Objective Morality?

[Mister Agenda]

I liked the part when he mentioned "against evolution"... I like it when people know little of natural selection. I find great amusement in it, but also great frustration.

Homosexuality would not be a natural selection, this would bring extinction to a species.

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How much homosexuality would cause a species to go extinct? 20%? 50%? 90%?

It depends on the species doesn't it? With desert mole rats, a colony typically consists of one breeding female, one to three breeding males, and about 70 or so sterile workers. So here is a mammal species that gets along fine with less than 6% of the population breeding.

As I pointed out before, natural selection acts on populations, not individuals, and as long as sufficient offspring are born to maintain the population, there's a lot of variation in what percentage of the adults have to actually breed. It's quite possible for a 10% homosexuality rate to be optimal for a population, perhaps if the 'gay uncle' hypothesis is correct (most of the uncle's genes are carried through nieces and nephews, more resources are available for them if he doesn't have children of his own), and selection would bring it back down if it got higher than 10%...and bring it back up if it got lower than 10%.

Homosexuality could be associated with a beneficial gene or gene-complex that offsets lowered reproduction: having one sickle cell anemia gene gives you protection from malaria, having two gives you protection from malaria and also gives you sickle cell anemia. Where there's malaria, you will find this gene is selected for, even though it increases the risk of sickle cell anemia.

AND...homosexuals can have children. Historically, it has probably been the norm for a homosexual man to marry and have children, because having children is so important in many subsistence cultures. Maybe homosexuals haven't been selected against because they've been keeping up with the straights when it comes to breeding, and now that it is more acceptable to be exclusively homosexual, if there is a strong genetic component to being gay, it MAY start being selected against.

I doubt it's that simple, though. The strongest known predictor of sexual orientation in males is fraternal birth order. The more older brothers you have, the more likely you are to be gay if you're a man. Of course 'strongest known predictor' is weak praise when it still only accounts for about 15% of homosexual prevalence in men.

For my part, I think it is probably a number of factors, probably including natal and epigenetic effects, although I doubt there's actually a homosexuality gene cluster.

But carry on thinking you know enough about biology to determine what is natural.