Genetics and homosexuality/evolution?

Question

I have to preface this because it contains a question about homosexuality. I have 4 very close people in my life who are gay and I love them with everything I am. I am not flaming gays.

With that said,
If only a small fraction of us are born gay, is this considered a birth defect like lets say dwarfism? Is dominance inheritance a key player within the evolutionary process when it comes to genetics? They say that 60% of birth defects come from unknown causes, so if it isnt a mother's environment for the fetus, its genetic. If it werent a birth defect wouldnt more of us be born gay? How much of a role does evolution play in this? I know this is alot of question and I should be charged 15 points, anything you can give me infowise is appreciated. Serious answers from informed individuals would be ideal. I posted in here because alot of you seem to be informed on topics like this. This is not a question for flaming others, thank you.

Aviator, I like the way you are looking at this, so we could assume from your answer that there are no real birth defects, we all just have genetic differences?

Rabble: Im not sure where you got that I believe homosexuality is some new trend or the fact I want to diminish the gay population, this wasnt the intention of the question. Its no secret that gays are a small fraction of all humankind as well.

Lao-my entire question was much more than evolution and homosexuality. It mainly was a genetic question.

I have to add a detail about people being offended by this question....Is it not clear I have NO IDEA how it all became through genetics and/or evolution? This is a question that included bouncing ideas around. There is absolutely no judgement in this question. Im not stating it is a defect in any way. I really am not, im coming to a basic logical conclusion based on not knowing a whole lot about genetics nor how the evolutionary process works. Why cant I ask and get informed. Im not on some platform stating homosexuals are lower than others and have defects...Im asking. I do appreicate those who understood my question and answered it in an informed way.

Answer 1

If it were a 'defect' it would have a deleterious effect, and evolution would have taken it out. But it has no such negative effect.

Which may seem counterintuitive, because one obvious feature is that gay people don't reproduce in most cases. That alone should mean that the genes involved are effectively coding for their own destruction. But you have to look further than that.

Remember that the genes involved in producing gay males, for instance, will also be present in females. What effect would they have? It appears that their effect is to produce a super-female, whose reproductive success is great enough to make up for the loss in the male.

Female reproductive success is composed of many factors. Firstly they must attract males with high status and access to large resources - in human terms, rich and successful.

The males must also be attractive themselves, because it's important that the male children ALSO be attractive to the next generation in order to continue the success: no point in having sons who are ugly, sexless goofs - the line will die out.

And, of course, both the Superfemale and her chosen mate must be healthy and have compatible immune systems, to ensure healthy offspring.

In short, the genes that produce gay males must, when expressed in females, produce a woman capable of capturing the attention of someone rich, powerful, healthy and handsome - the pick of the crop - to make up for the closed reproduction of the males.

CD

Answer 2

Uh, given that this category is full of people who HATE gays for being gays, it seems an odd choice.

Since these are scientific questions (biology), it would have made more sense to ask there.

We don't yet know why some people are gay.

One of the more recent theories I've heard is that the environment in the mother's womb has a lot to do with it; each time a woman has a boy, she's exposed to and extraordinary amount of male hormones, and her body reacts during subsequent pregnancies to the previous experiences, supressing them to some degree. (This was a theory based on how boys later in the birth order are more likely to be gay.)

Calling is a "defect" is offensive. It presupposes there's something wrong with it.

As for "if it weren't a birth defect wouldn't more of us be born gay?" is just wrong. Are blue eyes a birth defect?

Something can be biological without being genetic (as the hypothesis I gave).

I suspect that the search for a single cause is misguided. There's no reason to assume that there's only one reason behind all gay people's gayness. There could be a bunch of different reasons.

Answer 3

What I find fascinating aboutmany of the answers above is that they don't even make the other assumption that "gay" behavior might well be selected for in an evolutionary context and be something that confers a selective advantage to the family line.

It could be selected for as an adjuct to something else or because having homosexual behavior and/or homosexuals in a band might well actually INCREASE the number of offspring left by their relatives. Does this necessarily have to be because the homosexual individual leaves his/her own offspring? No. It could be that there is near-kin selection. After all, think about this - let's just assume we're talking about males here, because females of whatever sexual persuasion could be bred by more aggressive males in a hunter/gatherer society. Assume that three or four males are homosexual in a moderately small group and that they are related to the others there -- gosh, what a concept, huh? These men bring in more food, share with the tribe (relatives) and help survival of all in the group, and yet they basically don't infringe on the mating perogatives of the breeding males. There are also more males available for defense of the band. It won't cut down on the breeding numbers either, since again, all females will likely be pregnant anyway. The males aren't having fights among themselves and you have a possibly more stable situation than if you had non-breeding males who were seeking females. (Is this what happened? I don't know, but I can easily see an evolutionary context for it. Heck, Greylag Geese that have homosexual triads rear way more young-- a triad is a male bonded pair that also includes a female. ) What makes you think that such couplings aren't known in human populations too - and may well have been at least as common in the past as they are now? Since the non-breeding males (homosexual ones) help the tribe produce more young - and since the young are related to them, the frequency of genes that allow the behavior can spread in the population.

Answer 4

Wow, um, I don't have direct answers to all of your questions, but I will say that I have a science degree that included a strong evolution component, so I'll try to go off what I know.

I don't think homosexuality is a birth defect. I understand you're not trying to offend, but I think a lot of homosexual people would find that offensive. A "birth defect" is either a result of the fetus inheriting 2 recessive alleles, or a mutation in the transcription of the genetic code. If you want more information on these processes feel free to email me, it's a little too much to type here :-)

You should know that humans aren't the only species with homosexual individuals - it has been documented in many other species as well. Evolutionarily, it seems heterosexual individuals should be favored since they are the ones that will produce offspring. But we see many homosexual couples producing children. Again, that argument assumes it's tied to genetics. Because of the persistence of homosexual individuals, and the fact that a homosexual couple can have a child that will not necessarily be homosexual, I think we can safely conclude it's not some "genetic abnormality" or anything like that.

I don't have all the answers for this, other than to say that it is a natural thing that occurs in many species.

Answer 5

In order to qualify as a defect, it has to be shown to be detrimental.

As sexuality is not expressed at birth, it is not clear how strong the genetic predisposition is. Could a non-genetic gestational effect play a role? Absolutely. What happens between birth and the time sexuality expresses also matters.

That said, let's assume that there is a "gay" gene. It's prevalence in the population will reduce population growth. In times of famine, a high prevalence will result in less mouths to feed per adult, increasing the fitness of the population. In times of plenty, a low prevalence will allow for population growth. The gene could be a survival trait.

Answer 6

It is a naive view of evolution to say that homosexuality, in any species, is a "defect". There are may reasons why a society may need, or at least be compatible with, homosexual individuals.

Almost all mammal species have been observed to have homosexual individuals, at no detriment to the species as a whole. Quite simply, it is a very "natural occurrence". Indeed, it is much more "natural" that oral sex, of which only a very small number of species participate (namely humans, bonobos and dolphins...that's about it). Oral sex is much more "unnatural" than homosexual sex, from an evolutionary standpoint, and offers no better chance of procreation.

It is very naive to say the reproduction is the only way that a person can be useful to a clan or society. For example, I have aunts and uncles that were very useful to my family's happiness. I have no kids yet, but serve a very useful function to my nieces and nephews.

There are numerous bird species that have asexual or homosexual individuals that are pivotal to tending to babies and other tasks. The same is true of a variety of other species.

Even if homosexuality is has a genetic cause (it likely does), that doesn't mean it is a negative factor from an evolutionary standpoint. It definitely should not be considered a "defect".

Answer 7

Somebody said that it is nature's way of curbing overpopulation. I don't think that's the case at all. I think that it's a case of 'cultural selection', rather than 'natural selection.

Assume that homosexuality is 'genetic'... then consider this: based on 'biblical' imperitives, christians have striven to convince homosexuals that their urges are unnatural... sinful... satanically inspired. They convince these people to strive to be 'normal', as god intended them to be... get married... pass on your genes... keep the 'homosexual' genes (if there is such a thing) alive in the gene pool.

It seems to me that the christian's aims would be better served by understanding that homosexuality IS genetic... encouraging homosexuals to enter into same-sex realtionships, which do NOT produce offspring... and fulfill parental instincts through adoption.

In my mind, Christians are just reaping what they have sown. The high percentage of homosexuals in our present society is a direct consequence of the ignorant and misguided policies that christians have been implementing for centuries.
.

Answer 8

A lesser percent of an occurance does not define a defect. It is just a less dominant trait, like red hair, blue eyes and other traits that are less common. In fact, it is more likely that the lesser occurances in the total population define a superiour quality rather than a defective one. There are far fewer people born with a genius level IQ, so is that a defect or is it evolution trying to make us all stupid.

Your way of thinking needs to change because its clear you think of gay people as being less and not just being different.

Answer 9

People who are born left-handed make up only 5% of the population. Is left-handedness a birth defect? No. How about premature balding? Or going grey before you're 40? None of these are defects, they are VARIATIONS. That means they 'vary' from the 'norm'. The 'norm' is just another word for 'average'.

The percentage of people who have same-sex gender preference has hovered between 5-10% of the population since the beginning of recorded history, and therefore probably since well before we began recording. It is a variation.

Answer 10

Your entire question is based on the false concept that people are born gay. Homosexuality is a choice, not a genetic defect. There is no scientific proof that homosexuality is linked to genetics in any way.

n his book, Overcoming Homosexuality, Dr. Robert Kronemeyer says, "From my 25 years experience as a clinical psychologist, I firmly believe that homosexuality is a learned response to early painful experiences and that it can be unlearned."

Even homosexuals who are honest about their behavior have admitted they were not born gay. John Dececco, editor of The Journal Of Homosexuality, says homosexuality is a "behavior, not a condition" and that "the idea that people are born into one type of sexual behavior is entirely foolish." ["A Biological Theory For Sexual Preference," USA Today, (March 1, 1989), p. 40]

Bill Flatt, Ed. D. , says, "Conditioning is the predominant cause of homosexuality: conditioning by parents, siblings, by dating and other experiences. Genetics alone is never the cause. Genetic studies of homosexual and heterosexual groups cannot accurately distinguish between the two groups." [Counseling Homosexuals, (Jonesboro: National Christian Press, 1985) p. 65]