Georges Cuvier
Opposition to evolution

Cuvier was critical of theories of evolution, in particular those proposed by his contemporaries Lamarck and Geoffroy Saint-Hilaire, which involved the gradual transmutation of one form into another. He repeatedly emphasized that his extensive experience with fossil material indicated one fossil form does not, as a rule, gradually change into a succeeding, distinct fossil form. A deep-rooted source of his opposition to the gradual transformation of species was his goal of creating an accurate taxonomy based on principles of comparative anatomy. Such a project would become impossible if species were mutable, with no clear boundaries between them. According to the University of California Museum of Paleontology, "Cuvier did not believe in organic evolution, for any change in an organism's anatomy would have rendered it unable to survive. He studied the mummified cats and ibises that Geoffroy had brought back from Napoleon's invasion of Egypt, and showed they were no different from their living counterparts; Cuvier used this to support his claim that life forms did not evolve over time."

He also observed that Napoleon's expedition to Egypt had retrieved animals mummified thousands of years previously that seemed no different from their modern counterparts. "Certainly", Cuvier wrote, "one cannot detect any greater difference between these creatures and those we see, than between the human mummies and the skeletons of present-day men."

Lamarck dismissed this conclusion, arguing that evolution happened much too slowly to be observed over just a few thousand years. Cuvier, however, in turn criticized how Lamarck and other naturalists conveniently introduced hundreds of thousands of years "with a stroke of a pen" to uphold their theory. Instead, he argued that one may judge what a long time would produce only by multiplying what a lesser time produces. Since a lesser time produced no organic changes, neither, he argued, would a much longer time. Moreover, his commitment to the principle of the correlation of parts caused him to doubt that any mechanism could ever gradually modify any part of an animal in isolation from all the other parts (in the way Lamarck proposed), without rendering the animal unable to survive. In his Éloge de M. de Lamarck (Praise for M. de Lamarck), Cuvier wrote that Lamarck's theory of evolution

rested on two arbitrary suppositions; the one, that it is the seminal vapour which organizes the embryo; the other, that efforts and desires may engender organs. A system established on such foundations may amuse the imagination of a poet; a metaphysician may derive from it an entirely new series of systems; but it cannot for a moment bear the examination of anyone who has dissected a hand, a viscus, or even a feather.

Instead, he said, the typical form makes an abrupt appearance in the fossil record, and persists unchanged to the time of its extinction. Cuvier attempted to explain this paleontological phenomenon he envisioned (which would be readdressed more than a century later by " punctuated equilibrium ") and to harmonize it with the Bible. He attributed the different time periods he was aware of as intervals between major catastrophes, the last of which is found in Genesis.

Cuvier's claim that new fossil forms appear abruptly in the geological record and then continue without alteration in overlying strata was used by later critics of evolution to support creationism, to whom the abruptness seemed consistent with special divine creation (although Cuvier's finding that different types made their paleontological debuts in different geological strata clearly did not). The lack of change was consistent with the supposed sacred immutability of "species", but, again, the idea of extinction, of which Cuvier was the great proponent, obviously was not.

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, "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 bones found to that date. Cuvier's point was that all human bones found that he knew of, were of relatively recent age because they had not been petrified and had been found only in superficial strata. He was not dogmatic in this claim, however; 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, however, continued to discourage naturalists from speculating about the gradual transmutation of species, until Charles Darwin published On the Origin of Species more than two decades after Cuvier's death.
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