Abstract

Model organisms are at the centre of progress in biology but attributing them an excessive representational power and concentrating on a limited group of them, although efficient for research, can have negative consequences, mainly of epistemic nature. Here, I argue that model organisms are exploratory models with a perspectival modelling function, and that a deflated representational power is needed for their proper use. In support of this argument, I will analyse developmental biology as a case study. Firstly, I show that model organisms in developmental biology are not selected because of their representational capabilities, but mainly based on practical criteria. Secondly, I defend that the epistemic organization of developmental biology around questions fosters exploration and perspectival modelling and I propose that developmental biology is a ‘model organism situated knowledge’. Lastly, I use the study of the mechanisms of cell fate acquisition during early embryonic development in _C. elegans_ and mice as a case study to illustrate how a plurality of model organisms allows exploration and perspectival modelling. The use of model organisms for exploration and perspectival modelling, with a limited representational power, should allow more adequate inferences about human embryonic development and encourage the introduction of more model organisms for a comprehensive navigation of the space of possibilities.