In 1858, Alfred Russel Wallace, aged thirty-five, weak with malaria, isolated in the Spice Islands, wrote to Charles Darwin: he had, he said excitedly, worked out a theory of natural selection. Darwin was aghast--his work of decades was about to be scooped. Within two weeks, his outline and Wallace's paper were presented jointly in London. A year later, with Wallace still on the opposite side of the globe, Darwin published On the Origin of Species...