There was a book on that a little while ago by Shelly Kagan (decent excerpt at [1]). I think the evolutionary perspective is clearly "correct," but it doesn't quite answer the big questions for me. It establishes that "death is bad" is an axiom of our ethical system (and not a theorem of it,) but it has nothing to say when we ask whether we should attempt to adjust our morality.

1: http://chronicle.com/article/Is-Death-Bad-for-You-/131818/