Jean Baptiste Pierre Antoine de Monet de Lamarck

Born in 1744 in Picardy, France, Lamarck first served in the military before turning to science. He built a strong reputation as a botanist, and his work eventually led to a post at the Muséum national d’Histoire naturelle in Paris, where he focused on invertebrate animals and helped bring order to a vast part of the natural world that had been poorly classified.

He is best remembered for developing one of the earliest full theories of evolution. Lamarck argued that living things change over time in response to their environment and that acquired traits could be passed to offspring. Later science rejected much of that mechanism, but his larger idea—that species are not fixed forever—was an important step in the history of evolutionary thought.

Beyond evolution, Lamarck made lasting contributions to zoology and taxonomy, especially in the study of invertebrates. He spent his later years in difficult circumstances and died in 1829, but his name remains closely tied to the long effort to understand how life changes across generations.