Good "ANUS.com" article on natural selection process and morality vs. "meta-good", or reality.
The feel-good, emotionally influenced morality already mentioned will cause someone to wince and shriek in terror at things that are completely natural because they might think of them as "bad." The thought of a pack of wolves feasting on the carcass of a fawn, for instance, is horrifying to many. People don't want to see a helpless, harmless animal like a young deer torn apart by vicious carnivorous dogs, but love it or loathe it, this is Nature's way. Wolves need prey to survive; populations of animals that are preyed upon must also be regulated, or else plant life, and therefore the life of other species, will be put at risk. The way the natural world operates includes meta-good.
Meta-good is, in essence, stability and balance. Without things like death—the ultimate "bad"—living would be worry free, and everyone could go about their days with a smile on their face, knowing that every day would be a fine day and that life was good. Murderers would no longer walk among us, those wolves would no longer eat baby animals, and poor and starving people would live forever. This new death-free world would also disrupt the natural balance that all life depends on, of course. People would soon be piling on top of one another, starving and sick, with nowhere to go and no one to help them get any better. Animals, too, would be running around unrestrained, spreading even more diseases and filth, and competition would be seen in ways never before imagined. All carnivorous beings would cease to exist, leaving only their "vegan" counterparts, who would in turn smother all plant life (growing in what little room there is left), putting the members of its species and others in danger. The earth would be in the most chaotic state imaginable, and this simply would not do. Nature depends upon order.