Lamarckism(redirected from Lamarckianism)
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Related to Lamarckianism: catastrophism
A theory of biological evolution holding that the changes occurring in an organism through use and disuse of its body parts in response to environmental change are inherited by its offspring.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
LamarckismThe discredited doctrine that species can change into new species as a result of characteristics acquired as a result of striving to overcome environmental disadvantages. It was claimed that such acquired characteristics became hereditary. (Jean Baptiste Pierre Antoine de Monet, Chevalier de Lamarck, 1744–1829, French naturalist).
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
Lamarckismthe theory of inheritance of ACQUIRED CHARACTERS, which suggests that the structures developed during the lifetime of an organism, through use, are passed on as inherited characters to the next generation. Evolutionary change might thus be achieved through the transmission of these acquired characters. This theory, proposed by Jean Baptiste de LAMARCK, is now generally discounted in favour of DARWINISM, where favoured characters of use to a particular organism are maintained by selection, whereas unfavourable characters are selected against. Thus, Lamarck might have claimed that blacksmith's sons were brawny because of their father's profession, whereas Darwin would say that the reason the father was a blacksmith was because he was brawny and brawny men tend to have brawny offspring. LYSENKO attempted unsuccessfully to apply Lamarckian theory to the development of crop plants in the USSR in the 1930s.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005