QUOTE : Darwin found that if you looked closely enough, nature conveyed a very different message. How could, for instance, the Galápagos Islands serve as home to thirteen separate species of finches, each similar to the other, yet each peculiarly adapted with different-shaped beaks for their particular island habitats? Clearly these finches had migrated over time from the mainland and from one island to another, and then, once separated, had begun to diverge and to become distinct from one another. But how? And why? Why did the giant sloths, whose bones Darwin recovered on his voyage, go extinct, while other creatures thrived in the same environment at the same time? And how was it that some animals seemed poorly designed for their environments, in defiance of Paley’s perfect watchmaker—woodpeckers that lived on treeless terrain, land birds with webbed feet—yet they managed to adapt and survive through makeshift means that no divine designer would ever have intended? Why did pythons have vestigial legs, and why did the bones inside the wings of a bat parallel the bones in the human hand and arm? This was evidence not of a master design, Darwin realized, but of a slow and gradual change in existing forms, spread across the ages, inherited from remote—and shared—ancestors. The evidence he painstakingly assembled on his voyage, then presented, bit by bit, in his classic book, pointed to very slow, very gradual changes in living things over millions of years, to creatures suddenly dying out and disappearing when their forms no longer allowed them to survive in a changing climate or environment, and to new forms of life that emerged and thrived in their place.