David Hull's analysis of conceptual change in science, as presentedin his book, Science as a Process (1988), provides a useful framework for understanding one of the scientific controversies in which he actively and constructively intervened, the units of selectiondebates in evolutionary biology. What follows is a brief overview ofthose debates and some reflections on them.

We address the controversy in the literature concerning the definition of holobionts and the apparent constraints on their evolution using concepts from community population genetics. The genetics of holobionts, consisting of a host and diverse microbial symbionts, has been neglected in many discussions of the topic, and, where it has been discussed, a gene-centric, species-centric view, based in genomic conflict, has been predominant. Because coevolution takes place between traits or genes in two or more species and not, strictly speaking, between (...) species, it may affect some traits but not others in either host or symbiont. Moreover, when interacting species pairs are embedded in a larger community, indirect ecological effects can alter the expected pairwise dynamics. Mode of symbiont transmission and the degree of host inbreeding both affect the extent of microbial mixing across host lineages and thereby the degree to which selection on one trait of either partner affects other aspects of a holobiont phenotype. We discuss several potential defining criteria for holobionts using community genetics and population genetics models, suggesting their application and limitations. Using community genetics models, we show how conflict between genomes can be self-limiting, while cooperation and mutualism tend to be self-accelerating. It is likely that this bias in the evolutionary dynamics of interaction between hosts and symbionts is an important feature of holobionts. This bias in the evolutionary dynamic could contribute to explaining the absence of cheaters from natural mutualisms, although cheaters are predicted by gene-centered conflict theory to cause the evolutionary instability of mutualisms. Additionally, it may help explain the more frequent origin of mutualisms from parasitic than from free-living systems, an evolutionary trajectory opposite to that predicted by genome conflict theory. (shrink)

The conflation of two fundamentally distinct issues has generated serious confusion in the philosophical and biological literature concerning the units of selection. The question of how a unit of selection of defined, theoretically, is rarely distinguished from the question of how to determine the empirical accuracy of claims--either specific or general--concerning which unit(s) is undergoing selection processes. In this paper, I begin by refining a definition of the unit of selection, first presented in the philosophical literature by William Wimsatt, which (...) is grounded in the structure of natural selection models. I then explore the implications of this structural definition for empirical evaluation of claims about units of selection. I consider criticisms of this view presented by Elliott Sober--criticisms taken by some (for example, Mayo and Gilinsky 1987) to provide definitive damage to the structuralist account. I shall show that Sober has misinterpreted the structuralist views; he knocks down a straw man in order to motivate his own causal account. Furthermore, I shall argue, Sober's causal account is dependent on the structuralist account that he rejects. I conclude by indicating how the refined structural definition can clarify which sorts of empirical evidence could be brought to bear on a controversial case involving units of selection. (shrink)

This paper is the second of a two-part series on models and theories, the first of which appeared in International Studies in the Philosophy of Science, Vol. 11, No. 2, 1997. It further explores some of themes of the first paper and examines applications, including: the relations between “similarity” and “isomorphism”, and between “model” and “interpretation”, and the notion of structural explanation.

The paper, as Part I of a two-part series, argues for a hybrid formulation of the semantic view of scientific theories. For stage-setting, it first reviews the elements of the model theory in mathematical logic (on whose foundation the semantic view rests), the syntactic and the semantic view, and the different notions of models used in the practice of science. The paper then argues for an integration of the notions into the semantic view, and thereby offers a hybrid semantic view, (...) which at once secures the view's logical foundations and enhances its applicability. The dilemma of either losing touch with the practice of science or yielding up the benefits of the model theory is thus avoided. (shrink)

Modeling is an important scientific practice, yet it raises significant philosophical puzzles. Models are typically idealized, and they are often explored via imaginative engagement and at a certain “distance” from empirical reality. These features raise questions such as what models are and how they relate to the world. Recent years have seen a growing discussion of these issues, including a number of views that treat modeling in terms of indirect representation and analysis. Indirect views treat the model as a bona (...) fide object, specified by the modeler and used to represent and reason about some portion of the concrete empirical world. On some indirect views, model systems are abstract entities, such as mathematical structures, while on other views they are concrete hypothetical things. Here I assess these views and offer a novel account of models. I argue that regarding models as abstracta results in some significant tensions with the practice of modeling, especially in areas where non-mathematical models are common. Furthermore, viewing models as concrete hypotheticals raises difficult questions about model-world relations. The view I argue for treats models as direct, albeit simplified, representations of targets in the world. I close by suggesting a treatment of model-world relations that draws on a recent work by Stephen Yablo concerning the notion of partial truth. (shrink)

In this paper, a modest version of the Semantic View is motivated as both tenable and potentially fruitful for philosophy of science. An analysis is proposed in which the Semantic View is characterized by three main claims. For each of these claims, a distinction is made between stronger and more modest interpretations. It is argued that the criticisms recently leveled against the Semantic View hold only under the stronger interpretations of these claims. However, if one only commits to the modest (...) interpretation for all the claims, then the view obtained, the Modest Semantic View, is tenable and fruitful for the philosophy of science. (shrink)

The cybernetic definition of a living individual proposed previously (Korzeniewski, 2001) is very abstract and therefore describes the essence of life in a very formal and general way. In the present article this definition is reformulated in order to determine clearly the relation between life in general and a living individual in particular, and it is further explained and defended. Next, the cybernetic definition of a living individual is confronted with the real world. It is demonstrated that numerous restrictions imposed (...) on the cybernetic definition of life by physical reality imply a number of particular properties of life that characterize present life on Earth, namely: (1) a living individual must be a dissipative structure (and therefore a low-entropy thermodynamic system out of the state of equilibrium); (2) spontaneously-originated life must be based on organic compounds; (3) evolutionarily stable self-dependent, free-living individuals must have some minimal level of complexity of structure and function; (4) a living individual must have a record of identity separated from an executive machinery; (5) the identity of living individuals must mutate and may evolve; (6) living individuals may collect and accumulate information in subsequent generations over very long periods of time; (7) the degree of complexity of a living individual reflects the degree of complexity of its environment (ecological niche) and (8) living individuals are capable of supple adaptation to varying environmental conditions. Thus, the cybernetic definition of a living individual, when confronted with the real physical world, generates most of the general properties of the present life on Earth. (shrink)

Multiply realizable properties are those whose realizers are physically diverse. It is often argued that theories which contain them are ipso facto irreducible. These arguments assume that physical explanations are restricted to the most specific descriptions possible of physical entities. This assumption is descriptively false, and philosophically unmotivated. I argue that it is a holdover from the late positivist axiomatic view of theories. A semantic view of theories, by contrast, correctly allows scientific explanations to be couched in the most perspicuous, (...) powerful language available. On a semantic view, traditional notions of multiple realizability are thus very hard to motivate. At best, one must abandon either the idea that multiple realizability is an interesting scientific notion, or else admit that multiply realizable properties do not automatically block scientific reductions. (shrink)

Stephen Jay Gould is rightly remembered for many different kinds of contributions to our intellectual life. I focus on his criticisms of uses of evolutionary ideas to defend inegalitarian doctrines and on his attempts to expand the framework of Darwinian evolutionary theory. I argue that his important successes in the former sphere are applications of the idea of local critique, grounded in careful attention to the details of the inegalitarian proposals. As he became more concerned with the second project, Gould (...) was inclined to suggest that the abuses of evolutionary ideas rested on an insufficiently expanded Darwinism. I suggest that what is valuable in Gould's contribution to general evolutionary theory is the original claim about punctuated equilibrium (advanced, with Niles Eldredge in1972), and the careful defense of that claim through the accumulation of paleontological evidence. I try to show that the more ambitious program of a hierarchical expansion of neo-Darwinism is misguided, and that the endeavor to go beyond local critique fails. (shrink)

Selection operates at many levels. Some of the most obvious cases are organismic, such as changes in coloration under the influence of predation (cf. Kettlewell 1973; also Endler 1986). It also operates at other levels. Meiotic drive involves selection for a gene, independently of its effect on the organism. At a higher level, there may also be selection for patterns of colony growth in social insects, again under the influence of predation (cf. Wilson 1971). The appropriate level of selection is (...) a matter of the causal patterns exhibited, or the target of selection. It can also be understood as a question of the appropriate level at which to seek explanatory laws.Robert Brandon (1982, 1990) first clearly distinguished the question of the level of selection from debates over the units of selection. In doing so, he argued that the phenotype is commonly the target of selection, whatever the unit of selection might be. (shrink)

It has become customary in multilevel selection theory to use the same terms to denote both two explanatory goals and two explanatory means. This paper spells out some of the benefits that derive from avoiding this terminological conflation. I argue that keeping explanatory means and goals well apart allows us to see that, contrary to a popular recent idea, Price’s equation and contextual analysis—the statistical methods most extensively used for measuring the effects of certain evolutionary factors on the change in (...) the focal individual trait in multilevel selection scenarios—do not come with built-in notions of group selection and, therefore, the efficacy of these methods at analyzing various kinds of cases does not constitute a basis for deciding how group selection should best be defined. Moreover, contrary to another widely accepted idea, I argue that more than one type of group selection may serve as explanatory means when one’s goal is that of explaining the evolution of individual traits in multilevel selection scenarios and I spell out how this explanatory role should be understood. (shrink)

Larry Wright and others have advanced causal accounts of functional explanation, designed to alleviate fears about the legitimacy of such explanations. These analyses take functional explanations to describe second order causal relations. These second order relations are conceptually puzzling. I present an account of second order causation from within the framework of Eells' probabilistic theory of causation; the account makes use of the population-relativity of causation that is built into this theory.

According to the semantic view of scientific theories, theories are classes of models. I show that this view -- if taken seriously as a formal explication -- leads to absurdities. In particular, this view equates theories that are truly distinct, and it distinguishes theories that are truly equivalent. Furthermore, the semantic view lacks the resources to explicate interesting theoretical relations, such as embeddability of one theory into another. The untenability of the semantic view -- as currently formulated -- threatens to (...) undermine scientific structuralism. (shrink)

In a previous study, using experimental metapopulations of the flour beetle, Tribolium castaneum, we investigated phase III of Wright's shifting balance process (Wade and Griesemer 1998). We experimentally modeled migration of varying amounts from demes of high mean fitness into demes of lower mean fitness (as in Wright's characterization of phase III) as well as the reciprocal (the opposite of phase III). We estimated the meta-populational heritability for this level of selection by regression of offspring deme means on the weighted (...) parental deme means.Here we develop a Punnett Square representation of the inheritance of the group mean to place our empirical findings in a conceptual context similar to Mendelian inheritance of individual traits. The comparison of Punnett Squares for individual and group inheritance shows how the latter concept can be rigorously defined and extended despite the lack of explicitly formulated, simple Mendelian laws of inheritance at the group level. Whereas Wright's phase III combines both interdemic selection and meta-populational inheritance, our formulation separates the issue of meta-populational heritability from that of interdemic selection. We use this conceptual context to discuss the controversies over the levels of selection and the units of inheritance. (shrink)

Exact sciences are described as sciences whose theories are formalized. These are contrasted to inexact sciences, whose theories are not formalized. Formalization is described as a broader category than mathematization, involving any form/content distinction allowing forms, e.g., as represented in theoretical models, to be studied independently of the empirical content of a subject-matter domain. Exactness is a practice depending on the use of theories to control subject-matter domains and to align theoretical with empirical models and not merely a state of (...) a science. Inexact biological sciences tolerate a degree of “mismatch” between theoretical and empirical models and concepts. Three illustrations from biological sciences are discussed in which formalization is achieved by various means: Mendelism, Weismannism, and Darwinism. Frege’s idea of a “conceptual notation” is used to further characterize the notion of a form/content distinction. (shrink)

Throughout his career David Hull has sought to bring the philosophy of science into closer contact with science and especially with biological science (Hull 1969, 1997b). This effort has taken many forms. Sometimes it has meant ‘either explaining basic biology to philosophers or explaining basic philosophy to biologists’ (Hull 1996, p. 77). The first of these tasks, simple as it sounds, has been responsible for revolutionary changes. It is well known that traditional philosophy of science, modeled as it was on (...) theoretical physics, proved inadequate when philosophers turned their attention to biological science. Biological examples have driven major revisions of accounts of reduction (Hull 1974; Schaffner 1993, Ch. 9), laws of nature (Beatty et al. 1997), theories (Lloyd 1988) and natural kinds (Wilson 1999, Part III). Nor is explaining basic philosophy to biologists a task to be looked down upon. It is useful, not because philosophy has all the answers, but because scientists must think about how to do science, that is doing philosophy of science and scientists frequently reinvent philosophical views with known flaws. Early in his career Hull found biological systematists in the grip of a crude operationalism about scientific concepts and said so in the pages of Systematic Zoology (Hull 1968). For the next thirty years, as biologists debated the nature of species and the correct principles of classification, Hull added a philosophical note at the same congresses and in the same journals (Hull 1970, 1976, 1980, 1997a, 1999). (shrink)

Hamilton’s Rule, named after the evolutionary biologist Bill Hamilton, and the related concepts of inclusive fitness and kin selection, have been the bedrock of the study of social evolution for the past half century. In ’The Philosophy of Social Evolution’, Jonathan Birch provides a comprehensive introduction to the conceptual foundations of the Hamiltonian view of social evolution, and a passionate defence of its enduring value in face of the recent high profile criticism. In this review essay, I first outline the (...) version of Hamilton’s Rule defended by Birch, dubbed Hamilton’s Rule General, and its derivation. With this in place, I then navigate through the fierce disagreements that Hamilton’s Rule generates among social evolution researchers and evaluate Birch’s central argument of the book that HRG serves as an organizing framework for social evolution research under which we can compare and interpret more detailed causal models. I then spend the remainder of the review discussing what I take to be three of the most exciting implications of Hamilton’s thinking raised by Birch: the extension of Hamilton’s Rule to mobile genetic elements, maximization of inclusive fitness models and the idea of adaptation as organism design, and the relationship between Hamilton’s approaches to social behaviour and the gene’s-eye view of evolution. (shrink)

This special issue for the Journal for General Philosophy of Science is devoted to exploring the impact and many ramifications of current research in evolutionary epistemology. Evolutionary epistemology is an inter- and multidisciplinary area of research that can be divided into two ever-inclusive research avenues. One research avenue expands on the EEM program and investigates the epistemology of evolution. The other research avenue builds on the EET program and researches the evolution of epistemology. Since its conception, EE has developed three (...) schools of thought: adaptationist, non-adaptationist, and applied EE. Although diverse in outlook and theoretical background, these research avenues and schools share the same agenda of understanding how knowledge evolves, and how it relates to the world. In this paper, we first explain wherefrom evolutionary epistemological schools of thought developed, and then we highlight current debates in EE by briefly reviewing the papers that form part of this special issue. (shrink)

It has been proposed that natural selection occurs on a hierarchy of levels, of which the organismic level is neither the top nor the bottom. This hypothesis leads to the following practical problem: in general, how does one tell if a given phenomenon is a result of selection on level X or level Y. How does one tell what the units of selection actually are?It is convenient to assume that a unit of selection may be defined as a type of (...) entity for which there exists, among all entities on the same level as that entity, an additive component of variance for some specific component F of fitness which does not appear as an additive component of variance in any decomposition of this F among entities at any lower level. But such a definition implicitly assumes that if f(x, y) depends nonadditively on its arguments, there must be interaction between the quantities which x and y represent. This assumption is incorrect. And one cannot avoid this error by speaking of transformability to additivity instead of merely additivity. (shrink)

The history and theoretical role of the concept of a ``replicator''is discussed, starting with Dawkins' and Hull's classic treatmentsand working forward. I argue that the replicator concept is still auseful one for evolutionary theory, but it should be revised insome ways. The most important revision is the recognition that notall processes of evolution by natural selection require thatsomething play the role of a replicator.

Proponents of genic selectionism have claimed that evolutionary processes normally viewed as selection on individuals can be "represented" as selection on alleles. This paper discusses the relationship between mathematical questions about the formal requirements upon state spaces necessary for the representation of different types of evolutionary processes and causal questions about the units of selection in such processes.

Non-actual model systems discussed in scientific theories are compared to fictions in literature. This comparison may help with the understanding of similarity relations between models and real-world target systems. The ontological problems surrounding fictions in science may be particularly difficult, however. A comparison is also made to ontological problems that arise in the philosophy of mathematics.

Halvorson argues through a series of examples and a general result due to Myers that the “semantic view” of theories has no available account of formal theoretical equivalence. De Bouvere provides criteria overlooked in Halvorson’s paper that are immune to his counterexamples and to the theorem he cites. Those criteria accord with a modest version of the semantic view that rejects some of Van Fraassen’s apparent claims while retaining the core of Patrick Suppes’s proposal. I do not endorse any version (...) of the semantic view of theories. (shrink)

I argue that the orthodox account of probabilistic causation, on which probabilistic causes determine the probability of their effects, is inconsistent with certain ontological assumptions implicit in scientific practice. In particular, scientists recognize the possibility that properties of populations can cause the behavior of members of the populations. Such emergent population‐level causation is metaphysically impossible on the orthodoxy.

Philosophers of science increasingly believe that much of science is concerned with understanding the mechanisms responsible for the production of natural phenomena. An adequate understanding of scientific research requires an account of how scientists develop and test models of mechanisms. This paper offers a general account of the nature of mechanical models, discussing the representational relationship that holds between mechanisms and their models as well as the techniques that can be used to test and refine such models. The analysis is (...) supported by study of two competing models of a mechanism of speech perception. (shrink)

Sober and Lewontin's critique of genic selectionism is based upon the principle that a unit of selection should make a context‐independent contribution to fitness. Critics have effectively shown that this principle is flawed. In this paper I show that the context independence principle is an instance of a more general principle for characterizing causes,called the contextual unanimity principle. I argue that this latter principle, while widely accepted, is erroneous. What is needed is to replace the approach to causality characterized by (...) the contextual unanimity criterion with an approach based on the concept of causal mechanism. After sketching such an approach, I show how it can be used to shed light on the units of selection problem. (shrink)

Para algunos la selección natural se identifica con las diferencias de éxito de distintos organismos en la reproducción diferencial. Si esto fuese así, el principio de Hardy-Weinberg, por permitir determinar con bastante precisión bajo ciertos supuestos que la frecuencia génica en una población no es la esperada, podría ser visto como una versión cuantitativa de la selección natural cualitativa propuesta por Darwin. Es mi intención mostrar, a través del análisis de explicaciones dadas por Darwin, que la selección natural es más (...) que la mera diferencia en el éxito en la reproducción diferencial e investigar algunas relaciones entre la teoría de la selección natural y la genética de poblaciones. (shrink)

The concept of fitness has generated a lot of discussion in philosophy of biology. There is, however, relative agreement about the need to distinguish at least two uses of the term: ecological fitness on the one hand, and population genetics fitness on the other. The goal of this paper is to give an explication of the concept of ecological fitness by providing a reconstruction of the theory of natural selection in which this concept was framed, that is, based on the (...) way the theory was put to use in Darwin’s main texts. I will contend that this reconstruction enables us to account for the current use of the theory of natural selection. The framework presupposed in the analysis will be that of metatheoretical structuralism. This framework will provide both a better understanding of the nature of ecological fitness and a more complete reconstruction of the theory. In particular, it will provide what I think is a better way of understanding how the concept of fitness is applied through heterogeneous cases. One of the major advantages of my way of thinking about natural selection theory is that it would not have the peculiar metatheoretical status that it has in other available views. I will argue that in order to achieve these goals it is necessary to make several concepts explicit, concepts that are frequently omitted in usual reconstructions. (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.

Wigner famously referred to the `unreasonable effectiveness' of mathematics in its application to science. Using Wigner's own application of group theory to nuclear physics, I hope to indicate that this effectiveness can be seen to be not so unreasonable if attention is paid to the various idealising moves undertaken. The overall framework for analysing this relationship between mathematics and physics is that of da Costa's partial structures programme.