Evolutionary processes such as natural selection and random drift are commonly regarded as causes of population-level change. We respond to a recent challenge that drift and selection are best understood as statistical trends, not causes. Our reply appeals to manipulation as a strategy for uncovering causal relationships: if you can systematically manipulate variable A to bring about a change in variable B, then A is a cause of B. We argue that selection and drift can be systematically manipulated to produce (...) different kinds of population-level change. They should therefore be regarded as causes. (shrink)

Confirmation in evolutionary biology depends on what biologists take to be the genuine rivals. Investigating what constrains the scope of biological possibility provides part of the story: explaining how possible helps determine what counts as a genuine rival and thus informs confirmation. To clarify the criteria for genuine rivalry I distinguish between global and local constraints on biological possibility, and offer an account of how-possibly explanation. To sharpen the connection between confirmation and explaining how possible I discuss the view that (...) formal inquiry can provide a kind of confirmation-theoretic support for evolutionary models, and offer an example of how-possibly explanation interacting with testing practice. (shrink)

Confirmation in evolutionary biology depends on what biologists take to be the genuine rivals. Investigating what constrains the scope of biological possibility provides part of the story: explaining how possible helps determine what counts as a genuine rival and thus informs confirmation. To clarify the criteria for genuine rivalry I distinguish between global and local constraints on biological possibility, and offer an account of how-possibly explanation. To sharpen the connection between confirmation and explaining how possible I discuss the view that (...) formal inquiry can provide a kind of confirmation-theoretic support for evolutionary models, and offer an example of how-possibly explanation interacting with testing practice. (shrink)

We discuss the scientific task of historical reconstruction and the problem of epistemic access. We argue that strong epistemic support for historical claims consists in the consilience of multiple independent lines of evidence, and analyze the impact hypothesis for the End-Cretaceous mass extinction to illustrate the accrual of epistemic support. Although there are elements of the impact hypothesis that enjoy strong epistemic support, the general conditions for this are strict, and help to clarify the difficulties associated with reconstructing the deep (...) past. (shrink)

Evolutionary biology, indeed any science that attempts to reconstruct prehistory, faces practical limitations on available data. These limitations create the problem of contrast failure: specific observations may fail to discriminate between rival evolutionary hypotheses. Assessing the risk of contrast failure provides a way to evaluate testing protocols in evolutionary science. Here I will argue that part of the methodological critique in the Spandrels paper involves diagnosing contrast failure problems. I then distinguish the problem of contrast failure from the more familiar (...) philosophical problem of underdetermination, and demonstrate how contrast failure arises in scientific practice with an investigation into Lewontin and White’s estimation of an adaptive landscape. (shrink)

Does science successfully uncover the deep structure of the natural world? Or are the depths forever beyond our epistemic grasp? Since the decline of logical positivism and logical empiricism, scientific realism has become the consensus view: of course our scientific theories apprehend the deep structure of the world. What else could explain the remarkable success of science? This is the explanationist defense of scientific realism, the “ultimate argument.” Kyle Stanford starts here and, using the history of theorizing about biological inheritance (...) as his case study, constructs a convincing argument against the realist consensus in his thought provoking book, Exceeding Our Grasp.1 Here I will review the core of Stanford’s new argument for instrumentalism (§ 1) and discuss his considered view of theoretical science (§ 2). (shrink)

Can selection explain why individuals have the traits they do? This question has generated significant controversy. I will argue that the debate encompasses two separable aspects, to detrimental effect: (1) the role of selection in explaining the origin and evolution of biological traits and (2) the implications this may have for explaining why individuals have the traits they do. (1) can be settled on the basis of evolutionary theory while (2) requires additional, extra-scientific assumptions. By making a distinction between traits (...) affected by a single factor and traits affected by multiple factors I show that selection can, under certain conditions, help explain the origin of traits. Resolving the first aspect enables us to critically assess the various incompatible and independent philosophical commitments made within the second aspect of the debate. (shrink)

Do evolutionary processes such as selection and random drift cause evolutionary change, or are they merely convenient ways of describing or summarizing it? Philosophers have lined up on both sides of this question. One recent defense (Reisman and Forber 2005) of the causal status of selection and drift appeals to a manipulability theory of causation. Yet, even if one accepts manipulability, there are still reasons to doubt that genetic drift, in particular, is genuinely causal. We will address two challenges to (...) treating drift as causal within a manipulation framework. We will argue that both challenges ultimately fail, but that they raise interesting and subtle issues about the nature of causation and the differences between selection and drift. ‡Thanks to audiences at the ‘PBDB1' Conference and the 2006 PSA Meeting for valuable feedback. †To contact the authors, please write to: Patrick Forber, Tufts University, Philosophy Department, Miner Hall, Medford, MA 02155; e-mail: [email protected]. (shrink)

Eliminative reasoning seems to play an important role in the sciences, but should it be part of our best theory of science? Statistical evidence, prevalent across the sciences, causes problems for eliminative inference, supporting the view that probabilistic theories of confirmation provide a better framework for reasoning about evidence. Here I argue that deductive elimination has an important inferential role to play in science, one that is compatible with probabilistic approaches to evidence. Eliminative inferences help frame testing problems, an essential (...) step that determines the context for evaluating statistical evidence. I illustrate this process with examples from molecular evolutionary biology. (shrink)

We investigate how changes to the payoffs of cooperative behavior affect the evolutionary dynamics. Paradoxically, the larger the benefits of cooperation, the less likely it is to evolve. This holds true even in cases where cooperation is strictly dominant. Increasing the benefits from prosocial behavior has two effects: first, in some circumstances it promotes the evolution of spite; and second, it can decrease the strength of selection leading to nearly neutral evolution of strategies. In light of these results we must (...) reevaluate standard philosophical perspectives on the evolution of cooperation and morality. (shrink)

When can macroscopic data about a system be used to set parameters in a microfoundational simulation? We examine the epistemic viability of tweaking parameter values to generate a better fit between the outcome of a simulation and the available observational data. We restrict our focus to microfoundational simulations—those simulations that attempt to replicate the macrobehavior of a target system by modeling interactions between microentities. We argue that tweaking can be effective but that there are two central risks. First, tweaking risks (...) overfitting the simulation to the data and thus compromising predictive accuracy; and second, it risks compromising the microfoundationality of the simulation. We evaluate standard responses to tweaking and propose strategies to guard against these risks. (shrink)

We examine contemporary game-theoretic accounts of ownership as a convention. New results from dynamic networks complicate matters, suggesting that if ownership is conventional, it should not be as...

Recent studies in the evolution of cooperation have shifted focus from altruistic to mutualistic cooperation. This change in focus is purported to reveal new explanations for the evolution of prosocial behavior. We argue that the common classification scheme for social behavior used to distinguish between altruistic and mutualistic cooperation is flawed because it fails to take into account dynamically relevant game-theoretic features. This leads some arguments about the evolution of cooperation to conflate dynamical scenarios that differ regarding the basic conditions (...) on the emergence and maintenance of cooperation. We use the tools of evolutionary game theory to increase the resolution of the classification scheme and analyze what evolutionary inferences classifying social behavior can license. (shrink)

Evolutionary biology, indeed any science that attempts to reconstruct prehistory, faces practical limitations on available data. These limitations create the problem of contrast failure: specific observations may fail to discriminate between rival evolutionary hypotheses. Assessing the risk of contrast failure provides a way to evaluate testing protocols in evolutionary science. Here I will argue that part of the methodological critique in the Spandrels paper involves diagnosing contrast failure problems. I then distinguish the problem of contrast failure from the more familiar (...) philosophical problem of underdetermination, and demonstrate how contrast failure arises in scientific practice with an investigation into Lewontin and White’s estimation of an adaptive landscape. (shrink)

John Richardson (2002, 2004) argues that Nietzsche’s use of teleological notions, such as the “will to power” and psychological “drives,” can be naturalized within the Darwinian framework of natural selection. Although this ambitious project has merit, the Darwinian framework does not provide the strong teleology necessary to interpret Nietzsche’s explanatory project. Examining the logic of selection, the conceptual limitations on biological functions, and the evidential demands that must be met to deploy evolutionary theory show that Nietzsche’s explanatory project does not (...) cohere with the Darwinian framework. Thus, coherence with currently accepted evolutionary theory should not constrain the philosophical project of interpretation in this case. (shrink)

Climate negotiations under the United Nations Framework Convention on Climate Change have so far failed to achieve a robust international agreement to reduce greenhouse gas emissions. Game theory has been used to investigate possible climate negotiation solutions and strategies for accomplishing them. Negotiations have been primarily modelled as public goods games such as the Prisoner’s Dilemma, though coordination games or games of conflict have also been used. Many of these models have solutions, in the form of equilibria, corresponding to possible (...) positive outcomes—that is, agreements with the requisite emissions reduction commitments. Other work on large-scale social dilemmas suggests that it should be possible to resolve the climate problem. It therefore seems that equilibrium selection may be a barrier to successful negotiations. Here we use an N-player bargaining game in an agent-based model with learning dynamics to examine the past failures of and future prospects for a robust international climate agreement. The model suggests reasons why the desirable solutions identified in previous game-theoretic models have not yet been accomplished in practice and what mechanisms might be used to achieve these solutions. (shrink)

ABSTRACT Nietzsche's investigation into the origins of morality bears some striking similarities to contemporary investigations into human evolution. Here I investigate these similarities, using a comparison between Nietzsche's GM and Gould and Lewontin's influential “Spandrels” essay as a departure point. I argue that Nietzsche defends a proto-evolutionary psychology about morality, where the inheritance of enduring biological drives conflicts with our culturally evolved moral system. While Nietzsche's claims about the evolution of morality fit well within a Darwinian framework of natural selection, (...) his claims about our underlying biology do not. Those claims cohere better with the non-Darwinian views found in nineteenth-century German biology and embryology. (shrink)

John Richardson (2002, 2004) argues that Nietzsche’s use of teleological notions, such as the “will to power” and psychological “drives,” can be naturalized within the Darwinian framework of natural selection. Although this ambitious project has merit, the Darwinian framework does not provide the strong teleology necessary to interpret Nietzsche’s explanatory project. Examining the logic of selection, the conceptual limitations on biological functions, and the evidential demands that must be met to deploy evolutionary theory show that Nietzsche’s explanatory project does not (...) cohere with the Darwinian framework. Thus, coherence with currently accepted evolutionary theory should not constrain the philosophical project of interpretation in this case. (shrink)

Recognition of and responsiveness to the behavioral dispositions of others are key features of moral systems for facilitating social cooperation and the mediation of punishment. Here we investigate the coevolutionary possibilities of recognition and conditional social behavior with respect to both altruism and spite. Using two evolutionary models, we find that recognition abilities can support both spite and altruism but that some can only coevolve with spite. These results show that it is essential to consider harmful social behaviors as both (...) a product of and an influence on the core features of our moral systems. (shrink)

Evidence is an objective matter. This is the prevailing view within science, and confirmation theory should aim to capture the objective nature of scientific evidence. Modeling an objective evidence relation in a probabilistic framework faces two challenges: the probabilities must have the right epistemic foundation, and they must be specifiable given the hypotheses and data under consideration. Here I will explore how Sober's approach to confirmation handles these challenges of foundation and specification. In particular, I will argue that the specification (...) problem proves especially difficult, and undermines the law of likelihood as an adequate representation of the objective nature of scientific evidence. (shrink)

Spite (in the biological or evolutionary sense) is behavior that harms others at a cost to the actor. The presence of spite in human and animal populations presents an evolutionary puzzle. Recent work has suggested small populations and pre-play signaling can have a significant effect on the evolution of spite. Here, we use computational methods to explore these factors in fluctuating populations that may go extinct. We find that the presence of spite can make a population significantly more likely to (...) go extinct, but that this does not preclude the possibility of spite reliably evolving. Additionally, we find that the stochastic effects of small fluctuating populations allow for the evolution and predominance of signal-mediated conditional spite across a wide range of conditions. These results suggest that directed harm, even if costly, can play a significant early role in the evolution of social behaviors and this provides a possible origin for punishment. (shrink)

MacDonald and Kreitman (1991) propose a test of the neutral mutationrandom drift (NM-RD) hypothesis, the central claim of the neutral theory of molecular evolution. The test involves generating predictions from the NM-RD hypothesis about patterns of molecular substitutions. Alternative selection hypotheses predict that the data will deviate from the predictions of the NM-RD hypothesis in specifiable ways. To conduct the test Mac- Donald and Kreitman examine the evolutionary dynamics of the alcohol dehydrogenase (Adh) gene in three species of Drosophila. The (...) test compares the number of DNA sequence changes between species and within species. The number of DNA differences is an indicator of the evolutionary rate of the Adh gene. Based on the test they conclude that there is strong evidence for adaptive protein evolution at particular sites in the gene. Understanding the test requires some basic knowledge about molecular terms and the predictions of neutral theory. The two important terms are fixed differences and polymorphisms. These are determined by comparing DNA sequences made up of thousands of individual nucleotide sites. A site that is unchanged within a species but different from a related species counts as a fixed difference. These are mutations that occur in some common ancestor of the lineage such that all descendants inherit the change. A site that differs within a species counts as a polymorphism. Determining the number of fixed differences and polymorphisms requires placing 1 each individual gene sequence onto a phylogenetic tree. A coalescent tree charts the ancestral relationships for a set of individual gene sequences. Sequences sampled from within a species form a within-species tree. The common ancestors of each within-species tree form a between-species tree. A detected difference counts as a polymorphism or a fixed difference depending on where it occurs in the phylogenetic tree (cf. Table 1). The test uses the numbers of polymorphisms and fixed differences as indicators of evolutionary rates.. (shrink)