The properties that distinguish organisms as organisms appear to play no particular role in Modern Synthesis evolutionary biology. Yet, recent work, particularly in evolutionary developmental biology, suggests that they should. I argue that the principal impediment to incorporating organisms into evolutionary biology is methodological rather than empirical. Modern biology’s methodological commitment to mechanism stands in the way. I outline and defend an alternative to mechanism: Explanatory Emergence. According to explanatory emergence, every phenomenon has a complete mechanistic explanation, yet some phenomena also have emergent (teleological) explanations. Mechanistic and emergent explanations of the same phenomena are complete, complementary, and autonomous. The upshot is that in order to have a comprehensive understanding of certain phenomena, we have to explain them twice over: once by appeal to the mechanisms that produce them and once by appeal to the goals they subserve. I call this relation between mechanistic and teleological explanations of the same event ‘miscibility.’ I argue that the miscibility of explanations carves out an autonomous role for organisms in evolutionary explanations.
Denis Walsh is Canada Research Chair in the Philosophy of Biology. He is a member of the Department of Philosophy, Institute for the History and Philosophy of Science and Technology, and the Department of Ecology and Evolutionary Biology at the University of Toronto. He did his PhD in biology at McGill University on the systematics of amphibians and his PhD in Philosophy at Kings College London on modal logic and modal metaphysics. Dr. Walsh is currently a visiting fellow at the KLI.