Jean-Baptiste Lamarck
Jean-Baptiste Pierre Antoine de Monet, Chevalier de Lamarck (August 1, 1744 – December 28, 1829) was a French naturalist and an early proponent of the idea that evolution (descent with modification) occurred and proceeded in accordance with natural laws. Lamarck, however, is remembered today mainly in connection with his now superseded theory of heredity, the "inheritance of acquired traits" (see #Lamarckism).
Larmack was also one of the first to use the term biology in its modern sense.
Biography
Lamarck was born in Bazentin-le-Petit, Picardie into an impoverished family(hence the title of chevalier (knight)).
Lamarck served in the army before becoming interested in natural history and writing a multi-volume flora of France. This caught the attention of Georges-Louis Leclerc, Comte de Buffon who arranged for him to be appointed to the Muséum National d'Histoire Naturelle in Paris,France. After years working on plants, Lamarck was appointed curator of invertebrates — another term he coined. He began a series of public lectures. Before 1800, he was an essentialist who believed species were unchanging; however, after working on the molluscs of the Paris Basin, he grew convinced that transmutation or change in the nature of a species occurred over time. He set out to develop an explanation, which he outlined in his 1809 work, Philosophie Zoologique.
Lamarck developed two laws to explain evolution: the law of use and disuse, and the law of inheritance of acquired characteristics.
- (Use and disuse) 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.
- (Inheritance of acquired characteristics) 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.
Lamarck saw spontaneous generation as being ongoing, with the simple organisms thus created being transmuted over time (by his mechanism) becoming more complex and closer to some notional idea of perfection. He thus believed in a teleological (goal-oriented) process where organisms became more perfect as they evolved. During his lifetime he became controversial; his criticism of the palaeontologist Georges Cuvier’s anti-evolutionary stance won him no friends.
Lamarck married three, possibly four, times. His first marriage was to his mistress from 1777, Marie Delaporte, the mother of his first six children, whom he married on her deathbed in 1792. He remarried in 1795 to Charlotte, but she died in 1797. Lamarck married his third wife, Julie Mallet, in 1798. She died in 1819. Rumours exist of a fourth wife and widow but no documentary evidence exists of her.
Lamarck died penniless in Paris on December 28th, 1829.
Lamarackism
Lamarckism or Lamarckian evolution is a theory put forward by the French biologist Jean-Baptiste Pierre Antoine de Monet, Chevalier de Lamarck, based on heritability of acquired characteristics, the once widely accepted idea that an organism can pass on characteristics that it acquired during its lifetime to its offspring.
| Theories of Evolution |
|
It proposed that individual efforts during the lifetime of the organisms were the main mechanism driving species to adaptation, as they supposedly would acquire adaptative changes and pass them on to offspring. After publication of Charles Darwin's theory of natural selection, the importance of individual efforts in the generation of adaptation was considerably diminished. Later, Mendelian genetics supplanted the notion of inheritance of acquired traits, eventually leading to the development of the modern evolutionary synthesis, and the general abandonment of the Lamarckian theory of evolution in biology. In a wider context, Lamarckism is of use when examining the evolution of cultures and ideas, and is related to the theory of Memetics.
While enormously popular during the early 19th century as an explanation for the complexity observed in living systems, Lamarckism's acceptance within the scientific community dwindled following the dawn of the Darwinian synthesis, currently universally accepted as an explanation for the adaptive complexity of all life forms.
History
Between 1794 and 1796 Erasmus Darwin wrote Zoönomia suggesting "that all warm-blooded animals have arisen from one living filament... with the power of acquiring new parts" in response to stimuli, with each round of "improvements" being inherited by successive generations. Subsequently Jean-Baptiste Lamarck proposed in his Philosophie Zoologique of 1809 the theory that characteristics which were "needed" were acquired (or diminished) during the lifetime of an organism then passed on to the offspring. He saw this resulting in the development of species in a progressive chain of development towards higher forms.
Lamarck founded a school of French Transformationism which included Étienne Geoffroy Saint-Hilaire, and which corresponded with a radical British school of comparative anatomy based at the University of Edinburgh which included the surgeon Robert Knox and the anatomist Robert Edmund Grant. Professor Robert Jameson wrote an anonymous paper in 1826 praising "Mr. Lamarck" for explaining how the higher animals had "evolved" from the "simplest worms" – this was the first use of the word "evolved" in a modern sense. As a young student Charles Darwin was tutored by Grant, and worked with him on marine creatures.
The Vestiges of the Natural History of Creation, authored by Robert Chambers and published anonymously in England in 1844, proposed a theory modelled after Lamarckism, causing political controversy for its radicalism and unorthodoxy, but exciting popular interest and paving the way for Darwin.
Darwin's Origin of Species proposed natural selection as the main mechanism for development of species, but did not rule out a variant of Lamarckism as a supplementary mechanism. With the development of the modern synthesis of the theory of evolution and a lack of evidence for heritable acquired characteristics, Lamarckism fell from favour.
In the 1920s, experiments by Paul Kammerer on amphibians, particularly the midwife toad, appeared to find evidence supporting Lamarckism, but were discredited as having been falsified. In The Case of the Midwife Toad Arthur Koestler surmised that the specimens had been faked by a Nazi sympathiser to discredit Kammerer for his political views.
A form of Lamarckism was revived in the Soviet Union of the 1930s when Trofim Lysenko promoted Lysenkoism which suited the ideological opposition of Joseph Stalin to Genetics. This unscientific agricultural policy was later blamed for crop failures.
Since 1988 certain scientists have produced work proposing that Lamarckism could apply to single celled organisms. The discredited belief that Lamarckism holds for higher order animals is still clung to in certain branches of new-age pseudoscience under the term racial memory.
Neo-Lamarckism is a theory of inheritance based on a modification and extension of Lamarckism, essentially maintaining the principle that genetic changes can be influenced and directed by environmental factors.
Lamarck's theory
Lamarck based his theory on two observations, in his day considered to be generally true:
- Use and disuse – Individuals lose characteristics they do not require (or use) and develop characteristics that are useful.
- 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 (especially Acacias), strengthen and gradually lengthen their necks. These giraffes have offspring with slightly longer necks (also known as "soft inheritance").
- 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:
- 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.
- 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" do not appear in any meaningful sense to be inherited. For example, a human child must learn how to catch a ball even though his or her parents learned the same feat when they were children.
The argument that instinct in animals is evidence for hereditary knowledge is generally regarded within science as false. Such behaviours are more probably passed on through a mechanism called the Baldwin effect. Lamarck’s theories gained initial acceptance because the mechanisms of inheritance were not elucidated until later in the 19th Century, after Lamarck's death.
Several historians have argued that Lamarck's name is linked somewhat unfairly to the theory that has come to bear his name, and that Lamarck deserves credit for being an influential early proponent of the concept of biological evolution, far more than for the mechanism of evolution, in which he simply followed the accepted wisdom of his time. Lamarck died 30 years before the first publication of Charles Darwin's Origin of Species. As science historian Stephen Jay Gould has noted, if Lamarck had been aware of Darwin's proposed mechanism of natural selection, there is no reason to assume he would not have accepted it as a more likely alternative to his "own" mechanism. Note also that Darwin, like Lamarck, lacked a plausible alternative mechanism of inheritance - the particulate nature of inheritance was only to be observed by Gregor Mendel somewhat later, published in 1866. Its importance, although Darwin cited Mendel's paper, was not recognised until the Modern evolutionary synthesis in the early 1900s. An important point in its favour at the time was that Lamarck's theory contained a mechanism describing how variation is maintained, which Darwin’s own theory lacked.
Proponents
In the 1920s, Harvard University researcher William McDougall studied the abilities of rats to correctly solve mazes. He found that children of rats that had learned the maze were able to run it faster. The first rats would get it wrong 165 times before being able to run it perfectly each time, but after a few generations it was down to 20. McDougall attributed this to some sort of Lamarckian evolutionary process.[citation needed]
Ted Steele et al, formerly of the University of Wollongong, produced some indirect evidence for somatic transfer of antibody genes into sex cells via reverse transcription. Homologous DNA sequences from VDJ regions of parent mice were found in germ cells and then their offspring. However, there has been no definitive experiment. [1]
Lamarckism and single-celled organisms
While Lamarckism has been discredited as an evolutionary influence for larger lifeforms, some scientists controversially argue that it can be observed among microorganisms.[2] Whether such mutations are directed or not also remains a point of contention.
note:With respect to higher organisms, there is no evidence that such changes are transmissible genetically—the view associated with Lamarckism—but, among protozoans and bacteria, certain induced changes are heritable
In 1988, John Cairns at the Radcliffe Infirmary in Oxford, England, and a group of other scientists renewed the Lamarckian controversy (which by then had been a dead debate for many years).[3] The group took a mutated strain of E. coli that was unable to consume the sugar lactose and placed it in an environment where lactose was the only food source. They observed over time that mutations occurred within the colony at a rate that suggested the bacteria were overcoming their handicap by altering their own genes. Cairns, among others, dubbed the process adaptive mutagenesis.
If bacteria that had overcome their own inability to consume lactose passed on this "learned" trait to future generations, it could be argued as a form of Lamarckism; though Cairns later chose to distance himself from such a position. [4]. More typically, it might be viewed as a form of ontogenic evolution.
There has been some research into Lamarckism and prions. A group of researchers, for example, discovered that in yeast cells containing a specific prion protein Sup35, the yeast were able to gain new genetic material, some of which gave them new abilities such as resistance to a particular herbicide. When the researchers mated the yeast cells with cells not containing the prion, the trait reappeared in some of the resulting offspring, indicating that some information indeed was passed down, though whether or not the information is genetic is debatable: trace prion amounts in the cells may be passed to their offspring, giving the appearance of a new genetic trait where there is none.[5]
Finally, there is growing evidence that cells can activate low-fidelity DNA polymerases in times of stress to induce mutations. While this does not directly confer advantage to the organism on the organismal level, it makes sense at the gene-evolution level. While the acquisition of new genetic traits is random, and selection remains Darwinian, the active process of identifying the necessity to mutate is considered to be Lamarckian.
Lamarckism and societal change
Jean Molino (2000) has proposed that Lamarckian evolution may be accurately applied to cultural evolution. This was also previously suggested by Peter Medawar (1959) and Conrad Waddington (1961).
Legacy
His defenders believe he is unfairly vilified today. They note that he believed in organic evolution at a time when there was no theoretical framework to explain evolution. He also argued that function precedes form, an issue of some contention among evolutionary theorists at the time. On the other hand, the inheritance of acquired characteristics (also called the theory of adaptation) is now widely rejected. August Weismann claimed to disprove the theory by cutting the tails off mice, demonstrating that the injury was not passed on to the offspring. Jews and other religious groups have been circumcising men for hundreds of generations with no noticeable withering of the foreskin among their descendants. However, Lamarck did not count injury or mutilation as a true acquired characteristic, only those which were initiated by the animal's own needs were deemed to be passed on.
The idea of passing on to offspring characteristics that were acquired during an organism's lifetime is called Lamarckian. This view is inconsistent with modern genetics. Epigenetic inheritance is thought to be Lamarckian, by some, but this is not widely accepted by evolutionary biologists. Epigenetics itself is the study of various gene functions arising from the same gene in different environments. The same gene is passed on to offspring, and the environment determines its expression, so this process still fails to be Lamarckian.
The memetic theory of cultural evolution could be considered a form of Lamarckian inheritance of non-genetic traits. However, this is a point against memetics as a true parallel to genetics, not a point for Lamarckian inheritance.
Charles Darwin not only praised Lamarck in the third edition of The Origin of Species for supporting the concept of evolution and bringing it to the attention of others, but also accepted the idea of use and disuse, and developed his theory of pangenesis partially to explain its apparent occurrence. Darwin and many contemporaries also believed in the inheritance of acquired characteristics, an idea that was much more plausible before the discovery of the cellular mechanisms for genetic transmission.
The pejorative use of the term "Lamarckian" refers specifically to Lamarck's errors regarding the inheritance of acquired characteristics. Many people not properly educated in evolution assume evolution works in a Lamarckian manner, as well as fail to understand that "selection" does not refer to any conscious selecting process by a deity or the individual itself. To understand the way most modern biologists conceive the evolutionary process, it is important that people realize that "trait X was beneficial, so the population got trait X" is shorthand for "trait X was beneficial, individuals without trait X were less likely to propagate, resulting in the population having mostly individuals with trait X."
In botany, his auctorial abbreviation is Lam.
Major Works
Lamarck's writings are available in facsimile form (fr) at www.lamarck.cnrs.fr.
- 1809. Philosophie zoologique, ou Exposition des considérations relatives à l’histoire naturelle des animaux..., Paris.
On invertebrate classification:
- 1801. Système des animaux sans vertèbres, ou tableau général des classes, des ordres et des genres de ces animaux; présentant leurs caractères essentiels et leur distribution, d'après la considération de leurs..., Paris, Detreville, VIII : 1-432.
- 1815-1822. Histoire naturelle des animaux sans vertèbres, présentant les caractères généraux et particuliers de ces animaux..., Tome 1 (1815): 1-462; Tome 2 (1816): 1-568; Tome 3 (1816): 1-586; Tome 4 (1817): 1-603; Tome 5 (1818): 1-612; Tome 6, Pt.1 (1819): 1-343; Tome 6, Pt.2 (1822): 1-252; Tome 7 (1822): 1-711.
Notes
- ↑ Lamarck's Signature: How Retrogenes Are Changing Darwin's Natural Selection Paradigm. Edward J. Steele, Robyn A. Lindley, Robert V. Blanden. Perseus Books, 1998
- ↑ Adaptive mutation Genetics, Vol. 148, April 1998
- ↑ http://www.mun.ca/biochem/courses/4103/topics/adaptive_mutation.html Adaptive mutation in bacteria
- ↑ Adaptive mutation in E. coli, Journal of Bacteriology, August 2004, Vol. 186, No. 15
- ↑ Lamarckism and prions, New Scientist, 21 August 2004, Issue #2461
Further references
- Medawar, Peter (1959). "The threat and the glory." BBC Reith Lectures No. 6.
- Molino, Jean (2000). "Toward an Evolutionary Theory of Music and Language." In Brown, Merker & Wallin (Eds.), The Origins of Music, ISBN 0-262-23206-5.
- Waddington, Conrad (1961). The human evolutionary system. In: Michael Banton (Ed.), Darwinism and the Study of Society. London: Tavistock.
- Cairns, J., J. Overbaugh, and S. Miller. 1988. Nature 335: 142-145
- Culotta, Elizabeth; "A Boost for 'Adaptive' Mutation," Science, 265:318, 1994.)
- Vetsigian K, Woese C, Goldenfeld N. 2006. "Collective Evolution and the Genetic Code." PNAS 103: 10696-10701.
- Hall Barry G., Adaptive Evolution That Requires Multiple Spontaneous Mutations. I. Mutations Involving an Insertion Sequence
External links
- [1] Michael T. Ghiselin recounts Lamarck's times and writings.
- Epigenetics: Genome, Meet Your Environment
- Science Revolution Followers of Lamark
- Lamarck, the Founder of Evolution, His Life and Work, available for free via Project Gutenberg
| Basic topics in evolutionary biology | (edit) |
|---|---|
| Processes of evolution: evidence - macroevolution - microevolution - speciation | |
| Mechanisms: natural selection - genetic drift - gene flow - mutation - phenotypic plasticity | |
| Modes: anagenesis - catagenesis - cladogenesis | |
| History: History of evolutionary thought - Charles Darwin - The Origin of Species - modern evolutionary synthesis | |
| Subfields: population genetics - ecological genetics - human evolution - molecular evolution - phylogenetics - systematics |
| Persondata | |
|---|---|
| NAME | Lamarck, Jean-Baptiste |
| ALTERNATIVE NAMES | de Monet, Jean-Baptiste Pierre Antoine, Chevalier de Lamarck |
| SHORT DESCRIPTION | French naturalist |
| DATE OF BIRTH | August 1, 1744 |
| PLACE OF BIRTH | Bazentin-le-Petit, Picardy, France |
| DATE OF DEATH | December 28, 1829 |
| PLACE OF DEATH | Paris, France |
Credits
New World Encyclopedia writers and editors rewrote and completed the Wikipedia article in accordance with New World Encyclopedia standards. This article abides by terms of the Creative Commons CC-by-sa 3.0 License (CC-by-sa), which may be used and disseminated with proper attribution. Credit is due under the terms of this license that can reference both the New World Encyclopedia contributors and the selfless volunteer contributors of the Wikimedia Foundation. To cite this article click here for a list of acceptable citing formats.The history of earlier contributions by wikipedians is accessible to researchers here:
The history of this article since it was imported to New World Encyclopedia:
Note: Some restrictions may apply to use of individual images which are separately licensed.
