Evolution works because when the environment changes those members of a species with the genes best suited to the new conditions survive. But often these changes are sudden and extreme. Is it likely that, at every one of the many millions of transitions organisms had to pass through on their passage from prokaryotic cells to human beings, new genes appeared by accident every time in subsections of each population that enabled some of its members to survive? Some kind of inner guidance is a far more rational conclusion. If the choice is between genetic accident and some kind of great constructor beyond the sky, then the only option is genetic accident. But, except in the minds of biblical fundamentalists and atheists, this isn’t the choice.