Lamarckism, also known as Lamarckian inheritance or neo-Lamarckism, is the notion that an organism can pass on to its offspring physical characteristics that the parent organism acquired through use or disuse during its lifetime. It is also called the inheritance of acquired characteristics or more recently soft inheritance. The idea is named after the French zoologist Jean-Baptiste Lamarck (1744–1829), who incorporated the classical era theory of soft inheritance into his theory of evolution as a supplement to his concept of orthogenesis, a drive towards complexity.
Jean-Baptiste Lamarck repeated the ancient folk wisdom of the inheritance of acquired characteristics.
The long neck of the giraffe is often used as an example in popular explanations of Lamarckism. However, this was only a small part of his theory of evolution towards "perfection"; it was a hypothetical illustration; and he used it to discuss his theory of heredity, not evolution.
Edward Drinker Cope
Charles-Édouard Brown-Séquard tried to demonstrate Lamarckism by mutilating guinea pigs.
Jean-Baptiste Pierre Antoine de Monet, chevalier de Lamarck, often known simply as Lamarck, was a French naturalist, biologist, academic, and soldier. He was an early proponent of the idea that biological evolution occurred and proceeded in accordance with natural laws.
Lamarck by Charles Thévenin, c. 1802
Lamarck, late in life
Statue of Lamarck by Léon Fagel in the Jardin des Plantes, Paris
