http://www.newscientist.com/article/dn14146-gay...

My comment was focused: What studies have shown that homosexuality is genetic? Have there been any conclusive ones? Your response mentions none. That doesn't mean there aren't any out there. If there are any, I'd like to know. If there aren't any, then we might question the “sexual orientation is not elective” meme, at least if that meme is a reference to genetics. Is it?

Some people argue that gays are not a protected class of people regarding legal rights because homosexuality is not proven to be a genetic characteristic or predisposition, but is instead a choice much like which religion (if any) one chooses to believe. If that is true and sexual orientation is not genetic, then heterosexuality is also “a choice.” Therefore a legal prohibition against heterosexual marriage makes just as much sense as a prohibition against homosexual marriage.

For years it was easy to marginalize and hate gays by characterizing and stereotyping them as outrageous, depraved deviants who lived a disgusting and destructive lifestyle centered around sex. Now that gays and lesbians are proving that they are like everybody else, with many of them just wanting to settle down, get married, maybe have children and live a comfortable and productive life in society, they are suddenly very scary and threatening to some people. It was easy to demonize gays when they were so “different.” It's much harder to demonize somebody who's very much like you.

“For me, same-sex marriage is by far the simpler issue. I am one hundred percent for it on moral, civil rights and scientific grounds. (Sexual orientation is not elective.)”

The last phrase, “sexual orientation is not elective,” is a common refrain. A quick Google search shows that the genetics of sexual orientation has been examined, but no firm conclusion seems to have been reached. Maybe a conclusive study has flown under the radar?