Spates, Matt2012-05-142012-05-142012-04-18https://hdl.handle.net/11299/123414Faculty adviser: Professor Alan LoveModel organisms are central to contemporary biology and the studies of embryogenesis in particular. Biologists utilize only a small number of organisms to experimentally elucidate various properties of ontogeny. These experimental models allow researchers to investigate the phenomena and mechanisms of development in great depth. Critics have questioned whether these models are good representatives of their targets because of the inherent biases involved in selecting these organisms (e.g., rapid development and short generation time). This line of criticism raises two questions: (a) is the criterion of representation for model organisms more complex than earlier discussions have emphasized? (b) is representation the only relevant criteria in deciding if a model organism is a good model? Here we provide an analysis of the criteria involved in choosing model organisms that answers these questions. We show that the criterion of representation is highly structured and a key additional criterion—manipulability— has been largely neglected. In combination, these criteria explain how developmental biologists respond to the criticism about biases in existing models and also accounts for why microbes have not been considered "good" models for ontogeny. This analysis has both scientific and philosophical consequences. Scientifically, it suggests new avenues of research by making criteria of model organism selection explicit. Philosophically, it shows how the practical aspects of experimental biology—exemplified in the criterion of manipulability—must be scrutinized in order to understand scientific reasoning.en-USCollege of Liberal ArtsDepartment of PhilosophyPresentation