According to Marr, a computational-level theory consists of two elements, the what and the why. This article highlights the distinct role of the Why element in the computational analysis of vision. Three theses are advanced: that the Why element plays an explanatory role in computational-level theories, that its goal is to explain why the computed function is appropriate for a given visual task, and that the explanation consists in showing that the functional relations between the representing cells are similar to (...) the “external” mathematical relations between the entities that these cells represent. (shrink)

Among philosophers, controversy over the notion of drift in population genetics is ongoing. This is at least partly because the notion of drift has an ambiguous usage among population geneticists. My goal in this paper is to explicate the causal dimension of drift, to say what causal influences are responsible for the stochasticity in population genetics models. It is commonplace for population genetics to oppose the influence of selection to that of drift, and to consider how the dynamics of populations (...) are altered when each has greater or lesser influence. I define the causes that are referred to as drift when researchers speak this way. Introduction Populations and Variant Types The Cause–Effect Ambiguity of Drift Non-directional Factors in Population Genetics How N ev Is Used in Population Genetics Causal Conceptions of Drift 6.1 The Millstein/Beatty conception of drift 6.2 Rosenberg and Bouchard: Drift as initial conditions NINPICs 7.1 Why drift is instituted by NINPICs 7.2 How NINPICS work 7.3 NINPICs and random sampling 7.4 Independent sampling and effective population size 7.5 Variance in progeny number 7.6 Population effects of NINPICs NINPICs and the Stochastic Character of Selection Theory Conclusion Appendix CiteULike Connotea Del.icio.us What's this? (shrink)

I criticize some arguments against the causal interpretability of population genetics put forward by Denis Walsh ([2007], [2010]). In particular, I seek to undermine the contention that population genetics exhibits frame of reference relativity or subjectivity with respect to its formal representations. I also show that classical population genetics does not fall foul of some criteria for causal representation put forward by James Woodward ([2003]), although those criteria do undermine some causalist stances. 1 Introduction2 Modularity3 The Crucially Important Point4 The (...) Gillespie Case: Density-Dependent Selection5 Conclusion. (shrink)

In what follows, I consider the role of analogy in the first edition of Darwin’s Origin. I argue that Darwin follows Herschel’s methodology and hence exploits an analogy between artificial and natural selection that allows him generalize selection as a cause of evolutionary change. This argument strategy is not equivalent to an argument from analogy. Reading Darwin’s argument as conforming to Herschel’s two-step methodology of causal analysis followed by generalization allows us to understand the role and placement of Darwin’s discussion (...) of artificial selection in the Origin, without making the mistake of portraying Darwin’s argument for the existence and character of natural selection as an analogical argument. (shrink)

In what follows, I consider the role of analogy in the first edition of Darwin’s Origin. I argue that Darwin follows Herschel’s methodology and hence exploits an analogy between artificial and natural selection that allows him generalize selection as a cause of evolutionary change. This argument strategy is not equivalent to an argument from analogy. Reading Darwin’s argument as conforming to Herschel’s two-step methodology of causal analysis followed by generalization allows us to understand the role and placement of Darwin’s discussion (...) of artificial selection in the Origin, without making the mistake of portraying Darwin’s argument for the existence and character of natural selection as an analogical argument. (shrink)

In what follows, I critique the interpretation that Sober and Wilson offer of their group selection model in Unto Others. Sober and Wilson mistakenly claim that their model operates as an example of Simpson's paradox and defend an interpretation of their model according to which groups are operated upon by natural selection. In the place of their interpretation, I offer one that parallels the mathematical calculation of the model's outcome and does not depend on the postulation of a force of (...) group selection or a value for group fitness. (shrink)

Some writers have urged that evolutionary theory produces generalizations that hold only ceteris paribus, that is, provided “everything else is equal.” Others have claimed that all laws in the special sciences, or even all laws in science generally, hold only ceteris paribus. However, if we lack a way to determine when everything else really is equal, hedging generalizations with the phrase ceteris paribus renders those generalizations vacuous. I propose a solution to this problem for the case of causal equations from (...) classical population genetics. When coupled with the right proviso, equations in classical population genetics function as strict laws. (shrink)

In what follows, I argue that the semantic approach to scientific theories fails as a means to present the Wright—Fisher formalism (WFF) of population genetics. I offer an account of what population geneticist understand insofar as they understand the WFF, a variation on Lloyd's view that population genetics can be understood as a family of models of mid-level generality.

Australasian Journal of Philosophy, Volume 90, Issue 1, Page 192-195, March 2012.

This work is a critical consideration of several arguments recently given by Elliott Sober that are aimed at undermining the Laplacean stance on probability in evolutionary theory. The Laplacean contends that the only objective probability an event has is the one assigned to it by a complete description of the relevant microparticles. Sober alleges a formal demonstration that the Laplacean stance on probability in evolutionary theory is inconsistent. But Sober’s argument contains a crucial lacuna, one that likely cannot be repaired (...) to yield the conclusion that Sober draws. He also argues that the Laplacean is committed to inferring semantic facts about probabilities from pragmatic facts about agents’ reasons for using probabilities. But Sober’s arguments against inferring semantic facts from pragmatic constraints would only undermine one basis for Laplaceanism. The Laplacean who formulates her position carefully need not leave herself vulnerable to Sober’s objection to inferring semantics from pragmatics. (shrink)

Kerr and Godfrey-Smith argue that two mathematically equivalent, alternative formal representations drawn from population genetics, the contextualist and collectivist formalisms, may be equally good for quantifying the dynamics of some natural systems, despite important differences between the formalisms. I draw on constraints on causal representation from Woodward (Making things happen, Oxford University Press, New York, 2003) and Eberhardt and Scheines (Philos Sci 74(5):981–995, 2006) to argue that one or the other formalism will be superior for arbitrary natural systems in which (...) individuals form different types of groups. (shrink)

The reason why population genetics is a probabilistic theory has attracted considerable attention from philosophers. In what follows, I offer a novel account of what motivates the introduction of probabilities into classical population genetics. Probabilities make the theory easier to apply for researchers given their epistemic limitations and give the theory a recursive structure, thereby making possible inferences about the dynamics of systems over multiple generations. I argue that probabilities in population genetics can be given a credentist interpretation according to (...) which the probabilities reflect constraints on confidence or belief. (shrink)

This paper argues that the nonidentity problem is really an artifact of faulty causal reasoning. In order to solve the nonidentity problem, we must determine that an agent causes a loss of happiness to another agent by means of an action that also causes the victim to exist. Woodward’s test for actual causation yields just this result. Equally crucial to solving the problem is the recognition that harms must be intentional and that intentionality is a function of norm-violation; this latter (...) position is defended by Holton. That the solution proposed is adequate is defended on the grounds that it yields intuitively correct judgments for a host of imaginary scenarios contemplated by theorists focused on determining what should count as harms. (shrink)

In his “A New Program for Philosophy of Science?”, Ronald Giere expresses qualms regarding the critical and political projects I advocate for philosophy of science—that the critical project assumes an underdetermination absent from actual science, and the political project takes us outside the professional pursuit of philosophy of science. In reply I contend that the underdetermination the critical project assumes does occur in actual science, and I provide a variety of examples to support this. And I contend that the political (...) project requires no more than what other academic fields even in science studies are already providing. (shrink)

In a recent article, “Wayward Modeling: Population Genetics and Natural Selection,” Bruce Glymour claims that population genetics is burdened by serious predictive and explanatory inadequacies and that the theory itself is to blame. Because Glymour overlooks a variety of formal modeling techniques in population genetics, his arguments do not quite undermine a major scientific theory. However, his arguments are extremely valuable as they provide definitive proof that those who would deploy classical population genetics over natural systems must do so with (...) careful attention to interactions between individual population members and environmental causes. Glymour’s arguments have deep implications for causation in classical population genetics. (shrink)