Change increases entropy. The only variable; how fast the Universe falls towards chaos. Determining this rate is the complexity being carried. Complexity exists only to increase disorder.
Evolution is the refinement of a fitness metric.
It is the process of refining a criteria for the measurement of the capacity of a system to maximize its future potential to hold complexity. This metric becomes ever more sophisticated, and can never be predetermined. Evolution is the computation.
This image is stolen from the net. Last night, while camping at Alder Creek Campground above Truckee California, I was about to get up and walk to the camp bathroom, when I heard a strange sound. Next second, a BIG mountain lion walked so close to my tent that it brushed against the fabric. There was a light across the way so there was a perfect silhouette of the monster moving around my tent towards the absurdly thin mosquito netting at my head. I had about a second to decide whether to let him scare me or scare him first. So I made a rather awkward convulsive motion and grunted. He jumped away from the tent and let out a half truncated growl (still very scary) and ran down toward the stream. My third encounter with these solo travelers… a little too close this time.