By one point of view, our ethics evolved - as in, were created by biological evolution. And their form isn't arbitrary, just like evolution isn't - it can take

By one point of view, our ethics evolved - as in, were created by biological evolution. And their form isn't arbitrary, just like evolution isn't - it can take many forms, but what it generates must work in order to survive, and it must work with what it has. In particular, there are only so many ethical systems that can work for a social species like ours. If that is true, then our ethics predate humanity and are not arbitrary, or at least their core isn't. In some sense, then, our ethics are true and universal.