Published online by Cambridge University Press: 01 January 2022
According to a prominent view of evolutionary theory, natural selection and the processes of development compete for explanatory relevance. Natural selection theory explains the evolution of biological form insofar as it is adaptive. Development is relevant to the explanation of form only insofar as it constrains the adaptation-promoting effects of selection. I argue that this view of evolutionary theory is erroneous. I outline an alternative, according to which natural selection explains adaptive evolution by appeal to the statistical structure of populations, and development explains the causes of adaptive evolution at the level of individuals. Only together can a statistical theory of selection and a mechanical theory of development explain why populations of organisms comprise individuals that are adapted to their conditions of existence.
This paper grew up in public. I wish to thank audiences at Stirling, IUCN Dubrovnik, BSPS London, Storrs Connecticut, Wisconsin-Madison, ISHPSSB Quinnipiac, and the London-Pitt Philosophy of Science Workshop, London. I would particularly like to express my gratitude to André Ariew, Jessica Bolker, Jon Hodge, Deborah Kohn, Tim Lewens, Richard Lewontin, Elliott Sober, Kurt Schwenk and two extremely generous referees from this journal for discussion, guidance, and valuable help with the literature.