What country has done this? (none)
Many European countries.
Anybody who mentions "evolution" and "homoloveuality" in the same post is clearly a few years behind mentally.
Uh, it is either:
1) A hormone disorder.
2) Evolution noticed that said species can produce lodsa babies, so making certain people
not willing to have love with the "normal" opposite love would allow people to still have love if needed, but not make them love it so they wouldn't do it in normal circumstances. This would basically be easier since ripping out the part of the brain that wants love/taking away loveual organs would make that certain animal/human unable to have love. Now evolution does not want that, does it?
3) Decided in the womb due to current offspring's chance to make babies (probably why a large family of boys will most likely have a gay younger brother).
4) People choose to be gay and can easily switch back to great straightness by following Jesus.
5) Mental disorder/illness.