Georges Cuvier

Georges Cuvier (Georges Léopold Chrétien Frédéric Dagobert Cuvier, August 23, 1769 - May 13, 1832) founded vertebrate paleontology as a scientific discipline, the comparative method of organismal biology, and functional anatomy, the essence of which is that the knowledge of structure acquires meaning only when the purpose is known. He established the extinction of past lifeforms as an accepted scientific fact.

Cuvier was born on August 23, 1769, at Montbéliard, a French-speaking community ruled by the Duke of Württemberg. From 1784 to 1788, Cuvier studied at the Carolinian Academy in Stuttgart. He then was appointed as a tutor to a noble family in Normandy; this kept him away from the worst violence of the French Revolution, and gave him the opportunity to develop his reputation as a naturalist. In 1795, Geoffroy Saint-Hilaire invited him to Paris, where he was appointed an assistant (a supplecant ) to Mertrud, the Professor of Animal Anatomy at the Musée National d'Histoire Naturelle. . There, Cuvier was to spend all of his professional life. In 1800 he succeeded Daubenton as the Professor of Natural History at the College de France, and in 1802, on Merrud’s death, Cuvier was appointed to succeed him, redefining the Chair as Professor of Comparative Anatomy.

After Napoleon seized power in 1799, Cuvier was appointed to several government positions, including Inspector-General of public education. Cuvier was a state councillor under three Kings of France; when he died, of cholera, in 1832, he had served three different forms of government: revolutionary, Napoleonic, and monarchy. He died of natural causes, a Baron and a Peer of France.

Cuvier's Comparative Anatomy

Cuvier’s most famous work is the ‘’Règne animal distribué d'après son organisation’’ (1817; translated into English as ‘’The Animal Kingdom’’). Cuvier understood organisms as integrated wholes, in which each part's form and function were integrated into the whole body.

". .. the component parts of each must be so arranged as to render possible the whole living being, not only with regard to itself, but to its surrounding relations, and the analysis of these conditions frequently leads to general laws, as demonstrable as those which are derived from calculation or experiment."

A probably apocryphal story tells how one of his students dressed up in a devil's costume woke up Cuvier in the middle of the night, chanting "Cuvier, Cuvier, I have come to eat you." Cuvier responded "All creatures with horns and hooves are herbivores. You can't eat me," and went back to sleep.

Cuvier extended the classification scheme of Linnaeus by grouping related classes of animals into phyla. He extended this system to fossils, which he recognized as the organic remains of animals, some of which were extinct, including the ground sloth and pterodactyl. He attempted to classify all animals, living and extinct, into four "branches": Vertebrata, Articulata, Mollusca, and Radiata. For Cuvier, these branches differed fundamentally from each other and could not plausibly be connected by any evolutionary transformation. Cuvier's ideas were in opposition to the theories of many of his contemporaries, including Buffon, Lamarck, and St. Hilaire, who suggested that animal morphology might be changeable. In Cuvier's view, each animal was perfectly adapted to its position in the natural world, and he could find no evidence for a steady increase in complexity or perfection.

Palaeontology

In 1795, when Cuvier arrived in Paris, the Institut de France was founded, and Cuvier was elected a member of its Academy of Sciences. In 1796 he began to lecture at the École Centrale du Pantheon, and in April, at the opening of the National Institute, he read his first palaeontological paper, which was published in 1800 as Mémoires sur les espèces d'éléphants vivants et fossiles. It was the start of his careful, systematic comparison of fossil anatomy with the anatomy of living creatures. “The studies of elephant bones published up until now contain so little detail that even today a scientist cannot say whether they belong to one or another of our living species, and of the enormous quantity of fossil bones about which so many writers have spoken, we have good drawings of only two or three." He went on to publish studies that showed that the African and Indian elephants were distinct species, and that the fossil mammoths of Europe and Siberia were different from either of these.

For long before Cuvier, fossils had been understood to be the remains of once-living organisms, as Leonardo da Vinci and Robert Hooke had stated. da Vinci had found fossil shells in limestones far inland in Italy, some of these he found on mountain tops in such abundance that he concluded that the sea had once covered them. Buffon, had written that "We have monuments taken from the bosom of the Earth, especially from the bottom of coal and slate mines, that demonstrate to us that some of the fish and plants that these materials contain do not belong to species currently existing." But others did not believe that a God, having created all things, would allow them to be casually wiped out. Some interpreted fossils as the remains of living species: fossil mammoths in Italy were interpreted as the remains of elephants brought by Hannibal when he invaded Rome. Others thought that the organisms represented by fossils must survive in unexplored parts of the world; Thomas Jefferson had speculated that mammoths might yet be found living in the American wilderness.

In his second paper in 1796, Cuvier described a large fossil skeleton that had been found in Paraguay, which he named megatherium. He argued that this represented another extinct animal and, by comparing its skull with living species of tree dwelling sloths, he deduced that it was a kind of ground dwelling giant sloth. Cuvier documented the past existence of other large mammals that were like no living species, including the Irish elk, and the American mastodon.

In 1809, at the age of forty, he named a new genus after studying two fossil specimens. He called it Ptero-dactyle ("winged finger"), having concluded that this now extinct creature once had wings and flew. In that same year, Lamarck his ‘’Philosophie zoologique’’, the book which most clearly states Lamarck's theories of evolution. Like Cuvier, Lamarck made major contributions to the classification of organisms, particularly invertebrates; however their different views on evolutionary change brought them into intellectual conflict.

Evolutionary change and catastrophism

Lamarck recognised that a change in the environment causes changes in the needs of organisms living in that environment, which in turn changes their behavior. If this altered behavior leads to greater or lesser use of a given structure; he concluded that this would cause the structure to grow or to shrink. This is Lamarck’s "First Law" ; his "Second Law" stated that these changes were heritable. As a result all organisms change continuously, as they adapt to their environments, driving Lamarckian evolution.

By contrast, Cuvier did not believe in organic evolution; he thought that any non-trivial change in an organism's anatomy would have made it unable to survive. He had studied mummified cats and ibises that Geoffroy had brought back from Napoleon's invasion of Egypt, and had shown that they were not different from their living counterparts. On the contrary, he noted that species in the fossil record remained apparently unchanged morphologically over vast periods of time, until they abruptly disappeared. "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."

Cuvier believed that the Earth was immensely old, and that for most of its history conditions had been much like those of the present. However, periodically, species had been eliminated by natural "catastrophes". Although a lifelong Protestant, Cuvier did not identify these "catastrophes" with Biblical events. However, other geologists, notably Rev. William Buckland in England, suggested that the most recent catastrophe was none other than the Biblical Flood. This hypothesis remained popular until Louis Agassiz, who had studied with Cuvier, deduced that the "flood deposits" had been formed by glaciers.

Cuvier's theory of "catastrophes" was later supplanted by the uniformitarian theories of Charles Lyell and others. However, recently, catastrophes have re-emerged as plausible explanations for some of the mass extinction events that appear in the fossil record, such as the Cretaceous-Tertiary extinction event.

Name remembered

Cuvier is remembered by Cuvier Island, named after him by D'Urville, the French navigator. The island, off New Zealand was known to the Maori as Repanga. The many animals named after him include Cuvier’s Beaked Whale Ziphius cavirostris, first described by Cuvier in 1823, the tiger shark, Galeocerdo cuvier, Cuvier's Gazelle ‘’Gazella cuvieri’’, Cuvier's toucan, Ramphastos cuvieri Cuvier's Bichir, Polypterus senegalus and Anolis cuvieri. Some extinct animals are also named after Cuvier, including the South American giant sloth Catonyx cuvieri.

Bibliography

• Cuvier.[ http://www.victorianweb.org/science/science_texts/cuvier/cuvier_on_lamarck.htm Elegy of Lamarck]. "Thus, while Lavoisier was creating in his laboratory a new chemistry, founded on a beautiful and methodical series of experiments, M. de Lamarck, without attempting experiment, and destitute of the means of doing so, imagined that he had discovered another, which he did not hesitate to set in opposition to the former, although nearly the whole of Europe had received it with the warmest approbation."

• Cuvier, and Pierre A. Latreille. Le Règne Animal Distribué d'après son Organisation, pour Servir de Base à l'Histoire Naturelle des Animaux et d'Introduction à l'Anatomie Comparée. Tome I. L'Introduction, Les Mammifères et Les Oiseaux. Paris, 1817.
• Cuvier.[ http://www.victorianweb.org/science/science_texts/cuvier/cuvier-f.htm Discours sur les révolutions de la surface du globe, et sur les changemens qu'elles ont produits dans le règne animal] 3rd French edn 1825. "Why has not anyone seen that fossils alone gave birth to a theory about the formation of the earth, that without them, no one would have ever dreamed that there were successive epochs in the formation of the globe."
• Cuvier. Discourse on the revolutionary upheavals on the surface of the lobe and on the changes which they have produced in the animal kingdom. 1825. "Someone will say to me, Why would the present races not be modifications of these ancient ones which we find among the fossils, modifications produced by local circumstances and climatic changes, carried to this extreme difference by the long succession of years? This objection must appear especially strong to those who believe in the indefinite possibility of changes in the structure of forms in organic bodies and who think that through habit over centuries all species could change themselves from one species into another or result from a single one of their species. However, we can reply to them following their own logic that if the species have changed by degrees, we ought to have found traces of these gradual modifications, that we ought to have discovered certain intermediate structures between the palaeotherium and today's species and that up to the present time this has not happened at all. Why have the depths of the earth not preserved monuments of such a curious genealogy, unless it is because the earlier species were as unchanging as our own, or at least because the catastrophe which destroyed them did not leave them time to develop their variations?"
• Anon. Review of Essay on the Theory of the Earth The British Review and London Critical Journal, vol. v, 1813.
• Anon. Review of Essay on the Theory of the Earth, Edinburgh Review, January 1814
• Georges Cuvier (1769-1832)