The complete theory of Darwin was published in 1859, with the heading the origin of the species by means of the natural election. This book, that was more known only as the origin of the species, and of which if it said that ' ' it caused a commotion in mundo' ' , it was depleted in the first day of its publication and had been made six successive editions. Georges Louis Leclerc Buffon or conde of Buffon (1707-1788), French naturalist, author of one of first treated the global ones on history to not-based biology and geology in the Bible. Its main workmanship was natural History, work in 36 volumes published between 1749 and 1789. In it if it offers the first naturalistic version of the history of the Land, in which it appeals exclusively the empirical causes to explain the natural phenomena.
Georges Cuvier (1769-1832), French comparative anatomist, specialized in the reconstruction of fsseis and superior education. It defended the immutability of the species, affirming that the efficient drawing of each animal is the test of that this cannot be varied since its creation. Its great workmanship, the Animal Kingdom (1817), was considered basic in natural history of Great-Britain and France, until the publication, in 1859, of the Origin of the Species, Charles Darwin. Robert Malthus (1766-1834), economist and British demographer, its main contribution was the theory on the growth of the population. According to Malthus, when a superior increase of products to the one of the population happens, the growth tax is stimulated; when the population increases in relation to the food production, the growth is paralizado due to hunger, to the illnesses and the wars. The works of Malthus had stimulated the first systematic demographic studies. Its main workmanship is Essay on Population (Assay on the population).