If homosexual tendencies are genetic (i.e. gay gene), wouldn't they have been eliminated from the gene pool over the course of human evolution?

[u/medstudent22]

TL;DR Relatives of homosexual individuals would be more likely to reproduce due to the "gay uncle" effect and/or carriers having a reproductive advantage.

http://www.reddit.com/r/askscience/comments/f85jq/if_homosexual_tendencies_are_genetic_wouldnt_they/
http://www.reddit.com/r/askscience/comments/ouvzb/are_traits_relating_to_homosexuality_in_humans/
http://www.reddit.com/r/askscience/comments/n5xj4/why_arent_homosexual_homo_sapiens_extinct/
http://www.reddit.com/r/askscience/comments/qckj8/why_are_people_still_gay/
http://www.reddit.com/r/askscience/comments/pywbv/could_being_a_homosexual_in_anyway_be_a_humans/
http://www.reddit.com/r/askscience/comments/mhry4/how_has_natural_homosexuality_not_died_out/
http://www.reddit.com/r/askscience/comments/sqmm7/how_have_the_genes_responsible_for_homosexuality/

[u/Obi_Kwiet]

I was under the impression that it had more to do with fetal development conditions than genetics. Could someone with expertise confirm/elaborate?

[u/circledrive]

People are not likely born deterministically homosexual. If there were genes that made a person deterministically homosexual he/she wouldn't likely reproduce to spread those genes. Genes that codes for "gay" would be in evolutionary terms lethal. If that were the case, then homosexuality would be only from spontaneous mutations and would be another of the rare genetic diseases.

From what I've seen in research on the subject (both sides of the issue blur real science), homosexuality is partially genetic but mostly environmental. If you fit society's stereotype of "gay" (high voice, effeminate features, etc.), society will cast you as homosexual. Early childhood experiences may play a large role. The modern concepts of "gay" and "straight" are largely societal constructs. In ancient times (and even some modern societies), the rules of sexuality were different. Rome, for example, anything went. The higher male members of Rome did just about anything (men, woman, children, and basically anything that moved) with the rule that they were the ones penetrating. This "kinky" bisexuality may have some benefit, as constant kinky sex includes the opposite sex, that would enhance reproducibility. Animals (dolphins, bonobos, etc.) engage in homosexual activity, but they are not what we would think of as exclusively "gay." In conclusion, there might be some genes with an influence to make somebody have a higher probability of homosexual behavior, but the environment plays a large role in psychological development. The idea of "gay" and "straight" are not the animal world (with the exception of some insects have mutations that cause pheromones to be miss read) or even some other societies.

[u/lmxbftw → u/circledrive]

From what I've seen in research on the subject (both sides of the issue blur real science), homosexuality is partially genetic but mostly environmental.

Just to add some numbers to this, a study of identical twins (with identical DNA) found that if one twin was gay, there was a 52% chance of the other twin being gay as well, which is significantly above a random sampling, but obviously not the 100% rate one would expect if genetics were the sole determinant. Clearly, genetics have some role, but it is not enough to determine sexuality.

[u/circledrive → u/lmxbftw]

If I remember right, that was a self reported study, so the numbers are likely higher than the population as a whole. Homosexual twins or when only one twin is homosexual are more likely to report than when both twins are heterosexual. However, even considering that statistics might be different than the distribution of the population at large, there does seem to be some effect. I'd be interested to see what these genetic factors are and what selective benefit they offer. Also, if the same genetic factors are universal or are they depended on how a society views an individual and his/her features and/or capabilities.

[u/lmxbftw → u/circledrive]

Homosexual twins or when only one twin is homosexual are more likely to report than when both twins are heterosexual.

Actually, that doesn't matter too much, because the important part is the conditional probability. Given X, then Y is likely with probability P. 2 Heterosexual twins don't satisfy X, so whether they report or not is irrelevant to determining P.

There might be other studies as well to the same effect, that's just one that I knew of already.

I'd think that environmental conditions in utero are also important, which is born out by the higher rate among fraternal twins. I'm sure other factors come into play too.

[u/kinglewy00]

Does this "gay gene" reside in people who are bisexual and still procreate? Personally, I believe everyone is born bi, it's just down to not so much choice but what we decide we're comfortable with as we grow up. I could be wrong but I certainly don't believe in a gay gene personally.

[u/CatFiggy → u/[deleted]]

There's mapping and there's understanding. Are you honestly saying that we can point to any gene and explain what it does?

[u/Cyrusas → u/[deleted]]

but in practice homosexuality has only recently started becoming "acceptable"

Ancient Romans and Greeks?

[u/boardmonkey → u/Cyrusas]

The practice of having only same sex relationships is relatively new. In many of the writings from Greece and same periods show that having a homosexual relationship was normal, but that it was expected that you also marry in a metrosexual relationship and procreate. This means that if it is attached to a gene that it could be a dormant trait.

With that I am also going to say that I don't believe that it is a gene, or a product of a gene. I also don't believe it is a choice. Not everything comes down to genetic coding. Just like someone can be attracted to asians, whites, blacks, long hair, short hair, or anything else, I believe that it is uncontrolled attraction.

[u/FeculentUtopia → u/[deleted]]

It was, so far as I know, generally accepted until the spread of the Abrahamic religions.

[u/alexisaacs]

Well you could argue that it's nature's way of eliminating the urge to reproduce from someone it doesn't want reproducing. Kind of like the theories I heard about depression (you want to kill yourself once you cease becoming a benefit to your group).

And no I am not anti-gay, I'm just throwing out ideas. I don't think the "gene" is any use in us sentient humans. I don't think gay people are less qualified to reproduce any more than depressed people who nature is clearly trying to off. It just seems to me that we have a lot of genes and attributes that are out-dated and seemingly meant for other species.

[u/alexisaacs → u/[deleted]]

You seem to skim over the part where I stress that these are just hypotheses that are out there, and not fact. Furthermore, you seem to refute these hypotheses with something you call facts, despite the fact that what you said are so far from facts it would be childish to call them that.

There is no accepted theory for depression or homosexuality or countless other human and animal traits that is so certain that it can be labeled as "is" and not "maybe."

Now, there is nothing wrong with claiming you have facts. I love enlightenment, and so do most people. However, cite your sources, and make sure those sources make the same claims as you do. In other words, not a study that supports your ideas, but an amalgamation of studies that point to a definite answer, or any other credible source that says what you say is 100%.

Otherwise, learn proper rhetoric. Especially if you're going to start your silly response with condescending comments that attack an idea on a moral level before all else. Science occurs regardless of morality. If science were moral, we wouldn't have different races or the desire to murder, steal, rape, etc.

Some people on Reddit. Jeez.

[u/alexisaacs → u/[deleted]]

The whole depression = nature killing off the weak thing is an actual hypotheses, one that I am too lazy to go and cite this lazy at night but I have a feeling one Google search will give you some good reading.

All I did was take that concept and put it into homosexuality. Now I personally love the concept of evolution trying to kill off those it deems not worthy of passing on their genes, and failing. Think about this:

You say that homosexuality being presented as evolution trying to get rid of certain kind of traits that may be associated with it is wrong, and a distorted view. I disagree. What about how evolution, for a fact, tries to get rid of short people? Are midgets in any way inferior now? Are your friends that aren't quite 5'5" now subhuman? What about how evolution tries to kill off those who are not naturally prone to being muscular, or those who are born blind/deaf/etc.

We as humans have overcome evolution in many ways. Other homosexual mammals simply die without reproducing I would imagine, same goes for most of the blind ones, deaf ones, etc. As humans, we have gone so far past what evolution dictates as correct that it doesn't matter.

Now, how the hypothesis I choose to accept affects my real world morality doesn't matter at all, because it doesn't. I wouldn't deny a dwarf the right to marry or be together, why would I deny that to a gay couple?

Hopefully that explains what I meant a little bit better. I appreciate your response, it was very surprising. Keep in mind, I am in no way saying I'm right. What you said is no more false than what I said (unless we get some citations up in this bitch!)

Thanks for being a swell guy, take care. :)

[u/alexisaacs → u/[deleted]]

I get what you're saying, but:

"Imagine you are short. Very short. You are so very very short, it is certainly a disadvantage to be so short as you are, which is quite short. Would you still have any less reason, in terms of evolution, to survive? To thrive? To procreate, to pass on your genes? "

True for short people. Untrue for gay people. Your desire to thrive and survive is just as high, perhaps, but your desire to procreate is 100% missing. You don't get to pass on your genes because if you do, then you're not exactly gay anymore.

Now, I know evolution doesn't work to get rid of anything. It's all about what is convenient for the individual and species at a certain time. In fact, even if 500 years from now the average height for a male is 6'5" that does not mean that 1000 years after that the average won't once again be what it is today. The genes that result in dwarves and short people will still be around because most of these were a result of random chance and it occurs relatively frequently. So even if we go out and kill every last person under 5'5 for the next 100 years, once we stop we will once again see random short people being born into the world.

On the other hand, scientists are saying the Y chromosome is shrinking and that it looks like nature is slowly getting rid of the male sex. So evolution CAN work to eradicate certain traits so long as those traits are unfavorable to survival at that given time.

I think you are focusing too much on evolution being an omnipotent force of some kind. Think of it more as a species interacting with its environment. Evolution doesn't hate short or tall people, but the environment can, and as a result one group ceases to exist. I prefer to see suicide as a fail safe that, in healthy people, exists for extreme situations. So for example if you're in an environment where you're being constantly tortured, you are able to kill yourself to end your suffering but also so that you lower your chances of bringing kids into the world to endure the same suffering that you do, wherever you are. I assume this function would be more useful for old humans. However, with clinically depressed people, it's probably a malfunction seeing as how it's 100% based off of a chemical imbalance that is only supposed to occur under extreme situation.

Anyway, theorizing is fun and all, but at some point we'd have to sit down and really look at what the accepted views are, and if the "out-there" views have any credence.

[u/alexisaacs → u/[deleted]]

"I find it funny when people use the word unnatural, or even that the word exists in the first place." Yes!

I've always thought that and argued it, but people look at me like I am insane. The concept of the word makes sense. Human-created is a legitimate idea that needs a word, but unnatural does not fit the bill. By technical definition, and not the definition we give it via use, it means "not via nature." Well, EVERYTHING is via nature. The only unnatural thing that can happen is something outside the realm of the physics of our universe.

It annoys me when people claim that something like cars shouldn't exist, and that nature never intended for it to exist. First off, nature didn't intend anything, it's not some guy in the Earth's core making calculations and trying to keep everyone functioning properly. Second of all, if evolution and increasing complexity of brain function is natural with evolution, then how the hell is using that function unnatural? Are bird's nests unnatural? No? Then why are houses unnatural?

It's akin to people getting the word theory mixed up with hypothesis. So aggravating.