Your point seems to be that morality can exist independently of human society, and that is nonsense. Evolution may or may not have something to do with morality but to imbue morality with an objective reality that transcends its human context is absurd.
That’s not my point.
Morality is wholly unique to Humans.
You assume Evolution.
I don’t.
That would be an opinion, but that is what it means for something to be ‘objective’.
To go in to depth, morality ‘applies’ to agents, but only certain types of agents. Without human beings OR other suitable agents, it has nothing to apply itself to.
For instance, if the universe did not exist, gravity would not exist. But even so, we would still say the laws of gravity are objectively true, even if there is nothing that they would apply to. By the same token, I think it is fair to say that moral laws would still be objectively true, even if there was nothing they applied to.
Furthermore, I’m not sure that’s his point. Objective vs. Subjective morality is less about morality’s objective truth in the absence of appropriate agents, but more about its truth across appropriate agents through time and space.
Not to break Godwin’s Law, but the best and most striking example is this.
If Hitler had won WWII and exterminated or brainwashed everyone on the planet into believing that the Holocaust was a just and righteous act, would the act then be just and righteous?
If morality is objective, the answer is no. Regardless of opinion, morality is binding. Saying the Holocaust was righteous is as incorrect as saying 1 + 1 = 967.
If morality is subjective, the answer is yes, but only so far as morality becomes pretty much a pointless exercise applying human feelings and emotions to scenarios in the guise of something greater.
This is the philosophical morality debate. Personally, objective morality to me seems far more plausible and likely than its negation, and I take this to be a properly basic belief.