Now you are back to God - if it's "innate" then its either of divine origion or just subjective desire which can and does differ from person to person. If it's just some form of Darwinian survival mechanism then it holds no authority once it is recognized as such.
Just, appropriately to this thread, playing Devil’s Advocate here with you.
But say it is of evolutionary cause. Innate in the way that other species have common, universal traits such that humans nearly universally recognize the same components of morality. If it leads to a persistent consensus of what is moral behavior, why would that necessarily be lacking in authority?