Lamarck, Jean Baptiste Pierre Antoine de Monet, chevalier de

Lamarck, Jean Baptiste Pierre Antoine de Monet, chevalier de (1744–1829) A French naturalist who, in 1809, advanced the theory that evolutionary change may occur by the inheritance of characteristics acquired during the lifetime of the individual. This theory was also the basis for Lysenko's arguments on the inheritance of acquired plant characteristics. It is interesting to note that the theory of the inheritance of acquired characteristics did not hold a central position in Lamarck's own writings. His cardinal point was that evolution is a directional, creative process in which life climbs a ladder from simple to complex organisms. He believed the inheritance of acquired characteristics provided a mechanism for this evolution. Lamarck explained that this progress of life up the ladder of complexity is complicated by organisms being diverted by the requirements of local environments; thus, cacti have reduced leaves (and giraffes have long necks). Compare DARWIN, CHARLES ROBERT.