Why homosexuality is not genetic, page 3

Originally posted by Benevolent Heretic
They're twins, not clones.

Interesting article, I'll have to disagree with it in general terms tho, a clone is a twin and a twin is a clone, derived from different processes though. If I were to differentitate between them, I'd say that twins are clones that have the same ontogeny, and a clone has a seperate and distinct ontogeny. But for all intents and purposes, especially with respect to genetics, twins and clones are the same.

Of course, even identical twins have different fingerprints.

Nature/nuture/nuture/nature, round and round we go!

flyersfan
and natural selection says that homosexuality being genetic is impossible.

No, think of it this way. There are inheritable diseases that are absolutely fatal, and that can even result in death in the womb or just before reaching a child rearing age. Failure to reproduce and early death are precisely the same thing in evolutionary thinking. If we think of a hypothetical situation, and say that there is a gay gene (there doesn't appear to be one tho), it might be rare and recessive, such that a person would have to have two alleles of the Gay Gene to be Gay, but can have one gay allele and one straight allele, and thus be a 'carrier' of the gay 'trait', just like with rare recessive alleles, like the one for sickle cell anemia. If you have one copy of it, you get pretty sick from sickle cell, but won't die, if you get two copies, you die, horribly, in your youth.
So there definitly are ways for a 'gay' gene to work.

But really, we don't normally talk about 'hetersexual' genes, even though there's an obvious genetic components. All these sorts of behaviours and 'preferences' are structures in the inheritable brain, and that brain can have all sorts of genetic controls on its form to 'set the stage' for homosexual behaviour. A gay man's brain, from a study I've heard about but don't know the citation (

) found that gay men have brain structures similar to straight women, in the regions associated with sexuality.

Animals engage in homosexual behaviour, and we don't normally ascribe 'choice and preference' to animal actions, as another example.

Another interesting theory that I have heard is that the later born male children, ones who have lots of older brothers, have a 'tendency' to be gay, and its thought that perhaps there is some sort of immunization reaction within the mother. Sort of like being exposed to a foreign disease agent, and the body 'learning' to identify it and deal with it, with the first bunch of male children being that 'foreign' agent that the body learns to recognize. And then when the much later male child is conceived, the body is ready for it and 'does something' that affects the brain chemistry. Not really a 'genetic' issue tho, in a sense, but still somethign that is developmental.

CogitoErgoSum1
Humans and Dolphins are the only mammals I am aware of that have intercourse for pleasure.

Male Primates (outside of man) will fellate each other, and females will do the same to one another.

The most basic purpose of life is propagation of the species. The very nature of Homosexuality goes against this basic principle

Humans do a heck of a lot of things that are motivated beyond and often work against their own propagation (not propagation of the species btw, in nature organisms don't do stuff, normally, for the species, they do it for themselves and their genes). Homosexuality works against 'making more copies of yourself and spreading your genes', but, then again, so does not going to the sperm bank every other day and having your genes literally spread throughout the world. So does fighting in war, can't have more kids if yer dead. Humans are intelligent and can do stuff far beyond what 'mean' genetics and nature is limited to.
Besides, what does it matter if 'natural selection' disfavours homosexuality in general? Since when should one look to nature for morality and ethics? Darwin himself laid great stress upon the fact that nature is not a source of ethics and morality.