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Donnerstag 6.12.2007
16 Uhr 15 Hörsaal 1 (Zoologie)
Jean GAYON
Université Paris 1-Panthéon Sorbonne & Institut
d'Histoire et de Philosophie des Sciences et Techniques
Model Organisms in Biology and
Medicine: A Philosopher's Viewpoint
Abstract
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. Secondly 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).
Fourth, I deal with two distinct research contexts within which model organisms are currently used, biology and medicine. Although
the knowledge regimes associated to these two fields overlap to a certain extent, I defend that it is useful to contrast two different
purposes that model organisms do serve in practice: "exemplary organisms" and "tool-organisms". In both cases, model organisms
support inductive inferences beyond the class (the species) they belong to. But in the first case, induction leads to broad biological
generalizations, whereas in the second case, induction has a pragmatic motivation (e.g., testing pharmaceutically useful molecules).
This distinction is relative. I show that there exists a continuum between the two notions in biology and biomedicine.
This distinction leads me — fifth point — to nuance the epistemological interpretation of model organisms as a basis for induction.
First, induction may have two forms: either extrapolation to other specified organisms, especially humans in the case of medical
research (induction then takes the form of controlled analogical reasoning), or induction to many other classes of organisms.
Secondly, as shown by Weber (2005), model organisms permit a huge accumulation of knowledge on particular organisms
(Drosophila, E. Coli, etc.), which become an end by itself. This accumulation itself is then used as a tool for direct experimental
research on other organisms.
In conclusion, I express my skepticism vis-à-vis a popular view (especially among historians of science) that sees model organisms
as "artefacts." There are strong epistemic reasons (Weber 2005) and ethical arguments for not sharing this view.
References
Burian RM (1993) How the choice of experimental organism matters: Epistemological reflections on an
aspect of biological practice. Journal of the History of Biology 26: 351-367.
Gayon J (2006) Les organismes modèles en biologie et en médecine. In: Les organismes modèles dans la
recherche médicale (Gachelin G, dir), 9-43. Paris: PUF.
Keller EF (2000) Models of and models for: Theory and practice in contemporary biology. Philosophy of
Science 67.
Model Organisms (2003) The Scientist, Vol. 17, Suppl. 1 (special issue), June 2.
Weber M (2005) Philosophy of Experimental Biology. Cambridge UP.
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.univparis1.fr/gayon.html).
Note that because of a concurrent activity, there will be NO follow-up
discussion with the speaker at the Konrad Lorenz Institute for Evolution and
Cognition Research (KLI) on Friday this time !!!