Evolution is not a worldview. It not at all prescriptive, but merely a simple fact of nature. It doesn't even exclude the potential existence of moralistic God, so I don't see why you should wish it weren't true -- not that our understanding of factual reality should be defined by our preferred moralistic perspective anyway. But with all due respect, if you can't find reason to care for the well-being of others without believing the universe is dominated by an omniscient anthropomorphic immortal, then that's your problem. Why should you care about others? That's hardly something I can answer prescriptively and objectively. But nonetheless, people typically feel some sort of emotional compulsion to act "morally" whether they are religious or not. We are, after all, social creatures with senses of empathy and guilt that function independently of religion, to the extent that some concepts of ethics are apparently culturally universal. Indeed, I think it is safe to say that you too have emotional reasons behind your own sense of morality; you do, after all, seem to imply that it would be a bad thing if there was no deity to arbitrate ethics, even though in a hypothetical world where there is no such deity, ethics would be irrelevant anyway (at least, by your own description.) If there were no God, and someone were somehow able to successfully prove it to you, then would you suddenly cease to value human lives? I highly doubt you would. I certainly value human life, though I am not religious. I care about humanity not because I have logically reasoned that I should, but because I simply can't help but to do so. It is something as intrinsic to my being as my own desire for self preservation, or will to live.
