Jean-Baptiste Lamarck

Jean-Baptiste Pierre Antoine de Monet, Chevalier de Lamarck (1744–1829) was a French naturalist who developed one of the first comprehensive theories of biological evolution. Unlike his contemporaries who saw species as fixed, Lamarck proposed that life transforms over time through the interaction of organisms with their environments — a view he articulated most fully in his 1809 treatise Philosophie Zoologique.

Lamarck is best known for the mechanism he proposed: the inheritance of acquired characteristics. He was attempting to explain adaptation without divine design or random variation. The mechanism was wrong in its specifics, but the problem — how organisms become adapted to their environments through their own activity — remains one of the deepest questions in evolutionary biology.

Lamarck's real sin was not scientific error. It was proposing that organisms play an active role in their own evolution — a heresy against the passive-variation doctrine of the Modern Synthesis that epigenetics is only now forcing the field to reconsider.