The evolutionary problem of the units of selection has elicited a good deal of conceptual work from philosophers. We review this work to determine where the issues now stand.
The controversy regarding the unit of selection is fundamentally a dispute about what is the correct causal structure of the process of evolution by natural selection and its ontological commitments. By characterizing the process as consisting of two essential steps--interaction and transmission--a singular answer to the unit question becomes ambiguous. With such an account on hand, two recent defenses of competing units of selection are considered. Richard Dawkins maintains that the gene is the appropriate unit of (...)selection and Robert Brandon, in response, argues that the individual organism is better suited to the role. This paper argues that by making explicit the underlying questions that each of these views addresses, the apparent conflict can be resolved. Furthermore, such a resolution allows for a more complete and realistic understanding of the process of evolution by natural selection. (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)
In recent years philosophers have attempted to clarify the units of selection controversy in evolutionary biology by offering conceptual analyses of the term 'unit of selection'. A common feature of many of these analyses is an emphasis on the claim that units of selection are entities exhibiting heritable variation in fitness. In this paper I argue that the demand that units of selection be characterized in terms of heritability is unnecessary, as well as (...) undesirable, on historical, theoretical, and philosophical grounds. I propose a positive account of the proper referent of the term 'unit of selection', distinguishing between the processes of evolution and phenotypic selection. The main result of this analysis is greater clarity about the conceptual structure of evolutionary theory. (shrink)
The reductionistic vision of evolutionary theory, "the gene's eye view of evolution" is the dominant view among evolutionary biologists today. On this view, the gene is the only unit with sufficient stability to act as a unit of selection, with individuals and groups being more ephemeral units of function, but not of selection. This view is argued to be incorrect, on several grounds. The empirical and theoretical bases for the existence of higher-level units of selection (...) are explored, and alternative analyses discussed critically. The success of a multi-level selection theory demands the recognition and development of a multi-level genetics. The way to accomplish this is suggested. The genotype/phenotype distinction also requires further analysis to see how it applies at higher levels of organization. This analysis provides a way of defining genotype and phenotype for cultural evolution, and a treatment of the innate-acquired distinction which are both generalizeable to analyze problems of the nature and focus of scientific change. (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)
"Additive variance in fitness" is an important concept in the formal apparatus of population genetics. Wimsatt and Lloyd have argued that this concept can also be used to decide the "unit of selection" in an evolutionary process. The paper argues that the proposed criteria of Wimsatt and Lloyd are ambiguous, and several interpretations of their views are presented. It is argued that none of these interpretations provide acceptable criteria for deciding units of selection. The reason is that (...) additive variance in fitness can be both a cause of evolution, but also a byproduct of selection at another level. (shrink)
A correct analysis of hierarchical selection processes must specify 1) the objects that succeed differentially as units, and 2) the properties that provide the causal bases for differential success. Here I illustrate how failing to recognize the units/bases distinction creates a contradiction in Elliott Sober's recent account of selection. A revised criterion for units of selection is developed and applied to examples at several biological levels. Criteria for bases of selection are discussed in (...) terms of the degree of context-dependence and directness of a property's effect on the success of units. The significance of previous work by Sober, Wimsatt and Brandon is thereby clarified. (shrink)
Sober argues that the units of selection problem in evolutionary biology is to be understood and solved by applying the general analysis of what it means for C to cause E in a population. The account he utilizes is the unanimity account, according to which C causes E in a population when C raises the probability of E in each causal context. I argue that he does not succeed here, both because the unanimity account is not well grounded (...) in the general case, and because there are important differences between cases of population causation which do involve selection and those which do not. (shrink)
Much recent work in sociobiology can be understood as designed to demonstrate the sufficiency of selection operating at lower levels of organization by the development of models at the level of the gene or the individual. Higher level units are accordingly viewed as artifacts of selection operating at lower levels. The adequacy of this latter form of argument is dependent upon issues of the complexity of the systems under consideration. A taxonomy is proposed elaborating a series of (...) types, or grades, of hierarchically organized systems. These range from aggregative systems, in which there is no organization relevant to systemic properties, through several graded variations reflecting various degrees of functional interdependence of components, to integrated systems, which manifest component specialization and diversification as well as a subordination of component function to systemic function. It is suggested that the most complex form of organization is plausibly treated as indicative of higher level units of selection. (shrink)
The question "what is (are) the unit(s) of selection" can be interpreted in three different ways. These interpretations are discussed and it is shown that they prompt different answers; such units are shown to be individuals in the context of the given interpretation. One of these interpretations is argued, by examples, not always to have an unambiguously correct answer. An alternative approach to this question is sketched.
I discuss two subjects in Samir Okasha’s excellent book, Evolution and the Levels of Selection. In consonance with Okasha’s critique of the conventionalist view of the units of selection problem, I argue that conventionalists have not attended to what realists mean by group, individual, and genic selection. In connection with Okasha’s discussion of the Price equation and contextual analysis, I discuss whether the existence of these two quantitative frameworks is a challenge to realism.
Richard Lewontin's (1970) early work on the units of selection initiated the conceptual and theoretical investigations that have led to the hierarchical perspective on selection that has reached near consensus status today. This paper explores other aspects of his work, work on what he termed continuity and quasi-independence, that connect to contemporary explorations of modularity in development and evolution. I characterize such modules and argue that they are the true units of selection in that they (...) are what evolution by natural selection individuates, selects among, and transforms. (shrink)
The Units of Selection debate is a dispute about the causes of population change. I argue that it is generated by a particular `dynamical'' interpretation of natural selection theory, according to which natural selection causes differential survival and reproduction of individuals and natural selection explanations cite these causes. I argue that the dynamical interpretation is mistaken and offer in outline an alternative, `statistical'' interpretation, according to which natural selection theory is a fancy kind of (...) `bookkeeping''. It explains by citing the statistical structure of a population and not by citing the causes of survival and reproduction. From the perspective of the statistical interpretation there is no substantive Units of Selection issue. (shrink)
The theory of evolution by natural selection is, perhaps, the crowning intellectual achievement of the biological sciences. There is, however, considerable debate about which entity or entities are selected and what it is that fits them for that role. This article aims to clarify what is at issue in these debates by identifying four distinct, though often confused, concerns and then identifying how the debates on what constitute the units of selection depend to a significant degree on (...) which of these four questions a thinker regards as central. (shrink)
In an important article, Kim Sterelny and Philip Kitcher (1988) challenge the common assumption that for any biological phenomenon requiring a selectionist explanation, it is possible to identify a uniquely correct account of the relevant selection process. They argue that selection events can be modeled in any of a number of different, equally correct ways. They call their view 'Pluralism,' and explicitly connect it with various antirealist positions in the philosophy of science. I critically evaluate Sterelny and Kitcher's (...) Pluralism along with its attendant antirealist theses. In particular, I argue that there are serious problems with their pluralistic antirealism regarding units of selection. By correctly diagnosing these problems a more adequate position can be constructed. I defend such a position, which I designate Inclusive Hierarchical Monism, and show how it captures the important virtues of Sterelny and Kitcher's approach while avoiding its problems. (shrink)
This paper inquires into the very possibility of the units of selection debate’s origin in the problem of altruism, function in articulating the evolutionary synthesis, and philosophical status as a problem in clarifying what makes something a level or unit of selection. What makes the debate possible? In terms of origins, there are a number of logically possible ways to deviate from the model of Darwinian individual selection to explain evolved traits. In terms of function, adherence (...) to the evolutionary synthesis yields norms which restrict these possibilities to a manageable few. In terms of philosophical status, the abstract structure of selection mechanisms permits a causal construal, on which the unit of selection is identified with the “unit of possession”, that which possesses the causally efficacious trait selected for. It also allows a teleological interpretation, on which the unit of selection is identified with the “unit of benefit”, that for the sake of which the causally efficacious trait is selected. It is proposed that a unit of selection is really a pair of units, consisting of both a unit of possession and a unit of benefit. (shrink)
Brandon ([1982] 1984, 1990) has argued that Salmon's (1971) concept of screening-off can be used to characterize (i) the idea that natural selection acts directly on an organism's phenotype, only indirectly on its genotype, and (ii) the biological problem of the levels of selection. Brandon also suggests (iii) that screening-off events in a causal chain are better explanations than the events they screen off. This paper critically evaluates Brandon's proposals.
Developing a definition of group selection, and applying that definition to the dispute in the social sciences between methodological holists and methodological individualists, are the two goals of this paper. The definition proposed distinguishes between changes in groups that are due to group selection and changes in groups that are artefacts of selection processes occurring at lower levels of organization. It also explains why the existence of group selection is not implied by the mere fact that (...) fitness values of organisms are sensitive to the composition of groups. And, lastly, the definition explains why group selection need not involve selection for altruism. Group selection is thereby seen as an evolutionary force which is objectively distinct from other evolutionary forces. Applying the distinction between group and individual selection to the holism/individualism dispute has the desirable result that the dispute is not decidable a priori. This way of looking at the dispute yields a conception of individualism which is untainted by atomism and a conception of holism which is unspoiled by hypostatis. (shrink)
On the basis of distinctions between those properties of entities that can be defined without reference to other entities and those that (in different ways) cannot, this note argues that non-trivial forms of frequency-dependent selection of entities should be interpreted as selection occurring at a level higher than that of those entities. It points out that, except in degenerately simple cases, evolutionary game-theoretic models of selection are not models of individual selection. Similarly, models of genotypic (...) class='Hi'>selection such as heterosis cannot be legitimately interpreted as models of genic selection. The analysis presented here supports the views that: (i) selection should be viewed as a multi-level process; (ii) upper-level selection is ubiquitous; (iii) kin selection should be viewed as a type of group selection rather than individual selection; and (iv) inclusive fitness is not an individual property. (shrink)
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.
Genic selectionism holds that all selection can be understood as operating on particular genes. Critics (and conventional biological wisdom) insist that this misrepresents the actual causal structure of selective phenomena at higher levels of biological organization, but cannot convincingly defend this intuition. I argue that the real failing of genic selectionism is pragmatic – it prevents us from adopting the most efficient corpus of causal laws for predicting and intervening in the course of affairs – and I offer a (...) Pragmatic account of causation itself which ultimately bears out the claim that genic selectionism misrepresents the causal structure of selective contexts. (shrink)
Two controversies exist regarding the appropriate characterization of hierarchical and adaptive evolution in natural populations. In biology, there is the Wright-Fisher controversy over the relative roles of random genetic drift, natural selection, population structure, and interdemic selection in adaptive evolution begun by Sewall Wright and Ronald Aylmer Fisher. There is also the Units of Selection debate, spanning both the biological and the philosophical literature and including the impassioned groupselection debate. Why do these two discourses exist separately, (...) and interact relatively little? We postulate that the reason for this schism can be found in the differing focus of each controversy, a deep difference itself determined by distinct general styles of inquiry (e.g., Hacking 2002; Elwick 2007; Winther 2012, 2013) guiding each discourse. That is, the Wright-Fisher debate focuses on /adaptive process/, and tends to be instructed by the /mathematical modeling style/, while the focus of the Units of Selection controversy is /adaptive product/, and is typically guided by the /function style/. The differences between the two discourses can be usefully tracked by examining their interpretations of two contested strategies for theorizing hierarchical selection: /horizontal/ and /vertical/ averaging. (shrink)
Individual and group selection are usually conceived as opposed evolutionary processes. Though cases of synergy are occasionally recognized, the evolutionary importance of synergy is largely ignored. However, synergy is the plausible explanation for the evolution of collectives as higher level individuals i.e., collectives acting as adaptive units, e.g., genomes and colonies of social insects. It rests on the suppression of the predictable tendency of evolutionary units to benefit at the expense of other units or of the (...) wholes they contribute to build. It plausibly explains human cooperation and morality: the molding of human groups into adaptive units. (shrink)
Elliott Sober (1987). Parsimony and the Units of Selection. In Nancy J. Nersessian (ed.), The Process of Science: Contemporary Philosophical Approaches to Understanding Scientific Practice. Distributors for the United States and Canada, Kluwer Academic Publishers.score: 93.0
The debate about the levels of selection has been one of the most controversial both in evolutionary biology and in philosophy of science. Okasha’s book makes the sort of contribution that simply will not be able to be ignored by anyone interested in this field for many years to come. However, my interest here is in highlighting some examples of how Okasha goes about discussing his material to suggest that his book is part of an increasingly interesting trend that (...) sees scientists and philosophers coming together to build a broadened concept of “theory” through a combination of standard mathematical treatments and conceptual analyses. Given the often contentious history of the relationship between philosophy and science, such trend cannot but be welcome. (shrink)
In this paper, using a multilevel approach, we defend the positive role of natural selection in the generation of organismal form. Despite the currently widespread opinion that natural selection only plays a negative role in the evolution of form, we argue, in contrast, that the Darwinian factor is a crucial (but not exclusive) factor in morphological organization. Analyzing some classic arguments, we propose incorporating the notion of ‘downward causation’ into the concept of ‘natural selection.’ In our opinion, (...) this kind of causation is fundamental to the operation of selection as a creative evolutionary process. (shrink)
Natural selection is an important force that shapes the evolution of all living things by determining which individuals contribute the most descendents to future generations. The biological unit upon which selection acts has been the subject of serious debate, with reasonable arguments made on behalf of populations, individuals, individual phenotypic characters and, finally, individual genes themselves. In this essay, I argue that the usual unit of selection is the gene. There are powerful logical arguments in favor of (...) this conclusion, as well as many real-world examples. I also explore the possibility that epigenetic differences between individuals may be heritable between generations. Although few such examples exist, epigenetic differences provide an exciting source of potentially heritable variation that may allow rapid evolutionary change to occur, perhaps in response to environmental influences. (shrink)
The theory of evolution is supported by the theory of genetics, which provides a single causal mechanism to explain the activities of replicators and interactors. A common misrepresentation of the theory of evolution, however, is that interaction (involving interactors), and transmission (involving replicators), are distinct causal processes. Sandra Mitchell (1987) is misled by this. I discuss why only a single causal mechanism is working in evolution and why it is sufficient. Further, I argue that Mitchell's mistaken view of the causal (...) mechanism in evolution prevents her from resolving the conflict between Dawkins and Brandon. I conclude that the unit-of-selection question remains very much alive. (shrink)
In The Levels of Selection (Brandon, 1984), Robert Brandon provides a suggestive but ultimately unsuccessful attempt to use the probabilistic notion ofscreening off in providing a schema for dealing with an aspect of the units of selection question in the philosophy of biology. I characterize that failure, and suggest a revision and expansion of Brandon's account which addresses its key shortcoming.
A set of constraints forces trade-offs which prevent us from achieving the best possible definitions of the ‘level’ and ‘unit’ of natural selection. This set consists in decisions concerning conflicting pre-analytic intuitions in problematic cases, the relative roles of various conceptual resources in the definitions, which facts need to be accounted for using the definitions, how the relation between selection and evolution orients the definitions, and the relation between the level and unit concepts. Systematic reconstruction and evaluation of (...) leading analyses along these dimensions favors a new functional analysis over Williams’ consequentialist analysis, Sober’s causal analysis, and Dawkins’ teleological analysis. (shrink)
A set of constraints forces trade-offs which prevent us from achieving the best possible definitions of the ‘level’ and ‘unit’ of natural selection. This set consists in decisions concerning conflicting pre-analytic intuitions in problematic cases, the relative roles of various conceptual resources in the definitions, which facts need to be accounted for using the definitions, how the relation between selection and evolution orients the definitions, and the relation between the level and unit concepts. Systematic reconstruction and evaluation of (...) leading analyses along these dimensions favors a new functional analysis over Williams’ consequentialist analysis, Sober’s causal analysis, and Dawkins’ teleological analysis. (shrink)
How do fitness and natural selection relate to other evolutionary factors like architectural constraint, mode of reproduction, and drift? In one way of thinking, drawn from Newtonian dynamics, fitness is one force driving evolutionary change and added to other factors. In another, drawn from statistical thermodynamics, it is a statistical trend that manifests itself in natural selection histories. It is argued that the first model is incoherent, the second appropriate; a hierarchical realization model is proposed as a basis (...) for a statistical treatment. It emerges that natural selection does not cause evolution; it just is evolution. The theory incorporates relations of statistical correlation, but not the kind of causation found in fundamental physical processes. (shrink)
The capacity to engage with art is a human universal present in all cultures and just about every individual human. This indicates that this capacity is evolved. In this Critical Notice of Denis Dutton's The Art Instinct, I discuss various evolutionary scenarios and their consequences. Dutton and I both reject the "spandrel" approach that originates from the work of Gould and Lewontin. Dutton proposes, following work of Geoffrey Miller, that art is sexually selected--that art-production is a sign of a fit (...) genome in males. I argue that while assortative mating may well have had a role in the evolution of "the art instinct", group selection is a better explanation. I also take issue with Dutton's "cluster concept" approach to defining art, and argue that it is a universal and essential characteristic of art that it is appreciated both for what it expresses and for the way that it expresses. It thus requires a reflexive capacity that is not operative in the appreciation of sport spectacles and pornography. (shrink)
The explanatory role of natural selection is one of the long-term debates in evolutionary biology. Nevertheless, the consensus has been slippery because conceptual confusions and the absence of a unified, formal causal model that integrates different explanatory scopes of natural selection. In this study we attempt to examine two questions: (i) What can the theory of natural selection explain? and (ii) Is there a causal or explanatory model that integrates all natural selection explananda? For the first (...) question, we argue that five explananda have been assigned to the theory of natural selection and that four of them may be actually considered explananda of natural selection. For the second question, we claim that a probabilistic conception of causality and the statistical relevance concept of explanation are both good models for understanding the explanatory role of natural selection. We review the biological and philosophical disputes about the explanatory role of natural selection and formalize some explananda in probabilistic terms using classical results from population genetics. Most of these explananda have been discussed in philosophical terms but some of them have been mixed up and confused. We analyze and set the limits of these problems. (shrink)
Genic selectionists (Williams 1966; Dawkins 1976) defend the view that genes are the (unique) units of selection and that all evolutionary events can be adequately represented at the genic level. Pluralistic genic selectionists (Sterelny and Kitcher 1988; Waters 1991; Dawkins 1982) defend the weaker view that in many cases there are multiple equally adequate accounts of evolutionary events, but that always among the set of equally adequate representations will be one at the genic level. We describe a range (...) of cases all involving stable equilibria actively maintained by selection. In these cases genotypic models correctly show that selection is active at the equilibrium point. In contrast, the genic models have selection disappearing at equilibrium. For deterministic models this difference makes no difference. However, once drift is added in, the two sets of models diverge in their predicted evolutionary trajectories. Thus, contrary to received wisdom on this matter, the two sets of models are not empirically equivalent. Moreover, the genic models get the facts wrong. (shrink)
This paper distinguishes and critiques several forms of pluralism about the levels of selection, and introduces a novel way of thinking about the biological properties and processes typically conceptualized in terms of distinct levels. In particular, "levels" should be thought of as being entwined or fused. Since the pluralism discussed is held by divergent theorists, the argument has implications for many positions in the debate over the units of selection. And since the key points on which the (...) paper turns apply beyond this specific issue, the paper may prove of general interest in thinking about the metaphysics of science. (shrink)
Darwinians are realists about the force of selection, but there has been surprisingly little discussion about what form this realism should take. Arguments about the units of selection in general and genic selectionism in particular reveal two realist assumptions: (1) for any selection process, there is a uniquely correct identification of the operative selective forces and the level at which each impinges; and (2) selective forces must satisfy the Pareto-style requirement of probabilistic causation. I argue that (...) both assumptions are false; we must temper realism about the force of selection and revise the way we think about probabilistic causation. (shrink)
In this paper Wimsatt's analysis of units of selection is taken as defining the units of selection question. A definition of levels of selection is offered and it is shown that the levels of selection question is quite different from the units of selection question. Some of the relations between units and levels are briefly explored. It is argued that the levels of selection question is the question relevant to explanatory (...) concerns, and it is suggested that it is the question relevant to ontological concerns. (shrink)
The idea that clades might be units of selection, defended by a number of biologists and philosophers of biology, is critically examined. I argue that only entities which reproduce, i.e. leave offspring, can be units of selection, and that a necessary condition of reproduction is that the offspring entity be able, in principle, to outlive its parental entity. Given that clades are monophlyetic by definition, it follows that clades do not reproduce, so it makes no sense (...) to talk about a clade's fitness, so clade selection is impossible. Three possible responses to this argument are examined and found wanting. (shrink)
I shall introduce the units 0f decision problem in thc theory of decision, which as I shall explain is 21 sibling t0 thc units 0f selection problem in cvolutionary thcory. And I shall present an argument to thc cffcct that, contrary to Bayesian wisdom on the subject, undertaking decision in group settings (in multi-individual units) violates no precepts of rationality.
Philosophers have not taken the evolution of human beings seriously enough. If they did, argues Peter Munz, many long-standing philosophical problems would be resolved. One of the philosophical consequences of biology is that all the knowledge produced in evolution is a priori established hypothetically by chance mutation and selective retention rather than by observation and intelligent induction. For organisms as embodied theories, selection is natural. For theories as disembodied organisms, it is artificial. Following Karl Popper, the growth of knowledge (...) is seen to be continuous from "the amoeba to Einstein." Philosophical Darwinism brings perspective to contemporary debates. It has far-reaching implications for cognitive science and artificial intelligence, and questions attempts from the field of biology to reduce mental events to neural processes. Most importantly, it provides a rational postmodern alternative to what the author views as the unreasonable postmodern theories of Kuhn, Lyotard, and Rorty. (shrink)
Natural selection is an extremely powerful process – so powerful, in fact, that it is often tempting to deploy it in explaining phenomena as wide-ranging as the persistence of blue eyes, the origins or persistence of religious belief, or, the history of science. One long-standing debate among both critics and advocates of Darwin’s concerns the scope of Darwinian explanations, and how we are to draw the line. Peter Godfrey-Smith’s Darwinian Populations and Natural Selection is a detailed examination of (...) this question. The book explores the criteria for what may count as a “Darwinian population,” by which Godfrey-Smith means, which collections of entities have the capacity to undergo evolution via natural selection (p. 6). Drawing upon his answer to this question, Godfrey-Smith examines and provides his own solution to the following long-standing debates in philosophy of biology: (a) the twin problems of reproduction and individuation of biological entities, (b) the persistent “gene’s eye view,” (c) the levels and units of selection problem, and (d) the evolution of cultural artifacts and behaviors. (shrink)
This paper compares two well-known arguments in the units of selection literature, one due to , the other due to . Both arguments concern the legitimacy of averaging fitness values across contexts and making inferences about the level of selection on that basis. The first three sections of the paper shows that the two arguments are incompatible if taken at face value, their apparent similarity notwithstanding. If we accept Sober and Lewontin's criterion for when averaging genic fitnesses (...) across diploid genotypes is illegitmate, we cannot accept Sober and Wilson's criterion for when averaging individual fitnesses across groups is illegitimate, and vice versa. The final section suggests a possible way of reconciling the two arguments, by invoking an ambiguity in the concept of genic selection. (shrink)
This paper is about the reconstruction of the Darwinian Theory of Natural Selection. My aim here is to outline the fundamental law of this theory in an informal way from its applications in The Origin of Species and to make explicit its fundamental concepts. I will introduce the theory-nets of special laws that arise from the specialization of the fundamental law. I will assume the metatheoretical structuralist frame. I will also point out many consequences that my proposal has about (...) a few metatheoretical discussions around the theory and, finally, I will relate my propose to other reconstructions available. (shrink)
We distinguish dynamical and statistical interpretations of evolutionary theory. We argue that only the statistical interpretation preserves the presumed relation between natural selection and drift. On these grounds we claim that the dynamical conception of evolutionary theory as a theory of forces is mistaken. Selection and drift are not forces. Nor do selection and drift explanations appeal to the (sub-population-level) causes of population level change. Instead they explain by appeal to the statistical structure of populations. We briefly (...) discuss the implications of the statistical interpretation of selection for various debates within the philosophy of biologythe `explananda of selection' debate and the `units of selection' debate. (shrink)
It is shown that, for technical reasons, the additivity of variance criterion employed by Lloyd (1988) to define a unit of selection is, in almost all models of selection, inconsistent with the possibility that genes are sometimes not the unit of selection. A case when the latter view is particularly attractive is that of heterosis, and the additivity criterion is inadequate in even such an extreme case. The connection between that criterion and the so-called "fundamental theorem of (...) natural selection" is briefly explored. Skepticism is expressed about the value of measures such as variance in efforts to resolve any of the disputes about the "units of selection.". (shrink)
I address the controversy in evolutionary biology concerning which levels of biological entity (units) can and do undergo natural selection. I refine a definition of the unit of selection, first presented by William Wimsatt, that is grounded in the structure of natural selection models. I examine Elliott Sober's objection to this structural definition, the "homogeneous populations" problem; I find that neither the proposed definition nor Sober's own causal account can solve the problem. Sober, in his solution (...) using his causal view, imports precisely the information needed to make the structural definition effective. Finally, I indicate how the proposed definition can clarify which sorts of evidence could be brought to bear on the controversial case of the Myxoma virus. (shrink)
The beanbag genetics controversy can be traced from the dispute between Fisher and Wright, through Mayr''s influential promotion of the issue, to the contemporary units of selection debate. It centers on the claim that genic models of natural selection break down in the face of epistatic interactions among genes during phenotypic development. This claim is explored from both a conceptual and a quantitative point of view, and is shown to be defective on both counts.Firstly, an analysis of (...) the controversy''s theoretical origins demonstrates that this claim derives from a misinterpretation of the conceptual foundations of Fisher''s genetical theory of natural selection, and confounds his fundamentally different concepts of the average excess and average effect of a gene. Secondly, an extension of the genic approach is proposed which models the dynamics of selection among epistatically interacting complexes of many genes. Paradoxically, this preliminary, but fundamentally genic model provides quantitative support for some controversial qualitative claims regarding the evolutionary consequences of strong gene interactions made by opponents of genic selectionism, including Mayr''s theory of peripartric speciation. These findings foster hope that the proposed approach may eventually nudge the beanbag controversy out of its conceptual trenches into a more empirically oriented dialogue. (shrink)
Individuals are a prominent part of the biological world. Although biologists and philosophers of biology draw freely on the concept of an individual in articulating both widely accepted and more controversial claims, there has been little explicit work devoted to the biological notion of an individual itself. How should we think about biological individuals? What are the roles that biological individuals play in processes such as natural selection (are genes and groups also units of selection?), speciation (are (...) species individuals?), and organismic development (do genomes code for organisms)? Much of our discussion here will focus on organisms as a central kind of biological individual, and that discussion will raise broader questions about the nature of the biological world, for example, about its complexity, its organization, and its relation to human thought. (shrink)
Niche construction theory inherits flaws from previous gene-culture coevolutionary theories. Units of cultural transmission have not yet been defined. Vertical transmission is not necessarily an overwhelmingly important part of culture. The assumption that human genetic interests and human cultural interests are in synch is a form of naive group selection.
Selection operates at many levels. Robert Brandon has distinguished the question of the level of selection from the unit of selection, arguing that the phenotype is commonly the target of selection, whatever the unit of selection might be. He uses "screening off" as a criterion for distinguishing the level of selection. Cave animals show a common morphological pattern which includes hypertrophy of some structures and reduction or loss of others. In a study of (...) a cave dwelling crustacean, Gammarus minus, we find evidence for selection for both increased antennal size and reduction of eyes. The genetic structure of the population does not support the view that the phenotype screens off the genotype in explaining the differences in fitness. Nonetheless, the results do indicate that the level of selection is at least at the level of the phenotype in both cases. (shrink)
Biological theory demands a clear organism concept, but at present biologists cannot agree on one. They know that counting particular units, and not counting others, allows them to generate explanatory and predictive descriptions of evolutionary processes. Yet they lack a unified theory telling them which units to count. In this paper, I offer a novel account of biological individuality, which reconciles conflicting definitions of ‘organism’ by interpreting them as describing alternative realisers of a common functional role, and then (...) defines individual organisms as essentially possessing some mechanisms that play this role. (shrink)
Does natural selection act primarily on individual organisms, on groups, on genes, or on whole species? The question of levels of selection - on which biologists and philosophers have long disagreed - is central to evolutionary theory and to the philosophy of biology. Samir Okasha's comprehensive analysis gives a clear account of the philosophical issues at stake in the current debate.
Instead of using only one notion of selection I argue for a broader typology of different types of selection. Three such types are differentiated, namely simple one-step selection, iterated one-step selection, and multi-step selection. It is argued that this more general and more inclusive typology might face more effectively the possible challenges of a general account of selection.
Elliott Sober and his defenders think of selection, drift, mutation, and migration as distinct evolutionary forces. This paper exposes an ambiguity in Sober's account of the force of selection: sometimes he appears to equate the force of selection with variation in fitness, sometimes with ‘selection for properties’. Sober's own account of fitness as a property analogous to life-expectancy shows how the two conceptions come apart. Cases where there is selection against variance in offspring number also (...) show that selection and drift cannot be distinguished in the way Sober hopes for. These issues have significance beyond the parochial matter of the coherence of Sober's system. There is no good principled answer to the question of which features of a population should count among the contributors to fitness. This means there is no non-arbitrary account of the nature of selection. (shrink)
An influential argument due to Elliott Sober, subsequently strengthened by Denis Walsh and Joel Pust, moves from plausible premises to the bold conclusion that natural selection cannot explain the traits of individual organisms. If the argument were sound, the explanatory scope of selection would depend, surprisingly, on metaphysical considerations concerning origin essentialism. I show that the Sober-Walsh-Pust argument rests on a flawed counterfactual criterion for explanatory relevance. I further show that a more defensible criterion for explanatory relevance recently (...) proposed by Michael Strevens lends support to the view that natural selection can be relevant to the explanation of individual traits. (shrink)
Developmental systems theory (DST) expands the unit of replication from genes to whole systems of developmental resources, which DST interprets in terms of cycling developmental processes. Expansion seems required by DST's argument against privileging genes in evolutionary and developmental explanations of organic traits. DST and the expanded replicator brook no distinction between biological and cultural evolution. However, by endorsing a single expanded unit of inheritance and leaving the classical molecular notion of gene intact, DST achieves only a nominal reunification of (...) heredity and development. I argue that an alternative conceptualization of inheritance denies the classical opposition of genetics and development while avoiding the singularity inherent in the replicator concept. It also yields a new unit--the reproducer--which genuinely integrates genetic and developmental perspectives. The reproducer concept articulates the non-separability of "genetic" and "developmental" roles in units of heredity, development, and evolution. DST reformulated in terms of reproducers rather than replicators preserves an empirically interesting distinction between cultural and biological evolution. (shrink)
In this paper I propose a type-hierarchy approach to provide an intersubjective framework for the evaluation of evolutionary analogies. This approach develops David Hull’s and others’ attempts to provide full generalisation for selection processes, in order to show that sociocultural development and, particularly, scientific change can be considered as an instance of Darwinian selection. I argue that the recent work by Eileen Cornell Way on type hierarchies can offer the kind of generalisation needed to solve the main problems (...) that still affect Hull’s theory and to show that the evolutionary analogy is, after all, only a particular way of grouping phenomena together. If Hull’s main objective is a unified theory of selection, which supports the idea that science selection and natural selection obey the same laws, I also argue that the type hierarchy approach to models shows that this objective is unsustainable as it stands, and is in need of further development. I will firstly introduce the general outline of the type hierarchy approach to models. Then, after a brief recapitulation of Hull’s main points and difficulties, I will try and construct a hierarchy for a general abstraction of selection processes. Finally I will introduce the main criticisms that Hull’s work has faced from philosophers and scientists, and show how they compare with my proposal. (shrink)
The “negative view” is the claim that natural selection cannot explain why a particular individual has one trait, rather than another. Here, I modify an example from Lewens (2001) to show that this claim is sometimes false. I then advance a variation on the negative view. It is the claim that selection at the organism level within a lineage cannot explain why a particular individual in that lineage has one allele, rather than another. This formulation better describes the (...) explanatory role of selection. (shrink)
This chapter defends the positive thesis which constitutes its title. It argues first, that the mind has been shaped by natural selection; and second, that the result of that shaping process is a modular mental architecture. The arguments presented are all broadly empirical in character, drawing on evidence provided by biologists, neuroscientists and psychologists (evolutionary, cognitive, and developmental), as well as by researchers in artificial intelligence. Yet the conclusion is at odds with the manifest image of ourselves provided both (...) by introspection and by common-sense psychology. The chapter concludes by sketching how a modular architecture might be developed to account for the patently unconstrained character of human thought, which has served as an assumption in a number of recent philosophical attacks on mental modularity. (shrink)
DAVID HODGSON Abstract: This article supports the proposition that, if a judgment about the aesthetic merits of an artistic object can take into account and thereby be influenced by the particular quality of the object, through gestalt experiences evoked by the object, then we have free will. It argues that it is probable that such a judgment can indeed take into account and be influenced by the particular quality of the object through gestalt experiences evoked by it, so as to (...) make it probable that we do have free will. The proposition is supported by reference to two basic tricks apparently involved in conscious processes, which I call the qualia trick and the chunking trick; and it is suggested that these tricks make possible and indeed probable the existence of a third trick, which I call the selection trick. (shrink)
A number of authors argue that while species are evolutionary units, individuals and real entities, higher taxa are not. I argue that drawing the divide between species and higher taxa along such lines has not been successful. Common conceptions of evolutionary units either include or exclude both types of taxa. Most species, like all higher taxa, are not individuals, but historical entities. Furthermore, higher taxa are neither more nor less real than species. None of this implies that there (...) is no distinction between species and higher taxa; the point is that such a distinction is more subtle than many authors have claimed. (shrink)
Some naturalistic theories of consciousness give an essential role to teleology.1 This teleology is said to arise due to natural selection. Thus it is claimed that only certain states, namely, those that have been selected for by evolutionary pro- cesses because they contribute to (or once contributed to) an organism’s fitness, are conscious states. These theories look as if they are assigning a creative role to natural selection. If a state is conscious only if it has been selected (...) for, then selec- tion appears to be able to create a new feature of states, namely, their conscious nature. Yet, intuitively, natural selection cannot create anything. Natural selec- tion chooses certain features that already exist and makes them more (or less) prevalent in a population, but it cannot bring features into existence itself. Natu- ral selection can select for conscious states, but it cannot create them. This con- clusion has recently been argued for by Steven Horst (1999). If it is right, then teleological theories of conscious states should be rejected. A state cannot become a conscious experience in virtue of having been selected for by evolu- tionary process. (shrink)
Group-structured populations, of the kind prominent in discussions of multilevel selection, are contrasted with ‘neighbor-structured’ populations. I argue that it is a necessary condition on multilevel description of a selection process that there should be a nonarbitrary division of the population into equivalence classes (or an approximation to this situation). The discussion is focused via comparisons between two famous problem cases involving group structure (altruism and heterozygote advantage) and two neighbor-structured cases that resemble them. Conclusions are also drawn (...) about the role of correlated interaction in the evolution of altruism. 1 Introduction 2 Two Kinds of Population Structure 3 Objections and Replies 4 Particles on a Line 5 Conclusion Appendix: Neighborhoods and Selection CiteULike Connotea Del.icio.us What's this? (shrink)
Fisher’s ‘fundamental theorem of natural selection’ is notoriously abstract, and, no less notoriously, many take it to be false. In this paper, I explicate the theorem, examine the role that it played in Fisher’s general project for biology, and analyze why it was so very fundamental for Fisher. I defend Ewens (1989) and Lessard (1997) in the view that the theorem is in fact a true theorem if, as Fisher claimed, ‘the terms employed’ are ‘used strictly as defined’ (1930, (...) p. 38). Finally, I explain the role that projects such as Fisher’s play in the progress of scientific inquiry. (shrink)
Bayesian model selection has frequently been the focus of philosophical inquiry (e.g., Forster, Br J Philos Sci 46:399–424, 1995; Bandyopadhyay and Boik, Philos Sci 66:S390–S402, 1999; Dowe et al., Br J Philos Sci 58:709–754, 2007). This paper argues that Bayesian model selection procedures are very diverse in their inferential target and their justification, and substantiates this claim by means of case studies on three selected procedures: MML, BIC and DIC. Hence, there is no tight link between Bayesian model (...)selection and Bayesian philosophy. Consequently, arguments for or against Bayesian reasoning based on properties of Bayesian model selection procedures should be treated with great caution. (shrink)
Genes are thought to have evolved from long-lived and multiply-interactive molecules in the early stages of the origins of life. However, at that stage there were no replicators, and the distinction between interactors and replicators did not yet apply. Nevertheless, the process of evolution that proceeded from initial autocatalytic hypercycles to full organisms was a Darwinian process of selection of favourable variants. We distinguish therefore between Neo-Darwinian evolution and the related Weismannian and Central Dogma divisions, on the one hand, (...) and the more generic category of Darwinian evolution on the other. We argue that Hull’s and Dawkins’ replicator/interactor distinction of entities is a sufficient, but not necessary, condition for Darwinian evolution to take place. We conceive the origin of genes as a separation between different types of molecules in a thermodynamic state space, and employ a notion of reproducers. (shrink)
Kripke has argued that definitions of units of measurements provide examples of statements that are both contingent and a priori. In this paper I argue that definitions of units of measurement are intended to be stipulations of what Kripke calls theoretical identities: a stipulation that two terms will have the same rigid designation. Hence such a definition is both a priori and necessary. The necessity arises because such definitions appeal to natural kind properties only, which on Kripke's account (...) are necessary. (shrink)
The Nature of Selection is a straightforward, self-contained introduction to philosophical and biological problems in evolutionary theory. It presents a powerful analysis of the evolutionary concepts of natural selection, fitness, and adaptation and clarifies controversial issues concerning altruism, group selection, and the idea that organisms are survival machines built for the good of the genes that inhabit them. "Sober's is the answering philosophical voice, the voice of a first-rate philosopher and a knowledgeable student of contemporary evolutionary theory. (...) His book merits broad attention among both communities. It should also inspire others to continue the conversation."-Philip Kitcher, Nature "Elliott Sober has made extraordinarily important contributions to our understanding of biological problems in evolutionary biology and causality. The Nature of Selection is a major contribution to understanding epistemological problems in evolutionary theory. I predict that it will have a long lasting place in the literature."-Richard C. Lewontin. (shrink)
The debate about the levels of selection has been one of the most controversial both in evolutionary biology and in philosophy of science. Okasha’s book makes the sort of contribution that simply will not be able to be ignored by anyone interested in this field for many years to come. However, my interest here is in highlighting some examples of how Okasha goes about discussing his material to suggest that his book is part of an increasingly interesting trend that (...) sees scientists and philosophers coming together to build a broadened concept of “theory” through a combination of standard mathematical treatments and conceptual analyses. Given the often contentious history of the relationship between philosophy and science, such trend cannot but be welcome. (shrink)
Authors frequently refer to gene-based selection in biological evolution, the reaction of the immune system to antigens, and operant learning as exemplifying selection processes in the same sense of this term. However, as obvious as this claim may seem on the surface, setting out an account of “selection” that is general enough to incorporate all three of these processes without becoming so general as to be vacuous is far from easy. In this target article, we set out (...) such a general account of selection to see how well it accommodates these very different sorts of selection. The three fundamental elements of this account are replication, variation, and environmental interaction. For selection to occur, these three processes must be related in a very specific way. In particular, replication must alternate with environmental interaction so that any changes that occur in replication are passed on differentially because of environmental interaction. One of the main differences among the three sorts of selection that we investigate concerns the role of organisms. In traditional biological evolution, organisms play a central role with respect to environmental interaction. Although environmental interaction can occur at other levels of the organizational hierarchy, organisms are the primary focus of environmental interaction. In the functioning of the immune system, organisms function as containers. The interactions that result in selection of antibodies during a lifetime are between entities (antibodies and antigens) contained within the organism. Resulting changes in the immune system of one organism are not passed on to later organisms. Nor are changes in operant behavior resulting from behavioral selection passed on to later organisms. But operant behavior is not contained in the organism because most of the interactions that lead to differential replication include parts of the world outside the organism. Changes in the organism's nervous system are the effects of those interactions. The role of genes also varies in these three systems. Biological evolution is gene-based (i.e., genes are the primary replicators). Genes play very different roles in operant behavior and the immune system. However, in all three systems, iteration is central. All three selection processes are also incredibly wasteful and inefficient. They can generate complexity and novelty primarily because they are so wasteful and inefficient. Key Words: evolution; immunology; interaction; operant behavior; operant learning; replication; selection; variation. (shrink)
One way to understand science is as a selection process. David Hull, one of the dominant figures in contemporary philosophy of science, sets out in this volume a general analysis of this selection process that applies equally to biological evolution, the reaction of the immune system to antigens, operant learning, and social and conceptual change in science. Hull aims to distinguish between those characteristics that are contingent features of selection and those that are essential. Science and (...) class='Hi'>Selection brings together many of David Hull's most important essays on selection (some never before published) in one accessible volume. (shrink)
This paper argues in favor of the epistemic properties of inclusiveness in the context of democratic deliberative assemblies and derives the implications of this argument in terms of the epistemically superior mode of selection of representatives. The paper makes the general case that, all other things being equal and under some reasonable assumptions, more is smarter. When applied to deliberative assemblies of representatives, where there is an upper limit to the number of people that can be included in the (...) group, the argument translates into a defense of a specific selection mode of participants: random selection. (shrink)
The levels of selection problem was central to Maynard Smith’s work throughout his career. This paper traces Maynard Smith’s views on the levels of selection, from his objections to group selection in the 1960s to his concern with the major evolutionary transitions in the 1990s. The relations between Maynard Smith’s position and those of Hamilton and G.C. Williams are explored, as is Maynard Smith’s dislike of the Price equation approach to multi-level selection. Maynard Smith’s account of (...) the ‘core Darwinian principles’ is discussed, as is his debate with Sober and Wilson (1998) over the status of trait-group models, and his attitude to the currently fashionable concept of pluralism about the levels of selection. (shrink)
No other scientific theory has had as tremendous an impact on our understanding of the world as Darwin's theory as outlined in his Origin of Species, yet from the very beginning the theory has been subject to controversy. The Evolution of Darwinism focuses on three issues of debate - the nature of selection, the nature and scope of adaptation, and the question of evolutionary progress. It traces the varying interpretations to which these issues were subjected from the beginning and (...) the fierce contemporary debates that still rage on and explores their implications for the greatest questions of all: Where we come from, who we are and where we might be heading. Written in a clear and non-technical style, this book will be of use as a textbook for students in the philosophy of science who need to become familiar with the background to the debates about evolution. (shrink)
Hull et al. rightly point out the special character of selection as a causal mode, but ironically they seem to force selection back into traditional causal modes by decomposing it into replication, variation, and environmental interaction. Many processes are selective, and a taxonomy of a broad range of kinds of selection may be preferable to narrowing the applicability of the term.
... Difficulty of distinguishing between Varieties and Species — Origin of Domestic ... and Origin— Principle of Selection anciently followed, its Effects— ...
The aim of this paper is to outline a typologyof selection processes, and show that differentsub-categories have different explanatorypower. The basis of this typology of selectionprocesses is argued to be the difference ofreplication processes involved in them. Inorder to show this, I argue that: 1.Replication is necessary for selection and 2.Different types of replication lead todifferent types of selection. Finally, it isargued that this typology is philosophicallysignificant, since it contrasts cases ofselection (on the basis of the replicationprocesses (...) involved in them) whereby selectioncauses adaptation – and, therefore, can beused in explanations of the (real or apparent)teleology of Nature – and cases in whichselection lacks such explanatory power. (shrink)
For principled and substantially philosophical reasons, based largely on his reform of natural history by inverting the Paleyan notion of overarching and purposeful bene¢cence in the construction of organisms, Darwin built his theory of selection at the single causal level of individual bodies engaged in unconscious (and metaphorical) struggle for their own reproductive success. But the central logic of the theory allows selection to work e¡ectively on entities at several levels of a genealogical hierarchy, provided that they embody (...) a set of requisite features for de¢ning evolutionary individuality. Genes, cell lineages, demes, species, and cladesöas well as Darwin's favoured organismsöembody these requisite features in enough cases to form important levels of selection in the history of life. (shrink)
Variation or rearrangement of regulatory genes is responsible for cellular malignant change. These types of chromosomal variations also produce heterochrony or paedomorphic evolution at the organismal level. Analogously, neoplasia represents a cellular macroevolutionary event, and a tumour can be said to be an evolved population of cells. To understand this cellular evolution to malignancy, it may be necessary to go beyond a clonal selection (adaptationist) explanation of neoplastic alteration. In the pericellular environment natural selection consists of the organizational (...) restraints of surrounding cells as well as the host's immunological surveillance and non-specific monocyte-macrophage systems. Indirect evidence suggests that success for the neoplasm depends not upon clonal selection, but solely upon a genetic methodology—the function of which is to elude selection.The author has coined the term cellular heterochrony to illustrate analogic similarities in the molecular modes of speciation between anaplastic cancer cells and the heterochronic evolution of organisms. By reverting to a juvenile (embryonic) repertoire of cellular behaviour a tumour secures its own tenure or niche by usurping the host's armamentarium of selection forces, employing many of the same or similar methods by which implanting and invading tissues of the mammalian embryo forestall maternal detection and rejection. A number of ways by which the tumour blocks, subverts or evades selection are discussed. (shrink)
Examining the implications of a localist model for linguistic performance, I show the strengths of the P-graph, a network of elementary units of meaning where utterance results from relaxation through the operation of a dynamics of affect values. A unit of meaning is stored in a synaptic connection that brings together two words. Such a model, consistent with the anatomy and physiology of the neural tissue, eschews a number of traditional pitfalls of “semantic networks”: (1) ambiguity ceases to be (...) an issue, as similar uses of a word are automatically clustered together; (2) faster retrieval of words acquired early is explained by the larger number of their instances. In addition the P-graph takes advantage of a plausible form of information storage: the local topology of the neural tissue. (shrink)
Hull et al. make a direct connection between selection and replication. My view is that selection, at its causal crux, is not inherently connected to replication. I make plain the causal crux of selection, distinguishing it from replication. I discuss implications of my results for Hull et al.'s critique of Darden and Cain (1989).
The aim of this paper is to outline a typology of selection processes, and show that different sub-categories have different explanatory power. The basis of this typology of selection processes is argued to be the difference of replication processes involved in them. In order to show this, I argue that: 1. Replication is necessary for selection and 2. Different types of replication lead to different types of selection. Finally, it is argued that this typology is philosophically (...) significant, since it contrasts cases of selection (on the basis of the replication processes involved in them) whereby selection causes adaptation – and, therefore, can be used in explanations of the (real or apparent) teleology of Nature – and cases in which selection lacks such explanatory power. (shrink)
Behavioral theorists such as B. F. Skinner have argued that the thesis of selection by consequences applies to behavior just as much as to morphology. This commentary specifically examines certain respects in which the thesis of “selection by consequences” applies to the development of ontogenic operant behavior.
Hull et al. propose a set of features that can be used to identify explanatory systems as being selectionist. The commentary questions the necessity of identifying a unit of retention at the level of behavior-environment interactions. It is concluded that an answer to the question “Are units of retention necessary?” can only be given in light of a clear statement of the goals of a science of behavior.
Matthen (Philos Sci 76(4):464–487, 2009) argues that explanations of evolutionary change that appeal to natural selection are statistically abstractive explanations, explanations that ignore some possible explanatory partitions that in fact impact the outcome. This recognition highlights a difficulty with making selective analyses fully rigorous. Natural selection is not about the details of what happens to any particular organism, nor, by extension, to the details of what happens in any particular population. Since selective accounts focus on tendencies, those factors (...) that impact the actual outcomes but do not impact the tendencies must be excluded. So, in order to properly exclude the factors irrelevant to selection, the relevant factors must be identified, and physical processes, environments, and populations individuated on the basis of being relevantly similar for the purposes of selective accounts. Natural selection, on this view, becomes in part a measure of the robustness of particular kinds of outcomes given variations over some kinds of inputs. (shrink)
Developmental systems theory is an attempt to sum up the ideas of a research tradition in developmental psychobiology that goes back at least to Daniel Lehrman’s work in the 1950s. It yields a representation of evolution that is quite capable of accommodating the traditional themes of natural selection and also the new results that are emerging from evolutionary developmental biology. But it adds something else - a framework for thinking about development and evolution without the distorting dichotomization of biological (...) processes into gene and non-gene and the vestiges of the ‘black-boxing’ of developmental processes in the modern synthesis, such as the asymmetric use of the concept of information. Phenomena that are marginalized in current gene-centric conceptions, such as extra-genetic inheritance, niche construction and phenotypic plasticity are placed center stage. (shrink)
Charles Darwin's On the Origin of Species is unquestionably one of the chief landmarks in biology. The Origin (as it is widely known) was literally only an abstract of the manuscript Darwin had originally intended to complete and publish as the formal presentation of his views on evolution. Compared with the Origin, his original long manuscript work on Natural Selection, which is presented here and made available for the first time in printed form, has more abundant examples and illustrations (...) of Darwin's argument, plus an extensive citation of sources. (shrink)
The group selection controversy largely focuses on altruism (e.g., Wilson 1983; Lloyd 2001; Shavit 2004; Okasha 2006, 173ff; Borrello 2010; Leigh 2010; Rosas 2010; Hamilton and Dimond in press). Multilevel selection theory is a resolution of this controversy. Whereas kin selection partitions inclusive fitness into direct and indirect components (via influencing the replication of copies of genes in other individuals), multilevel selection considers within-group and between-group components of fitness (Gardner et al. 2011; Lion et al. 2011). (...) Two scenarios of multilevel selection are often distinguished (Damuth and Heisler 1988; Okasha 2006; Pigliucci 2010): (1) group structure only divides individual fitnesses into within- and between-group components (MLS1); and, (2) groups get their own component of fitness and also, in most definitions, a group-level adaptation (MLS2). (shrink)
Perhaps the most readable and accessible of the great works of scientific imagination, The Origin of Species sold out on the day it was published in 1859. Theologians quickly labeled Charles Darwin the most dangerous man in England, and, as the Saturday Review noted, the uproar over the book quickly "passed beyond the bounds of the study and lecture-room into the drawing-room and the public street." Yet, after reading it, Darwin's friend and colleague T. H. Huxley had a different reaction: (...) "How extremely stupid not to have thought of that." Based largely on Darwin's experience as a naturalist while on a five-year voyage aboard H.M.S. Beagle, The Origin of Species set forth a theory of evolution and natural selection that challenged contemporary beliefs about divine providence and the immutability of species. A landmark contribution to philosophical and scientific thought, this edition also includes an introductory historical sketch and a glossary Darwin later added to the original text. Charles Darwin grew up considered, by his own account, "a very ordinary boy, rather below the common standard of intellect." A quirk of fate kept him from the career his father had deemed appropriate--that of a country parson--when a botanist recommended Darwin for an appointment as a naturalist aboard H.M.S. Beagle from 1831 to 1836. Darwin is also the author of the five-volume work Zoology of the Voyage of the Beagle (1839) and The Descent of Man (1871). (shrink)
Natural selection in the sense of Darwin always means physical propagation (positive case) or disappearance (negative case) of living organisms due to differential reproduction. If one concentrates on this simple materialist principle, one arrives at a much better method of discerning true selection processes from largely nonrandom processes of internal rearrangement (somatic mutations) and reorganisation (operant learning).
Activity anorexia illustrates selection of behavior at the biological, behavioral, and neural levels. Based on evolutionary history, food depletion increases the reinforcement value of physical activity that, in turn, decreases the reinforcement effectiveness of eating – resulting in activity anorexia. Neural opiates participate in the selection of physical activity during periods of food depletion.
Here I advance two related evolutionary propositions. (1) Natural selection is most often considered to require competition between reproducing “individuals”, sometimes quite broadly conceived, as in cases of clonal, species or multispecies-community selection. But differential survival of non-competing and non-reproducing individuals will also result in increasing frequencies of survival-promoting “adaptations” among survivors, and thus is also a kind of natural selection. (2) Darwinists have challenged the view that the Earth’s biosphere is an evolved global homeostatic system. Since (...) there is only one biosphere, reproductive competition cannot have been involved in selection for such survival-promoting adaptations, they claim. But natural selection through survival could reconcile Gaia with evolutionary theory. (shrink)
Observations with respect to the relationship between symptoms and diseases can seriously be biased by selection phenomena. This selection may occur from the general population, via consultation behavior, diagnostic and therapeutic activities of the general practitioner, and by referral.Relationships may be suggested and reproduced even if they do not exist in unselected populations, as a product of diagnostic routines. Correction for selection bias can only be achieved by choosing proper (...) comparison groups. While this can be done in a general practice setting, this is almost impossible after referral, as is demonstrated in this paper. Surprisingly, the most unbiased estimation of the relationship between symptoms and diseases after referral can be made from patient groups that are referred for reason unrelated to the disease under study. (shrink)
This commentary is an attempt to sharpen some of the issues raised in the paper and thereby increase the generality of the proposal. Some implications of an exact definition of behavior for strategies of measurement and hence behavioral variability are discussed. The role of both respondent and operant behavior in natural selection is emphasized.
