I don't want to get into the whole religious issue, but I do want to point out that homosexually has been around since dawn of the age & it has been witnessed among animals, too. So, that makes me believe its "genetically natural" b/c it exist in nature. Beside, gay people have been persecuted around the world, & if it was not natural, than why would anyone chosse to be gay? It doesn't make sense to me.
Homosexuality during Roman and Greek times was done so by choice. It was never considered a natural compulsion, rather an issue of choice. Hey today I will sleep with a man tomorrow a woman. Its all good. The issue of it being witnessed amongst animals I keep hearing this yet one can actually provide a link to a study that documents this. Got a link? I am seriously interested.
As for why would one choose to be gay? Beats me. Its like asking why someone would want a sex change operation.