evolution

Slow process of change from one form or level to a better or higher one, or that brings into being a superior or new order. Evolution does not occur in a straight, steady progression but is marked by false starts and dead ends, random leaps in different directions, and long periods of no fruitful activity. And, contrary to the popular belief, constant adaptation (see natural selection) is not the main feature of evolution. By far the most dominant evolutionary phenomenon is the preservation of whatever is working well. The fundamental natural principle as borne out by fossil (paleontological) research is: "If it works, don't mess with it."