Of the five years he spends circling the world on the H.M.S. Beagle, Darwin spends a mere five weeks in the Galapagos islands and, contrary to conventional belief, his greatest epiphanies do not occur on the famed islands. Instead, they are a cultivation of years exploring the wilds of South America where forests become the cathedral of Darwin's religion. Darwin's senses are overwhelmed by a world teeming with life, but what he finds along the way is perplexing to a 19th century naturalist. He questions why the fossils he discovers look like giant versions of the sloths and armadillos still living nearby; why do the penguins and other birds he sees use their wings as flippers, fins, or sails - but not for flying; how could sea shells be found embedded in rock layers more than 100 miles from the sea? It is not until after he leaves the Galapagos - where mockingbirds, not finches capture his attention - that he is able to fully appreciate everything he has encountered and pull together his masterwork: On The Origin of Species.