Jean Baptiste Pierre Antoine de Monet, Chevalier de Lamarck, the French biologist and formulator of the first comprehensive theory of evolution, was born at Bazentin-le-Petit, a village in northeastern France. As a youth he studied briefly for the priesthood, but later withdrew to follow the family tradition of army service. While in Paris recovering from an injury and intermittently studying medicine, he met Jean-Jacques Rousseau, through whom he became interested in botany. This interest led to investigations that culminated in the publication of a large work on the flora of France, which brought Lamarck immediate fame and election to the Academy of Sciences. From 1783 to 1793 he held a small post at the Jardin du Roi, which was reorganized and expanded along lines proposed by Lamarck to include a museum of natural history and twelve professorial chairs. The last of these, for the...