Natural evolution has stopped with the coming of self-awareness. People don't think of themselves as what they really are, a multitude of cells, each alive, each with its own needs, but as a consciousness that is righteously in control of the body it calls its own. It's really ironic that life has accidentally evolved beyond its own control to the point where it can destroy itself. Because, thinking strictly about evolution, a pluricellular organism has appeard due to the association of more unicellular organisms in an attempt to become harder to kill, to more easily sustain themselves and to more easily perpetuate their existence through offspring. And so through more and more associations of this kind, the unicellular organsims that were looking to sustain themselves have come to evolve into a pluricellular organism that can simply choose to let itself be killed, not to sustain itself and not to produce offspring. This says something about greed and egocentrism.
We, humans, are not alive. We are simply an electric current that flows through a bunch of living cells who cannot live without us. We are a plague that nature has set upon life for being greedy.
I wrote a story about this once. Called Total Assault. It was set in the year 2099, the dying year of the 21st century, and mankind had colonized many planets around the Galaxy. But we also began destroying these planets with pollution, factories and such, and this came to the attention of a hostile lifeform known as The Zodiac. It intended to end mankind before it destroyed the universe, and so a war broke out. I know, cliche right?