"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) Charles Darwin remains one of the most famous scientists in history. His life and work have been intensively investigated by historians for decades. In comparison, the other man to conceive of evolution by natural selection is comparatively forgotten - Alfred Russel Wallace. This book is based on the most thorough research programme ever conducted on Wallace. There are many surprises. As he travelled from island to island collecting vast numbers of exotic birds and insects, his ideas about species gradually evolved. This book reveals for the first time how Wallace solved one of the greatest mysteries of life on Earth.