Jean Gayon

In Darwinism's Struggle for Survival Jean Gayon offers a philosophical interpretation of the history of theoretical Darwinism. He begins by examining the different forms taken by the hypothesis of natural selection in the nineteenth century and the major difficulties which it encountered, particularly with regard to its compatibility with the theory of heredity. He then shows how these difficulties were overcome during the seventy years which followed the publication of Darwin's Origin of Species, and he concludes by analysing the major features of the genetic theory of natural selection, as it developed from 1920 to 1960. This rich and wide-ranging study will appeal to philosophers and historians of science and to evolutionary biologists.

Chance comes into plays at many levels of the explanation of the evolutionary process; but the unity of sense of this category is problematic. The purpose of this talk is to clarify the meaning of chance at various levels in evolutionary theory: mutations, genetic drift, genetic revolutions, ecosystems, macroevolution. Three main concepts of chance are found at these various levels: luck (popular concept), randomness (probabilistic concept), and contingency relative to a given theoretical system (epistemological concept). After identifying which concept(s) of chance fit(s) with these levels, the question is raised whether these concepts can be reduced to a smaller number, and whether chance in evolutionary theory has a subjective or an objective sense