Lamarckian theory of use and disuse
A technical term in evolutionary biology referring to Lamarck's idea that organs or traits strengthen with use and weaken or disappear with disuse, and that these acquired characteristics can be inherited. Rare in everyday language; used mainly in academic or historical contexts.
See also: ラマルク説
The theory of use and disuse was proposed by Lamarck to explain why the giraffe's neck became long.