Difference between revisions of "Jean-Baptiste Lamarck"

Revision as of 04:43, August 29, 2007

Jean Baptiste Lamarck thought that the way an animal behaved during its life could affect the form of its offspring. The best example to illustrate this is in considering how the giraffe came to have a long neck.

Lamarck's theory suggests that giraffes developed a long neck because the animals constantly stretched upwards to reach the highest leaves while it was feeding. As a consequence of this, its young were born with longer necks.

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-'''Jean Baptiste Lamarck''' was one of the first scientists to develop the idea of evolution (though a different version than [[Darwin]]'s).
+'''Jean Baptiste Lamarck''' thought that the way an animal behaved during its life could affect the form of its offspring.
-Jean-Baptiste Pierre Antoine de Monet was born in the village of Bazentin-le-Petit in the north of [[France]], on August 1, 1744. He was the youngest of eleven children in a family with a centuries-old tradition of military service; his father and several of his brothers were soldiers.
-The young Lamarck entered the Jesuit seminary at Amiens around 1756, but not long after his father's death, Lamarck rode off to join the French army campaigning in [[Germany]] in the summer of 1761; in his first battle, he distinguished himself for bravery under fire and was promoted to officer.
-After peace was declared in 1763, Lamarck spent five years on garrison duty in the south of France, until an accidental injury forced him to leave the army. After working as a bank clerk in Paris for a while, Lamarck began to study medicine and botany, at which he rapidly became expert; in 1778 his book on the plants of France, ''Flore Française'', was published to great acclaim, in part thanks to the support of [[Georges-Louis Leclerc|the Comte de Buffon]].
-On the strength of ''Flore Française'', Lamarck was made assistant botanist at the royal botanical garden, the Jardin des Plantes. In 1793, this became the ''Musée National d'Histoire Naturelle'' (National Museum of Natural History). This institution boasted 12 professors in 12 different scientific fields. Lamarck was appointed professor of the natural history of [[insects]] and [[worms]], something he knew nothing about at the time! It was also seen as the lowliest position, since few naturalists of the 18th Century considered [[insects]] and [[worms]] worthy of study.
-Lamarck, however, proved equal to the task and was responsible for coining the term ''[[invertebrate]]''. In effect, he created a whole new field of [[biology]] with his studies. In 1803, after 10 years of study, he lectured his students that:
-:''We perceive that, relative to the animal kingdom, we should chiefly devote our attention to the [[invertebrate animals]], because their enormous multiplicity in nature, the singular diversity of their systems of organization, and of their means of multiplication, … show us, much better than the higher animals, the true course of nature, and the means which she has used and which she still unceasingly employs to give existence to all the living bodies of which we have knowledge.''
-Lamarck published a series of books on [[invertebrate]] [[zoology]] and [[paleontology]]. Of these, ''Philosophie Zoologique'', published in 1809, most clearly states Lamarck's theories of [[evolution]]. The first volume of ''Histoire naturelle des animaux sans vertèbres'' was published in 1815, the second in 1822. Aside from Lamarck's contributions to evolutionary theory, his works on invertebrates represent a great advance over existing classifications; he was the first to separate the [[Crustacea]], [[Arachnida]], and [[Annelida]] from the [[Insecta]]. His classification of the mollusks was far in advance of anything proposed previously; Lamarck broke with tradition in removing the [[tunicates]] and the [[barnacles]] from the [[Mollusca]]. He also anticipated the work of [[Schleiden]] & [[Schwann]] in [[cell theory]] in stating that:
-:''No body can have life if its constituent parts are not cellular tissue or are not formed by cellular tissue.''
-Lamarck even found time to write papers on [[physics]] and [[meteorology]], including some annual compilations of [[weather]] data.
-== How does Lamarck's theory differ from Darwin's?==
-In basic terms, Lamarck thought that the way an animal behaved during its life could affect the form of its offspring. [[Darwin]] meanwhile thought that an individual animal might have a characteristic that gave it an advantage over other individuals of the same [[species]], meaning that it would be more successful in reproduction.
 The best example to illustrate this is in considering how the [[giraffe]] came to have a long neck.
-'''Lamarck's''' theory suggests that giraffes developed a long neck because the animals constantly stretched upwards to reach the highest leaves while it was feeding. As a consequence of this, its young were born with longer necks.
+Lamarck's theory suggests that giraffes developed a long neck because the animals constantly stretched upwards to reach the highest leaves while it was feeding. As a consequence of this, its young were born with longer necks.
-'''Darwin's''' theory suggests that giraffes developed as they did because an animal with a longer than average neck would have an advantage in reaching foliage that its shorter-necked fellows could not. Therefore it would be healthier, more successful in breeding and hence more likely to pass on its long-necked genes.
-While Lamarck's theories were rejected relatively quickly, Darwin's have proved more enduring.
 {{DEFAULTSORT: Lamarck, Jean-Baptiste}}
 [[Category:Biologists]]

Difference between revisions of "Jean-Baptiste Lamarck"

Revision as of 04:43, August 29, 2007

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