Georges-Louis Leclerc, Comte de Buffon (1707-1788) was a French naturalist, famous for his great 36 volume work Histoire Naturelle, Générale et Particulière (1749–1778). Aside from coining the word 'prehensile' and creating lasting phrases such as 'Le style c’est l'homme même' (The style is the man himself), Buffon’s notions that species must have both 'improved' and 'degenerated' after dispersing away from a centre of creation, and that climate change facilitated the dispersal, had an enormous influence on naturalists such as Jean-Baptiste Lamarck and Darwin. At its base level, 'degeneration' was a simple form of evolution.
M. de Buffon, Histoire Naturelle, Générale et Particulière. Vol. I. Paris, 1769. DeB Fb 1769 B
In Histoire Naturelle, Buffon mentioned 'unlimited fecundity' and diminishing food supplies, single species variations in form, an underlying template of design, the need for a greatly lengthened 'world' time-scale, and that some animals on earth had become extinct. Darwin crystallized much of this in his Origin of Species. Indeed, in the 6th edition (cabinet 11), Darwin credited Buffon as the first author in modern times to treat natural selection in a scientific spirit.
____, Histoire Naturelle, Générale et Particulière. Vol. VII. Paris, 1769. DeB Fb 1769 B
A great 'Chain of Being' which linked animal and plant life together was the idea that French naturalist Jean-Baptiste Lamarck (1744-1829) advocated. To Lamarck, the 'Chain' was formed by a process of evolution that occurred and which operated in accordance with natural laws. While Darwin certainly read Lamarck's works, many of his ideas were first introduced to him by Robert Grant, a lecturer at Edinburgh who was an invertebrate zoologist and a convinced evolutionist. Here is Lamarck opposite some beautifully hand-coloured butterflies.
The Naturalist's Library. Entomology. Vol. V. W. H. Lizars: Edinburgh, 1837. DeB Sb 1833 N E5
French naturalist Baron Georges Cuvier (1769-1832) was a catastrophist who believed that a multiple series of creations had taken place successively in distinct geological epochs, and that at the close of each revolution, life was supposed to be created anew. In this process, God was inextricably involved. Cuvier was opposed to any notion of evolution. Significantly, his work with fossil vertebrates helped establish that extinction was a fact, something that Darwin assimilated into his own developing notions on evolutionary thought.
Baron Cuvier, The Animal Kingdom. Vol. III. London: George B. Whittaker, 1827. Special Collections QL 45 C271