In this paper, I argue (contra some recent philosophical work) that an objective distinction between natural selection and drift can be drawn. I draw this distinction by conceiving of drift, in the most fundamental sense, as an individual-level phenomenon. This goes against some other attempts to distinguish selection from drift, which have argued either that drift is a population-level process or that it is a population-level product. Instead of identifying drift with population-level features, the account introduced here can explain these population-level features based on a property that I label driftability. Additionally, this account shows that biology’s “first law”—the Principle of Drift (Brandon, J Phil 102(7):319–335 2006)—is not a foundational law, but is a consequence of driftability.
KeywordsDrift Fitness Selection Evolution Population Individual
This paper was the subject of a symposium at the 2011 meeting of the Pacific Division of the American Philosophical Association. I thank my commentators, Vadim Keyser, Mohan Matthen, and Sarah Roe for their insightful comments. This paper was also presented at the 2011 Workshop on Metaphysics of Microevolutionary Processes at the University of Alabama at Birmingham. I thank the organizer, Marshall Abrams, as well as the other attendees for their input. I also thank Robert Brandon, Yoichi Ishida, Bence Nanay, Charles Pence, and the anonymous reviewers for reading and commenting on earlier versions of this paper.
- Abrams, M. (2007). How do natural selection and random drift interact? In: C. Bicchieri & J. Alexander (Eds.), Proceedings of the 2006 biennial meeting of the Philosophy of Science Association. Part I: Contributed papers. Philosophy of Science, 74(5), 666–679.Google Scholar
- Brandon, R. N. (2006). The principle of drift: Biology’s first law. Journal of Philosophy, 102(7), 319–335.Google Scholar
- Darwin, C. (1859). On the origin of species. London: John Murray.Google Scholar
- Haldane, J. B. S. (1927). A mathematical theory of natural and artificial selection, part v: Selection and mutation. Proceedings of the Cambridge Philosophical Society (pp. 838–844). Oxford: Oxford University Press.Google Scholar
- Haldane, J. B. S. (1954). The measurement of natural selection. Proceedings on IX International Congress Genetics, 1, 480–487.Google Scholar
- Pence, C., Ramsey, G. (forthcoming). A new foundation for the propensity interpretation of fitness. British Journal for the Philosophy of Science.Google Scholar
- Rosenberg, A. (1994). Instrumental biology or the disunity of science. Chicago: University of Chicago Press.Google Scholar
- Sober, E. (1984). The nature of selection. London: MIT Press.Google Scholar
- Sober, E. (2001). The two faces of fitness. In E. Sober (Ed.), Conceptual issues in evolutionary biology (pp. 25–38). London: MIT Press.Google Scholar
- Wagner, G. (2010). The measurement theory of fitness. Evolution, 64(5), 1358–1376.Google Scholar
- Woodward, J. F. (2005). Making things happen: A theory of causal explanation. Oxford: Oxford University Press.Google Scholar