Doubting Didymus

I suggest you take a quick squizz at this thread

I summarised at the end with the following list of problems with the adaptationist theory of homosexuality.

1: A lack of evidence that homosexuality is genetic (or simply, 'heritable', for those of us here who are not gene centrists).

2: A lack of evidence that homosexuality significantly impairs reproductive success.

3: For those hypothesis that rely on homosexuals as 'sterile helpers', a lack of evidence that homosexuals in a human family setting benifits the relatives more than the drain on resources that any individual represents.

4: Theoretical problems exist for those hypotheses that have homosexuality as a population control device. Natural selection, (the only mechanism by which adaptations arise), can not favour traits unless the trait increases its own replication prospects. Altruism is one such trait, sterility is not.

5: Sterility is not hard to come by. It is one of the most common effects of deleterious mutations, so why would homosexuals evolve to fill the 'helpful non-breeder' and 'population limiter' roles, instead of sterile individuals?

In other words, the necessary evidence that would suggest that homosexuality is evolutionarily adaptive is much too poor.

Machiavelli

mecca, you could stick your head in the sand and refuse to partake, but that doesn't in any way impact your personal preference. You can choose to repress it, but nonetheless, your preference still exists.

Antichris- yes it is. it would be immoral for a person to yearn to have a child with MS, I believe it would be immoral for a person to want a child to be gay. How can I say this? Suppose the proverbial shit hits the fan on earth and as a species we find ourselves fighting for survival, what sexual orientation do you think will be succesful? Intelligence, physical ability, reproductive capacity, are our points success as a species, and insofar as it adds to the survival of the human species, it is moral to sustain and nurture these characteristics.

Everyone tried to sterilize thier choice for heterosexuality by saying that it's just too hard to be homosexual in todays world.

But, because it's my hypothetical, I get to make the rules.

New presumption for my hypothetical, there is no additional hardship placed on a person based on their sexual orientation.

Now how would you answer.

Bill Snedden

Although I didn't answer before, my answer wouldn't change in this scenario: I don't care and therefore wouldn't select for either. It will make no difference to me if my child is homosexual or heterosexual.

Regards,

Bill Snedden

Daleth

I have a condition which causes my body to attack and kill the fetus when I am pregnant. It can most likely be treated, and someday I'll probably be able to have a child. My condition may be heritable. Is it immoral for me to have a child because in some hypothetical future we may find the species at risk of dying out, and in such dire circumstances it might not be possible for my descendant to get the same treatment that's available to me? I also have terrible eyesight. Should I not reproduce because in some possible apocolyptic future my descendants could have a real hard time?

I don't believe I have a moral obligation to ensure the future existance of the species, only to not do things to endanger it.

Flip a coin, if I had to choose. It really doesn't matter.

I'd have said the same before you added this element to your hypothetical. If we were to make our decision about what sort of child to have based on whether our child would be the safest from physical and emotional harm, we'd honestly all have to also choose to have boys. The world is safer for males than for females. That wouldn't work out very well, would it? So I wouldn't have chosen heterosexual to avoid hardship. Flip a coin.

Nowhere357

1: A lack of evidence that homosexuality is genetic (or simply, 'heritable', for those of us here who are not gene centrists).

Even "shyness" seems to have a genetic or heritable component. I see no reason to assume a priori that homosexuality is any different. The fact that hs occurs elsewhere in the animal kingdom suggests it is nature and not merely nurture. Hs is not just a "choice".

2: A lack of evidence that homosexuality significantly impairs reproductive success.

I agree with this.

3: For those hypothesis that rely on homosexuals as 'sterile helpers', a lack of evidence that homosexuals in a human family setting benifits the relatives more than the drain on resources that any individual represents.

I agree with this, also.

4: Theoretical problems exist for those hypotheses that have homosexuality as a population control device. Natural selection, (the only mechanism by which adaptations arise), can not favour traits unless the trait increases its own replication prospects. Altruism is one such trait, sterility is not.

No, the effect has suvival value in other species, I don't think that is controversial. So it certainly can have a similar affect for humans. The last sentence in #4 is a non-sequitor - that sterility does not meet the conditions, has no bearing on whether hs meets the conditions. Your #2 supports this.

5: Sterility is not hard to come by. It is one of the most common effects of deleterious mutations, so why would homosexuals evolve to fill the 'helpful non-breeder' and 'population limiter' roles, instead of sterile individuals?

I have no problem with this.

So Imo #1 and #4 are flawed.

Btw "squizz" is a cool word. Where'd you get it?

Nowhere357

I understand this point. But:

Other than hunting/gathering, every possible human pursuit would have the same problem. If everyone only built houses, we would all starve to death, since there would be no farmers, ranchers, or hunters. But house building does not oppose survival. If everyone only practiced medicine, or everyone only made shoes, etc etc. While if everone only produced food, we would have no shelter, no doctors, and no shoes.

So the argument "if everyone did it" is flawed.

Daleth

This sounds wrong to me (but do tell me if I'm mistaken). It's my understanding that natural selection doesn't favour traits at all... it merely selects against traits that endanger the species. Therefore you end up with a lot of traits that are survival-neutral, like maybe the shape of a nose or having freckles.

If that's right, then homosexuality wouldn't have to favor survival of the species to avoid being selected out of the gene pool. It would only have to not be an impediment to survival, which it isn't if only a small percentage of the population is homosexual and/or if homosexuals can and do reproduce.

Ensign Steve

You keep saying this as though homosexuals are incapable of reproducing. We are not necessarily sterile. We are born with the same ovaries or testes as heterosexual people, and many of us do give in to that animal urge to breed and pass on our genetic material. Being homosexual is not a reproductive incapacity.

tronvillain

No one ever seems to bring up the possibility that male and female homosexuality might have completely different causes. Anyway, I mention this and have already done so, but I might as well go into a little more detail about the "older bird pushing the younger birds out of the nest thing." It seems plausible that male homosexuality is a result of the brain failing to become completely masculine, and instead partially (at the very least the portions responsible for sexual attracting) remaining in a feminine state. Now, apparently the probability of homosexuality in males increases with birth order in males but not in female, and it has been suggested that earler males sensitize the mother's immune system to certain antigens in the brain and that an immune response to those antigens inhibits masculine brain development. In other words, the older brothers are trying to decrease competition for mates from their younger brothers, a less lethal variation of older birds pushing younger birds out of the next.

Of course, that is probably not the only explanation (I would say that it is almost certainly not the only explanation). There is certainly a genetic foundation to homosexuality, but it may be an unnavoidable quirk of how our reproductive and developmental systems are set up rather than any specific allele or set of alleles "for" homosexuality. In that case it would not actually be "for" anything or increase reproductive success, but would simply be something that natural selection is unable to eliminate without tearing apart the whole system and starting from scratch. On the other hand, it could be an allele or set of alleles that has spread simply because of memes for marriage and procreation or because it does has some unknown benefit.

tronvillain

Ensign Steve:
What urge to breed would that be? I assume you mean the desire to have children, but even given that the absence of a desire for sex with someone of the opposite sex the opposite sex seems quite likely to negatively impact reproductive success in the long term. You seem to be assuming modern knowledge, lifespans, and social structures that were lacking for virtually all of human evolutionary history.