SELECTION AND EXPLANATION

Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences, 2010

One approach to assess the explanatory power of natural selection is to ask what type of facts it can explain. The standard list of explananda includes facts like trait frequencies or the survival of particular organisms. Here, I argue that this list is incomplete: natural selection can also explain a specific kind of individual-level fact that involves traits. The ability of selection to explain this sort of fact ('trait facts') vindicates the explanatory commitments of empirical studies on microevolution. Trait facts must be distinguished from a closely related kind of fact, that is, the fact that a particular individual x has one trait rather than another. Whether or not selection can explain the latter type of fact is highly controversial. According to the so-called 'Negative View' it cannot be explained by selection. I defend the Negative View against Nanay's (2005) objection.

Biology and Philosophy, 1991

Recent philosophical discussions have failed to clarify the roles of the concept fitness in evolutionary theory. Neither the propensity interpretation of fitness nor the construal of fimess as a primitive theoretical term succeed in explicating the empirical content and explanatory power of the theory of natural selection. By appealing to the structure of simple mathematical models of natural selection, we separate out different contrasts which have tended to confuse discussions of fitness: the distinction between what fitness is defined as versus what fitness is a function of, the contrast between adaptedness as an overall property of organisms and specific adaptive capacities, the distinction between actual and potential reproductive success, the role of chance versus systematic causal relations, fitness as applied to organisms as opposed to fitness applied to genotype classes, heritable adaptive capacities of genotypes as opposed to relations between genotypes and the environment. We show how failure to distinguish and properly interrelate these different aspects of "fitness" adds confusion to a number of already complex issues concerning evolutionary theory. On the basis of our discussion of these different aspects of"fitness", we propose a terminology which makes the necessary distinctions. A central result of our analysis is that the concept of fitness as the overall adaptedness of organisms does not enter into the causal structure of evolutionary explanation, at least to the extent that this structure is represented in the mathematical models of natural selection.

Biology and Philosophy, 1991

Our approach to explicating the concept of fitness is to examine the parameters and variables that appear in models used in population biology, how they are interpreted, and what general relationships exist among them. When these models are examined, three general kinds of variables or parameters can be distinguished: rates of increase of genotypes, parameters representing the environment and heritable properties of genotypes. Beginning with R.A. Fisher, the concept of fitness refers to a genotype's rate of increase (F-fitness), which is the bottom line in evolution. As mentioned in our paper, there are other fitness concepts, for example, expected reproductive success, that appear in the models. However, since these concepts are intervening functions used in the calculation of F-fitness we do not belabor them. Maynard Smith notes that F-fitness is not the measure of Darwinian fitness w as expected number of progeny per individual. The terminology can be confusing here, but the bottom line fitness of a genotype which determines expected gene frequency change is F-fitness, which includes the rate of increase due to the genetic system. Why is there a need for general explication of the concept "fitness"? One such need arises from the tortuous discussions of the purported tautology problem by critics of Darwinian evolution. Evolutionists have sometimes been goaded into giving responses which deepen rather than alleviate the confusion. Many evolutionists, however, feel that there is nothing wrong with their actual use of the concept "fitness" (Darwinian fitness, selection coefficients) in their models. Why then should they bother with philosophical analyses of the "real meaning" of 'fitness'? Aside from the notorious tautology challenge there are complexities in interpreting fitness, adaptedness and related concepts due both to ambiguities among different uses of the terms and to subtleties concerning evolutionary explanation. We want some understanding of what various models of evolution

CRITICA, 2023

There is a widespread philosophical interpretation of natural selection in evolutionary theory: natural selection, like mutation, migration, and drift are seen as forces that propel the evolution of populations. Natural selection is thus a population level causal process. This account has been challenged by the Statistics, claiming that natural selection is not a population level cause but rather a statistical feature of a population. This paper examines the nature of the aforementioned ontological debate and the nature of statistical explanations given by population genetics. I claim that the Modern Synthesis provides good explanations of the changes in trait structure of populations without appealing to detailed causal information about the individual trajectories of the members of a population.

The debate between the dynamical and the statistical interpretations of natural selection is centred on the question of whether all explanations that employ the concepts of natural selection and drift are reducible to causal explanations. The proponents of the statistical interpretation answer negatively, but insist on the fact that selection/drift arguments are explanatory. However, they remain unclear on where the explanatory power comes from. The proponents of the dynamical interpretation answer positively and try to reduce selection/drift arguments to some of the most prominent accounts of causal explanation. In turn, they face the criticism raised by statisticalists that current accounts of causation have to be violated in some of their core conditions or otherwise used in a very loose manner in order to account for selection/drift explanations. We propose a reconciliation of both interpretations by conveying evolutionary explanations within the unificationist model of scientific explanation. Therefore, we argue that the explanatory power in natural selection arguments is a result of successful unification of individual-and population-level facts. A short case study based on research on sympatric speciation will be presented as an example of how population-and individual-level facts are

Manuscrito

In this essay I will argue that natural selection is more important to functional explanations than it has been normally thought in some of the literature in philosophy of biology. I start by giving a brief overview of the two paradigms cases of functional explanations: etiological functions and causal-role functions. I then consider one particular attempt to conciliate both perspectives given by David Buller (1998). Buller's trial to conciliate both etiological functions and causal-role functions results in what he calls a weak etiological theory. I argue that Buller has not succeeded in his construal of the weak etiological theory: he underestimates the role that selective processes have in functional explanations and so his theory may not be classified as an etiologial theory. As an alternative, I consider the account of etiological functions given by Ruth Millikan (1984) and I argue that Millikan's theory is more comprehensive to assess contentious case in biology like exaptations. Finally, I conclude by analyzing where the adoption of Millikan's theory leave us. I argue, contrary to Millikan and others, that once we assume the importance of natural selection in functional explanations, there is no strong reason to resist a linguistic reform of the word function and hence that the attempts to conciliate both etiological functions and causal-role functions are misplaced.

2009

We have argued elsewhere that natural selection is not a cause of evolution, and that a resolution-of-forces (or vector addition) model does not provide us with a proper understanding of how natural selection combines with other evolutionary influences. These propositions have come in for criticism recently, and here we clarify and defend them. We do so within the broad framework of our own'hierarchical realization model'of how evolutionary influences combine.

Encyclopedia of Systems Biology. Dordrecht: Springer, 2013

Evolutionary theory is the general framework for modern biology, in the sense that all living phenomena have an evolutionary history which somehow accounts for them being the way they are. Ernst Mayr usefully distinguished two sets of inquiries in biology: the "functional biology," looking for "proximate causes" of a trait in an organism, that is, causes pertaining to the lifetime of the individual, and the "evolutionary biology," looking for "ultimate causes," namely, causes at the level of the history of the species to which belongs the individual. The former includes physiology, molecular biology, developmental biology, etc., whereas the latter includes paleontology, population genetics, behavioral ecology, systematics, etc. Evolutionary explanation is the set of explanatory styles to be met in this field (Ridley ).

Erkenntnis (2012) 76:171–194

This paper investigates the conception of causation required in order to make sense of natural selection as a causal explanation of changes in traits or allele frequencies. It claims that under a counterfactual account of causation, natural selection is constituted by the causal relevance of traits and alleles to the variation in traits and alleles frequencies. The ''statisticalist'' view of selection (Walsh, Matthen, Ariew, Lewens) has shown that natural selection is not a cause superadded to the causal interactions between individual organisms. It also claimed that the only causation at work is those aggregated individual interactions, natural selection being only predictive and explanatory, but it is implicitly committed to a process-view of causation. I formulate a counterfactual construal of the causal statements underlying selectionist explanations, and show that they hold because of the reference they make to ecological reliable factors. Considering case studies, I argue that this counterfactual view of causal relevance proper to natural selection captures more salient features of evolutionary explanations than the statisticalist view, and especially makes sense of the difference between selection and drift. I eventually establish equivalence between causal relevance of traits and natural selection itself as a cause.

Studies in History and Philosophy of Science …, 2005

This paper explores whether natural selection, a putative evolutionary mechanism, and a main one at that, can be characterized on either of the two dominant conceptions of mechanism, due to Glennan and the team of Machamer, Darden, and Craver, that constitute the "new mechanistic philosophy." The results of the analysis are that neither of the dominant conceptions of mechanism adequately captures natural selection. Nevertheless, the new mechanistic philosophy possesses the resources for an understanding of natural selection under the rubric.