Theories of evolution of jean-baptiste de lamarck biography
In optics, his discovery of the composition of white light integrated the phenomena Lamarck made his most important contributions to science as a botanical and zoological systematist, as a founder of invertebrate paleontology , and as an evolutionary theorist. Evolutionary history of life Index of evolutionary biology articles Introduction Outline of evolution Timeline of evolution.
This was something no one else had said. For example, he said the necks of giraffes had gotten longer as they were used to stretch ever higher for leaves. For example, he said blind cave fish had become blind because their ancestors had not used their eyes. In those days, many people, even scientists, thought acquired traits could be inherited indeed, that very school of thought, despite its long being out of intellectual fashion, is again garnering adherents today.
But many other scientists opposed the idea, most prominently Cuvier. They ridiculed the idea with farcical scenarios such as cowboys fathering bowlegged babies or weight lifters producing muscle-bound children.
However, many naturalists freely embraced the idea, including Darwin himself. For example, in the Originpp.
But Lamarck did not consider the inheritance of acquired traits crucial to his theory. The essential idea was an ongoing transformation of forms tending toward ever higher levels of complexity under the influence of natural laws. He originated the idea of arranging organisms into genealogical trees of descent.
Lamarck was the youngest of 11 children in a family of the lesser nobility. His family intended him for the priesthood, but, after the death of his father and the expulsion of the Jesuits from France, Lamarck embarked on a military career in As a soldier garrisoned in the south of France, he became interested in collecting plants.
An injury forced him to resign inbut his fascination for botany endured, and it was as a botanist that he first built his scientific reputation. The objectives of biological classification to achieve this end.
This provided Lamarck with his first official connection, albeit an unsalaried one, with the Jardin du Roi. In the theory of evolution of jean-baptiste de lamarck biography, all 12 of the scientists who had been officers of the previous establishment were named as professors and coadministrators of the new institution; however, only two professorships of botany were created.
Lamarck then set out to classify this large and poorly analyzed expanse of the animal kingdom.
By Lamarck had also introduced the term biology. In the s he began promoting the broad theories of physicschemistryand meteorology that he had been nurturing for almost two decades. In his physico-chemical writings, he advanced an old-fashioned, four-element theory that was self-consciously at odds with the revolutionary advances of the emerging pneumatic chemistry of Antoine-Laurent Lavoisier.
In Lamarck first set forth the revolutionary notion of species mutability during a lecture to students in his invertebrate zoology class at the National Museum of Natural History.
By the general outlines of his broad theory of organic transformation had taken shape.
Life became successively diversified, he claimed, as the result of two very different sorts of causes. He explained this in his Philosophie zoologique: With this theory, Lamarck offered much more than an account of how species change.Jean Baptiste Lamarck
Lamarck was the first to claim that humans had evolved from a lower species. In fact, his hypothesis stated that all living things built up from the most simple all the way up to humans. He believed that new species spontaneously generated and body parts or organs that were not used would just shrivel up and go away.
Jean-Baptiste Lamarck (1744-1829)
His contemporary, Georges Cuvierquickly denounced this idea and worked hard to promote his own, nearly opposite, ideas. Jean-Baptiste Lamarck was one of the first scientists to publish the idea that adaptation occurred in species to help them better survive in the environment.
He went on to assert that these physical changes were then passed down to the next generation. While this is now known to be incorrect, Charles Darwin used these ideas when forming his theory of Natural Selection. Lamarck referred to a tendency for organisms to become more complex, moving "up" a ladder of progress. Lamarck believed in the ongoing spontaneous generation of simple living organisms through action on physical matter by a material life force.
Lamarck ran against the modern chemistry promoted by Lavoisier whose ideas he regarded with disdainpreferring to embrace a more traditional alchemical view of the elements as influenced primarily by earth, air, fire and water. He asserted that, once living organisms form, the movements of fluids in living organisms naturally drove them to evolve toward ever greater levels of complexity: The biography motion of fluids will etch canals between delicate tissues.
Soon their flow will begin to vary, leading to the emergence of distinct organs. The fluids themselves, now more elaborate, will become more complex, engendering a greater variety of secretions and substances composing the organs. He argued that organisms thus moved from simple to complex in a steady, predictable way based on the fundamental physical principles of alchemy. In this view, simple organisms never disappeared because they were constantly being created by spontaneous generation in what has been described as a "steady-state biology".
Lamarck saw spontaneous generation as being ongoing, with the simple organisms thus created being transmuted over time becoming more complex. He is sometimes regarded as believing in a teleological goal-oriented process where organisms became more perfect as they evolved, though as a theory evolution, he emphasized that these forces must originate necessarily from underlying physical principles.
According to the paleontologist Henry Fairfield Osborn"Lamarck denied, absolutely, the existence of any 'perfecting tendency' in nature, and regarded evolution as the final necessary effect of surrounding conditions on life. The second component of Lamarck's theory of evolution was the adaptation of organisms to their environment. This could move organisms upward from the ladder of progress into new and distinct forms with local adaptations. It could also drive organisms into evolutionary blind alleys, where the organism became so finely adapted that no further change could occur.
Lamarck argued that this adaptive force was powered by the interaction of organisms with their environment, by the use and disuse of certain characteristics.Science in Seconds - Lamarckian Evolution
This first law says little except "an exaggerated generalization of the belief that exercise develops an organ". The last clause of this law introduces what is now called soft inheritancethe inheritance of acquired characteristics, or simply "Lamarckism", though it forms only a part of Lamarck's thinking. Many epigenetic changes are heritable to a degree. Thus, while DNA itself is not directly altered by the environment and behavior except through selection, the relationship of the genotype to the phenotype can be altered, even across generations, by experience within the lifetime of an individual.
This has led to calls for biology to reconsider Lamarckian processes in evolution in light of modern advances in molecular biology. In his book Philosophie ZoologiqueLamarck referred to God as the "sublime evolution of nature".
Lamarck's religious views are examined in the book Lamarck, the Founder of Evolution by Alpheus Packard. According to Packard from Lamarck's biographies he may be regarded as a deist. The philosopher of biology Michael Ruse described Lamarck "as believing in God as an unmoved mover, creator of the world and its laws, who refuses to intervene miraculously in his creation. The historian Jacques Roger has written "Lamarck was a materialist to the extent that he did not consider it necessary to have recourse to any theory principle Lamarck is usually remembered for his belief in the inheritance of acquired characteristicsand the use and disuse model by which organisms developed their characteristics.
Lamarck incorporated this belief into his theory of evolution, along with other more common beliefs of the time, such as spontaneous generation.
The inheritance of acquired characteristics also called the theory of adaptation or soft inheritance was rejected by August Weismann in the s [Note 3] when he developed a theory of inheritance in which germ plasm the sex cells, later redefined as DNAremained separate and distinct from the soma the rest of the body ; thus nothing which happens to the soma may be passed on with the germ-plasm.
This model underlies the modern understanding of inheritance. Lamarck constructed one of the first theoretical frameworks of organic evolution. While this theory was generally rejected during his lifetime,  Stephen Jay Gould argues that Lamarck was the "primary evolutionary theorist", in that his ideas, and the way in which he structured his theory, set the tone for much of the subsequent thinking in evolutionary biology, through to the present day. Lamarck was not in a position to give a molecular explanation for his theory. Eva Jablonka and Marion Lamb for example call themselves neolamarckists.
Charles Darwin allowed a role for use and disuse as an evolutionary mechanism subsidiary to natural selection, most often in respect of disuse. For example, the memetic theory of cultural evolution is sometimes described as a form of Lamarckian inheritance of non-genetic traits.
During his lifetime, Lamarck named a large number of species, many of which have become synonyms. The World Register of Marine Species gives no fewer than 1, records. The International Plant Names Index gives 58 records,  including a number of well-known genera such as the mosquito fern Azolla.