Darwin is credited with discovering evolution through natural selection, but Alfred Russel Wallace saw the same process at work in nature and elaborated the same theory. Dispelling misperceptions of Wallace as a secondary figure, James Costa reveals the two naturalists as equals in advancing one of the greatest scientific discoveries of all time.

A beautifully illustrated volume follows a lesser-known Victorian naturalist and explorer on his global journeys — and reveals how he developed his own theory of evolution. Everyone knows Charles Darwin, the famous naturalist who proposed a theory of evolution. But not everyone knows the story of Alfred Russel Wallace, Darwin’s friend and rival who simultaneously discovered the process of natural selection. This sumptuously illustrated book tells Wallace’s story, from his humble beginnings to his adventures in the Amazon rain forest and Malay Archipelago, and demonstrates the great contribution he made to one of the most important scientific discoveries of all time.

“The facts of variability, of the struggle for existence, of adaptation to conditions, were notorious enough; but none of us had suspected that the road to the heart of the species problem lay through them, until Darwin and Wallace dispelled the darkness.”T H Huxley (1887)Darwin is one of the most famous scientists in history. But he was not alone. Comparatively forgotten, Wallace independently discovered evolution by natural selection in Southeast Asia. This book is based on the most thorough research ever conducted on Wallace's voyage. Closely connected, but worlds apart, Darwin and Wallace's stories hold many surprises. Did Darwin really keep his theory a secret for twenty years? Did he plagiarise Wallace? Were their theories really the same? How did Wallace hit on the solution, and on which island? This book reveals for the first time the true story of Darwin, Wallace and the discovery that would change our understanding of life on Earth forever.

"Quammen brilliantly and powerfully re-creates the 19th century naturalist's intellectual and spiritual journey."--Los Angeles Times Book Review Twenty-one years passed between Charles Darwin's epiphany that "natural selection" formed the basis of evolution and the scientist's publication of On the Origin of Species. Why did Darwin delay, and what happened during the course of those two decades? The human drama and scientific basis of these years constitute a fascinating, tangled tale that elucidates the character of a cautious naturalist who initiated an intellectual revolution.

Marking the centennial of Alfred Russel Wallace's death, James Costa presents an elegant edition of the "Species Notebook" of 1855-1859, which Wallace kept during his Malay Archipelago expedition. Presented in facsimile with text transcription and annotations, this never-before-published document provides a window into the travels, trials, and genius of the co-discoverer of natural selection. In one section, headed "Note for Organic Law of Change"--a critique of geologist Charles Lyell's anti-evolutionary arguments--Wallace sketches a book he would never write, owing to the unexpected events of 1858. In that year he sent a manuscript announcing his discovery of natural selection to Charles Darwin. Lyell and the botanist Joseph Hooker proposed a joint reading at the Linnean Society of his scientific paper with Darwin's earlier private writings on the subject. Darwin would go on to publish On the Origin of Species in 1859, to much acclaim; pre-empted, Wallace's first book on evolution waited two decades, but by then he had abandoned his original concept. On the Organic Law of Change realizes in spirit Wallace's unfinished project, and asserts his stature as not only a founder of biogeography and the preeminent tropical biologist of his day but as Darwin's equal.