Neo-Lamarckism

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The theory, based on Lamarckism, that response to environmental influence can be inherited and transmitted through the action of natural selection.

Century Dictionary and Cyclopedia

1. n. A modification of the opinions of the French naturalist, the Chevalier de Lamarck (1744–1829), on the origin of Species. Lamarck, who was one of the earliest advocates of the mutability of species, regarded the structural changes that are produced in animals by their activities under the stimulus of new habits and new needs and new desires, and those that are produced in plants by the direct modifying influence of external conditions, as the means of transformation and adaptation. The word neoLamarckism was introduced into biological literature by A. S. Packard, an American entomologist and biologist (1839–1905), who held that species cannot arise through the survival of the fittest in the struggle for existence without the aid of the modifying influence of external conditions. Packard attributed the blindness of cave-animals to the inheritance of the effects of disuse; and as it is clear that use and disuse and the external conditions of life cannot give rise to new species unless their effects are inherited, the defense of the belief in the inheritance of ‘acquired characters’ occupies so prominent a place in the literature of neo-Lamarckism that this belief is commonly regarded as the meaning of the term, although one who admits that ‘acquired characters’ may be inherited without admitting that this inheritance is a means for modifying species is not a neo-Lamarckian.

GNU Webster's 1913

1. n. (Biol.) Lamarckism as revived, modified, and expounded by recent biologists, esp. as maintaining that the offspring inherits characters acquired by the parent from change of environment, use or disuse of parts, etc.; -- opposed of Neo-Darwinism (which see, above).

WordNet 3.0

1. n. a modern Lamarckian theory emphasizing the importance of environmental factors in genetic changes and retaining the notion of the inheritance of acquired characters