My comments will focus on the second and third chapters of Sober’s book , which explore Darwin’s ideas about altruism, group selection and kin selection , and sex-ratio evolution . Sober makes a persuasive argument for his main claim: that Darwin was a subtler thinker on these topics than he is often taken to be. While there is much that I admire in Sober’s lucid discussion, I will focus on points of disagreement. Readers should note that this is not the (...) first time that Sober and I have disagreed on these issues .Sober begins his chapter on group selection with a brief history of the modern debate on the topic, which began in earnest in the 1960s. One of the key figures in this debate was George Williams, whose book Adaptation and Natural Selection helped convince many biologists that group selection was unlikely to be an important factor in evolution. Sober is critical of many of Williams’ arguments, though .. (shrink)

This paper provides a philosophical analysis of the ongoing controversy surrounding R.A. Fisher's famous ‘fundamental theorem’ of natural selection. The difference between the ‘traditional’ and ‘modern’ interpretations of the theorem is explained. I argue that proponents of the modern interpretation have captured Fisher's intended meaning correctly and shown that the theorem is mathematically correct, pace the traditional consensus. However, whether the theorem has any real biological significance remains an unresolved issue. I argue that the answer depends on whether we accept (...) Fisher's non-standard notion of environmental change, on which the theorem rests; arguments for and against this notion are explored. I suggest that there is a close link between Fisher's fundamental theorem and the modern ‘gene's eye’ view of evolution. Introduction What Does the Fundamental Theorem Say? Key Concepts Explained Alleged Significance of the FTNS Traditional versus Modern Interpretations of the FTNS The Modern Interpretation Illustrated Fisher's Concept of ‘Environmental Change’ Causality and the Modern Interpretation The Significance of the FTNS Re-considered Appendix CiteULike Connotea Del.icio.us What's this? (shrink)

In models of multi-level selection, the property of Darwinian fitness is attributed to entities at more than one level of the biological hierarchy, e.g. individuals and groups. However, the relation between individual and group fitness is a controversial matter. Theorists disagree about whether group fitness should always, or ever, be defined as total (or average) individual fitness. This paper tries to shed light on the issue by drawing on work in social choice theory, and pursuing an analogy between fitness and (...) utility. Social choice theorists have long been interested in the relation between individual and social utility, and have identified conditions under which social utility equals total (or average) individual utility. These ideas are used to shed light on the biological problem. (shrink)

“The Role of the Individual in Evolution” is a prescient yet neglected 1941 work by the 20th century’s most important paleontologist, George Gaylord Simpson. In a curious intermingling of explanation and critique, Simpson engages questions that would become increasingly fundamental in modern biological theory and philosophy. Did individuality, adaptation, and evolutionary causation reside at more than one level: the cell, the organism, the genetically coherent reproductive group, the social group, or some combination thereof? What was an individual, anyway? In this (...) introduction, we highlight two points in a wider historical context. First, recognizing the political context of Simpson’s writing profoundly deepens our understanding of the development of his science as the Modern Evolutionary Synthesis infused biology. Second, this story illuminates the emergence of debates around what would eventually come to be called multilevel selection theory. The organism-centered concept of biological individuality defended by Simpson is situated in relation to the then-emerging Synthesis, in which he was a renowned player, and also in relation to the views he opposed: the “metaphysical” ideas of paleontologists such as Henry Fairfield Osborn, who claimed that some evolutionary trends derived from potentialities already implanted in the germplasm; and the organicist ideas of Ralph W. Gerard and the Chicago School of ecologists, which he derided as all too congenial to totalitarianism. We find parallels between the ways that Simpson thought then about human individuality under totalitarianism and the way he thought about individuality in evolution; not that any causal relationship linked the two, but that commonalities of hierarchical structure exist between single entities and groups in both instances. We then trace the subsequent development of Simpson’s political and philosophical takes on the role of the individual in evolution through the 1960s and lightly sketch out the later fate of the organicist ideas of the Chicago School. Simpson’s paper, originally published in the Journal of the Washington Academy of Sciences, is available as supplementary material in the online version of this article, as part of the "Classics in Biological Theory" collection. (shrink)

Molecular methods have revolutionised virtually every area of biology, and metazoan phylogenetics is no exception: molecular phylogenies, molecular clocks, comparative phylogenomics, and developmental genetics have generated a plethora of molecular data spanning numerous taxa and collectively transformed our understanding of the evolutionary history of animals, often corroborating but at times opposing results of more traditional approaches. Moreover, the diversity of methods and models within molecular phylogenetics has resulted in significant disagreement among molecular phylogenies as well as between these and earlier (...) phylogenies. How should this broad and multifaceted problem be tackled? I argue that the answer lies in integrating evidence to infer the best evolutionary scenario. I begin with an overview of recent development in early metazoan phylogenetics, followed by a discussion of key conceptual issues in phylogenetics revolving around phylogenetic evidence, theory, methodology, and interrelations thereof. I then argue that the integration of different kinds of evidence is necessary for arriving at the best evolutionary scenario rather than merely the best-fitting cladogram. Finally, I discuss the prospects of this view in stimulating interdisciplinary cross-talk in early metazoan research and beyond, and challenges that need to be overcome. (shrink)

According to a once influential view of selection, it consists of repeated cycles of replication and interaction. It has been argued that this view is wrong: replication is not necessary for evolution by natural selection. I analyze the nine most influential arguments for this claim and defend the replication–interaction conception of selection against these objections. In order to do so, however, the replication–interaction conception of selection needs to be modified significantly. My proposal is that replication is not the copying of (...) an entity, the replicator, but the copying of a property. Thus, we can have a replication process without there being a replicator that is being copied. (shrink)

One of the most deeply entrenched ideas in Popper's philosophy is the analogy between the growth of scientific knowledge and the Darwinian mechanism of natural selection. Popper gave his first exposition of these ideas very early on. In a letter to Donald Campbell, 1 Popper says that the idea goes back at least to the early thirties. 2 And he had a fairly detailed account of it in his "What is dialectic?", a talk given in 1937 and published in 1940: (...) 3 If we want to explain why human thought tends to try out every conceivable solution for any problem with which it is faced, then we can appeal to a highly general sort of regularity. The method by which a solution is approached is .. (shrink)

Pluralism is widely appealed to in many areas of philosophy of science, though what is meant by ‘pluralism’ may profoundly vary. Because explanations of behaviour have been a favoured target for pluralistic theses, the sciences of behaviour offer a rich context in which to further investigate pluralism. This is what the topical collection The Biology of Behaviour: Explanatory pluralism across the life sciences is about. In the present introduction, we briefly review major strands of pluralist theses and their motivations. We (...) highlight three distinct types of pluralisms—type pluralism, fragmentation pluralism and insular pluralism—and introduce the articles of the topical collection. (shrink)

The contextual approach is a prominent framework for thinking about group selection. Here, I highlight ambiguity about what the contextual approach is. Then, I discuss problematic entailments the contextual approach has for what processes count as group selection—entailments more troublesome than typically noted. However, Sober and Wilson’s version of the Price approach, which is the main alternative to the contextual approach, is problematic too: it leads to an underappreciated paradox called the vanishing selection problem and thereby generates the wrong qualitative (...) account of whether group selection is occurring in a certain family of cases. In response, I develop an account of group selection that can deal with the counterexamples to both the contextual approach and the Price approach. I then discuss the role that contextual analysis can continue to play in the discussion of individual fitness and metapopulation evolution. (shrink)

‘Gouldian arguments’ appeal to the contingency of a scientific domain to establish that domain’s autonomy from some body of theory. For instance, pointing to evolutionary contingency, Stephen Jay Gould suggested that natural selection alone is insufficient to explain life on the macroevolutionary scale. In analysing contingency, philosophers have provided source-independent accounts, understanding how events and processes structure history without attending to the nature of those events and processes. But Gouldian Arguments require source-dependent notions of contingency. An account of contingency is (...) source-dependent when it is indexed to some pattern and some process. Positions like Gould’s do not turn on the mere fact of life’s contingency—that life’s shape could have been different due to its sensitivity to initial conditions, path-dependence or stochasticity. Rather, Gouldian arguments require that the contingency is due to particular kinds of processes: in this case, those which microevolutionary theory cannot account for. This source-dependent perspective clarifies both debates about the nature and importance of contingency, and empirical routes for testing Gould’s thesis. (shrink)

Even after Quine’s critique of the analytic-synthetic distinction in “Two Dogmas of Empiricism,” Wilfrid Sellars maintained some forms of analyticity or truth in virtue of meaning. This paper aims to reconstruct his neglected account of the analytic-synthetic distinction and the revisability of analytic sentences, its connection to his inferentialist account of meaning, and his response to Quine. While Sellars’s account of how analytic sentences can be revised bears certain similarities with Carnap’s and Grice and Strawson’s accounts, it is still striking (...) in that it is part of his broader picture of how our language develops dynamically in our ongoing inquiry. I aim to show how it relates within his broader picture to his account of how the diachronic continuity in meaning, language, or conceptual framework can be preserved through a revision of analytic sentences, and to his evolutionary account of the development of our language or conceptual framework. (shrink)

Why do we have social norms—of fairness, cooperation, trust, property, or gender? Modern-day Humeans, as I call them, believe these norms are best accounted for in cultural evolutionary terms, as adaptive solutions to recurrent problems of social interaction. In this paper, I discuss a challenge to this “Humean Program.” Social norms involve widespread behaviors, but also distinctive psychological attitudes and dispositions. According to the challenge, Humean accounts of norms leave their psychological side unexplained. They explain, say, why we share equally, (...) but not why we disapprove of those who don’t. I defend the Humean Program against this challenge. In particular, I suggest an idea for how to extend the Program to account for the psychological side of norms. Socially adaptive behaviors aren’t just likely to emerge in a group; They are also likely to be widely taught within it. The transmission of these behaviors through instruction explains why they are associated with distinctive normative attitudes and dispositions. These attitudes play a pedagogical role in helping transmit these behaviors to children and newcomers. (shrink)

Thinking about organisms as if they were rational agents which could choose their own phenotypic traits according to their fitness values is a common heuristic in the field of evolutionary theory. In a 1998 paper, however, Elliott Sober has emphasized several alleged shortcomings of this kind of analogical reasoning when applied to the analysis of social behaviors. According to him, the main flaw of this heuristic is that it proves to be a misleading tool when it is used for predicting (...) the evolution of cooperation. Here, I show that these charges raised against the heuristic use of this analogy are misguided. I argue, contra Sober, that such a heuristic turns out to be a perfect predictive tool in all relevant contexts where cooperation can at least evolve. Moreover, I argue that it constitutes a powerful and sufficient methodological framework for the analysis of social evolution. (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)

This paper provides a philosophical analysis of the Price equation and its role in evolutionary theory. Traditional models in population genetics postulate simplifying assumptions in order to make the models mathematically tractable. On the contrary, the Price equation implies a very specific way of theorizing, starting with assumptions that we think are true and then deriving from them the mathematical rules of the system. I argue that the Price equation is a generalization-sketch, whose main purpose is to provide a unifying (...) framework for researchers, helping them to develop specific models. The Price equation plays this role because, like other scientific principles, shows features as abstractness, unification and invariance. By underwriting this special role for the Price equation some recent disputes about it could be diverted. (shrink)

Science depends on judgments of the bearing of evidence on theory. Scientists must judge whether an observation or the result of an experiment supports, disconfirms, or is simply irrelevant to a given hypothesis. Similarly, scientists may judge that, given all the available evidence, a hypothesis ought to be accepted as correct or nearly so, rejected as false, or neither. Occasionally, these evidential judgments can be made on deductive grounds. If an experimental result strictly contradicts a hypothesis, then the truth of (...) the data deductively entails the falsity of the hypothesis. In the great majority of cases, however, the connection between evidence and hypothesis is non-demonstrative, or inductive. In particular, this is so whenever a general hypothesis is inferred to be correct on the basis of the available data, since the truth of the data will not deductively entail the truth of the hypothesis. It always remains possible that the hypothesis is false even though the data are correct. (shrink)

One of the major developments in cancer research in recent years has been the construction of models that treat cancer as a cellular population subject to natural selection. We expand on this idea, drawing upon multilevel selection theory. Cancer is best understood in our view from a multilevel perspective, as both a by-product of selection at other levels of organization, and as subject to selection at several levels of organization. Cancer is a by-product in two senses. First, cancer cells co-opt (...) signaling pathways that are otherwise adaptive at the organismic level. Second, cancer is also a by-product of features distinctive to the metazoan lineage: cellular plasticity and modularity. Applying the multilevel perspective in this way permits one to explain transitions in complexity and individuality in cancer progression. Our argument is a reply to Germain’s scepticism towards the explanatory relevance of natural selection for cancer. The extent to which cancer fulfills the conditions for being a paradigmatic Darwinian population depends on the scale of analysis, and the details of the purported selective scenario. Taking a multilevel perspective clarifies some of the complexities surrounding how to best understand the relevance of evolutionary thinking in cancer progression. (shrink)

While the struggle for life played an important role in the process of natural selection as it was conceived by Darwin, natural selection is commonly characterized today as a process which does not necessarily involve struggle. Nevertheless, there have been some attempts to show the importance of struggle to the process of natural selection. The present paper aims to continue these attempts and clarify the precise evolutionary role of struggle. The paper focuses on a recent dispute regarding the role of (...) struggle between Peter Godfrey-Smith and Tim Lewens. Godfrey-Smith argues that struggle makes populations into "paradigm cases of Darwinian populations", meaning that struggle leads natural selection to produce adaptations. Lewens, in contrast, argues that Godfrey-Smith's argument fails to show that struggle plays such a role. I argue that Godfrey-Smith's argument that struggle leads selection to produce adaptations can be understood in two different ways. Lewens interprets Godfrey-Smith's argument in one of these ways, and rightly argues that thus understood, this argument fails to show that struggle leads selection to produce adaptations. However, I show that understood in a second way, Godfrey-Smith's argument does show that struggle plays such a role. Still, I show that there is an additional problem with Godfrey-Smith's argument that struggle makes populations into "paradigm cases of Darwinian populations". It does not capture the precise role played by struggle in the relation between selection and adaptation. Thus, the present paper clarifies the unique role that struggle plays in the relation between selection and adaptation in evolutionary theory. (shrink)

The neutral theory of biodiversity purports that patterns in the distribution and abundance of species do not depend on adaptive differences between species (i.e. niche differentiation) but solely on random fluctuations in population size (“ecological drift”), along with dispersal and speciation. In this framework, the ultimate driver of biodiversity is speciation. However, the original neutral theory made strongly simplifying assumptions about the mechanisms of speciation, which has led to some clearly unrealistic predictions. In response, several recent studies have combined neutral (...) community models with more elaborate speciation models. These efforts have alleviated some of the problems of the earlier approaches, while confirming the general ability of neutral theory to predict empirical patterns of biodiversity. However, the models also show that the mode of speciation can have a strong impact on relative species abundances. Future work should compare these results to diversity patterns arising from non‐neutral modes of speciation, such as adaptive radiations. (shrink)

Is the mammalian embryo/fetus a part of the organism that gestates it? According to the containment view, the fetus is not a part of, but merely contained within or surrounded by, the gestating organism. According to the parthood view, the fetus is a part of the gestating organism. This paper proceeds in two stages. First, I argue that the containment view is the received view; that it is generally assumed without good reason; and that it needs substantial support if it (...) is to be taken seriously. Second, I argue that the parthood view derives considerable support from a range of biological and physiological considerations. I tentatively conclude in favour of the parthood view, and end by identifying some of the interesting questions it raises. (shrink)

Okasha claims at the outset of his book "Evolution and the Levels of Selection" (2006) that the Price equation lays bare the fundamentals underlying all selection phenomena. However, the thoroughness of his subsequent analysis of multi-level selection theories leads him to abandon his fundamentalist commitments. At critical points he invokes cost benefit analyses that sometimes favors the Price approach and sometimes the contextual approach, sometimes favors MLS1 and sometimes MLS2. And although he doesn’t acknowledge it, even the Price approach breaks (...) down into a family of alternative equations that parse the causes in different ways, none of which is uniquely correct and none of which achieves the ultimate isolation of effects due to what Okasha believes are the fundamental causes. I argue that his book provides good reason to re-conceive our understanding of evolutionary theorizing in terms of a toolbox view (developed here) and to stop subjecting the analyses of evolutionary concepts to a universalist standard. (shrink)

The proper function of the heart is pumping the blood. According to what we call the type etiological view, this is because previous tokens of the type HEART were selected for pumping the blood. Nanay :412–431, 2010) argues that the type etiological view is viciously circular. He claims that the only plausible accounts of trait type individuation use proper functions, such that whenever the type etiological view is supplemented with a plausible account of trait type individuation, the result is a (...) view that uses proper functions to explain proper functions. We refine this objection, and argue that Nanay at most establishes a potentially benign definitional circularity. However, we show that the type etiological view’s reliance on types nevertheless generates a vicious regress. Hence the type etiological view is false. We reject dispositional and modal alternatives to the type etiological view for the reason that they either cannot accommodate malfunction, or do so at the cost of proliferation; and then formulate a novel token etiological view that overcomes both problems because it makes no reference to trait types. (shrink)

Immunology and its philosophy are a primary source for thinking about biological individuality. Through its discriminatory function, the immune system is believed to delineate organism and environment within one generation, thus defining the physiological individual. Based on the paradigmatic instantiations of immune systems, immune interactions and, thus, the physiological individual are believed to last only for one generation. However, in recent years, transgenerationally persisting immune responses have been reported in several phyla, but the consequences for physiological individuality have not yet (...) been explored. In this article, I will introduce an invertebrate immune system that is RNA-based and operates through a heritable silencing/licensing paradigm. I will discuss how such a perspective on immune systems can illuminate our conceptions of individuality. I will particularly introduce an account of immunological individuality that is not restricted to one generation. (shrink)

In "Some Criticism of the Contextual Approach, and a Few Proposals" in Biological Theory, Brian McLoone discusses some of the points about the contextual approach that I made in a recent paper. Besides offering a reply to McLoone’s comments on my paper, in this article I show why McLoone’s discussion of the two main frameworks for thinking about group selection—the contextual and the Price approach—is partly misguided. In particular, I show that one of McLoone’s main arguments against the contextual approach (...) is missing the target and that one of his (and Elliott Sober’s) arguments in defense of the Price approach is flawed. Criticizing these arguments will help me present an entirely different picture than McLoone’s of the current status of multilevel selection theory. More precisely, I argue that the idea that we are dealing with "multilevel selection" in the type of multigroup cases in which the focal units are the individuals (and their traits) has recently come under threat. Finally, I discuss the ways in which this idea might be salvaged by appealing either to the contextual or to the Price approach. (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)

This paper argues that the contextual approach to natural selection does not offer an estimation of the contributions of individual and group selection to evolutionary change in multi-level selection scenarios, and that this is so because the term “group selection”, as defined by the contextual approach, does not refer to a process taking place at the group level. In the contextual analysis framework, this term simply denotes an evolutionary change that takes place due to the fact that, overall, individual types (...) do not share similar contexts or environments, and the only way to claim that such an evolutionary change is a result of selection is by admitting that “group selection” is in fact a kind of frequency-dependent selection, i.e. a selection process taking place at the individual level. Therefore, under the names “individual selection” and “group selection”, the contextual approach actually isolates two aspects of the relation between individual types and their environment, and not two distinct levels of selection. (shrink)

In this paper, I identify two general positions with respect to the relationship between environment and natural selection. These positions consist in claiming that selective claims need and, respectively, need not be relativized to homogenous environments. I then show that adopting one or the other position makes a difference with respect to the way in which the effects of selection are to be measured in certain cases in which the focal population is distributed over heterogeneous environments. Moreover, I show that (...) these two positions lead to two different interpretations—the Pricean and contextualist ones—of a type of selection scenarios in which multiple groups varying in properties affect the change in the metapopulation mean of individual-level traits. Showing that these two interpretations stem from different attitudes towards environmental homogeneity allows me to argue: that, unlike the Pricean interpretation, the contextualist interpretation can only claim that drift or selection is responsible for the change in frequency of the focal trait in a given metapopulation if details about whether or not group formation is random are specified; that the traditional main objection against the Pricean interpretation—consisting in arguing that the latter takes certain side-effects of individual selection to be effects of group selection—is unconvincing. This leads me to suggest that the ongoing debate about which of the two interpretations is preferable should concentrate on different issues than previously thought. (shrink)

In this short paper, I argue against what I call the “belonging to” interpretation of group selection in scenarios in which a group’s fitness is defined as the per capita reproductive output of the individuals of the group. According to this interpretation, group selection acts on “belonging to” properties of individuals, i.e. on relational or contextual properties that all the individuals of a group share simply by belonging to that group; thus, if differences in the individuals’ “belonging to” properties cause (...) differences in their fitness, group selection sensu the “belonging to” interpretation is said to be at work. I argue that the main problem with the “belonging to” interpretation is that it confuses evolutionary changes due to differences in environmental quality with evolutionary changes due to selection. In other words, I argue that, in the majority of cases, this interpretation actually takes the “selection” out of the “group selection” notion it aims to interpret: by adopting this perspective, one implicitly commits to explaining the evolutionary change under consideration not by a kind of selection, but by differences in the environmental quality experienced by individual types. (shrink)

Most attempts to answer the question of whether populations of groups can undergo natural selection focus on properties of the groups themselves rather than the dynamics of the population of groups. Those approaches to group selection that do emphasize dynamics lack an account of the relevant notion of equivalent dynamics. I show that the theory of ‘dynamical kinds’ I proposed in Jantzen :3617–3646, 2014) can be used as a framework for assessing dynamical equivalence. That theory is based upon the notion (...) of a dynamical symmetry, a transformation of a system that commutes with its evolution through time. In the proposed framework, structured sets of dynamical symmetries are used to pick out equivalence classes of systems. These classes are large enough to encompass the range of phenomena we associate with natural selection, yet restrictive enough to guarantee a sort of causal homogeneity. By characterizing dynamical kinds via symmetry structures in this way, the question of levels of selection becomes a precise question about which populations respect the dynamical symmetries of Darwinian evolution. Standard population genetic models suggest that populations undergoing evolution by natural selection are partially characterized by a group of fitness-scaling symmetries. I demonstrate conditions under which these symmetries may be satisfied by populations of individuals, populations of groups of individuals, or both simultaneously. (shrink)

Social evolution theory provides a wide array of successful evolutionary explanations for cooperative traits. However and surprisingly, a number of cases of unexplained cooperative behaviour remain. Shouldn’t they cast doubt on the relevance of the theory, or even disconfirm it? This depends on whether the theory is akin to a research programme such as adaptationism, or closer to a theory – a set of compatible, confirmable hypotheses. In order to find out, we focus on the two main tenets of social (...) evolution theory, namely reciprocity explanations and kin selection. Reciprocity-based explanations are extremely hard to confirm. This is due, first to the multiple realisability of explanatory processes, factors and strategies, despite apparent reasons to the contrary; second, to the high quantity, and limited availability of data needed to eliminate or back up such explanations. One of our target cases vividly illustrates these limitations. Moreover, kin selection, while relatively easy to disconfirm in particular cases, seems to enjoy a more limited explanatory scope than previously thought. Overall, social evolution theory turns out to be neither a research programme nor a theory, but a heterogeneous scientific entity, composed of parts that are amenable to confirmation and others barely so. (shrink)

Evolution by natural selection has been extended to several supraorganismic levels, but whether it can apply to ecosystems remains controversial on two main counts. First, local ecosystems are loosely individuated, so that it is unclear how they manifest heredity and fitness. Second, even if they did, the meta-ecosystem formed by this population of local ecosystems will also suffer from a very low degree of cohesion, which will jeopardize any ENS. We suggest a way to overcome both issues, focusing on ecosystem (...) properties rather than on ecosystemic individuals. First, we follow recent theoretical developments which deny the centrality of reproduction in ENS. This leads us to merge heredity and fitness in a single process, in which a local ecosystem causally influences its neighbors, in a way responsible for their phenotypic similarity. Second, we suggest that the resulting meta-ecosystem need not meet the criteria of individuality. Instead, the evolving meta-ecosystem is best understood as a homeostatic property cluster, i.e., a set of phenotypes that together evolve by ENS at the ecosystem level. We illustrate this conceptual framework with a hypothetical example of local ecosystems that vary in terms of stability, productivity, diversity, and complementarity between species. Finally, we stress that our property-based account of ecosystemic ENS can help understand evolution at other biological levels, such as early life evolution and holobionts. (shrink)

We consider the Stag Hunt in terms of Maynard Smith’s famous Haystack model. In the Stag Hunt, contrary to the Prisoner’s Dilemma, there is a cooperative equilibrium besides the equilibrium where every player defects. This implies that in the Haystack model, where a population is partitioned into groups, groups playing the cooperative equilibrium tend to grow faster than those at the non-cooperative equilibrium. We determine under what conditions this leads to the takeover of the population by cooperators. Moreover, we compare (...) our results to the case of an unstructured population and to the case of the Prisoner’s Dilemma. Finally, we point to some implications our findings have for three distinct ideas: Ken Binmore’s group selection argument in favor of the evolution of efficient social contracts, Sewall Wright’s Shifting Balance theory, and the equilibrium selection problem of game theory. (shrink)

The pervasive use of computer simulations in the sciences brings novel epistemological issues discussed in the philosophy of science literature since about a decade. Evolutionary biology strongly relies on such simulations, and in relation to it there exists a research program (Artificial Life) that mainly studies simulations themselves. This paper addresses the specificity of computer simulations in evolutionary biology, in the context (described in Sect. 1) of a set of questions about their scope as explanations, the nature of validation processes (...) and the relation between simulations and true experiments or mathematical models. After making distinctions, especially between a weak use where simulations test hypotheses about the world, and a strong use where they allow one to explore sets of evolutionary dynamics not necessarily extant in our world, I argue in Sect. 2 that (weak) simulations are likely to represent in virtue of the fact that they instantiate specific features of causal processes that may be isomorphic to features of some causal processes in the world, though the latter are always intertwined with a myriad of different processes and hence unlikely to be directly manipulated and studied. I therefore argue that these simulations are merely able to provide candidate explanations for real patterns. Section 3 ends up by placing strong and weak simulations in Levins’ triangle, that conceives of simulations as devices trying to fulfil one or two among three incompatible epistemic values (precision, realism, genericity). (shrink)

Evolutionary theorists often talk as if natural selection were choosing the most adapted traits, or if organisms were deciding to do the most adaptive strategy. Moreover, the payoff of those decisions often depend on what others are doing, and since Hamilton (1964), biologists possess conceptual tools such as kin selection and inclusive fitness to make sense of outcomes of evolution in these contexts, even when they seem unadaptive (such as sterility). The link between selection and adaptation through which selection or (...) organisms can be seen as agents, as well as the scope and nature of Hamiltonian conceptions of social evolution, stimulated many formal elaborations (such as, initially, Fisher’s “Fundamental theorem of natural selection”), but also raise major philosophical issues about causation and statistics, and about rationality and adaptation or selection. Two recent philosophy books, Okasha’s Agents and goals in evolution, and Birch’s Philosophy of social evolution, tackle those question. This essay reflects on them in order to think of those two issues. After having reviewed the books, I try to sketch some philosophical lessons onto which they concur. (shrink)

Biological modalities (e.g., biological possibility, necessity and counterfactuality) play an important explanatory role in biological practice. However, biological modalities lack truth conditions and the inferential relationship between biological and other modalities is unclear. This thesis addresses these problems, first, by improving upon Daniel Dennett's Library of Mendel. Second, a family of modal logics is introduced. In the simplest model, states are interpreted as codons, the binary relation is interpreted as single substitution mutation and the valuation induces a partition of blocks (...) of codons that code for some amino acid. In addition, the proposed framework allows for a grading of biological possibility and captures various competing notions of biological possibility. Applications include a model checker and a lawless Lewis-style semantics for biological counterfactuals. In short, this thesis lays the groundwork for a theory of biological modalities. (shrink)

Gers (Biol Philos, 2011) provides a positive and constructive view of the project to generalise Darwinian principles in Geoffrey Hodgson and Thorbjørn Knudsen’s Darwin’s Conjecture. We note considerable overlap with his work and ours, and also with important recent work of Godfrey-Smith ( 2009 ), which Gers cites extensively. But we also note that there are differences in research objectives between Gers and Godfrey-Smith, on the one hand, and ourselves, on the other. Gers and Godfrey-Smith focus on the elucidation of (...) the most general principles possible. Our aim is to derive principles that are sufficiently abstract to span the natural and human social worlds, and then add additional principles to help understand the Darwinian evolution of human society. Furthermore, Gers and Godfrey-Smith critique a replicator concept that is different from ours. Once these points are made apparent, the criticisms are essentially disabled, and we end up in a position with different but complementary and overlapping research projects. (shrink)

Life on Earth descends from a common ancestor. However, it is likely that there are other instances of life in the universe. If so, each abiogenesis event will have given rise to an independently originated life clade, of which Earth-life is an example. In this paper, I argue that the set of all IOLCs in the universe forms a Darwinian population subject to natural selection, with more widely dispersed IOLCs being less likely to face extinction. As a result, we should (...) expect that, over time, more planets will become inhabited by fewer, more successful IOLCs. (shrink)

In this article we focus on the emergence of biological individuality by association, trying to formulate some theoretical conditions to think about the process of collective individualization. The starting point of our analysis is the notion of “major evolutionary transition.” A major evolutionary transition is the result of the integration of a multiplicity of initially independent biological entities that, by managing to organize their interactions, become a collective of components having an identity oriented towards a common goal. When biological organisms (...) are concerned, a major transition corresponds to a phenomenon of fusion between them. We shall argue that the emergence of a new biological level of individuality implies the establishment of constitutive relationships between individuals that change their status as autonomous entities. As a result, the emergence of a new type of entity in the living world implies that individuals enter into relationships that intrinsically transform them, a transformation sufficient for a “whole” to become a “part” that forms another “whole”, that is, a new level of organismality. (shrink)

The presence of various mechanisms of non-genetic inheritance is one of the main problems for current evolutionary theory according to several critics. Sufficient empirical and conceptual reasons exist to take this claim seriously, but there is little consensus on the implications of multiple inheritance systems for evolutionary processes. Here we use the Price Equation as a starting point for a discussion of the differences between four recently proposed categories of inheritance systems; genetic, epigenetic, behavioral and symbolic. Specifically, we address how (...) the components of the Price Equation encompass different non-genetic systems of inheritance in an attempt to clarify how the different systems are conceptually related. We conclude that the four classes of inheritance systems do not form distinct clusters with respect to their effect on the rate and direction of phenotypic change from one generation to the next in the absence or presence of selection. Instead, our analyses suggest that different inheritance systems can share features that are conceptually very similar, but that their implications for adaptive evolution nevertheless differ substantially as a result of differences in their ability to couple selection and inheritance. (shrink)

The life of George Price (1922-1975), the eccentric polymath genius and father of the Price equation, is used as a prism and counterpoint through which to consider an age-old evolutionary conundrum: the origins of altruism. This biographical project, and biography and history more generally, are considered in terms of the possibility of using form to convey content in particular ways. Closer to an art form than a science, this approach to scholarship presents both a unique challenge and promise.

All disciplines must define their basic units and core processes. In evolutionary biology, the core process is natural selection and the basic unit of selection and adaptation is the individual. To operationalize the theory of natural selection we must count individuals, as they are the bearers of fitness. While canonical individuals have often been taken to be multicellular organisms, the hierarchy of life shows that new kinds of individuals have evolved. A variety of criteria have been used to define biological (...) individuality. Some criteria rely on the presence/absence of a particular property while others advocate an approach that reflects the process of natural selection. The plethora of approaches to classifying individuality has resulted in confusion regarding how to study individuality in a given taxon. (shrink)

I spell out and update the individuality thesis, that species are individuals, and not classes, sets, or kinds. I offer three complementary presentations of this thesis. First, as a way of resolving an inconsistent triad about natural kinds; second, as a phylogenetic systematics theoretical perspective; and, finally, as a novel recursive account of an evolved character. These approaches do different sorts of work, serving different interests. Presenting them together produces a taxonomy of the debates over the thesis, and isolates ways (...) it has been productive. This goes to the larger point of this paper: a defense of the individuality thesis in terms of its utility, and an update of it in light of recent theoretical developments and empirical work in biology. (shrink)

Thomas Pradeu’s The Limits of the Self provides a precise account of biological identity developed from the central concepts of immunology. Yet the central concepts most relevant to this task are themselves deemed inadequate, suffering from ambiguity and imprecision. Pradeu seeks to remedy this by proposing a new guiding theory for immunology, the continuity theory. From this, an account of biological identity is provided in terms of uniqueness and individuality, ultimately leading to a defense of the heterogeneous organism as expressing (...) the highest degree of individuality. (shrink)

Sharon Street defines her constructivism about practical reasons as the view that whether something is a reason to do a certain thing for a given agent depends on that agent’s normative point of view. However, Street has also maintained that there is a judgment about practical reasons which is true relative to every possible normative point of view, namely constructivism itself. I show that the latter thesis is inconsistent with Street’s own constructivism about epistemic reasons and discuss some consequences of (...) this incompatibility. (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)

Alan M. Turing’s last published work and some posthumously published manuscripts were dedicated to the development of his theory of organic pattern formation. In “The Chemical Basis of Morphogenesis” (1952), he provided an elaborated mathematical formulation of the theory of the origins of biological form that had been first proposed by Sir D’Arcy Wendworth Thompson in On Growth and Form (1917/1942). While arguably his most mathematically detailed and his systematically most ambitious effort, Turing’s morphogenetical writings also form the most thematically (...) self-contained and least philosophically explored part of his work. We dedicate our inquiry to the reasons and the implications of Turing’s choice of biological topic and viewpoint. We will probe for possible factors in Turing’s choice that go beyond availability and acquaintance with On Growth and Form. On these grounds, we will explore how and to what extent his theory of morphogenesis actually ties in with his concept of mechanistic computation. Notably, Thompson’s pioneering work in biological ‘structuralism’ was organicist in outlook and explicitly critical of the Darwinian approaches that were popular with Turing’s cyberneticist contemporaries—and partly used by Turing himself in his proto-connectionist models of learning. Resolving this apparent dichotomy, we demonstrate how Turing’s quest for mechanistic explanations of how organisation emerges in nature leaves room for a non-mechanist view of nature. (shrink)