Jean Gayon

The first objective of the paper is to propose a classification and characterize the major approaches to the modes of cultural evolution: (1) Research programs on the origins of the cultural capacity of the human species. (2) Description and explanation of cultural change with the help of concepts or models inspired by the schemes of population genetics. (3) Research on parallel evolution of genes and culture. (4) Narrow coupling between biological evolution and cultural evolution, or the “gene-culture coevolution paradigm.” These four modes of cultural evolution make sense at a different time-scale (respectively: more than 100 000 years; less than 100 years; greater than 1000 years; less than 1000 years). The second section of the paper provides an evaluation of the various programs, from various points of view: methodological, ethical, and epistemological.

Dans la théorie contemporaine de l’évolution, trois sens classiques de la notion de hasard interviennent : la notion ordinaire de chance, la notion probabiliste de l’aléatoire, et la notion épistémologique de contingence relativement à un système théorique. Ces trois notions suffisent à définir le statut du hasard aux principaux niveaux du processus évolutif où l’on invoque communément des effets fortuits : mutations, dérive génétique, révolutions génétiques, changements écologiques, macroévolution. On se demande enfin si les divers sens du hasard rencontrés dans cette étude peuvent être ramenés à l’unité, et s’ils renvoient à un hasard subjectif ou à un hasard objectif. In the contemporary theory of evolution, three classical meanings of the notion of chance come into play : the ordinary meaning of chance, the probabilistic notion of randomness, and the epistemological notion of contingency with reference to a theoretical system. These three notions are sufficient in order to define the status of chance on the principal levels of the evolutive process where fortuitous effects are commonly invoked : mutations, genetic deviations, genetic revolutions, ecological changes, macroevolution. The question is raised, finally, whether the diverse meanings of chance considered in the present study may be brought to one, and whether they refer to a subjective form of chance or to an objective chance.