FACTOID # 6: Michigan is ranked 22nd in land area, but since 41.27% of the state is composed of water, it jumps to 11th place in total area.
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
People who viewed "Lamarckian" also viewed:


FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:



(* = Graphable)



Encyclopedia > Lamarckian

Lamarckism is a now discredited theory of biological evolution developed by French biologist Jean-Baptiste Pierre Antoine de Monet, Chevalier de Lamarck in the 19th century. Lamarckism holds that traits acquired (or diminished) during the lifetime of an organism can be passed on to the offspring. Lamarck based his theory on two observations, in his day considered to be generally true:

  1. Use and disuse – Individuals lose characteristics they do not require (or use) and develop characteristics that are useful.
  2. Inheritance of acquired traits – Individuals inherit the traits of their ancestors.

Examples of Lamarckism would include:

  • Giraffes stretching their necks to reach leaves high in trees, strengthen and gradually lengthen their necks. These giraffes have offspring with slightly longer necks.
  • A blacksmith, through his work, strengthens the muscles in his arms. His sons will have similar muscular development when they mature.

With this in mind, Lamarck developed two laws:

  1. In every animal which has not passed the limit of its development, a more frequent and continuous use of any organ gradually strengthens, develops and enlarges that organ, and gives it a power proportional to the length of time it has been so used; while the permanent disuse of any organ imperceptibly weakens and deteriorates it, and progressively diminishes its functional capacity, until it finally disappears.
  2. All the acquisitions or losses wrought by nature on individuals, through the influence of the environment in which their race has long been placed, and hence through the influence of the predominant use or permanent disuse of any organ; all these are preserved by reproduction to the new individuals which arise, provided that the acquired modifications are common to both sexes, or at least to the individuals which produce the young.

In essence, a change in the environment brings about change in "needs" (besoins), resulting in change in behavior, bringing change in organ usage and development, bringing change in form over time—and thus the gradual transmutation of the species. While such a theory might explain the observed diversity of species and the first law is generally true, the main argument against Lamarckism is that experiments simply do not support the second law—purely "acquired traits" are not inherited. The mechanisms of inheritance were not elucidated until later in the 19th Century, after Lamarck's death.

Jean Molino (2000) has proposed that Lamarckian evolution may be accurately applied to cultural evolution.

See also


  • Molino, Jean (2000). "Toward an Evolutionary Theory of Music and Language", The Origins of Music, Brown, Merker, and Wallin, eds. ISBN 0262232065.

  Results from FactBites:
Human evolution theory founded on female sexual selection and neoteny: the origins of left handedness, Lamarckian ... (836 words)
Human evolution theory founded on female sexual selection and neoteny: the origins of left handedness, Lamarckian theory and the origins of autism.
The work that this web site represents is a step back to Darwin’s original thesis (the one he died with), that all three processes are integral to an understanding of evolution.
Sexual selection, Lamarckian selection (or the adopting of acquired characteristics), and additional selective processes outlined in this work, were created by the branching evolution of the selective processes themselves.
Jean-Baptiste Lamarck - Wikipedia, the free encyclopedia (791 words)
Nowadays, the idea of passing on to offspring characteristics that were acquired during an organism's lifetime is called Lamarckian.
The memetic theory of cultural evolution could be considered a form of Lamarckian inheritance of non-genetic traits.
The pejorative use of terms like Lamarckian stems from the confusion of students on the mechanisms of evolution.
  More results at FactBites »



Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m