Jean-Baptiste de Lamarck (1744 - 1829) was a French naturalist, botanist and zoologist who advanced one of the earliest coherent theories of biological evolution. [1] He held that species gradually transform over time and that traits acquired through use or disuse could be inherited, an idea later known as Lamarckism. [2] Lamarck also pioneered the systematic study of invertebrate animals and helped establish the modern discipline of biology. [1]
Early life and military career
Jean-Baptiste Pierre Antoine de Monet, Chevalier de Lamarck, was born on 1 August 1744 in Bazentin, in the Picardy region of northern France. [1] The youngest of many children in a family of modest nobility, he first pursued a military career, serving in the French army during and after the Seven Years' War. [3] After an injury ended his service, he turned to the study of medicine and natural history in Paris. [1]
Botanical work
Lamarck established his early reputation as a botanist. His Flore française (1778) provided a practical guide to the plants of France and introduced a dichotomous key for identifying species, which brought him recognition and election to the Académie des sciences. [2] Through the patronage of the naturalist Buffon he secured a post associated with the royal botanical garden in Paris. [1]
Invertebrate zoology and biology
When the garden was reorganised as the Muséum national d'Histoire naturelle in 1793, Lamarck was appointed professor of the natural history of insects and worms. [1] He devoted the rest of his career to these animals, coining the term invertebrate and dividing them into a series of distinct groups. His multi-volume Histoire naturelle des animaux sans vertèbres became a foundational work in the field, and he was among the first to use the word biology for the general science of living things. [3]
Theory of evolution
In Philosophie zoologique (1809) Lamarck set out a full theory of the transformation of species over time, rejecting the idea that living forms are fixed. [2] He proposed that organisms adapt to their environment through the use and disuse of organs, and that such acquired changes are passed to their descendants. [2] Although the mechanism he described was later rejected, his insistence that life evolves anticipated central themes of nineteenth-century biology. [3]
Later life and legacy
Lamarck spent his final years in poverty and, having lost his sight, dictated his last works to his daughters before dying in Paris on 18 December 1829. [1] His evolutionary ideas were overshadowed by the work of Charles Darwin, and "Lamarckism" became a byword for a discredited theory of inheritance. [3] Nonetheless he is remembered as a founder of invertebrate zoology and as an early advocate of the idea that species change through time. [2]
