Murder

At some point in human history someone got the idea to kill another human. According to the Bible, it came when Cain, out of jealousy, struck down his brother. For most scientists, they will admit they do not know when the first murder happened, but they will state it was probably a battle over land or food that escalated to murder. In most cultures, throughout all times, murder has been made illegal. However, this is a dual sign, showing how wrong we consider it yet how inevitable murder seem to be for humanity. What does that really say about us?