What's amazing about evolution is how mutation would enable an animal not simply to behave in a new way, but to judge situations in a new way: that is to judge instinctively that something desirable or undesirable is to engaged in a certain way. When I think of how much more difficult it is to imagine the cause of alteration of judgment, I can see why Darwin gave in to the temptation to resort to the Lamarkian notion of use/disuse to explain how human cognition evolves. To treat evolution merely in behavioral terms is them like robots or near zombies rather than as judging and experiencing animals.
Commentary and discussion regarding science, faith and culture by Leo White