When Charles Darwin, then age 22, first saw the HMS Beagle, he thought it looked "more like a wreck than a vessel commissioned to go round the world." But travel around the world it did, taking Darwin to South America, Australia, New Zealand, Tahiti, and of course the Galapagos Islands, in a journey of discovery that lasted almost five years. Now, in Fossils, Finches and Fuegians, Richard Keynes, Darwin's great grandson, offers the first modern full-length...