Definition
"Lamarck" refers primarily to Jean-Baptiste Lamarck, a French naturalist. He is best known for his theory of inheritance of acquired characteristics. This theory proposed that organisms could pass on traits acquired during their lifetime to their offspring. While this theory has been largely discredited by modern genetics, Lamarck made important contributions to the field of biology. He helped lay the groundwork for evolutionary theory. Think of it as an early, though ultimately incorrect, attempt to explain how traits change.