Theoretical results

This project has put forth a trait-centered definition of selection, as well as a refinement of the important notions that are intimately related to natural selection. Like other trait-centered definitions of selection, ours sees natural selection as the causal relation between a difference in trait and a difference in reproductive success; however, unlike existing trait-centered definitions, we also showed that a satisfactory definition must specify that this causal relation must be understood as one of contributing causation.

Our research has led to the conclusion that this definition is preferrable to the type of definitions that have dominated the philosophical literature for the past decades, namely fitness-centered definitions. Indeed, the latter is unable to accommodate cases of opposing selection (on correlated traits and on a single trait), cases that are regularly encountered in quantitative genetics and in life-history theory. On the other hand, adopting a trait-centered view built around a relation of contributing causation has no such difficulties.

That being said, a systematic trait-centered account of natural selection must also provide a convincing manner of 1) identifying traits that are selectable and distinguishing them from those that are not; 2) distinguishing selection from random genetic drift; and, finally, 3) spelling out the relationship between selection and environment. With respect to the first of these points, the project has argued that the properties that may legitimately be considered susceptible of undergoing selection – i.e. selectable – are not only intrinsic properties (as has been argued in the literature), but also extrinsic properties that supervene on relations that hold between the intrinsic properties of the individuals of a population. This, we have shown, allows us to not rule out frequency-dependent selection cases.

Secondly, we have shown that once one embraces a trait-centered definition of selection, two notions of drift become – at least theoretically – possible. Whereas philosophers have been arguing about whether selection and drift are distinct processes, we have shown that one type of drift (circumstantial-drift) involves a distinct process from that of natural selection, whereas the other type (probabilistic-drift) does not involve such a distinct process.

Thirdly, we have argued – against a widely accepted thesis in the philosophy of biology – that natural selection (understood in our trait-centered manner) does not require homogeneous selective environments. To put it otherwise, selection – in the sense we defended – may act across heterogeneous environments, though in order to assess its effects we do need to try, to the extent to which it is possible, to compare the performances of types within the homogeneous sub-environments composing the heterogeneous environment in question. Moreover, we have shown that the same conclusion applies to the other important extant views of selection and of the selection-environment relation.

Developing our trait-centered account has also allowed us to intervene in some contemporary philosophical debates surrounding the processual nature of selection or drift, and the level at which selection is acting. 

Publications and conferences

Published articles:

1. Ciprian Jeler: "Environmental homogeneity, selective paths, and the individuation of selection processes." Erkenntnis (IF: 0.9), 2024, doi: 10.1007/s10670-025-00989-7

2. Ciprian Jeler: "Two kinds of drift?" Synthese (IF: 1.3), 204(3):99, 2024, doi: 10.1007/s11229-024-04737-2

3. Ciprian Jeler: "Trait-centered vs. fitness-centered definitions of natural selection." Biology & Philosophy (IF: 1.7), 39(5):27, 2024, doi: 10.1007/s10539-024-09965-x

4. Ciprian Jeler: "How should we distinguish between selectable and circumstantial traits?" History and Philosophy of the Life Sciences (IF: 1.6), 46(1):6, 2024, doi: 10.1007/s40656-023-00604-4 .

5. Ciprian Jeler: "Environments, populations, and natural selection." Prolegomena: Journal of Philosophy, 23(1):19-41, 2024, doi: 10.26362/20240102

6. Mihail-Valentin Cernea: "Causalism versus propensionism in the philosophy of biology. A case of philosophical underdetermination?", Filozofia, 79(10):1083-1096, 2024, doi: 10.31577/filozofia.2024.79.10.2.

Conferences: 

1. Ciprian Jeler: "Distinguishing between selectable and circumstantial traits." EENPS 2022 - The 2022 Conference of the East European Network for Philosophy of Science, University of Tartu, Estonia, August 17-19, 2022 (Online presentation).

2. Ciprian Jeler: "How should we distinguish between selectable and circumstantial traits?." PSA 2022 - The 28th Biennial Meeting of the Philosophy of Science Association, Pittsburgh, USA, November 10-13, 2022.

3. Ciprian Jeler: "Natural selection and environmental homogeneity." ISHPSSB 2023 – The 2023 Meeting of the International Society for the History, Philosophy and Social Studies of Biology, University of Toronto, Canada, July 9-15, 2023.

4. Mihai Cernea: "Pluralism about Causation in Natural Selection." ECAP 11 – The 11th European Congress of Analitic Philosophy, University of Vienna, Austria, August 21-25, 2023.

5. Ciprian Jeler: "On two kinds of genetic drift." EPSA 2023 – The 9th biennial meeting of the European Philosophy of Science Association, Belgrade, Serbia, September 20-23, 2023.

6. Ciprian Jeler: "Another problem with the notion of fitness (and a tentative solution)." Talk given at the CLPS Seminar (Seminar of the Center for Logic and Philosophy of Science), KU Leuven, Belgium, November 17, 2023