I'm not sure, but it seems that the 2nd sentence in the example claim in 'Appeal to Nature' is supposed to be true. "You don't see same-sex animals copulating." If I am not mistaken, homosexual behavior has been documented in many species, from bonobos to mosquitoes. It seems I am correct: https://en.wikipedia.org/wiki/Homosexual_behavior_in_animals
I'm not sure, but it seems that the 2nd sentence in the example claim in 'Appeal to Nature' is supposed to be true. "You don't see same-sex animals copulating." If I am not mistaken, homosexual behavior has been documented in many species, from bonobos to mosquitoes. It seems I am correct: https://en.wikipedia.org/wiki/Homosexual_behavior_in_animals