Most species do their own evolving, making it up as they go along, which is the way Nature intended. And this is all very natural and organic and in tune with mysterious cycles of the cosmos, which believes that there's nothing like millions of years of really frustrating trial and error to give a species moral fiber and, in some cases, backbone.
Reaper Man: A Novel of Discworld (ed. Harper Collins, 2009) - ISBN: 9780061807053