Brandon Ambrosino in The New Republic admits that homosexuality is a choice, not an identity:

“One of the reasons I think our activism is so insistent on sexual rigidity is because, in our push to make gay rights the new black rights, we’ve conflated the two issues. The result is that we’ve decided that skin color is the same thing as sexual behavior. I don’t think this is true. When we conflate race and sexuality, we overlook how fluid we are learning our sexualities truly are. To say it rather crassly: I’ve convinced a few men to try out my sexuality, but I’ve never managed to get them to try on my skin color. In other words, one’s sexuality isn’t as biologically determined as race. Many people do feel as if their sexuality is something they were born with, and I have no reason to disbelieve them. But as I and other queer persons will readily confirm, there are other factors informing our sexualities than simply our genetic codes.”

Well, yes.  The Human Genome project has been completed and there is no gay gene. Of course, there isn’t a clear heterosexual gene, either.

Sexual roles are both biological and sociological. They are genetic, congenital, and socially constructed.

But not so constructed that you can just turn a man into a woman by castrating him and raising him as a girl, as the tragic case of David Reimer illustrates.

But since it makes good political sense to invent a category of identity and appropriate the moral high-ground of civil rights activism, gay activists invented one.