Imagine a population of moths that vary in their coloration. Some are more easily spotted and eaten by predators. The offspring of the survivors resemble their parents, so the offspring generation is [harder for the predators to see] than the parental generation. If we repeat the process over many generations, the moths will become very hard for the predators to spot.He goes on to answer that question.
Is that all there is? Just about. Learning about natural selection is like having a premature orgasm. You think it will take a long time and lead to a tremendous climax, but then it's over almost as soon as it began!
The main question about natural selection is not "What is it?" but "Why is it such a big deal?"
Suppose you were asked to explain how some object obtained its properties. Before Darwin you would have had only two options. You could say that God designed it according to His intentions. Or you could dismantle it and explain the whole as a product of its parts. The big deal about evolution is that it provides a third way of explaining the properties of an object.In other words dynamic (as distinguished from static) entities, which must extract energy from their environment to persist, must adapt to their environment when the environment changes — or cease to exist. (See sections 4 and 7 of "Putting Complex Systems to Work" for more on my theory of entities.)
Suppose that I place a clay sculpture in your hand and asked you how it obtained it properties. You would spend most of your time talking about the shape imposed by the artist, not the properties of the clay. The clay permits but does not cause the properties of the sculpture. In just the same way, heritable variation turns organisms into a kind of living clay that can be molded by natural selection.