Organized by Jean GAYON ( Université Paris 1-Panthéon Sorbonne & Institut d'Histoire et de Philosophie des Sciences et Techniques)

Model organisms play a huge role in contemporary biomedical research. They are a major part of so-called "experimental systems." For some years, they have generated interest among historians of science and, to a lesser degree, philosophers of science (Model Organisms 2003). My talk intends to provide a general appraisal of the philosophical problems related to model organisms and allied notions. I will first provide some information about the origin of the term. As far as I knew there is no reliable work on the subject. The oldest occurrences of the expression that I know can be traced back to the early 1970s. But: (1) the expression almost certainly existed in the 1960s; (2) it has deep and complex relations to other terms that preexisted, such as: "laboratory animals," "experimental animals," "experimental organisms," "animal model" (of a disease), or "living model system"; (3) whether the term "model organism" should be restricted to recent times (and then applied to organisms such as E. coli, C. elegans, A. Thaliana, etc.), or retrospectively applied to organisms that have played a similar role in experimental biology since the 17th century (frog, chicken, sea-urchin, etc.) is an open question, which I examine further in this talk. Then I examine the current connotations of the modern notion of model organism. One is technical: (1) a model organism is a standardized organism, both in terms of its experimental environment and genetic make-up. Another one is epistemic: (2) a model organism is an organism that permits fertile inductions, much beyond that particular organism. This distinction clarifies the question whether the notion applies to periods when there was no genetical standardization. Only (2) applies to older times. Modern "model organisms" ordinarily satisfy criteria (1) and (2). In the third part of the talk, I examine the relationship between the common uses of the notion of "model" in scientific methodology and the notion of "model organism". Model organisms are concrete models (as was, for instance, the camera obscura in optics in the 14th century). But, among concrete models, model organisms have a particular characteristic: they are themselves organisms, so that the knowledge accumulated on them is primarily a knowledge of a particular class of organisms rather than a knowledge of a class of phenomena (Keller 2004). Biological knowledge acquired through model organisms cannot be assessed only in terms of experimental method; it must always be contextualized relative to a historical (or evolutionary) framework (Burian 1993). Biographical note Jean Gayon is Professor at the Université Paris 1-Panthéon Sorbonne and at the Institut d'Histoire et de Philosophie des Sciences et des Techniques (CNRS, ENS). He studied evolutionary genetics at the Université Paris 7 and Biology at the Université Paris 6, and obtained his PhD in philosophy from the Université Paris 1. He has previously been a professor at the universities Paris 7 and Bourgogne. Dr. Gayon's research is mostly concerned with the history of contemporary biology (evolutionary theory, genetics, biometrics), the philosophy of the life sciences, and general philosophy of science. He has also worked on social, political, and ethical aspects of the life and medical sciences, in particular eugenics, human diversity, and biodiversity. He is the author of numerous books and articles (his list of publications is available at http://edph.univ-paris1.fr/gayon.html).