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.
Terry PratchettMost horses don't walk backwards voluntarily, because what they can't see doesn't exist.
Terry PratchettSybil's female forebears had valiantly backed up their husbands as distant embassies were besieged, had given birth on a camel or in the shade of a stricken elephant, had handed around the little gold chocolates while trolls were trying to break into the compound, or had merely stayed at home and nursed such bits of husbands and sons as made it back from endless little wars. The result was a species of woman who, when duty called, turned into solid steel.
Terry Pratchett