In 1809 -- the year of Charles Darwin's birth -- Jean-Baptiste Lamarck published Philosophie zoologique, the first comprehensive and systematic theory of biological evolution. The Lamarckian approach emphasizes the generation of developmental variations; Darwinism stresses selection. Lamarck's ideas were eventually eclipsed by Darwinian concepts, especially after the emergence of the Modern Synthesis in the twentieth century. The different approaches -- which can be seen as complementary rather than mutually exclusive -- have important implications for the kinds of questions...