MrDarwin

Left-handedness is an interesting and counterintuitive case. It turns out that right-handedness is genetic, but left-handedness isn't. Or rather, determinate hand dominance is dominant but indeterminate hand dominance is recessive. Most people get a dominant allele that makes him or her right-handed. But there is a recessive allele for which if you have two copies, your handedness isn't determined, so you could turn out either right- or left-handed. This explains why about half the identical twin brothers of left-handed people are right-handed; the ratio for homosexual twins is similar. Maybe being gay works the same way, at least for some people.

Claudia

Coming back to initial subject, I think that we have free will in our sexual behaviour: it is possible to chose to act following our inclination (but I think that this inclination is genetic+environment dependant). True for homosexuals or heterosexuals. People can chose to stay virgin. Given how hard it is to make this choice all life long for heterosexuals, why would it be easier for homosexuals?

MrDarwin

Another possibility: homosexuality might be a by-product of something that's good for a female. For example, if a woman inherits a particular gene, it makes her more feminine, or more promiscuous, or more fertile, or more nurturing--any of which might encourage the passing on of her genes. This gene would have a similar effect on her female offspring; but if one of her male offspring inherits this same gene, maybe he turns out homosexual--but his decreased fertility (in an evolutionary sense) might be more than compensated for by the increased fecundity of his mother and female siblings.

A similar but more clear-cut case is found with sickle-cell anemia in Africa. This disease is caused by a single recessive allele, which causes the red blood cells to produce a defective form of hemoglobin, which deforms the shape of the cell (hence the name). Since people who are homozygous (have two copies) for the sickle cell allele usually die young, and even those who are heterozygous for the allele suffer from the disease (albeit in a less serious form), it's a mystery how this disease would continue in the population... until you factor in malaria. People who are heterozygous for the sickle cell gene (i.e., have one copy of the sickle cell allele, and one copy of the "normal" allele) are more resistant to malaria than people who do not have the gene at all.

People who lack the sickle cell gene entirely tend to die of malaria; those who have two copies of the gene die of sickle cell anemia; but those who are heterozygous, i.e., have one of each, tend to live longer and have more children. Thus there is a selective pressure to maintain this gene's heterozygosity in the population. In this sense, sickle-cell anemia is an unpleasant by-product of a gene that confers resistance to malaria.

tronvillain

Well, I sort of intended to include that in the first option: "You can't get there from here... because getting rid of it gets rid of something else."

There is also the possibility that homosexuality is in of itself useful from an evolutionary perspective - the creation of a few workers who won't be distracted by families of their own or something to that effect.

idiom

Hmmm.... Christians are specifically told in the Bible not to expect non-christians to live by christian rules.

The idea goes that if they're not christians they have much bigger problems than their sexual orientation.

Anyways the Bible is against Hetrosexuality for the most part too. there are many verses similar to "before worrying about the speck in your brothers eye worry about the FREAKING plank in your own." (amplified version)

I would consider homosexuality to be as natural as heterosexuality. Singular Heterosexual Monogamy is quite possibly an unnatural state.

If God required you to do what you would naturally do anyway what would be the point?

cricket

And... in your opinion, what is the point?

idiom

Many Christians will cite that it is to live supernaturally. Which you can't without Jesus. 'parently thats what the fall was all about. wot comes natural got a lot "worse" cuz your natural was given a whole bunch of new ideas.

This is the gospel, the way I heard it.

Polar Bear

I've never heard it put this way before. Makes perfect sense.

Rain Dog

I’m not an expert in evolutionary biology, or homosexuality, for that matter. I think someone has already mentioned that if there is a genetic basis for homosexuality then it might confer other evolutionary benefits. In a “mild form”, for instance, it might, and this is pure speculation, enable one to better relate to the opposite sex and thereby gain a mating advantage. An example of this sort of thing is sickle cell anemia, which disproportionately affects person persons of African decent. The disease is deadly in homozygous carriers, but heterozygous carriers are conferred with a resistance against malaria, an obvious advantage if one is living in Africa.

As for “state of nature” arguments, I offer the example of Bonobos, primates very much like Chimpanzees (and humans), who are almost uniformly bisexual. In fact the word “bisexual” doesn’t do justice to the Bonobos – omni-sexual might be a better description. Socially, Bonobos use sex for simply everything. Type “Bonobo” into a Google search.

Lastly, let me just say, “who cares?” How consenting adults choose to screw is none of my, or anyones, damn business. Whether it’s a choice or not might be interesting from the standpoint of biology and sociology. But if it is a choice, as opposed to a genetic inheritance, it should be even more protected. People should be free to do what they wish with the stipulation that it does not harm others. How can two people making love in the manner of their own choosing harm anyone else?

-RD

Theophage

I will never think of a brain the same way again :^)