Published online by Cambridge University Press: 01 January 2022
We distinguish dynamical and statistical interpretations of evolutionary theory. We argue that only the statistical interpretation preserves the presumed relation between natural selection and drift. On these grounds we claim that the dynamical conception of evolutionary theory as a theory of forces is mistaken. Selection and drift are not forces. Nor do selection and drift explanations appeal to the (sub-population-level) causes of population level change. Instead they explain by appeal to the statistical structure of populations. We briefly discuss the implications of the statistical interpretation of selection for various debates within the philosophy of biology—the ‘explananda of selection’ debate and the ‘units of selection’ debate.
We wish to thank the following for help and discussion. Alexander Bird, Anjan Chakravartty, Kent Holsinger, Deborah Kohn, Peter Lipton, Joel Pust, Alex Rosenberg, various members of the Philosophy Workshop, HPS, University of Cambridge, attendees at the ISHPSSB conference in Quinnipiac. We would like to acknowledge the invaluable comments offered by Elliott Sober. We would also like to thank the Seven Stars Bakery in Providence, Rhode Island for all the coffee and for not minding all the noise. We reserve especial thanks to R. C. Lewontin, for inspiration, hospitality, and support. Some of the ideas in this paper converge on those expressed in Matthen and Ariew (2002). These were developed largely independently.