. obviously this is most problematical early on in the reproductive effort.there are also other things that do not come down strictly to genes, and certainly the availability of building materials can have an effect too.I believe there are genes that control the development of attraction that are seperate from the genes that control for sex although they may usually be on the same chromosome. an occasional replication error would cross those wires with inevitable results.certainly men are attracted to different kinds of women ... and vice versa.

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we are limited in our ability to understand
by our ability to understand RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

But, as I believe RAZD is arguing, it's not just about your DNA sequence.If something environmental overrides the genetic developmental program, the resulting morphology/physiology may continue even after the environmental insult is removed, even without changes to DNA.As an example, humans exposed to dioxins during development may be born with cleft palate as a result. This is not due to changes in DNA, but rather due to interaction of dioxin with the developing palate at the protein level. Once the dioxin is removed, the cleft palate remains, despite the child's DNA being unchanged.A very speculative example: Perhaps hormonal imbalances in utero due to maternal genetics cause brain development (and sexual preference/identity) to proceed in the embryo in a way that is not overridden during post-natal development and puberty.Hopefully that makes sense.