Our morality is based on our instinct, that's why people in a remote location that never even heared of a guy called Jesus are not so different to us.
Lets see:
Animals would fights over territory, territory to an Animal means resources (food/water/other stuff).
Humans fight over territory, territory to a human means resources.
Animals (of the same species) don't usually kill each other, only enemies.
Guess what, so do humans.
Humans live in a group that's has a leader.
What do you know, a lot of animals do exactly that.
You can go on forever finding similarities between humans and animals, you wanna know why, because we're also animals.
Have you ever heared about a species that got extinct because they killed each other for a lack of morality, it's all cowdung, don't get me started.