If homosexuality has a genetic basis, how has it persisted?

Question

I'd read of a study that claims there is a genetic basis - not a single gene, but a trend of genetic information - that gives a statistically significant increase in the likelihood of an individual being homosexual.

If this is the case, and as homosexuality has to be seen as an impediment to genetic inheritance, how has the genetic trend persisted through the evolutionary chain?

Answer 1

I have a theory. I think there is a fine line between being a heterosexual man who is very sexually attractive to women and being gay.
Women often say gay men are hot.
I think bi-sexual and men who are marginally heterosexual have probably been the most prolific impegnators of women through the ages.

EDIT:
Here is a great analogy my friend....sickle cell anaemia. If you carry only a single copy of the gene for SCA you are protected from maleria. So maybe it's a simillar thing with homosexuality. In other words if you are carrying one copy of the gay gene and not two this can actually be an advantage to you, namely that it makes you more sexually attractive to women. Any good?

Answer 2

An interesting question. The reason is this: just because homosexuality is genetically passed on because of this trend does not mean that heterosexual activity won't pass the genetic trend on. How genes are expressed is complicated, and there are continual expressions of genes that you think have been bred out, or are not observed. Not all people with genes that predispose to cancer or musical ability will inherit either.

Also we do not know what else a genetic tendency is linked with, so to say tat homosexuality is an impediment to genetic inheritance is not to fully understand heritability. If this was the case, then insect communities would collapse because of the use of non-breeding individuals for the greater benefit of the community. There are mammals that have communities that work on a similar basis where individuals who do not breed look after offspring from siblings.

Homosexual individuals in the community do have children, also those that don't reproduce have brothers or sisters that do, thus passing on their genes. Or they may take on the care of non-related offspring so that they can pass on their genetic traits.
Genetics is not that simple.

Answer 3

There really hasn't been a truly scientific and un-biased study on it. A few years ago, some gay scientists claimed that homosexuality shouldn't be considered a disease and made their studies, but they only used gay men. The same happened in a retaliation study short afterwards where homophobic men used only heterosexual men in their study and concluded that it was genetic because they weren't gay. Recently, a more serious study was conducted involving women who had 3 or more gay sons, and the scientists concluded that in similar cases, there could be an augmentation of femenine hormones in those guys and could therefore be more propense to become homosexual, but all this needs further serious investigation. At the moment, no-one can say for sure if homosexuality has a genetic basis.

Answer 4

Human sexuality is infinitely varied, and it isn't just restricted to gender preference.

There are things such as bisexuality, beastiality,dominance, violence, sadism, paedophilia, submission, masochism, fetishes, sublimation, those who are virtually non-sexual, teen preferences, older preferences.....and so the list goes on.

I have no scientific evidence to back up an idea I have long held, that the sheer variety of human sexuality may well be the mortar which permits human-society to function as a group animal, rather than as isolated hunters and occasional breeders.

I suspect that it is so incredibly complex, there is no real answer.

Perhaps the better question would be to ask if there is a genetic logic to sexual diversity, for the simple reason that survival is rather more than mere procreation, and it may well be that those who do not immediately breed down a specific line, are those who play a vital role in making it possible for others to continue to do so.

I think the "science" of that would be virtually impossible, even assuming that it served any useful purpose.

Answer 5

Random spontaneous genetic mutations.

Mutations can happen randomly with no other factors present, however it is easy for a mother to be exposed to teratongenics during early months of pregnancy, when the fetus is most vulnerable and when the mother may not know they are pregnant.

Answer 6

I am reading a book at the moment called "They F*** us up" by Oliver James referring to parenthood and it explains that how we were brought up especially from a very early age has the biggest effect on how we develop and our sexuality is said to be very highly if not completely affected by this rather than our genes. Possibly there is a genetic disposition that allows homosexuality to occur with certain triggers brought about by parenting during childhood as is the case with Schizophrenia (to take an extreme example). Its a very interesting read aimed at children to reflect on how they were brought up rather than for parents to assess their parenting. It's not just this Guy's opinion either, it looks at scientific studies and various other studies and interviews with people which to me seem highly plausible when just the other week i would have said being homosexual is what we are born with, like being left handed, my view is now completely altered and i think for the right reason.

Answer 7

Well to begin with, homosexual people can be parents, you know!!

Don't forget also that some people are bi-sexual.

But I think the study suggests that there is a genetic pre-disposition. I would say that life circumstance usually make a difference.

Answer 8

These quirks happen in all forms of natural development, because homosexuals don't naturally procreate, they tend to die out so the incidence of their being born in nature is kept to a minimum.
We humans tend to think we are so clever and try to buck natures system by making special arrangements to give freedom to these people, and good luck to them, but the fact is they are not intended to survive in natures plan.
There is evidence of same sex attachments with the animal kingdom and I can only assume that they are happy with their lot, there is a chance that they may happen upon an abandoned youngster of their own kind and care for it, so I guess they are not so different from us.
BUT, sperm doning, and other special arrangements are not on for them, so, in nature they die out as nature intended.

Answer 9

Until recently, most homosexuals where closeted and would marry and have children. Even now, some Gay couples are electing to have biological children with either a surrogate mother or sperm donor.

Answer 10

Oh dear! Is this question a complaint? Or just a fascination? Homosexulaity within genes in my understanding is just like the determination of eye colour/hair colour... have these qualties in human de'sisted over time... no! Homosexulaity existed a long long time ago...and is very much and will be part of our present and long term future.. get used to it!