NationStates Jolt Archive

I'm not trying to challenge anybody, but I have a question which I would like answered nicely (no flamebait):

If our biological goal is to pass on our "good" genes to the next generation, how is that compatible with homosexuality, which, well, does not have a biological next generation?

I have a dangerous and discriminatory interpretation, you see, and it's so controversial I won't raise it unless someone asks me to, nicely.

Firstly, you don't pass on good 'genes' to the next generation, you pass on the good alleles. We all have the gene involved in Cystic fibrosis, it's just that many of us have the two dominant alleles meaning we do not pass on any chance of CF personally.

Secondly, you assume that the allele for homosexuality has no positive benefits. It has been suggested, and some small proof shown, that the allele(s) associated with male homosexuality actually have an entirey different role in the female - the allele(s) increase female fertility.

Thirdly, you assume that homosexuals never have children. Before our sexually liberal era, homosexuals were forced to be 'in the closet' by society. Homosexuals would probably often have had children then for the sake of appearing heterosexual in order to avoid a prison sentence, social outcast or their murder.

Fourthly, you assume that being homosexual implies you have no urge to have children of your own. This is simply not true.

And I'd like to hear your opinion, regardless of its possible extreme nature.

Firstly, you don't pass on good 'genes' to the next generation, you pass on the good alleles. We all have the gene involved in Cystic fibrosis, it's just that many of us have the two dominant alleles meaning we do not pass on any chance of CF personally.

Secondly, you assume that the allele for homosexuality has no positive benefits. It has been suggested, and some small proof shown, that the allele(s) associated with male homosexuality actually have an entirey different role in the female - the allele(s) increase female fertility.

Thirdly, you assume that homosexuals never have children. Before our sexually liberal era, homosexuals were forced to be 'in the closet' by society. Homosexuals would probably often have had children then for the sake of appearing heterosexual in order to avoid a prison sentence, social outcast or their murder.

Fourthly, you assume that being homosexual implies you have no urge to have children of your own. This is simply not true.

And I'd like to hear your opinion, regardless of its possible extreme nature.

Obviously I have been under-informed. Thank you! I need to get rid of those assumptions...lol...

No...I might offend somebody...so it's safer not to say it, if you understand...

I don't think homosexuality is purely genetic, it's probably a combination of environmental and genetic factors. Also, there are dominant and recessive genes that influence expression with "different strength", so a "bad" gene can be passed on without having and effect on the individual.

One gets just as much of their own genes passed on if they help take care of siblings as if they have offspring of their own. If they help take care of nieces and nephews, their lineage is getting passed on just as if they had grandchildren.

Thus, in social animals, having a subset of animals who do not reproduce, but contribute to the pack/pride/tribe/whatever and help raise the offspring of their relations, their genetic lineage can be more likely to get passed on than if everyone in the pack/pride/tribe/etc. is reproducing all the time and most of the offspring aren't getting enough care to survive.

There is also the fact that it is very unlikely that a single genetic factor causes homosexuality. Like most complex traits, sexuality is most likely affected by a number of factors, some of them genetic, some of them hormonal, and some of the environmental. Thus, there would be no single gene to breed out. In other combinations, those same genes would contribute to other sexualities. The combination that causes homosexuality in males may increase fertility in females - thus providing them with an advantage. The same may be true in reverse.

I know that people want to condense genetics and evolution into very simple terms, but they simply aren't. We are talking about very complex systems here with a variety of inputs and outputs. While it may seem at a first simple glance that homosexuality "could not have developed" or "would have been bred out", the more factors one brings into the discussion, the less likely either of those statements seem.

I don't think homosexuality is purely genetic, it's probably a combination of environmental and genetic factors. Also, there are dominant and recessive genes that influence expression with "different strength", so a "bad" gene can be passed on without having and effect on the individual.

You're right. I assumed wrongly *once again* homosexuality was genetic.

I'm not trying to challenge anybody, but I have a question which I would like answered nicely (no flamebait):

If our biological goal is to pass on our "good" genes to the next generation, how is that compatible with homosexuality, which, well, does not have a biological next generation?

I have a dangerous and discriminatory interpretation, you see, and it's so controversial I won't raise it unless someone asks me to, nicely.
Ok, look at a pride of lions. Most male lions don't tolerate another male in the pride. They want all that lioness pussy to themselves. Let's say a couple of Bi male lions come along. They outnumber the lone male and can take his females. Since they screw each other they don't tend to want to kill each other. Their cubs inherit a proclivity towards homosexual behavior. In some that homo gene may be so strong as to make female lions unattractive.

Pure speculation on my part, but there you go.

Ok, look at a pride of lions. Most male lions don't tolerate another male in the pride. They want all that lioness pussy to themselves. Let's say a couple of Bi male lions come along. They outnumber the lone male and can take his females. Since they screw each other they don't tend to want to kill each other. Their cubs inherit a proclivity towards homosexual behavior. In some that homo gene may be so strong as to make female lions unattractive.

Pure speculation on my part, but there you go.
You've just got a lion fetish. Go on, admit it.

Although that raises an interesting issue - is bestiality genetic?

You've just got a lion fetish. Go on, admit it.

Although that raises an interesting issue - is bestiality genetic?
Oh goodness. I hope not...

I think in such a psychologically complex animal it's very easy for something to get mixed up, hence fetishes.

Ok, look at a pride of lions. Most male lions don't tolerate another male in the pride. They want all that lioness pussy to themselves. Let's say a couple of Bi male lions come along. They outnumber the lone male and can take his females. Since they screw each other they don't tend to want to kill each other. Their cubs inherit a proclivity towards homosexual behavior. In some that homo gene may be so strong as to make female lions unattractive.

Pure speculation on my part, but there you go.

This is another aspect.

In some birds, two males will form a pair bond. In some cases, they'll just steal a nest from a female. However, during mating season sometimes one of them will mate with a female. Once she lays the eggs, they drive her away to raise them together. These eggs are going to be hatched and raised in a larger territory, but parents that protect that territory more aggressively. Thus, they are more likely to survive.

You've just got a lion fetish. Go on, admit it.

Although that raises an interesting issue - is bestiality genetic?
Nah, I've got a naked lady fetish. For as long as I can remember naked ladies have turned me on.

In most social animal species (which live in groups or bands), such as wolves, prairie dogs and monkeys, there are SOME individuals who won't reproduce. They'll be responsible of other individuals' offsprings. So life is not always about reproduction or the "selfish gene", it's also about survival of the group. And having dedicated babysitters is a good evolutionary solution.

Now I'm not saying that homosexuals serve the same purpose (or any purpose at all, from a scientific point of view), but I'd like to stress the point that, in social animals, the reproductive instinct has much to do with the group's cohesion.

You've just got a lion fetish. Go on, admit it.

Although that raises an interesting issue - is bestiality genetic?
Oh goodness. I hope not...

Do you have any particular cause for concern?

:p

Lol. This thread's funny. Imagine humanity wipes itself out in the next 200 years because everybodies homo. That would be hilarious. I should write a script about it. Maybe you might see it in Hollywood next. :D

The savior would be this hemaphrodite. The X-men. Or the next evolution of humanity. He and his offspring would conquer the world!

A lot of these issues are discussed in the truely excellent book Adam's Curse, by Bryan Sykes. He's a professor of genetics at the Institute of Molecular Medicine at Oxford. You might recall his first book, The Seven Daughters of Eve in which he discusses mitochondrial DNA. Adam's Curse deals with the Y chromosome but also goes through things like possible genetic bases for altruism, homosexuality, aggression, and infertility. If you're not scientifically-minded it might be a little difficult to get through, but I'm a laymen in genectics myself and I found it fascinating.

Sorry if this sounds like a book report, but this just fits so well into this thread, I couldn't resist...

Lol. This thread's funny. Imagine humanity wipes itself out in the next 200 years because everybodies homo. That would be hilarious. I should write a script about it. Maybe you might see it in Hollywood next. :D

The savior would be this hemaphrodite. The X-men. Or the next evolution of humanity. He and his offspring would conquer the world!
Hey, that would be a good porn movie! This guy is the only heterosexual male left in the world and he has to save humanity by impregnating as many females as he can.

:D

I'm not trying to challenge anybody, but I have a question which I would like answered nicely (no flamebait):

If our biological goal is to pass on our "good" genes to the next generation, how is that compatible with homosexuality, which, well, does not have a biological next generation?

I have a dangerous and discriminatory interpretation, you see, and it's so controversial I won't raise it unless someone asks me to, nicely.

i agree nearly completely with the point you're trying to make.

Firstly, you don't pass on good 'genes' to the next generation, you pass on the good alleles. We all have the gene involved in Cystic fibrosis, it's just that many of us have the two dominant alleles meaning we do not pass on any chance of CF personally.


Eh? Maybe I have had too much binary math today but I though the CF chances were the basic 25% No carrier, 50% carrier, 25% have the disease?

Not a pity attempt but I lost a kid to CF. Just curious as both my wife and I are carriers.

I have an unsubstantiated theory that homosexuality evolved in order to combat overpopulation.

I have an unsubstantiated theory that homosexuality evolved in order to combat overpopulation.

Hmmm?

Then how do you explain it's purpose in Greek, Spartan, and Roman times?

Lol. This thread's funny. Imagine humanity wipes itself out in the next 200 years because everybodies homo. That would be hilarious. I should write a script about it. Maybe you might see it in Hollywood next. :D

The savior would be this hemaphrodite. The X-men. Or the next evolution of humanity. He and his offspring would conquer the world!

The Y-cromosome is shrinking, that is a large problem, not someones sexuality.

Hmmm?

Then how do you explain it's purpose in Greek, Spartan, and Roman times?

Simple.

Traits develop in a population under certain conditions, regardless of conditions present where the population is not.

Homosexuality would have developed in a city(or cities) where living space was scarce. Just because a specific area is over populated doesn't mean the whole world is. Humanity evolved to fit the conditions that were present in that particular area. Those changes were passed on later, and voila we have homosexuality today.

EDIT:This makes homosexuals like, the saviors of the human race.

Homosexuality: Saving the world, one couple at a time.

It is often overlooked that men and women almost entirely share the same genes. A gene that makes you want to have sex with men helps reproduction when found in a woman and is a "gay" gene when found in a man. A gene that makes you want to have sex with women helps reproduction when found in a man and is a "lesbian" gene when found in a woman.

This fact is simple, but important.

It is often overlooked that men and women almost entirely share the same genes. A gene that makes you want to have sex with men helps reproduction when found in a woman and is a "gay" gene when found in a man. A gene that makes you want to have sex with women helps reproduction when found in a man and is a "lesbian" gene when found in a woman.

This fact is simple, but important.

So is this a good thing or a bad thing for the human race?

Simple.

Traits develop in a population under certain conditions, regardless of conditions present where the population is not.

Homosexuality would have developed in a city(or cities) where living space was scarce. Just because a specific area is over populated doesn't mean the whole world is. Humanity evolved to fit the conditions that were present in that particular area. Those changes were passed on later, and voila we have homosexuality today.

EDIT:This makes homosexuals like, the saviors of the human race.

Homosexuality: Saving the world, one couple at a time.

So are homosexuals part of the Homo Sapiens, or are they Homo Sapiens +/- 1?

So are homosexuals part of the Homo Sapiens, or are they Homo Sapiens +/- 1?

They're Homo Sapiens, just a little different...

I mean, they are exactly the same as any other human, except for a single gene(well maybe a few genes, who knows?) that makes them atracted to the same sex.

Maybe evolved is the wrong word...

They're Homo Sapiens, just a little different...

I mean, they are exactly the same as any other human, except for a single gene(well maybe a few genes, who knows?) that makes them atracted to the same sex.

Maybe evolved is the wrong word...


Maybe homosexuality is not a genetic thing...who knows for sure?

Maybe homosexuality is not a genetic thing...who knows for sure?

Well it could be a combination of numerous things like genetics/environment/etc. However I never really one day just said you know what I think I want to screw women.

Maybe homosexuality is not a genetic thing...who knows for sure?

That's a possibility too, they haven't proven anything. For all we know it could that the alien chips the Scientologists say are in our brains have been malfunctioning.

I wasn't including it in my first post because, in the context of Swimmingpool's and The Black Forrest's posts, homosexuality is assumed to be genetic.

I think that no matter what it is, it isn't a choice.

Personally, I think it is genetic, but again, it's just speculation on my part.

I'm not gonna say anything about what may or may not cause homosexuality or what its purported "purpose" is. I just wanna address that in the original post, the poster mentioned a "biological goal". I know I'm being a nitpicky biologist, but I wanted to remind people that from a biological, scientific perspective, life does not have a "goal". Evolution is directionless, not progressive. It is not a movement of something to somewhere. No trait "evolves for" something. Variation exists independently of the current conditions. But because creatures exhibit variation, some will do better than others in their environment, producing differential reproductive success ("natural selection"). But animals do not reproduce because they "want to" (leaving humans out of the discussion for the moment). Animals follow their natural behaviors. A male cat doesn't mount a female because he wants her to have kittens. He mounts her because that's what his physiology drives him to do. To the extent to which these behaviors are genetically determined, they can be passed on to offspring. If certain behaviors are conducive to reproduction, there will probably be more such individuals in successive generations. But viewing evolution as making changes arise in critters is putting the cart before the horse. Variation arises on its own. Then it is put to the test.

As for homosexuality, I don't know whether people choose it or not and, frankly, I don't think it matters. I will never be convinced that a loving, committed homosexual relationship is in any way morally inferior to that same type of relationship in heterosexuals (speaking as someone who is currently in said heterosexual relationship).

So is this a good thing or a bad thing for the human race?I wouldn't say it's good or bad. That's just the way genes work. Men and women share the same genes. The environment, both internal and external, determines the expression of a gene and what it is "for." Half the time a gene will find itself in a male body, the other half the time it will find itself in a female body. In a female body a gene could be a "straight" gene. In a male body it could be a "gay" gene.

If you wanted to you could argue that it is good for the human race because there seem to be plenty of humans around, but keep in mind that genes have no way of knowing that there is a human race, they just want to get replicated.

Many genetic conditions are the determined by genes at two or more loci, often on different chromosones (polygenic). Bipolar disorder, for example, has been possibly linked to chromosomes 4, 12, 16, and 21.
link (http://www.cnsforum.com/imagebank/section/Gentics_Bipolar/default.aspx)
These traits often express in intermediate degrees. They are almost always affected by environment.

In addition, conditions that are controlled by a single gene may be harmful or helpful. For example, homozygous recessive carriers of Sickle cell have resistance to falciparum malaria because their misshapen, deflated red cells are poor hosts. Those who are heterozygous (Aa) have moderately good resistance to malaria, but they rarely develop the severe life threatening anemia. Those who are homozygous dominant carriers have nomal suceptability to malaria but don't develop the anemia.

Finally, genetic conditions that are inevitably fatal (retinoblastoma for example) can also be the result of mutations in sex cells.


AFAIK, homosexuality is thought to be a recessive polygenic trait, with the degree being controlled by womb environment. Birth order of male children seems to contribute, as the mother's immune system becomes sensitized to H-Y antigens, which are expressed primarily in the male brain. The production of antibodies to those antigens may prevent or at least decrease "masculinization" of the brain by hormones.
In addition, it is likely that heterzygous carriers or carriers of part of the gene set may very well carry benificial traits. Among those I have seen suggested are intelligence, creativity, and increased male sex drive.

If our biological goal is to pass on our "good" genes to the next generation, how is that compatible with homosexuality, which, well, does not have a biological next generation?

Oh, and I might add that assigning a goal to genetics is to misunderstand the theory. Genetics and evolution operate just like any other part of the natural world. Rocks don't have a goal to become sand, for example. It's just the way the world works.

Rocks don't have a goal to become sand, for example.

of course they don't. everyone knows that the real goal of all rocks is to get to the center of the earth.

of course they don't. everyone knows that the real goal of all rocks is to get to the center of the earth.

No, you're wrong.

The goal of rocks is to trip, injure, or otherwise inconvenience humanity, and then laugh about it while we're not looking.

Don't got no 'spect them rocks, they don't.

Okay. I'm not a genetisist or biologist, but I do have at least a decent education and healthy curiousity...so I'm able to follow along with a lot of what is being said.

Here are some questions/thoughts/scenarios for those of you more in the know about this stuff....

With the talk about homosexuality, I wonder where you would put in those of us that are transgendered/transexual/two spirited people?

Speaking as someone who is transgendered, I can tell you the following:
There was no incest/rape or abuse growing up as a child.
There was not an over dominate mother or father figure.
I was encouraged to follow my heart and what I felt was right for me.
My family, although not saints in any shape form or manner, was large when looking at my numerous aunts/uncles/cousins/neices/nephews etc.

Now. I read somewhere, can't remember where for the life of me, that the number of male babies being born was extremely lower in ratio to female babies...something like 7 females to 1 male. I don't know if this still holds true or not, or if it actually was correct in the begining. But this makes me wonder about this:

There seem to be a lot more gay men than lesbians.
There seem to be a lot more FTM's than MTF's.

Is it possible that somehow, nature is just trying to set things back to a more equal balance? Of course, there's always my grandmother's response to why there is homosexuality and transgendered people. She said it had to do with the soul of the person having been the opposite sex in a previous life and not having completed everything they needed done before they died. So, that soul is holding onto that identity in some ways to complete some task in this life.

And what about genetic memories? There are some people that would say that the stronger male or female memories that get passed down cause the sexuality to alter in some ways. By genetic memories, for example, I was born female, but my father's genetic memory traits were stronger than my mothers. Could those very genetic memory traits be a part of the reason that in some people being female they might be lesbian or in my case feel that there was a body switch at the last minute?

Bah, who am I kidding. It's all a role of the dice anyway.

GOD created man with free will. Since then, man has created mostly erroneous and perverted things. The only compatibility that evolution and homosexuality have, is that they were both created by man.

GOD created man with free will. Since then, man has created mostly erroneous and perverted things.

Like Christianity.

I'm not trying to challenge anybody, but I have a question which I would like answered nicely (no flamebait):

If our biological goal is to pass on our "good" genes to the next generation, how is that compatible with homosexuality, which, well, does not have a biological next generation?

I have a dangerous and discriminatory interpretation, you see, and it's so controversial I won't raise it unless someone asks me to, nicely.


Biologically homosexuality can be explained as a control mechanism to reduce the population growth of an overly sussesful species :D

Christianity was created by Jesus, the son of GOD and the only perfect man to ever walk this Earth. Therefore, since Jesus is perfect, in the same sense so is Christianity.

Biologically homosexuality can be explained as a control mechanism to reduce the population growth of an overly sussesful species :D

Must be Too much McDonalds.

Thirdly, you assume that homosexuals never have children. Before our sexually liberal era, homosexuals were forced to be 'in the closet' by society. Homosexuals would probably often have had children then for the sake of appearing heterosexual in order to avoid a prison sentence, social outcast or their murder.


That's an interesting point, as this would mean that by condemning homosexuality those who opposed it strengthened it in fact.

With the talk about homosexuality, I wonder where you would put in those of us that are transgendered/transexual/two spirited people?

I don't know in humans. However, we may get something from a discussion of bighorn sheep, the only other animal I know of that has clear animals that might be called transgendered.

Throughout most of the year, bighorn sheep are split into male herds and female herds. If these herds come together outside the mating season, the males will try to mount some of the females, but the females will not allow it. The males mount each other constantly and don't seem to care what gender they are mounting, even during mating season there is same-sex hanky-panky.

Well, there are sheep that are biologically male (penis and everything), but actually travel with and act exactly like a female. They also will not allow males to mount them outside of the mating season. They travel always with the female herd. Their behavior is the same as the females.

Why would such a trait evolve? I have some ideas. For instance, like most animals, male sheep are larger and stronger than females - more imposing. Thus, having a male with the female herd could be beneficial. And, since this male acts female, it doesn't disrupt the herd.

Could humans have developed in a similar manner? Perhaps. Perhaps there were men who didn't go out on the hunt and stayed with the women instead. However, they were still statistically stronger and even perhaps a bit more aggressive. Thus, having them stay with the women could have been protective in early humans.

Anyways, its an idea.

More boring biology...

A lot of people on here seem to be saying that homosexuality would evolve as a population control. That's an argument from group selection and doesn't work. Genes don't work "for the good of the species". Only what happens to individual alleles matters. If an allele codes for something that hinders its being passed on to the next generation, that allele will disappear. It's called the theory of Evolutionary Stable Strategy and it debunks group selection (though not kin selection, or inclusive fitness).

In other words, even if homosexuality in the population benefited the population by controlling growth, it wouldn't benefit the individual, so it wouldn't persist. All of the members of the next generation would have alleles promoting reproduction.

/end boringness

I don't know in humans. However, we may get something from a discussion of bighorn sheep, the only other animal I know of that has clear animals that might be called transgendered.

Throughout most of the year, bighorn sheep are split into male herds and female herds. If these herds come together outside the mating season, the males will try to mount some of the females, but the females will not allow it. The males mount each other constantly and don't seem to care what gender they are mounting, even during mating season there is same-sex hanky-panky.

Well, there are sheep that are biologically male (penis and everything), but actually travel with and act exactly like a female. They also will not allow males to mount them outside of the mating season. They travel always with the female herd. Their behavior is the same as the females.

Why would such a trait evolve? I have some ideas. For instance, like most animals, male sheep are larger and stronger than females - more imposing. Thus, having a male with the female herd could be beneficial. And, since this male acts female, it doesn't disrupt the herd.

Could humans have developed in a similar manner? Perhaps. Perhaps there were men who didn't go out on the hunt and stayed with the women instead. However, they were still statistically stronger and even perhaps a bit more aggressive. Thus, having them stay with the women could have been protective in early humans.

Anyways, its an idea.

Oh, dammit. Arguing with you is so much more fun.

I've heard a lot about the explanation you just gave. The advantage of the spectrum of brain formation rather being specifically one end or the other of the spectrum allowed for men and women that were better suited to performing middle of the road roles (like men staying back in the cave, thus not hunting, but protecting it from predators, while have better speech abilities so as to get along better in the social roles of the cave and childrearing, or women who had small changes in the way they think, better sense of direction, better spacial relations, that made it better for them to leave the cave and gather).

Christianity was created by Jesus, the son of GOD and the only perfect man to ever walk this Earth. Therefore, since Jesus is perfect, in the same sense so is Christianity.

:eek: You think Christianity is perfect? I'm Christian, and I'm sure that Christianity isn't perfect, to even make that claim is stupid.

Your reasoning is flawed. Let's apply that logic to something else.

George Washington was the perfect President. Therefore the American government must be the perfect government as well. Regardless that the government Washington worked with is completely different than the government we have now.

Eh? Maybe I have had too much binary math today but I though the CF chances were the basic 25% No carrier, 50% carrier, 25% have the disease?

Not a pity attempt but I lost a kid to CF. Just curious as both my wife and I are carriers.
What I meant is that the frequency of the recessive CF allele, call it c for arbitrary purposes is much lower than the frequency of the dominant non-CF causing allele, C. Therefore, people are likely to be CC in much higher numbers. I suppose that if you use Hardy-Weinberg (p^2 + 2pq + q^2 = 1) then the heterozygotes may come out in higher numbers in the population than homozygous non-CF people, but I'd have to look at the numbers. The basic point I was making was that there are only 1 in 1000 babies with CF because if one of the partners is homozygous dominant, the couple have absolutely 0% chance of an F1 child with the trait. If that makes sense.

Of course, using CF as an analogy to genetic trait homosexuality is effectively useless because of the relatively small number of traits controlled by just one gene and the much larger chance of environmental factors affecting the person's choice in the matter.

EDIT: TBF, since both you and your wife are carriers, you would have a 25% chance of giving birth to a child with CF within your family. In the population, it all depends upon how frequently the certain alleles appear within members of the population.

Hi, this is me again. I'd just like to point out that there is no need to posit any particular value to a "gay" gene other then sexual attraction. Sure, there could be other advantages, but the fact that a gene makes you sexually attracted to men has definate reproductive value when it is in a woman and that can be enough to get it passed on. Sure, such a "gay" gene could have advantages for males that have it, but it doesn't have to. As long as the advantage to the reproduction of females it is in isn't outweighed by disadvantage to the reproduction of males it is in, it this "gay" gene can continue to be passed on.

More boring biology...

A lot of people on here seem to be saying that homosexuality would evolve as a population control. That's an argument from group selection and doesn't work. Genes don't work "for the good of the species". Only what happens to individual alleles matters. If an allele codes for something that hinders its being passed on to the next generation, that allele will disappear. It's called the theory of Evolutionary Stable Strategy and it debunks group selection (though not kin selection, or inclusive fitness).

In other words, even if homosexuality in the population benefited the population by controlling growth, it wouldn't benefit the individual, so it wouldn't persist. All of the members of the next generation would have alleles promoting reproduction.

/end boringness

You didn't actually read the thread did you. Oh well, nothing new there.

Your argument has several fatal flaws.

The first is your assumption that homosexuality would be completely related to a single allele on a single gene. This has already been pointed out as being highly unlikely in such a complex trait. It is more likely that a combination of factors contribute to sexuality.

The second is the fact that you ignore genetic traits that can be detrimental to reproduction in some cases, but actually be helpful in others. An example is a genetic trait that contributes to homosexuality in males, but makes a female more fertile. In other words, if a female got the trait, her reproductive success would likely be higher than other females. The same would be true for any female children she passed it on to. However, any male children she passed it on to would have a tendency towards homosexuality.

The third is the fact that you ignore the concept of altruism. A sibling, for instance, shares just as many traits with you as your own offspring would. Thus, you can help continue the lineage of your family (the traits that were passed to you) by helping to raise your siblings. Your sibling's children would share just as much genetic material with you as any grandchildren you might have. Thus, a family with non-breeding members that contribute to the survival of the offspring that are produced would have a better chance of passing on any traits common to that family.

I'm not trying to challenge anybody, but I have a question which I would like answered nicely (no flamebait):

If our biological goal is to pass on our "good" genes to the next generation, how is that compatible with homosexuality, which, well, does not have a biological next generation?

I have a dangerous and discriminatory interpretation, you see, and it's so controversial I won't raise it unless someone asks me to, nicely.
Because homosexuality isn't about sex. Or even love. Two men can have sex together, and not be homosexuals. Similarly, two men can love each other deeply without being homosexuals. Homosexuality is about relationships, which have nothing to do with biological imperatives. There is nothing to reconcile.