Jean Baptiste Pierre Antoine de Monet de Lamarck

Born in Picardy, France, in 1744, Lamarck began adult life in the army before turning to science. He became known first as a botanist, then as a professor at the Muséum national d'Histoire naturelle in Paris, where he took on the study of animals that lacked backbones and helped organize that field in a new way.

Today he is most famous for proposing one of the earliest broad theories of evolution: the idea that species change over time according to natural laws. His explanation for how that change happened, especially the inheritance of acquired characteristics, was later rejected by modern genetics, but his willingness to argue that life was not fixed marked an important step in the history of biology.

Lamarck also helped popularize the term "biology" and made lasting contributions as a classifier of plants and animals. He died in Paris in 1829, and although many of his specific ideas were overturned, his place in the story of evolutionary thought remains secure.