Jean Baptiste de Lamarck was a French naturalist with great controversy to his name. Here are some key points on Lamarck's life and studies.

  • Born August 1, 1744, in Bazentin, France.
  • Youngest of eleven children, in a family of military service. His father and many of his brothers were soldiers.
  • Entered the Jesuit seminary at Amiens in 1756.
  • Joined the French Army in 1761, shortly after his father's death.
  • Left the army after an injury to work as a bank clerk and study medicine and botany.
  • Published Flore français (French Flora) in 1778.
  • Appointed assitant botanist at the King's Gardens in Paris, 1782.
  • Professor of invertebrates at the National Musem of Natural History. Coined the word "invertebrates", the study of insects and worms, creating a new field of biology.
  • Published a series of books on zoology and paleontology, until in 1809, Philosophie zoologique was published, stating most of his evolutionary theories.
  • Lamarck is well known for his theory of inheritance of acquired traits. He believed that a change in environment caused changes in the needs of the organisms living in that environment, which in turn caused changes to their behavior, and that these changes were inherited by the offspring.
  • To illustrate these views, he mentioned the giraffe's long neck, and that in stretching for distant leaves their necks grew and were then inherited by the offspring.
  • His views held a mystical assumption, as he thought organisms strived for a "perfection" and became increasingly complex.
  • Charles Darwin openly disagreed with his theory of acquired traits.
  • His scientific theories were ignored or attacked during his lifetime, and he died in poverty and obscurity on December 28, 1829.
  • Buried in a rented grave, after five years his remains were moved. They have not been found today.
French naturalist and evolutionary theorist.
Born: August 1, 1744
Died: December 28, 1829

Lamarck became an expert in Botany after leaving the army due to an injury.
In 1778 he published a book on the plants of France, which got him appointed as an assistant botanist at the Royal Botanical Garden. In 1793 the garden was reorganized as the National Museum of Natural History and Lamarck was made a professor of "the natural history of insects and worms."
This was not something he knew anything about, and these animals were not widely studied at the time, so Lamarck had to learn the material even as he was essentially creating a new field of biology. He made several advances in this field.

Lamarck is better known for his work in evolutionary theory.
He started to publish his theory in 1801. The mechanism of change in his theory was:

  1. A change in environment changes the needs of organisms in the environment, so they alter their behavior to fulfill those needs.
  2. This change in behavior causes the organisms to use certain parts either more or less, which causes the parts in question to either grow or shrink.
  3. These changes are passed to the next generation via heredity.
Lamarck used much of the same evidence in support of his theories as did later theorists such as Darwin. However, they are different from more modern theories in other ways than the mechanism of change. For example, Lamarck believed that species that disappeared evolved into new species rather than becoming extinct. His theories were largely ridiculed in his time. However, they regained attention in the middle of the 19th century and were considered an alternative to the theories of Darwin until the beginning of the 20th century when the laws of Mendel, with which they were incompatible, were rediscovered.
When Lamarck died, he was buried in a rented grave.
"Lamarck was the first man whose conclusions on the subject excited much attention. This justly celebrated naturalist first published his views in 1801. . . he first did the eminent service of arousing attention to the probability of all changes in the organic, as well as in the inorganic world, being the result of law, and not of miraculous interposition."

Charles Darwin, 1861

Source: http://www.ucmp.berkeley.edu/history/lamarck.html

"Do we not therefore perceive that by the action of the laws of organization . . . nature has in favorable times, places, and climates multiplied her first germs of animality, given place to developments of their organizations, . . . and increased and diversified their organs? Then. . . aided by much time and by a slow but constant diversity of circumstances, she has gradually brought about in this respect the state of things which we now observe.
Lamarck - a lecture at The Museum of Natural History, Paris, May 1803

History

Jean-Baptiste Lamarck was born on August 1, 1744 in a village in Northern France. As the youngest of 11 children Lamarck struggled with obscurity and eventually entered Jesuit seminary at age 12 (right after his father’s death). Following a history of family military service, Lamarck entered the French army and was soon promoted to officer for bravery in his first battle. In 1764, peace was declared between Germany and France, so Lamarck took up garrison duty in southern France. During those five years, Lamarck suffered an injury that forced him off duty. After a brief stint as a bank clerk, he took up botany and medicine. Lamarck's book on native French flora, Flore Francaise, won him not only praise, but a job at the royal center for biology (Jardin des Plantes). He was poor, but an intellectual.

Lamarck continued to work at the center as an assistant botanist, but was severely underpaid, as not much credit was given to his profession. At one point Lamarck had to defend the necessity of his job to restructuring bureaucrats. In 1794, the center became the National Museum of Natural History under a structure proposed by Lamarck himself. The museum had twelve sections run by twelve professors, and Lamarck was the professor of “natural history of insects and worms” (despite his lack of knowledge in that field).

Lamarck began to study invertebrates (in fact he came up with the name invertebrates) at a time when the word wasn’t even used, for the organisms weren’t considered worth the time. He dedicated more than a decade to studying the numerous species of invertebrates and wrote series of books. The advancements that Lamarck brought in the field of invertebrates were numerous and progressive; he was the first to distinguish Arachnidia and Annelida from the “Insecta.” Lamarck also separated the tunicates and the barnacles from the “Mollusca.”

Evolution

Lamarck’s Philosophie zoologique defines his theories on evolution for which he is so famous.

In 1801 he wrote:
Time and favorable conditions are the two principal means which nature has employed in giving existence to all her productions. We know that for her time has no limit, and that consequently she always has it at her disposal.
Although the term “Lamarckism” is used as a derogatory term, due to his incorrect views on evolution, his ideas were not completely off base, for even Darwin later used similar thoughts for his theory. Lamarck published his theory of evolution in 1809 (which just happens to be the birth year of Charles Darwin). Lamarck saw that older (ranging to younger) fossils seemed to create several lines of decent into modern species. Lamarck felt that species change to fit their “sentiment interieurs,” or felt needs. This concluded that individuals strive to make themselves perfect, and this is passed onto the next generation. Lamarck’s examples include the biceps of a blacksmith, and the neck of giraffe. The necessary muscles get used, thus bigger. In the case of the giraffe they needed to stretch their necks to get food, so the stretched neck passed onto the next generation. Although we now know the majority of this theory to be untrue Lamarck was on track with his idea that adaptation to the environment plays a role.

Essentially, Lamarck had two rules to his theory:
Rule 1: Use and Disuse (as dictated by environment) causes change in an organism
Rule 2: These changes are heritable(passed on)

Although it is now known that Lamarck’s theory was incorrect, he was in line with Darwin on some aspects. Both determined that evolutionary changes are driven by changes in an organisms environment over time. Lamarck even alluded to the possibility of “natural selection,” but never focused on it. Darwin did concede to Lamarck that in the case of vestigial organs and such, that the law of disuse most likely played a part.

Lamarck contributed greatly to every scientific area he touched upon, especially evolution. His, it seemed, was a struggle with poverty and to add to it, he eventually went blind. In the care of his daughters, he died on December 28, 1829 a poor man (I’m not kidding he was buried in a rented grave, dug up 5 years later and lost!). His theory on evolution was more popular than Darwin's until the beginning of the 20th century, only then did his name become synonymous with mistaken logic.

Although incorrect Lamarck is credited with being a topnotch zoologist and a ground breaker in the field of evolution. According to Darwin:
Lamarck was the first man whose conclusions on the subject excited much attention. This justly celebrated naturalist first published his views in 1801. . . he first did the eminent service of arousing attention to the probability of all changes in the organic, as well as in the inorganic world, being the result of law, and not of miraculous interposition.
    Where Lamarck went wrong:
  • The thought that organisms change due to an effort to “perfect” themselves, not random mutation.
  • The heritability of non-genetic traits.


Works cited:
Various Articles. (Encyclopedia.com)
Jean-Baptiste Lamarck. Encyclopedia Britannica. (eb.com)
Jean-Baptiste Lamarck. {http://www.ucmp.berkeley.edu/history/lamarck.html}

Cletus the Foetus says re: Jean Baptiste de Lamarck: It is perhaps worth noting that, strictly speaking, Lamarckianism and Darwinism are not necessarily mutually exclusive. Also with the rise in technology human evolution could very well take on a Lamarckian character.

Cletus the Foetus also says re Jean Baptiste de Lamarck: It's also probably worth noting that Lamarck was three generations older than Darwin, and laid foundations from which Darwin worked (critically, but that's science for ya)

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