French naturalist who classified the invertebrates, which had been only poorly organized by Linnaeus. Lamarck founded modern invertebrate zoology in Historie Naturelle des Animaux sans Vertèbres (Natural History of Invertebrates) in 1815-1822. He also maintained that man belonged to the animal kingdom in the class of mammals.

Lamarck also proposed a theory of evolution in Zoological Philosophy (1809) which maintained that animals acquired useful characteristics during their lifetimes which they then passed on to their offspring. In Zoological Philosophy, Lamarck stated "continued use of any organ leads to its development, strengthens it and even enlarges it, while permanent disuse of any organ is injurious to its development, causes it to deteriorate, and ultimately disappear if the disuse continues for a long period through successive generations." Lamarck maintained, for instance, that the giraffe developed a long neck by stretching to reach tall trees, then passed this characteristic to its young. This theory of inheritance of acquired characteristics was replaced by Charles Darwin's theory of natural selection.

Darwin (Charles)