Dispositions in Evolutionary Biology: A Metaphysically Realist Account
I argue for a dispositionalist account of causation at the foundation of evolutionary theory. By analyzing causation within evolutionary theory this way, we’re able to see that the so-called “Propensity Interpretation” of biological fitness is explanatorily indispensable. That is to say, evolutionary trends should be explained in terms of the capacities of organisms and how these capacities, via causal interaction, give rise to higher level (e.g. population-based) explanatory strategies. I cover several types of evolutionary phenomena to advance this claim, including: density dependent selection, allele replacement (i.e. “population genetics”), evolvability (both from population perspectives and developmental perspectives), and instances of selection due to competition (interspecific and intraspecific). I further argue, against rival views in the metaphysics of science (such as “Ontic Structural Realism”) that our explanatory practices in evolutionary theorizing demand that we maintain a realist interpretation of dispositions and their conceptual attachments to material objects of scientific inquiry.