Georges Cuvier

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Georges Cuvier : biography

23 August 1769 – 13 May 1832

Many writers have unjustly accused Cuvier of obstinately maintaining that fossil human beings could never be found. In his Essay on the Theory of the Earth, he did say that "no human bones have yet been found among fossil remains", but he made it clear exactly what he meant: "When I assert that human bones have not been hitherto found among extraneous fossils, I must be understood to speak of fossils, or petrifactions, properly so called". Petrified bones, which have had time to mineralize and turn to stone, are typically far older than ordinary bones. Cuvier’s point was that all human fossils that he knew of were of relatively recent age because they had not been petrified and had been found only in superficial strata.; English translation quoted from But he was not dogmatic in this claim. When new evidence came to light, he included in a later edition an appendix describing a skeleton that he freely admitted was an "instance of a fossil human petrifaction".

The harshness of his criticism and the strength of his reputation continued to discourage naturalists from speculating about the gradual transmutation of species, right up until Charles Darwin published On the Origin of Species more than two decades after Cuvier’s death.

Extinction

At the time Cuvier presented his 1796 paper on living and fossil elephants, it was still widely believed that no species of animal had ever become extinct. Authorities such as Buffon had claimed that fossils found in Europe of animals such as the woolly rhinoceros and mammoth were remains of animals still living in the tropics (i.e. rhinoceros and elephants), which had shifted out of Europe and Asia as the earth became cooler. Cuvier’s early work demonstrated conclusively that this was not the case.

Catastrophism

Cuvier came to believe that most if not all the animal fossils he examined were remains of species that were now extinct. Near the end of his 1796 paper on living and fossil elephants he said:

All of these facts, consistent among themselves, and not opposed by any report, seem to me to prove the existence of a world previous to ours, destroyed by some kind of catastrophe.

This led Cuvier to become an active proponent of the geological school of thought called catastrophism that maintained that many of the geological features of the earth and the history of life could be explained by catastrophic events that had caused the extinction of many species of animals. Over the course of his career Cuvier came to believe that there had not been a single catastrophe but several, resulting in a succession of different faunas. He wrote about these ideas many times, in particular he discussed them in great detail in the preliminary discourse (introduction) to a collection of his papers, Recherches sur les ossements fossiles de quadrupèdes (Researches on quadruped fossil bones), on quadruped fossils published in 1812. The ‘Preliminary Discourse’ became very well known, and unauthorized (and in the case of English not entirely accurate) translations were made into English, German and Italian. In 1826 Cuvier would publish a revised version under the name Discours sur les révolutions de la surface du globe (Discourse on the upheavals of the surface of the globe).Baron Georges Cuvier

After Cuvier’s death the catastrophic school of geological thought lost ground to uniformitarianism, as championed by Charles Lyell and others, which claimed that the geological features of the earth were best explained by currently observable forces, such as erosion and volcanism, acting gradually over an extended period of time. However, the increasing interest in the topic of mass extinction starting in the late 20th century has led to a resurgence of interest among historians of science and other scholars in this aspect of Cuvier’s work.

Stratigraphy

Cuvier collaborated for several years with Alexandre Brongniart, an instructor at the Paris mining school, to produce a monograph on the geology of the region around Paris. They published a preliminary version in 1808 and the final version was published in 1811. In this monograph they identified characteristic fossils of different rock layers that they used to analyze the geological column, the ordered layers of sedimentary rock, of the Paris basin. They concluded that the layers had been laid down over an extended period during which there clearly had been faunal succession and that the area had been submerged under sea water at times and at other times under fresh water. Along with William Smith’s work during the same period on a geological map of England, which also used characteristic fossils and the principle of faunal succession to correlate layers of sedimentary rock, the monograph helped establish the scientific discipline of stratigraphy. It was a major development in the history of paleontology and the history of geology.