1. For more characterizations of natural selection, particularly, as labeled by Charles Darwin in the first edition of the Origin, see Havstad (2011, 513).

2. Three most prominent characterizations of mechanisms advocated in the new mechanistic philosophy of science are as follows: (1) “Mechanisms are entities and activities organized such that they are productive of regular changes from start or set-up to finish or termination conditions” (Machamer et al., 2000, 3); (2) “A mechanism for a phenomenon of behavior is: a complex system that produces that behavior by the interaction of a number of parts, where the interactions between parts can be characterized by direct, invariant, change-relating generalizations” (Glennan 2002, S344); and (3) “A mechanism is a structure performing a function in virtue of its component parts, component operations, and their organization. The orchestrated functioning of the mechanism is responsible for one or more phenomena” (Bechtel and Abrahamsen 2005, 423).

3. In this paper, we do not examine those accounts in detail. Rather, we focus on Skipper and Millstein’s (2005) general framing of the whole issue, which is important for our view on natural selection as, at least partially, including specific pathway features.

4. Ross (2023) argues for yet another causal structure, that is, a cascade, which is distinct from causal structures such as mechanisms and pathways. However, in the present paper, we do not address the issue whether the natural selection schema can be characterized as a cascade. In particular, we do so, because of the investigative strategy of mapping out that is prominent in Ross’ (2021) analysis of the pathway concept, which, we believe, can better characterize the natural selection schema, at least in its crucial stages.

5. We examine those features in Sect. 3, where we, to some degree, also tackle question (iii), namely, the question whether, and how, the concepts of mechanism and pathway relate to each other.

6. We borrow this style of comparisons from Illari and Williamson (2010), where they compared a canonical example of a mechanism, i.e., protein synthesis, with natural selection.

7. We return to the individual stages of this schema and corresponding illustration in the next section, particularly, when we examine whether the natural selection schema can be partially characterized as a pathway.

8. We would like to add that Skipper and Millstein (2005), besides these two points, also analyze the differences between Glennan’s (1996; 2002) and MDC’s (2000) accounts of mechanism. We do not address those differences, because that analysis surpasses the scope of the present paper.

9. For instance, Glennan’s (1996) prime example of a mechanism is a toilet, and MDC’s (2000) prime biological examples of mechanisms are protein synthesis and neural depolarization. Accordingly, MDC (2000, 3) claim that: “entities often must be appropriately located, structured, and oriented, and the activities in which they engage must have a temporal order, rate, and duration”.

10. Although they are not clear whether Glennan (2002) tries to capture the stochastic causal relation that they have in mind, Skipper and Millstein (2005) claim that Woodward (2003) does so. They do that, by pointing out that Woodward’s understanding of generalizations governing causal relations is promising in the way in which Skipper and Millstein (2005) perceive natural selection. According to them, the main point lies in an adequate account of probabilistic causal relations.

11. At this point, Matthewson and Calcott (2011, 754) give the following clarification: “To make sense of scientists’ talk of the mechanism of natural selection, we neither need to expand the concept of what a mechanism is, nor do we need to squeeze natural selection into the existing framework. What must be addressed is whether or not natural selection can be represented as though it is a mechanism and whether or not this has some explanatory payoff”.

12. More specifically, we do not consider their characterizations of the pathway concept in more detail because of the following three main reasons: (1) both characterizations do not address the issue of investigative strategy that is prominent in Ross (2021), i.e., the mapping/expanding out strategy of delineating pathway networks, which we apply to Skipper and Millstein’s (2005) natural selection schema; (2) we believe that their characterizations are basically related to question (iii), that is, to the relationship between mechanisms and pathways. On the one hand, Thagard (2003, 237) argues that “biochemical pathways are a kind of mechanism”. On the other, Ioannidis and Psillos (2017, 2) introduce the concept of “methodological mechanism”, namely, “the claim that to be committed to mechanism is to adopt a certain methodological postulate, i.e. to look for causal pathways for the phenomena of interest”. In other words, they (Ioannidis and Psillos 2017, 5) are advocating the “Truly Minimal Mechanism”, that is, the “mechanism = causal pathway” account. While we claim that both characterizations deserve further examination regarding question (iii), in the present paper, we focus instead on questions (i) and (ii). That is, we examine the application of the Strategic Mechanism and Strategic Pathway theses; (3) similarly to Ross (2021), both above characterizations do not address pathways in the settings of evolutionary biology. Nonetheless, Ross’ account tries to apply to a variety of biological disciplines. Thus, we follow that thread within evolutionary biology.

13. This feature is of particular interest for the investigative strategy based on the pathway concept, which we examine more closely in the next section. Ross (2021, 146) argues that “as pathways emphasize causal connection, they are often used to represent a complex web of causal connections in some domain before any explanatory target, effect, or outcome of interest is identified”. In that sense, this feature of the pathway concept is depicting the strategy of building a causal map and so-called “pathway network”, which, we believe, is better suited to characterize stages II, III, and IV of the natural selection schema.

14. Ross (2021) notes that (a) does not capture the real difference between pathways and mechanisms because both causal structures show sequential causal steps.

15. See Brzović et al. (2021) for a more detailed analysis of Ross’ (2021) features in question and, in addition, objections concerned with the differences between mechanisms and pathways.

16. However, we would like to point out that we do not want to address the issue whether there are also three distinctive kinds of pathways, as there are three kinds of new mechanisms (see Levy 2013), since that would require a paper of its own.

17. It is important to note that Ross (2021, 149) argues that biologists use many causal terms to refer to causal structures. Thus, the mechanistic strategy and the pathway strategy are not rivals in the sense that one replaces the other. Rather, each has its own distinctive features and, according to Ross, an account of biological explanation should accommodate them both (see Brzović et al. 2021).

18. One can argue that each stage, that is, stages II, III, and IV, can be characterized through their own Strategic Pathways theses, namely, each stage consists in its own distinct Strategic Pathway thesis. However, we argue that these three stages are characterized through a single Strategic Pathway thesis, since its investigative strategy relates to building a single causal map and a pathway network.

Parts of this paper were presented at the following events: The Fourth International Conference of the German Society for Philosophy of Science (GWP.2022), at Technische Universität Berlin in 2022, and the Sixth European Advanced School in the Philosophy of the Life Sciences (EASPLS 2022), Bordeaux 2022. We thank the audiences at these events for their helpful comments, in particular, Thomas Reydon and Marcel Weber. We also thank Zdenka Brzović and Ema Lalić for their valuable comments. Special thanks to two anonymous reviewers and editors for their exceptionally insightful and precise comments. This paper is an output of the research project “Theoretical Underpinnings of Molecular Biology” (ThUMB), funded by the Croatian Science Foundation, project grant number: HRZZ-IP-2018-01-3378, and doctoral grant number: DOK-2018-09-7078. We would also like to acknowledge the support from the research project “Metaphilosophy”, funded by the Croatian Science Foundation (grant number HRZZ-IP-2022-10-2550), and the University of Rijeka (projects “Classification in Biology and Medicine”, uniri-human-18-265, and “Functions in Biology and Medicine”, uniri-iskusni-human-23-227).

This work was funded by Hrvatska Zaklada za Znanost, Grant no: IP-2018-01-3378, Predrag Šustar, Grant no: DOK-2018-09-7078, Vito Balorda, Grant no: IP-2022-10-2550, Vito Balorda, University of Rijeka, Grant no: uniri-human-18-265, Predrag Šustar, Grant no: uniri-human-23-227, Predrag Šustar.

Authors and Affiliations

1. Department of Philosophy, Faculty of Humanities and Social Sciences, University of Rijeka, Rijeka, Croatia

   Vito Balorda & Predrag Šustar

Corresponding authors

Correspondence to Vito Balorda or Predrag Šustar.

Conflict of interest

No potential conflict of interest.