Prim wrote:
For an increase in homosexual orientation to be a product of population pressure requires a mechanism, and it can't be an intellectual one; it has to be biological. And the effect must somehow be produced before birth, in the next generation.
The only comparable thing I can think of is the shutdown of menstruation and thus fertility in starving women. But that's a simple feedback mechanism.
Since we don't know what causes sexual preference, we can't begin to guess how the biological mechanism works. But there is no reason why it can't be a simple feedback mechanism. A host of physiological changes take place in all mammals in response to changes in population density.
In truth, I don't know whether the percentage of homosexuality is increasing in the population, because we don't have sufficient data. I made my statement based on deduction from characterisic mammalian behavior and not from sociological data. Mammals are inherently bisexual. That should give us a tiny clue where in the brain to start looking for sexual preference, if anyone is interested in looking.
To investigate the causes and mechanisms associated with sexual preference we would need much more than sociological data. We'd need data from
homo habilis and before.
nel wrote:
But I do not understand how you can reconcile your idea with the large numbers of homosexuals who seek to have their own, biological children. <> And gay people, broadly, do not seem particularly disposed to abstain from having children - whether based on conscious thought or on subconscious instinct.
nel, I'm not sure I am willing to accept at face value that the gay community as a whole is as anxious to procreate as you claim, though I don't dispute that it is true of the people whom you know. But even if this were true it would not be a challenge to the hypothesis, for the reason given by Prince A:
Prince A wrote:
Overpopulation isn't caused by one couple having one or two children... It is caused by people having many children, and then their children having many children...
Natural selection acts on the individuals but influences the population via the law of large numbers. It is sufficient for there to be a gradient in reproduction rates for the mechanism to 'work' as it should.
Non-reproduction is the default position for homosexuals, and they must enjoin a third party to change that. This alone is sufficient to cause a gradient in reproduction rates. You have to remember that whatever the biology of homosexuality is, it's been there for ~40 million years, whereas the human sociology of it has only been around for ~70,000 years.
vison wrote:
I read recently that the Hemophilia in the descendants of Queen Victoria was due to a rare but not unknown spontaneous mutation: it had not existed in that bloodline before. The article I read said it was not due to cousins marrying.
That's interesting, vison. I think you posted that once before somewhere - I had a deja vu when I read it! It is true, though, that you can trace the carriers of hemophilia through the European noble families and see how the incidence of two recessives influences the outcome.
Jn