Interpretation of Probability in Evolutionary Theory

Abstract

The ubiquitous probabilities of evolutionary theory (ET) spark the question: Which inter- pretation of probability is the most appropriate for ET? There is reason to think that, whatever we take probabilities in ET to be, they must be consistent with both determinism and indeterminism. I argue that the probabilities used in ET are objective in a realist sense, if not in an indeterministic sense. Furthermore, there are a number of interpretations of proba- bility that are objective and would be consistent with deterministic evolution and indeter- ministic evolution. However, I suggest that evolutionary probabilities are best understood as propensities of population-level kinds.