Contemporary biological research has suggested that some host–microbiome multispecies systems (referred to as “holobionts”) can in certain circumstances evolve as unique biological individual, thus being a unit of selection in evolution. If this is so, then it is arguably the case that some biological adaptations have evolved at the level of the multispecies system, what we call hologenomic adaptations. However, no research has yet been devoted to investigating their nature, or how these adaptations can be distinguished from adaptations at the (...) species-level (genomic adaptations). In this paper, we cover this gap by investigating the nature of hologenomic adaptations. By drawing on the case of the evolution of sanguivory diet in vampire bats, we argue that a trait constitutes a hologenomic adaptation when its evolution can only be explained if the holobiont is considered the biological individual that manifests this adaptation, while the bacterial taxa that bear the trait are only opportunistic beneficiaries of it. We then use the philosophical notions of emergence and inter-identity to explain the nature of this form of individuality and argue why it is special of holobionts. Overall, our paper illustrates how the use of philosophical concepts can illuminate scientific discussions, in the trend of what has recently been called metaphysics of biology. (shrink)

Bourrat and Griffiths :33, 2018) have recently argued that most of the evidence presented by holobiont defenders to support the thesis that holobionts are evolutionary individuals is not to the point and is not even adequate to discriminate multispecies evolutionary individuals from other multispecies assemblages that would not be considered evolutionary individuals by most holobiont defenders. They further argue that an adequate criterion to distinguish the two categories is fitness alignment, presenting the notion of fitness boundedness as a criterion that (...) allows divorcing true multispecies evolutionary individuals from other multispecies assemblages and provides an adequate criterion to single out genuine evolutionary multispecies assemblages. A consequence of their criterion is that holobionts, as conventionally defined by hologenome defenders, are not evolutionary individuals except in very rare cases, and for very specific host-symbiont associations. This paper is a critical response to Bourrat and Griffiths’ arguments and a defence of the arguments presented by holobiont defenders. Drawing upon the case of the hologenomic basis of the evolution of sanguivory in vampire bats, I argue that Bourrat and Griffiths overlook some aspects of the biological nature of the microbiome that justifies the thesis that holobionts are evolutionarily different to other multispecies assemblages. I argue that the hologenome theory of evolution should not define the hologenome as a collection of genomes, but as the sum of the host genome plus some traits of the microbiome which together constitute an evolutionary individual, a conception I refer to as the stability of traits conception of the hologenome. Based on that conception I argue that the evidence presented by holobiont defenders is to the point, and supports the thesis that holobionts are evolutionary individuals. In this sense, the paper offers an account of the holobiont that aims to foster a dialogue between hologenome advocates and hologenome critics. (shrink)

If there is a single discipline of science calling the basic concepts of biology into question, it is without doubt microbiology. Indeed, developments in microbiology have recently forced us to rethink such fundamental concepts as the organism, individual, and genome. In this paper I show how microorganisms are changing our understanding of natural aggregations and develop the concept of a Darwinian population to embrace these discoveries. I start by showing that it is hard to set the boundaries of a Darwinian (...) population, and I suggest thinking of a Darwinian population as a relative property of a Darwinian individual. Then I argue, in contrast to the commonly held view, that Darwinian populations are multispecies units, and that in order to accept the multispecies account of Darwinian populations we have to separate fitness from natural selection. Finally, I show how all these ideas provide a theoretical framework leading to a more precise understanding of the ecology of endosymbiosis than is afforded by poetic metaphors such as ‘slavery’. (shrink)

What are the prospects for a monistic view of biological individuality given the multiple epistemic roles the concept must satisfy? In this paper, I examine the epistemic adequacy of two recent accounts based on the capacity to undergo natural selection. One is from Ellen Clarke, and the other is by Peter Godfrey-Smith. Clarke’s position reflects a strong monism, in that she aims to characterize individuality in purely functional terms and refrains from privileging any specific material properties as important in their (...) own right. I argue that Clarke’s functionalism impairs the epistemic adequacy of her account compared to a middle-ground position taken by Godfrey-Smith. In comparing Clarke and Godfrey-Smith’s account, two pathways emerge to pluralism about biological individuality. The first develops from the contrast between functionalist and materialist approaches, and the second from an underlying temporal structure involved in using evolutionary processes to define individuality. (shrink)

I defend a radical interpretation of biological populations—what I call population pluralism—which holds that there are many ways that a particular grouping of individuals can be related such that the grouping satisfies the conditions necessary for those individuals to evolve together. More constraining accounts of biological populations face empirical counter-examples and conceptual difficulties. One of the most intuitive and frequently employed conditions, causal connectivity—itself beset with numerous difficulties—is best construed by considering the relevant causal relations as ‘thick’ causal concepts. I (...) argue that the fine-grained causal relations that could constitute membership in a biological population are huge in number and many are manifested by degree, and thus we can construe population membership as being defined by massively multidimensional constructs, the differences between which are largely arbitrary. I end by showing that positions in two recent debates in theoretical biology depend on a view of biological populations at odds with the pluralism defended here. (shrink)

An understanding of the factors behind the evolution of multicellularity is one of today’s frontiers in evolutionary biology. This is because multicellular organisms are made of one subset of cells with the capacity to transmit genes to the next generation and another subset responsible for maintaining the functionality of the organism, but incapable of transmitting genes to the next generation. The question arises: why do somatic cells sacrifice their lives for the sake of germline cells? How is germ/soma separation maintained? (...) One conventional answer refers to inclusive fitness theory, according to which somatic cells sacrifice themselves altruistically, because in so doing they enhance the transmission of their genes by virtue of their genetic relatedness to germline cells. In the present article we will argue that this explanation ignores the key role of policing mechanisms in maintaining the germ/soma divide. Based on the pervasiveness of the latter, we argue that the role of altruistic mechanisms in the evolution of multicellularity is limited and that our understanding of this evolution must be enriched through the consideration of coercion mechanisms. (shrink)

In this article I develop a big picture of the evolution of human cooperation, and contrast it to an alternative based on group selection. The crucial claim is that hominin history has seen two major transitions in cooperation, and hence poses two deep puzzles about the origins and stability of cooperation. The first is the transition from great ape social lives to the lives of Pleistocene cooperative foragers; the second is the stability of the social contract through the early Holocene (...) transition to complex hierarchical societies. The first of these transitions is driven, at least initially, by individual advantage: cooperation paid off for individual foragers, initially through mutualist interaction, then through reciprocation. This argument leads to a reanalysis of the role of violence and the nature of the freeriding threat to cooperation. But the conditions that select for cooperative individuals in the Pleistocene were eroded in the Pleistocene–Holocene transition. So we need an alternative account of the survival, and indeed the expansion, of cooperation in the Holocene. Group selection driven by intercommunal conflict really may well be central to this second transition. (shrink)

Here I reply to Jean Gayon's, Tim Lewens's, and Samir Okasha's comments on Did Darwin write the Origin backwards? The topics addressed include: Darwin's thinking that common ancestry is "evidentially prior" to natural selection; how Darwin uses phylogenetic trees to test hypotheses concerning natural selection; how group and indivdiual selection should be defined, and how each is related to the concept of adaptation.

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.

Philosophers have shown that the Aristotelian conception of mind and body is capable of resolving the problems confronting dualism. In this paper the resolution of the mind–body problem is extended with a scientific solution by integrating the Aristotelian framework with evolutionary theory. It is discussed how the theories of Fisher and Hamilton enable us to construct and solve hypotheses about how the mind evolved out of matter. These hypotheses are illustrated by two examples: the evolutionary transition from cells to multicellular (...) organisms, and the evolutionary transition from babbling to doing things with words and later reasoning and giving reasons. The first transitions resulted in the sensitive psyche of the other animals, the second in the rational psyche of humans. It is discussed how exploratory behaviour of lower-level entities facilitated these evolutionary transitions. (shrink)

Williams argued that Darwin replaced teleology by natural selection. This article argues that this idea is based on a misunderstanding of Darwin’s critique of the argument from design. Darwin did not replace teleology by evolutionary explanations but showed that we can understand teleology without referring to a Designer. He eliminated the concept of design and rehabilitated Aristotelian teleological explanations. The implication is that adaptations should not be investigated as if designed, but with the help of both teleological and evolutionary explanations. (...) It is argued that elaborations of teleological explanations enable us to reconcile evolutionary theory and other fields in science. (shrink)

Williams argued that Darwin replaced teleology by natural selection. This article argues that this idea is based on a misunderstanding of Darwin’s critique of the argument from design. Darwin did not replace teleology by evolutionary explanations but showed that we can understand teleology without referring to a Designer. He eliminated the concept of design and rehabilitated Aristotelian teleological explanations. The implication is that adaptations should not be investigated as if designed, but with the help of both teleological and evolutionary explanations. (...) It is argued that elaborations of teleological explanations enable us to reconcile evolutionary theory and other fields in science. (shrink)

Heyes’ book is an important contribution that rightly integrates cognitive development and cultural evolution. However, understanding the cultural evolution of cognitive gadgets requires a deeper appreciation of complexity, feedback, and self-organization than her book exhibits.

We review Evolution and the Levels of Selection by Samir Okasha. This important book provides a cohesive philosophical framework for understanding levels-of-selections problems in biology. Concerning evolutionary transitions, Okasha proposes that three stages characterize the shift from a lower level of selection to a higher one. We discuss the application of Okasha’s three-stage concept to the evolutionary transition from unicellularity to multicellularity in the volvocine green algae. Okasha’s concepts are a provocative step towards a more general understanding of the major (...) evolutionary transitions; however, the application of certain ideas to the volvocine model system is not straightforward. (shrink)

Understanding good design requires addressing the question of what units undergo natural selection, thereby becoming adapted. There is, therefore, a natural connection between the formal Darwinism project (which aims to connect population genetics with the evolution of design and fitness maximization) and levels of selection issues. We argue that the formal Darwinism project offers contradictory and confusing lines of thinking concerning level(s) of selection. The project favors multicellular organisms over both the lower (cell) and higher (social group) levels as the (...) level of adaptation. Grafen offers four reasons for giving such special status to multicellular organisms: (1) they lack appreciable within-organism cell selection, (2) they have multiple features that appear contrived for the same purpose, (3) they possess a set of phenotypes, and (4) they leave offspring according to their phenotypes. We discuss why these rationales are not compelling and suggest that a more even-handed approach, in which multicellular organisms are not assumed to have special status, would be desirable for a project that aims to make progress on the foundations of evolutionary theory. (shrink)

Adaptations can occur at different hierarchical levels, but it can be difficult to identify the level of adaptation in specific cases. A major problem is that selection at a lower level can filter up, creating the illusion of selection at a higher level. We use optimality modeling of the volvocine algae to explore the emergence of genuine group adaptations. We find that it is helpful to develop an explicit model for what group fitness would be in the absence of group-level (...) relationships between traits and group fitness. We call this “counterfactual fitness,” because in many actual cases of interest there are group-level relationships. Once counterfactual fitness is modeled, the difference between effects that filter up and genuine group selection is explicit and so, therefore, is the distinction between apparent and genuine group adaptations. We call the latter group-specific adaptations. Recognizing group-specific adaptations is important because only group-specific adaptations would cause the lower-level units to be maladapted if they were to leave the group and enter a global cell-level population. Thus, as group-specific adaptations evolve, they create selective pressure for increased cohesiveness and individuality of groups. This article suggests that group-specific adaptations could be present in the simplest, earliest branching colonial volvocine species, which do not have distinct specialized cells. The article also makes predictions about the kind of empirical evidence needed to support or refute the hypothesis that a particular trait is a group-level adaptation. (shrink)

A number of scholars have recently defended the claim that there is a close connection between the evolutionary biological notion of fitness and the economic notion of utility: both are said to refer to an organism’s success in dealing with its environment, and both are said to play the same theoretical roles in their respective sciences. However, an analysis of two seemingly disparate but in fact structurally related phenomena—‘niche construction’ (the case where organisms change their environment to make it fit (...) to their needs) and ‘adaptive preferences’ (the case where agents change their wants to make them fit to what the world has given them)—shows that one needs to be very careful about the postulation of this sort of fitness–utility connection. Specifically, I here use the analysis of these two phenomena to establish when connecting fitness and utility is and is not possible. (shrink)

In this paper, I consider the recent resurgence of “evolutionary economics”—the idea that evolutionary theory can be very useful to push forward key debates in economics—and assess the extent to which it rests on a plausible foundation. To do this, I first distinguish two ways in which evolutionary theory can, in principle, be brought to bear on an economic problem—namely, evidentially and heuristically—and then apply this distinction to the three major hypotheses that evolutionary economists have come to defend: the implausibility (...) of rational choice theory as an account of economic rationality, the idea that firms are autonomous economic agents, and the need for a more dynamic, less equilibrium-focused economic methodology. In each of these cases, I conclude negatively: the relevant evolutionary considerations neither suggest interesting and novel hypotheses to investigate further nor are backed up by the needed data to constitute genuine evidence. I end by distinguishing this criticism of evolutionary economics from others that have been put forward in the literature: in particular, I make clear that, unlike those of other critics, the arguments of this paper are based on epistemic—not structural—considerations and therefore leave more room for a plausible form of evolutionary economics to come about in the future. (shrink)

I distinguish two versions of kin selection theory—a purely genetic version and a version that also appeals to cultural forms of cooperation —and present an argument in favor of using the former when it comes to accounting for the evolution of cooperation in non-human organisms. Specifically, I first show that both GKST and WKST are equally mathematically coherent—they can both be derived from the Price equation—but not necessarily equally empirically plausible, as they are based on different assumptions about the inheritance (...) system underlying the cooperative phenotype. Given this, I then, second, present a model selection theoretic argument in favor of GKST over WKST. This argument is based on the fact that, in non-human cases, the former theory is likely to be as empirically successful as WKST, while containing fewer degrees of freedom. I end by defending both the intrinsic importance of this argument and its relevance to the discussion surrounding the “gene’s eye view of evolution.”. (shrink)

This article is a systematic critical survey of work done in the philosophy of biology within the logical empiricist tradition, beginning in the 1930s and until the end of the 1950s. It challenges a popular view that the logical empiricists either ignored biology altogether or produced analyses of little value. The earliest work on the philosophy of biology within the logical empiricist corpus was that of Philipp Frank, Ludwig von Bertalanffy, and Felix Mainx. Mainx, in particular, provided a detailed analysis (...) of biology in the 1930s and 1940s in his contribution to the logical empiricists’ Encyclopedia of Unified Science. However, the most important contributions to the philosophy of biology were those of Joseph Henry Woodger and Ernest Nagel. Woodger is primarily remembered for deploying the axiomatic method in biology but he also used semiformal methods for the analysis of many biological problems. While Woodger’s axiomatic work was often derided by some later philosophers of biology (e.g., David Hull and Michael Ruse), this article defends both the biological and the philosophical significance of some of that work, for instance, those aspects that led to the recognition of the conceptual complexity of mereology and temporal identity in biological systems. Woodger’s semiformal analyses were even more important, for instance, his explication of the concepts of the Bauplan and of innateness. Nagel’s importance lies in his analyses of reduction and emergence in the context of all empirical sciences and his use of these analyses in a careful exploration of biological problems. While Nagel’s model of reduction was generally rejected by philosophers of science in the 1970s and 1980s, particularly for biological contexts, it has recently been sympathetically reconstructed by many commentators; this article defends its continued relevance for the philosophy of biology. (shrink)

Two questions are raised for Grafen’s formal darwinism project of aligning evolutionary dynamics under natural selection with the optimization of phenotypes for individuals of a population. The first question concerns mean fitness maximization during frequency-dependent selection; in such selection regimes, not only is mean fitness typically not maximized but it is implausible that any parameter closely related to fitness is being maximized. The second question concerns whether natural selection on inclusive fitness differences can be regarded as individual selection or whether (...) it leads to a departure from the central motivation that led to the formal darwinism project, viz., to show that “Darwinian” evolution through individual selection leads to “good design” or phenotypic adaptation through trait optimization. (shrink)

The idea that natural selection can operate on cultural as well as genetic variation is central to recent theories of cultural evolution. This raises an overarching question: how much of traditional evolutionary theory, which was formulated in population-genetic terms, can survive intact once the possibility of cultural inheritance is taken into account? This question is addressed in relation to R. A. Fisher’s “fundamental theorem” of natural selection. Though Fisher’s theorem may appear to be an essentially genetic result, a version of (...) the theorem can be derived that applies to any evolving population, with an arbitrary inheritance mechanism. However, I argue that the biological significance of this “generalized” version of the fundamental theorem is less than that of the Fisherian original. (shrink)

Social evolution theory conventionally takes an externalist explanatory stance, treating observed cooperation as explanandum and the positive assortment of cooperative behaviour as explanans. We ask how the circumstances bringing about this positive assortment arose in the first place. Rather than merely push the explanatory problem back a step, we move from an externalist to an interactionist explanatory stance, in the spirit of Lewontin and the Niche Construction theorists. We develop a theory of ‘social niche construction’ in which we consider biological (...) entities to be both the subject and object of their own social evolution. Some important cases of the evolution of cooperation have the side-effect of causing changes in the hierarchical level at which the evolutionary process acts. This is because the traits that act to align the fitness interests of particles in a collective can also act to diminish the extent to which those particles are bearers of heritable fitness variance, while augmenting the extent to which collectives of such particles are bearers of heritable fitness variance. In this way, we can explain upward transitions in the hierarchical level at which the Darwinian machine operates in terms of particle-level selection, even though the outcome of the process is a collective-level selection regime. Our theory avoids the logical and metaphysical paradoxes faced by other attempts to explain evolutionary transitions. (shrink)

Current Perspectives in Philosophy of Biology.

Both Popper and van Fraassen have used evolutionary analogies to defend their views on the aim of science, although these are diametrically opposed. By employing Price's equation in an illustrative capacity, this paper considers which view is better supported. It shows that even if our observations and experimental results are reliable, an evolutionary analogy fails to demonstrate why conjecture and refutation should result in: (1) the isolation of true theories; (2) successive generations of theories of increasing truth-likeness; (3) empirically adequate (...) theories; or (4) successive generations of theories of increasing proximity to empirical adequacy. Furthermore, it illustrates that appeals to induction do not appear to help. It concludes that an evolutionary analogy is only sufficient to defend the notion that the aim of science is to isolate a particular class of false theories, namely those that are empirically inadequate. (shrink)

Holobionts, consisting of a host and diverse microbial symbionts, function as distinct biological entities anatomically, metabolically, immunologically, and developmentally. Symbionts can be transmitted from parent to offspring by a variety of vertical and horizontal methods. Holobionts can be considered levels of selection in evolution because they are well-defined interactors, replicators/reproducers, and manifestors of adaptation. An initial mathematical model is presented to help understand how holobionts evolve. The model offered combines the processes of horizontal symbiont transfer, within-host symbiont proliferation, vertical symbiont (...) transmission, and holobiont selection. The model offers equations for the population dynamics and evolution of holobionts whose hologenomes differ in gene copy number, not in allelic or loci identity. The model may readily be extended to include variation among holobionts in the gene identities of both symbionts and host. (shrink)

The paper argues that the evident features of all human affairs of interest to the social scientist demand Darwinian explanations. It must however be recognized that the range of regularities, models, theories that a successful Darwinian research program will inspire must be heterogeneous, operate at very different scales, identify a diversity of distinct and often unrepeated processes operating through multifarious instances of blind variation and environmental selection. There will be no canonical statement of a Darwinian theory of cultural and/or social (...) affairs. (shrink)

The history of biological systematics documents a continuing tension between classifications in terms of nested hierarchies congruent with branching diagrams (the ‘Tree of Life’) versus reticulated relations. The recognition of conflicting character distribution led to the dissolution of the scala naturae into reticulated systems, which were then transformed into phylogenetic trees by the addition of a vertical axis. The cladistic revolution in systematics resulted in a representation of phylogeny as a strictly bifurcating pattern (cladogram). Due to the ubiquity of character (...) conflict—at the genetic or morphological level, or at any level in between—some characters will necessarily have to be discarded ( qua noise) in favor of others in support of a strictly bifurcating phylogenetic tree. Pattern analysts will seek maximal congruence in the distribution of characters (ultimately of any kind) relative to a branching tree-topology; process explainers will call such tree-topologies into question by reference to incompatible evolutionary processes. Pattern analysts will argue that process explanations must not be brought to bear on pattern reconstruction; process explainers will insist that the reconstructed pattern requires a process explanation to become scientifically relevant, i.e., relevant to evolutionary theory. The core question driving the current debate about the adequacy of the ‘Tree of Life’ metaphor seems to be whether the systematic dichotomization of the living world is an adequate representation of the complex evolutionary history of global biodiversity. In ‘Questioning the Tree of Life’, it seems beneficial to draw at least four conceptual distinctions: pattern reconstruction versus process explanation as different epistemological approaches to the study of phylogeny; open versus closed systems as expressions of different kinds of population (species) structures; phylogenetic trees versus cladograms as representations of evolutionary processes versus patterns of relationships; and genes versus species as expressions of different levels of causal integration and evolutionary transformation. (shrink)

While evolutionary thinking is increasingly becoming popular in fields of investigation outside the biological sciences, it remains unclear how helpful it is there and whether it actually yields good explanations of the phenomena under study. Here we examine the ontology of a recent approach to applying evolutionary thinking outside biology, the generalized Darwinism approach proposed by Geoffrey Hodgson and Thorbjørn Knudsen. We examine the ontology of populations in biology and in GD, and argue that biological evolutionary theory sets ontological criteria (...) that GD fails to meet. We suggest two options to revise the population concept in GD: reformulating the concept in terms of inheritance and reproduction such that it comes to pick out individuals similar to evolving populations, or trying to build an adequate population concept on a principle of differential retention instead of differential reproduction. 1 Introduction2 Generalized Darwinism2.1 What is generalized Darwinism?2.2 Darwinian principles3 The Ontology of Generalized Darwinism: What Are Populations?3.1 The population concept of generalized Darwinism3.2 The population concept in evolutionary theory4 Locating Evolving Systems in Generalized Darwinism5 Conclusion. (shrink)

The goal of forming a science of intentional behavior requires a more richly detailed account of symbolic systems than is assumed by the authors. Cultural systems are not simply the equivalent in the ideational domain of culture of the purported Baldwin Effect in the genetic domain. © 2014 Cambridge University Press.

Reciprocal altruism was originally formulated in terms of individual selection and most theorists continue to view it in this way. However, this interpretation of reciprocal altruism has been challenged by Sober and Wilson (1998). They argue that reciprocal altruism (as well as all other forms of altruism) evolves by the process of group selection. In this paper, we argue that the original interpretation of reciprocal altruism is the correct one. We accomplish this by arguing that if fitness attaches to (at (...) minimum) entire life cycles, then the kind of fitness exchanges needed to form the group-level in such situations is not available. Reciprocal altruism is thus a result of individual selection and when it evolves, it does so because it is individually advantageous. (shrink)

Biological fitness is a foundational concept in the theory of natural selection. Natural selection is often defined in terms of fitness differences as “any consistent difference in fitness (i.e., survival and reproduction) among phenotypically different biological entities” (Futuyma 1998, 349). And in Lewontin’s (1970) classic articulation of the theory of natural selection, he lists fitness differences as one of the necessary conditions for evolution by natural selection to occur. Despite this foundational position of fitness, there remains much debate over the (...) nature of fitness, especially whether fitness differences can truly be said to cause evolutionary change. In recent years these debates have crystalized into two camps: (1) causalists, who see fitness differences as being one of the causes of evolutionary change, and (2) statisticalists, who deny the causal efficacy of fitness and instead hold that “fitness is a mere statistical, noncausal property of trait types” (Walsh 2010, 148). (shrink)

The emergence of individuality during the evolutionary transition from single cells to multicellularity poses a range of problems. A key issue is how variation in lower‐level individuals generates a corporate (collective) entity with Darwinian characteristics. Of central importance to this process is the evolution of a means of collective reproduction, however, the evolution of a means of collective reproduction is not a trivial issue, requiring careful consideration of mechanistic details. Calling upon observations from experiments, we draw attention to proto‐life cycles (...) that emerge via unconventional routes and that transition, in single steps, individuality to higher levels. One such life cycle arises from conflicts among levels of selection and invokes cheats as a primitive germ line: it lays the foundation for collective reproduction, the basis of a self‐policing system, the selective environment for the emergence of development, and hints at a plausible origin for a soma/germ line distinction. (shrink)

The organism is one of the fundamental concepts of biology and has been at the center of many discussions about biological individuality, yet what exactly it is can be confusing. The definition that we find generally useful is that an organism is a unit in which all the subunits have evolved to be highly cooperative, with very little conflict. We focus on how often organisms evolve from two or more formerly independent organisms. Two canonical transitions of this type—replicators clustered in (...) cells and endosymbiotic organelles within host cells—demonstrate the reality of this kind of evolutionary transition and suggest conditions that can favor it. These conditions include co-transmission of the partners across generations and rules that strongly regulate and limit conflict, such as a fair meiosis. Recently, much attention has been given to associations of animals with microbes involved in their nutrition. These range from tight endosymbiotic associations like those between aphids and Buchnera bacteria, to the complex communities in animal intestines. Here, starting with a reflection about identity through time, we consider the distinctions between these kinds of animal–bacteria interactions and describe the criteria by which a few can be considered jointly organismal but most cannot. (shrink)

This paper reviews Rosenberg’s and McShea’s textbook in philosophy of biology, entitled Philosophy of Biology. A Contemporary Introduction. I insist on the excellent quality of this textbook, then I turn to more critical comments, which deal mainly with what philosophy of biology is, and what it should be.

Biological individuality is a major topic of discussion in biology and philosophy of biology. Recently, several objections have been raised against traditional accounts of biological individuality, including the objections of monism, theory-centrism, ahistoricity, disciplinary isolationism, and the multiplication of conceptual uncertainties. In this introduction, I will examine the current philosophical landscape about biological individuality, and show how the contributions gathered in this special issue address these five objections. Overall, the aim of this issue is to offer a more diverse, unifying, (...) and scientifically informed conception of what a biological individual is. (shrink)

The definition of biological individuality is one of the most discussed topics in philosophy of biology, but current debate has focused almost exclusively on evolution-based accounts. Moreover, several participants in this debate consider the notions of a biological individual and an organism as equivalent. In this paper, I show that the debates would be considerably enriched and clarified if philosophers took into account two elements. First, physiological fields are crucial for the understanding of biological individuality. Second, the category of biological (...) individuals should be divided into two subcategories: physiological individuals and evolutionary individuals, which suggests that the notions of organism and biological individual should not be used interchangeably. I suggest that the combination of an evolutionary and a physiological perspective will enable biologists and philosophers to supply an account of biological individuality that will be both more comprehensive and more in accordance with scientific practices. (shrink)

The dominant view in the cognitive science of religion (the ‘Standard Model’) is that religious belief and behaviour are not adaptive traits but rather incidental byproducts of the cognitive architecture of mind. Because evidence for the Standard Model is inconclusive, the case for it depends crucially on its alleged methodological superiority to selectionist alternatives. However, we show that the Standard Model has both methodological and evidential disadvantages when compared with selectionist alternatives. We also consider a pluralistic approach, which holds that (...) religion or various aspects of religion originated as byproducts of evolved cognitive structures but were subsequently co-opted for adaptive purposes. We argue that when properly formulated, the pluralistic approach also has certain advantages over the Standard Model. (shrink)

In this paper, I argue that the increasing data about non-genetic inheritance requires the construction of a new conceptual framework that should complement the inclusive approaches already discussed in the literature. More precisely, I hold that this framework should be epistemologically relevant for evolutionary biologists in capturing the limits of extended inheritance and in reassessing the boundaries of biological systems that transmit traits to their offspring. I outline the first elements of an organizational account of extended inheritance. In this account, (...) the category of inherited factors is neither restricted to genes nor extended to stable resources related to trans-generational similarities. Instead, it includes persisting constitutive elements appearing as difference makers for heterogeneous organizational constraints, namely for heterogeneous constitutive parts whose specific role is to harness flows of matter and energy across generations of clearly delimited extended organized systems. This both inclusive and restrictive framework opens an additional way to apprehend how extended inheritance may affect evolutionary trajectories. (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)

With an increasing number of ways to ‘assist’ reproduction, some bioethicists have started to wonder what it takes to become a genetic parent. It is widely agreed that sharing genes is not enough to substantiate the parent–offspring relation, but what is? Without a better understanding of the concept of reproduction, our thinking about parent–offspring relations and the ethical issues surrounding them risk being unprincipled. Here, I address that problem by offering a principled account of reproduction—the Overlap, Development and Persistence account—which (...) I believe best captures the meaning of ‘genetic parenthood’. (shrink)

It is an unfortunate fact of academic life that there is a sharp divide between science and philosophy, with scientists often being openly dismissive of philosophy, and philosophers being equally contemptuous of the naivete ́ of scientists when it comes to the philosophical underpinnings of their own discipline. In this paper I explore the possibility of reducing the distance between the two sides by introducing science students to some interesting philosophical aspects of research in evolutionary biology, using biological theories of (...) the origin of religion as an example. I show that philosophy is both a discipline in its own right as well as one that has interesting implications for the understanding and practice of science. While the goal is certainly not to turn science students into philoso- phers, the idea is that both disciplines cannot but benefit from a mutual dialogue that starts as soon as possible, in the classroom. (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)

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)