If homosexuality was genetic, it would have been bred out of the system eons ago.
That's what he writes in the column--sorta.
If general evolutionary beliefs were also true.
I read an article that was based on research publish for peer review. Not a debatable point like the post above. He had scientific evidence that during early stages of pregnancy that a protein was responsible for same sex attraction. I cannot remember specific details but something in mothers protects the baby from this happening.
I believe the current thinking is that homosexuality has a biological cause, though not a genetic cause. The theory goes that at a crucial point in fetal development, some pre-borns get the proper dosage of hormones and develop normal sexuality, and some don’t and end up homosexual. Once again, I don’t think the jury is in on this yet.