Evolution is About Populations, But Its Causes are About Individuals

  • Pierrick BourratEmail author
Original Article


There is a tension between, on the one hand, the view that natural selection refers to individual-level causes, and on the other hand, the view that it refers to a population-level cause. In this article, I make the case for the individual-level cause view. I respond to recent claims made by McLoone that the individual-level cause view is inconsistent. I show that if one were to follow his arguments, any causal claim in any context would have to be regarded as vindicating a form of population-level cause view. I show why this is implausible and how a consistent individual-level cause position can be held within the interventionist account of causation. Finally, I argue that there is one sense in which natural selection might be said to refer to population-level causes of evolutionary change. The upshot is that, as noted by others, natural selection can be regarded as referring to a population-level cause in the context of frequency-dependent selection and other situations of fitness-altering interactions between the individuals of a population. But whether this statement is true will depend on the empirical case investigated, not some a priori conceptual distinction. Thus, even though situations of frequency dependence might be ubiquitous, it is orthogonal to the conceptual question of whether frequency-independent natural selection—McLoone’s target—refers to individual- or population-level causes.


Causation Drift Individual-level causes Modularity Natural selection Population-level causes 



I am thankful to Mathieu Charbonneau, Paul Griffiths, Jun Otsuka, Peter Takacs, and two anonymous reviewers for comments on previous versions of the manuscript. I also thank the members of the Theory and Method in Biosciences group at the University of Sydney and in particular Stefan Gawronski who proofread the final manuscript. This research was supported by a Macquarie University Research Fellowship and a Large Grant from the John Templeton Foundation (Grant ID 60811).


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Copyright information

© Konrad Lorenz Institute for Evolution and Cognition Research 2019

Authors and Affiliations

  1. 1.Department of PhilosophyMacquarie UniversityNorth RydeAustralia
  2. 2.Department of Philosophy & Charles Perkins CentreUniversity of SydneySydneyAustralia

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