OK, I got a problem with this. If man is a part of nature, not the image of a divinity, merely another species in the animal kingdom... what kind of arrogance would imbue him with an inherent morality non-existant in the rest of nature. Nature is amoral. All of God's critters are running around killing each other without compunction.
Yes, human beings are animals, but no, a supernatural being didn't create a thing, because there is no such being. But, let's say there is a God. Why would that "perfect" being create something with innate immorality? If nature is amoral, as you claim, then it must be innate.
Comparing nature and the animal kingdom to human beings, in regards to morality, just doesn't make sense. All animals that are carnivores, kill only for their survival. Even if animals (outside of the apes) were cognizant of morality, nothing would change; there's no checkout aisle at the grocery store specifically for lion's purchasing organically fed free range zebras.
Chimpanzees (our closest relative) are altruistic (a form of morality), they care for each other etc. They act just as moral human beings do.
I would contend that any rational human being would consider it immoral if another human being (totally cognizant) took a crap on the floor and someone's house, but they wouldn't consider it immoral if a baby or a dog did the same thing. Just as it would be immoral for a human if they grabbed food from a table without consent, but it doesn't make it immoral if the dog does the same; simply because they have no sense of morality.
