The Gal pagos Islands are a paradise for birders, botanists, geologists, and snorkelers, with many islands still devoid of human habitation. Since they lie more than 600 miles west of South America and were never connected to the mainland, almost all plant and animal life arrived here by chance. As Charles Darwin discovered, the evolution of plants and animals is more visible here than anywhere else on earth. John Kricher, a renowned ecologist and...