Jean Lamarck
...observations on evolution, referred to as transformism or transmutation in the early 19th century, preceded his extensive observational work on invertebrates. With his colleagues, French naturalists Georges Cuvier and Geoffroy Saint-Hilaire, Lamarck accepted the view that animals in nature were arranged on one continuous scala naturae (natural scale). According to Lamarck, once nature formed life, the arrangement of all subsequent forms of life was the result of time and environment interacting with the organization of organic beings. From the simplest forms of life, more complex forms emerged naturally. These ideas were initially presented in Lamarck's major theoretical work, Philosophie zoologique (Zoological Philosophy, 1809), and he elaborated on them throughout his career. His final treatment of his hypothesis was included in his multi-volume work on invertebrates. Here, Lamarck explains his marche de la nature (scale of nature) as being controlled by three biological laws: environmental influence on organ development, change in body structure based on use and disuse of parts, and the inheritance of acquired characteristics. However, Lamarck's views were never clearly presented nor coherently argued; as a result, his ideas were not seriously entertained during his lifetime. His theory of evolution suffered at the hands of Cuvier, who championed his own ideas from a more powerful scientific and political position. Lamarck died with little scientific recognition of his work or his ideas. Not until the second half of the 19th century were Lamarck's ideas seriously considered again. Although the name "Lamarck" is now associated with a discredited view of evolution, the French biologist's notion that organisms inherit the traits acquired during their parents' lifetime had common sense on its side. In fact, the "inheritance of acquired characters" continued to have supporters well into the 20th century. Unlike Darwin, Lamarck believed that living things evolved in a continuously upward direction, from dead matter, through simple to more complex forms, toward human "perfection." Species didn't die out in extinctions, Lamarck claimed. Instead, they changed into other species. Since simple organisms exist alongside complex "advanced" animals today, Lamarck thought they must be continually created by spontaneous generation. According to Lamarck, organisms altered their behavior in response to environmental change. Their cha...