Alfred Russel Wallace is best known as the co-originator of the theory of evolution by natural selection, an honor he shares with his contemporary Charles Darwin. Among the ten essays in this volume is his seminal paper on natural selection, "On the Tendency of Varieties to Depart Indefinitely from the Original Type," which was presented with Darwin's "On the Origin of Species" at a meeting of the Linnean Society of London in July 1858. This edition of Wallace's "Contributions to the Theory of Natural Selection" is the first entry in the Foundations of Biological Thought series published by...