Mention the Galápagos Islands to almost anyone, and the first things that spring to mind are iguanas, tortoises, volcanic beaches, and, of course, Charles Darwin. But there are people living there, too -- nearly 20,000 of them. A wild stew of nomads and grifters, dreamers and hermits, wealthy tour operators and desperately poor South American refugees, these inhabitants have brought crime, crowding, poaching, and pollution to the once-idyllic islands....