Why hasn't natural selection eliminated the homosexual gene?

Question

It seems obvious to me that such a gene is counterproductive to the continuation of a species. I've never really heard this addressed, and I'm curious as to what sort of answers have been given.

Answer 1

Excellent, thought-provoking question, Andrew.
While I'm not a geneticist, I've read theories that it is related to other genetically-determined characteristics that are more necessary for survival of the species. There may be other characteristics that are beneficial for survival and share many of the same genetic traits. Perhaps when there's enough of a confluence of these genetic traits in one person, the liklihood of that person being gay increases.

*edit in response to Ron S*
It's wholly inaccurate to say that there is no evidence that it runs in families. Just to name two examples:
1) Bailey, J.M., Dunne, M.P., Martin, N.G. (2000). Genetic and environmental influences on sexual orientation and its correlates in an Australian twin sample. Journal of Personality and Social Psychology, 78(3).
2) Wilson, G. and Rahman, Q., (2005). Born Gay. London: Peter Owen Publishers.

*edit in response to Proof is in the Pudding*
It is also wholly inaccurate to say that homosexuality does not occur in other species. This is well-documented in the following source:
Bagemihl, Bruce. Biological Exuberance: Animal Homosexuality and Natural Diversity. St. Martin's Press, 1999. ISBN 0-312-19239-8
This book not only lists animals where that behavior is observed, but also provides sourcing and references to the relevant journal articles and other studies for each, as it is essentially a compilation. A list pulled directly from the book is available here:
http://en.wikipedia.org/wiki/List_of_animals_displaying_homosexual_behavior

Answer 2

Well, in theory the 'gay gene' would become extinct, because gay couples would adopt straight children. But, now you have to worry about the nurture aspect, also. This is where the gay children to straight parents would come into play, where when the child develops odepus complex (which is pretty inevitable), it is on the father for the boy and mother for the girl. Thus, the 'gay gene' is exterminated, but there are still children who are being raised gay, albeit unknowingly. Also, artificial insemination is not foold proof, but i'm sure that if the couple were set on having a child, they would try and try again without a monetary limit. Then, there would still be one 'gay gene' and one 'straight gene', as has been existent for eternity. In conclusion, in theory: 'gay gene' would die off, but nurtured homosexuality would be around forever. ps:great question.

Answer 3

The only logical explanation is population control. Scientists haven't explored this option despite the fact that it's common sense. They say that it may hold an advantage within large families and prevent the "competition" for mates

I would say that it is more of a way to control the population and eliminate the competition for female mates (and males for those who are lesbian) in the individuals own gender. This isn't rocket science, the population is very large and there's only a limited amount of resources available. Nature has blessed humans...specifically males (sorry to be sexist but science is science) with the ability to reproduce at any time, with multiple women. So many children can be born. The population of humans are not decreasing, but rather continuing to expand. Nature has to control it someway...through disease, environmental changes, and homosexuality. It's not the individual's fault but Nature has to do what it has to do for the benefit of the entire world.

Only 4-5 percent of the world's population identifies as homosexual, so it doesn't appear to be a major concern for the entire human race but it's not like nature condemns homosexuals from leading productive and satisfying lives. And those who do end up having children tend to be just as good if not better parents than heterosexuals and there is no difference in child-rearing.

Answer 4

Not all is genetic. Obviously it serves some purpose or is robust. It is a form of population control in a world in which we are doubling every 50 to 100 years and running out of space. And some homosexual couples are adopting unwanted babies.

Since it comes from heterosexuals, it's not being breeded out, either.

No one seems to be pinning any gene down that is about to change things. Redundant body areas like the tonsils and appendix are still thriving.

But this type of process is said to work slowly. No one seems to truly understand the whole process. The identification of the homosexual gene is not even conclusive, they are simply linking a brain chemistry function to a genetic process. They could be totally wrong on that, although from those I talk with it seems to be true for they knew what they were at age 4 or 5.

Answer 5

Ever hear of a recessive gene trait? A trait that does not surface until it is the strongest one or when some outside influence such as a particular hormone released by a mother during a time of stress during pregnancy.....
Perhaps a bit of research into genetics would help. It goes quite a bit deeper than traits inherited directly from the mother or father.

Answer 6

There has never been any proof that such a gene exists and obviously being gay or lesbian isn't hereditary. That's my first point. My second point is that in this day of modern medicine, when even the most premature babies can survive, what reason would there be for a perfectly healthy person, whether gay or lesbian, to die needlessly!

Answer 7

Well - sicience has found that the percentage of homosexuals and bisexuals is growing. This means that natural selection must be getting rid of the straight folks instead. Kind of says you f'ed up the world and it is time for you to go. Now what

Answer 8

it is true that homosexuals do not bring life into this world but have you thought that maybe we are here to give homes to the thousands of un wanted children out there (adoption). Most Homosexuals are very caring and in touch with their feelings and emotions. they are also very brave courageous people, they have to be to have come out in the first place.
these atributes score highly when bringing up children, we are also very open minded which is great to pass on to the next generation.

in evolution however it is survival of the fittest and as homosexuals are no fitter of weaker than hetrosexuals then there is not need for it to dissapear.

Maybe we are here to control birth rates as if every one was to have children we would be over populated.

Answer 9

The drive to survive as a species is even greater.

Answer 10

Excellent question. I think if there was such a thing as a "homosexual gene", natural selection would have taken care of it. I have not seen any proof of any other species of animals being homosexual. This is a pretty good case for gayness being a conscious choice someone makes and not a trait they are born with.