Do you think humankind can ever change? And if so why?

Do you think the human race as a whole can ever evolve past war and violence? Do you believe that in millions of years we will not need police? Are we as a species doomed to kill each other?

Please post your thoughts, comments, and reasoning.
(please explain your reasoning as to why you believe the way you do)

I got this question from my favorite podcast (Radio Lab) and I thought it was to fascinating to be left alone.