Question for Evolutionist about evil?

This is not a debating question but more out of curiousity. I know very little about evolution and whatever we were suppose to evolve from. I wonder where did evil come into play at. Now saying that, animals to my knowledge are not evil, they kill to survive but man can be evil, he has been from the beginning. So how could evil have appeared within mankind, without an originator of it? Hope that made sense.