Levels and Units of Selection, Misc

The unit of selection is the concept of that ‘something’ to which biologists refer when they speak of an adaptation as being ‘for the good of’ something. Darwin identified the organism as the unit of selection because for him the ‘struggle for existence’ was an issue among individuals. Later on it was suggested that, in order to understand the evolution of social behavior, it is necessary to argue that groups, and not individuals, are the units of selection. The last addition (...) to this debate was the formulation by Dawkins, in 1976, that the genes themselves are the units of selection while organisms are merely the temporary receptacles and vehicles for such genes. Thus, the preposterous dissolution of the organism into genes and the proteins coded by such genes has been introduced in the evolutionary discourse by neglecting that the explanations for biological phenomena can be either synchronic or diachronic, depending on the phenomenon to be explained. Therefore explanations in molecular biology are synchronic while evolutionary biology needs diachronic explanations. Nevertheless, for ultra-Darwinians such as Dawkins, efficient replication is all that biology is about. Here I develop an argument in order to show that there is nothing in molecular and cell biology that might support such a contention and that the idea of the gene as the unit of selection is incompatible with the evident evolution of biological complexity. (shrink)

In their 2010 book, Biology’s First Law, D. McShea and R. Brandon present a principle that they call ‘‘ZFEL,’’ the zero force evolutionary law. ZFEL says (roughly) that when there are no evolutionary forces acting on a population, the population’s complexity (i.e., how diverse its member organisms are) will increase. Here we develop criticisms of ZFEL and describe a different law of evolution; it says that diversity and complexity do not change when there are no evolutionary causes.

Evolutionary, ecological and ethical studies are, at the same time, specific scientific disciplines and, from an historical point of view, structurally linked domains of research. In a context of environmental crisis, the need is increasingly emerging for a connecting epistemological framework able to express a common or convergent tendency of thought and practice aimed at building, among other things, an environmental policy management respectful of the planet’s biodiversity and its evolutionary potential.

In evolutionary biology and ecology, ontological and epistemological perspectives based on the replicator and the interactor have become the background that makes it possible to transcend traditional biological levels of organization and to achieve a unified view of evolution in which replication and interaction are fundamental operating processes. Using the transactional perspective proposed originally by John Dewey and Arthur Fisher Bentley, a new ontological and methodological category is proposed here: the transactor. The transactional perspective, based on the concept of the (...) transactor, bridges the dichotomy between organisms and environment that characterizes the interactional perspective on evolution and provides epistemological support for the emergentist, systemic view of evolutionary and developmental processes. (shrink)

Among mycologists, questions persist about what entities should be treated as the fundamental units of fungal populations. This article articulates a coherent view about populations of heterokaryotic fungi and the individuals that comprise them. Using Godfrey-Smith’s minimal concept of a Darwinian population, I argue that entities at two levels of the biological hierarchy satisfy the minimal concept in heterokaryotic fungi: mycelia and nuclei. I provide a preliminary answer to the question of how to understand the relation between these two populations. (...) This article contributes to discussions about the nature of biological individuality, organismality, and evolutionary transitions. (shrink)

Eukaryogenesis is widely viewed as an improbable evolutionary transition uniquely affecting the evolution of life on this planet. However, scientific and popular rhetoric extolling this event as a singularity lacks rigorous evidential and statistical support. Here, we question several of the usual claims about the specialness of eukaryogenesis, focusing on both eukaryogenesis as a process and its outcome, the eukaryotic cell. We argue in favor of four ideas. First, the criteria by which we judge eukaryogenesis to have required a genuinely (...) unlikely series of events 2 billion years in the making are being eroded by discoveries that fill in the gaps of the prokaryote:eukaryote “discontinuity.” Second, eukaryogenesis confronts evolutionary theory in ways not different from other evolutionary transitions in individuality; parallel systems can be found at several hierarchical levels. Third, identifying which of several complex cellular features confer on eukaryotes a putative richer evolutionary potential remains an area of speculation: various keys to success have been proposed and rejected over the five-decade history of research in this area. Fourth, and perhaps most importantly, it is difficult and may be impossible to eliminate eukaryocentric bias from the measures by which eukaryotes as a whole are judged to have achieved greater success than prokaryotes as a whole. Overall, we question whether premises of existing theories about the uniqueness of eukaryogenesis and the greater evolutionary potential of eukaryotes have been objectively formulated and whether, despite widespread acceptance that eukaryogenesis was “special,” any such notion has more than rhetorical value. (shrink)

E. O. Wilson (1974: 54) describes the problem that social organisms pose: “On what bases do we distinguish the extremely modified members of an invertebrate colony from the organs of a metazoan animal?” This framing of the issue has inspired many to look more closely at how groups of organisms form and behave as emergent individuals. The possible existence of “superorganisms” test our best intuitions about what can count and act as genuine biological individuals and how we should study them. (...) As we will discuss, colonies of certain organisms display many of the properties that we usually reserve only to individual organisms. Although there is good reason to believe that many social insects form genuine emergent biological individuals, the conclusion offered here is of a slightly different sort. I will argue that to understand some social insects' interactions and the emergent traits they give rise to, it may be helpful to shift our understanding from a community-level approach to an ecosystem-level approach. I will argue that viewing certain insect colonies (termites) as parts of ecosystems allows us to better understand some of the adaptations that have emerged from their evolution. (shrink)

In this paper I argue against the claim, recently put forward by some philosophers of biology and evolutionary biologists, that there can be two or more ontologically distinct levels of selection. I show by comparing the fitness of individuals with that of collectives of individuals in the same environment and over the same period of time – as required to decide if one or more levels of selection is acting in a population – that the selection of collectives is a (...) by-product of selection at the individual level; thus, talking about two or more levels of selection represents merely a different perspective on one and the same process. (shrink)

This article argues that various deviations from the basic principles of the scientific ethos – primarily the appearance of pseudoscience in scientific communities – can be formulated and explained using specific models of game theory, such as the prisoner’s dilemma and the iterated prisoner’s dilemma. The article indirectly tackles the deontology of scientific work as well, in which it is assumed that there is no room for moral skepticism, let alone moral anti-realism, in the ethics of scientific communities. Namely, on (...) the basis of the generally accepted dictum of scientific endeavor as the pursuit of knowledge exclusively for knowledge’s sake, scientifically »right« behavior is seen to be clearly defined and distinguishable from scientifically »wrong« behavior. After elucidating the basic principles of game theory, the article illustrates – by using imaginary and real cases, as well as some views from the philosophyof biology (the units of selection debate) – how this sort of reasoning could be applied in an analysis of the functioning of science. (shrink)

Understanding how cooperation evolves is central to explaining some core features of our biological world. Many important evolutionary events, such as the arrival of multicellularity or the origins of eusociality, are cooperative ventures between formerly solitary individuals. Explanations of the evolution of cooperation have primarily involved showing how cooperation can be maintained in the face of free-riding individuals whose success gradually undermines cooperation. In this paper I argue that there is a second, distinct, and less well explored, problem of cooperation (...) that I call the generation of benefit. Focusing on how benefit is generated within a group poses a different problem: how is it that individuals in a group can (at least in principle) do better than those who remain solitary? I present several different ways that benefit may be generated, each with different implications for how cooperation might be initiated, how it might further evolve, and how it might interact with different ways of maintaining cooperation. I argue that in some cases of cooperation, the most important underlying “problem” of cooperation may be how to generate benefit, rather than how to reduce conflict or prevent free-riding. (shrink)

The concept of adaptation is pivotal to modern evolutionary thinking, but it has long been the subject of controversy, especially in respect of the relative roles of selection versus constraints in explaining the traits of organisms. This paper tackles a different problem for the concept of adaptation: its interpretation in light of multilevel selection theory. In particular, I arbitrate a dispute that has broken out between the proponents of rival perspectives on multilevel adaptations. Many experts now say that multilevel and (...) kin selection views are mathematically equivalent to one another—that the mathematical accounting of evolution can be carried out at any hierarchical level one chooses. But what does this formal equivalence imply - are they equivalent in other ways too? I show here that significant conceptual non-equivalence has survived: the two sides commit to different views regarding how much selection has to act at a level before we can call traits at that level adaptations; about whether policing mechanisms are adaptations, and about whether non-organisms can bear adaptations. (shrink)

Clade selection is unpopular with philosophers who otherwise accept multilevel selection theory. Clades cannot reproduce, and reproduction is widely thought necessary for evolution by natural selection, especially of complex adaptations. Using microbial evolutionary processes as heuristics, I argue contrariwise, that (1) clade growth (proliferation of contained species) substitutes for clade reproduction in the evolution of complex adaptation, (2) clade-level properties favoring persistence – species richness, dispersal, divergence, and possibly intraclade cooperation – are not collapsible into species-level traits, (3) such properties (...) can be maintained by selection on clades, and (4) clade selection extends the explanatory power of the theory of evolution. (shrink)

Contemporary evolutionary biology comprises a plural landscape of multiple co-existent conceptual frameworks and strenuous voices that disagree on the nature and scope of evolutionary theory. Since the mid-eighties, some of these conceptual frameworks have denounced the ontologies of the Modern Synthesis and of the updated Standard Theory of Evolution as unfinished or even flawed. In this paper, we analyze and compare two of those conceptual frameworks, namely Niles Eldredge’s Hierarchy Theory of Evolution (with its extended ontology of evolutionary entities) and (...) the Extended Evolutionary Synthesis (with its proposal of an extended ontology of evolutionary processes), in an attempt to map some epistemic bridges (e.g. compatible views of causation; niche construction) and some conceptual rifts (e.g. extra-genetic inheritance; different perspectives on macroevolution; contrasting standpoints held in the “externalism–internalism” debate) that exist between them. This paper seeks to encourage theoretical, philosophical and historiographical discussions about pluralism or the possible unification of contemporary evolutionary biology. (shrink)

In this landmark volume, an international group of scientists has synthesized their collective expertise and insight into a newly unified vision of insect ...

The aim of the book is to explore common concerns regarding methodological individualism in different fields of the life sciences broadly construed. It will address conceptual problems regarding individuals and their relation and dependence on the collectivities they are part of and consider innovative new viewpoints, grounded in specific scientific projects that question the present descriptions and understanding and raise challenges. A wide variety of recent, influential contributions in the life sciences utilize notions of collectivity, sociality, rich interactions and emergent (...) phenomena, as essential explanatory tools to handle numerous persistent scientific questions in the life sciences. -/- Examples range from gene expression and regulation, the dynamics of bacterial populations, the ecological developmental biology of symbiosis, levels of selection, to communication, motion and patterns of behavior in diverse life forms, the role of social institutions and cultural dynamics in human evolution, and the psychological basis for social norms. The book is being structured so that fruitful and rewarding disciplinary interactions take place among researchers and scholars who have been concerned with overcoming methodological individualism. -/- The books includes a section of four papers on holobionts and the hologenome theory and a special memorial article on the work of the late Prof. Eshel Ben-Jacob authored by Herbert Levine. (shrink)

Sometimes themes can be found in common across very different systems in which change occurs. Imre Lakatos developed a theory of change in science, and one involving entities visible at different levels. There are theories defended at a particular time, and there are also research programs, larger units that bundle together a sequence of related theories and within which many scientists may work. Research programs are competing higher-level units within a scientific field. Scientific change involves change within research programs, and (...) change in the ensemble of research programs present at a time, where some will be growing, some shrinking, some progressing, some degenerating. These are also themes in biological evolution. Recent biology has often found itself dealing with the relation between change at a level of "collectives" – such as organisms like us – and change at a lower level – the level of cells, genes, and other evolving parts. This work is continuous with an older discussion, one that arose when biological evolution was no more than a vague speculation, round the beginning of the 19th century. What is the living individual? What is the basic unit of life or living organization? Questions like this were pursued by Goethe, by Erasmus Darwin, the grandfather of Charles, and many others. Initially it was plants, especially, that were seen to raise these problems, and then newly described marine animals with strange life cycles. The discussion was influenced by the rise of the cell theory in the early 19th century, but some writers looked for individuals well below the level of the cell. (shrink)

Two major clarifications have greatly abetted the understanding and fruitful expansion of the theory of natural selection in recent years: the acknowledgment that interactors, not replicators, constitute the causal unit of selection; and the recognition that interactors are Darwinian individuals, and that such individuals exist with potency at several levels of organization (genes, organisms, demes, and species in particular), thus engendering a rich hierarchical theory of selection in contrast with Darwin’s own emphasis on the organismic level. But a piece of (...) the argument has been missing, and individuals at levels distinct from organisms have been denied potency (although granted existence within the undeniable logic of the theory), because they do not achieve individuality with the same devices used by organisms and therefore seem weak by comparison. We show here that different features define Darwinian individuality across scales of size and time. In particular, species-individuals may develop few emergent features as direct adaptations. The interactor approach works with emergent fitnesses, not with emergent features; and species, as a consequence of their different mechanism for achieving individuality (reproductive exclusivity among subparts, that is, among organisms), express many effects from other levels. Organisms, by contrast, suppress upwardly cascading effects, because the organismic style of individuality (by functional integration of subparts) does not permit much competition or differential reproduction of parts from within. Species do not suppress the operation of lower levels; such effects therefore become available as exaptations conferring emergent fitness—a primary source of the different strength that species achieve as effective Darwinian individuals in evolution. (shrink)

Exploring whether clades can reproduce leads to new perspectives on general accounts of biological development and individuation. Here we apply James Griesemer's general account of reproduction to clades. Griesemer's account of reproduction includes a requirement for development, raising the question of whether clades may bemeaningfully said to develop. We offer two illustrative examples of what clade development might look like, though evaluating these examples proves difficult due to the paucity of general accounts of development. This difficulty, however, is instructive about (...) what a general account of development should look like and how it may usefully be applied to research problems (further suggesting a means for evaluating general accounts of development). Reproduction also requires individuation of parent and offspring. We argue that there is no special problem of individuating older and younger clades. The vagaries involved with determining when clades begin, mature, and end are precisely the same as those that arise when the same questions are asked of cells, organisms, or species. Though the question of clade reproduction and selection may still be open, the process of discovery presents new insights into old problems. (shrink)

My general aim is to clarify the foundational difference between Stephen Jay Gould and Richard Dawkins concerning what biological entities are the units of selection in the process of evolution by natural selection. First, I recapitulate Gould’s central objection to Dawkins’s view that genes are the exclusive units of selection. According to Gould, it is absurd for Dawkins to think that genes are the exclusive units of selection when, after all, genes are not the exclusive interactors: those agents directly engaged (...) with, directly impacted by, environmental pressures. Second, I argue that Gould’s objection still goes through even when we take into consideration Sterelny and Kitcher’s defense of gene selectionism in their admirable paper “The Return of the Gene.” Third, I propose a strategy for defending Dawkins that I believe obviates Gould’s objection. Drawing upon Elisabeth Lloyd’s careful taxonomy of the various understandings of the unit of selection at play in the philosophy of biology literature, my proposal involves realizing that Dawkins endorses a different understanding of the unit of selection than Gould holds him to, an understanding that does not require genes to be the exclusive interactors. (shrink)

The notion of structure of evolution is proposed to capture what it means to say that two situations exhibit the same or similar constellations of factors affecting evolution. The key features of holobiont evolution and the hologenome theory are used to define a holobiont structure of evolution. Finally, Cultural Group Selection, a set of hypotheses regarding the evolution of human cognition, is shown to match the holobiont structure closely though not perfectly.

This paper applies the conceptual toolkit of Evolutionary Developmental Biology (evo‐devo) to the evolution of the genome and the role of the genome in organism development. This challenges both the Modern Evolutionary Synthesis, the dominant view in evolutionary theory for much of the 20th century, and the typically unreflective analysis of heredity by evo‐devo. First, the history of the marginalization of applying system‐thinking to the genome is described. Next, the suggested framework is presented. Finally, its application to the evolution of (...) genome modularity, the evolution of induced mutations, the junk DNA versus ENCODE debate, the role of drift in genome evolution, and the relationship between genome dynamics and symbiosis with microorganisms are briefly discussed. (shrink)

This book brings together important essays by one of the leading philosophers of science at work today. Elisabeth A. Lloyd examines several of the central topics in philosophy of biology, including the structure of evolutionary theory, units of selection, and evolutionary psychology, as well as the Science Wars, feminism and science, and sexuality and objectivity. Lloyd challenges the current evolutionary accounts of the female orgasm and analyses them for bias. She also offers an innovative analysis of the concept of objectivity. (...) Lloyd analyses the structure of evolutionary theory and unlocks the puzzle of the units of selection debates into four distinct aspects, illuminating several mysteries in the biology literature. Central to all essays in this book is the author's abiding concern for evidence and empirical data. (shrink)

I argue that four of the fundamental claims of those calling themselves `genic pluralists'Philip Kitcher, Kim Sterelny, and Ken Watersare defective. First, they claim that once genic selectionism is recognized, the units of selection problems will be dissolved. Second, Sterelny and Kitcher claim that there are no targets of selection. Third, Sterelny, Kitcher, and Waters claim that they have a concept of genic causation that allows them to give independent genic causal accounts of all selection processes. I argue that each (...) one of these claims is either false or misleading. Moreover, the challenge that arises from the availability of genic causal accounts, namely, the inability to choose on rational grounds among genic and higher-level accounts, is unsupported. (shrink)

I admire Wilson & Sober's (W & S's) aim, to alert social scientists that group selection has risen from the ashqs, and to explicate its relevance to the behavioral sciences. Group selection has beenwidely misunderstood; furthermore, both authors have been instrumental in illuminating conceptual problems surrounding higher-level selection. Still, I find that this target article muddies the waters, primarily through its shifting and confused definition of a "vehicle" of selection. The fundamental problem is an ambiguity in the definition of "adaptation." (...) On the one hand, any evolutionary change that results from a selection process could be called an adaptation, by definition; I call this the "weak" view of adaptation. A "strong" view of adaptation, on the other hand, includes some notion of design - the evolution of a specific complex trait understood, in an engineering sense, to provide a mechanism favoring its owner's success in contributing to the evolutionary lineage. (shrink)

Most models of generational succession in sexually reproducing populations necessarily move back and forth between genic and genotypic spaces. We show that transitions between and within these spaces are usually hidden by unstated assumptions about processes in these spaces. We also examine a widely endorsed claim regarding the mathematical equivalence of kin-, group-, individual-, and allelic-selection models made by Lee Dugatkin and Kern Reeve. We show that the claimed mathematical equivalence of the models does not hold. *Received January 2007; revised (...) April 2008. †To contact the authors, please write to: Elisabeth Lloyd, Department of History and Philosophy of Science, 130 Goodbody Hall, Indiana University, Bloomington, IN 47405; e-mail: ealloyd@indiana.edu; Richard Lewontin, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138; Marcus Feldman, Department of Biological Sciences, Stanford University, Stanford, CA 94305; e-mail: marc@charles.stanford.edu. (shrink)

this requirement for adaptations. Emergent characters are always potential adaptations. Not all selection processes produce adaptations, however. The key issue, in delineating a selection process, is the relationship between a character and fitness. The emergent character approach is more restrictive than alternative schemas that delineate selection..

Standard biological and philosophical treatments assume that dramatic genotypic or phenotypic change constitutes instantaneous speciation, and that barring such saltation, speciation is gradual evolutionary change in individual properties. Both propositions appear to be incongruent with standard theoretical perspectives on species themselves, since these perspectives are (a) non-pheneticist, and (b) tend to disregard intermediate cases. After reviewing certain key elements of such perspectives, it is proposed that species-membership is mediated by membership in a population. Species-membership depends, therefore, not on intrinsic characteristics (...) of an organism, but on relationship of an organism to others. A new definition of speciation is proposed in the spirit of this proposal. This definition implies that dramatic change is neither necessary nor sufficient for speciation. It also implies, surprisingly, that an organism can change species during its lifetime. (shrink)

We have argued elsewhere that: (A) Natural selection is not a cause of evolution. (B) A resolution-of-forces (or vector addition) model does not provide us with a proper understanding of how natural selection combines with other evolutionary influences. These propositions have come in for criticism recently, and here we clarify and defend them. We do so within the broad framework of our own “hierarchical realization model” of how evolutionary influences combine.

Review of Cooperation and its Evolution, edited by Kim Sterelny, Richard Joyce, Brett Calcott, and Ben Fraser.

Samuel Bowles and Herbert Gintis have argued that individual-selection accounts of human cooperation flounder in the face of the free-rider identification problem. Kim Sterelny has responded to this line of argument for group selection, arguing that the free-rider identification problem in fact poses no theoretical difficulty for individual-selection accounts. In this article, I set out to clarify Bowles and Gintis’ argument. As I see matters, the real crux of their argument is this: solving the free-rider identification problem, even in modestly (...) sized social groups, requires that group members are disposed to share social information with one another. The difficulty for individual-selection accounts, according to Bowles and Gintis, is that these accounts have no explanation for why individuals should be disposed to behave in this way. Having clarified their argument, I then turn to Sterelny’s criticism, and argue that Sterelny underestimates the challenge being raised by Bowles and Gintis. More specifically, I argue that it is unclear whether the expected benefits of having a disposition to share social information would have outweighed the expected costs for an individual belonging to a Pleistocene social group. Importantly, this is not to say that I am persuaded by Bowles and Gintis’ argument; on the contrary, what I claim is that more theoretical (and in particular) empirical work is necessary before the issues under discussion can be settled. I formulate some specific questions which I think future research in this area should aim to address. (shrink)

Since, it has become clear that individuality is not to be considered as a given, but rather as something which needs to be explained. How has individuality emerged through evolution, and how has it subsequently been maintained? In particular, why is it that multicellular organisms appeared and persisted, despite the obvious interest of each cell of favoring its own replication? Several biologists see the immune system as one of the key components for explaining the maintenance of multicellular organisms’ individuality. Indeed, (...) the immune system exerts a constant surveillance on all the constituents of the organism, including “cheaters” like tumor cells, which favor their own replication at the expense of the whole organism. In most cases, the immune system eliminates those cheaters. This is the “immune surveillance” hypothesis, first suggested by Burnet and Thomas. In this paper, I account for recent findings on immune surveillance in order to determine the precise role of the immune system in the emergence and maintenance of individuality. This investigation gives rise to a critical question for the domain of biological individuality: should immunity be considered as something unique to multicellular organisms? If it is indeed unique, should the multicellular organism be considered as an individual to a higher degree than any other living entity? If it is not unique, what precisely are the equivalents of the immune system in other living individuals? (shrink)

Views on the evolution of altruism based upon multilevel selection on structured populations pay little attention to the difference between fortuitous and deliberate processes leading to assortative grouping. Altruism may evolve when assortative grouping is fortuitously produced by forces external to the organism. But when it is deliberately produced by the same proximate mechanism that controls altruistic responses, as in humans, exploitation of altruists by selfish individuals is unlikely and altruism evolves as an individually advantageous trait. Groups formed with altruists (...) of this sort are special, because they are not affected by subversion from within. A synergistic process where altruism is selected both at the individual and at the group level can take place. (shrink)

The chapter explains why evolutionary genetics – a mathematical body of theory developed since the 1910s – eventually got to deal with culture: the frequency dynamics of genes like “the lactase gene” in populations cannot be correctly modeled without including social transmission. While the body of theory requires specific justifications, for example meticulous legitimations of describing culture in terms of traits, the body of theory is an immensely valuable scientific instrument, not only for its modeling power but also for the (...) amount of work that has been necessary to build, maintain, and expand it. A brief history of evolutionary genetics is told to demonstrate such patrimony, and to emphasize the importance and accumulation of statistical knowledge therein. The probabilistic nature of genotypes, phenogenotypes and population phenomena is also touched upon. Although evolutionary genetics is actually composed by distinct and partially independent traditions, the most important mathematical object of evolutionary genetics is the Mendelian space, and evolutionary genetics is mostly the daring study of trajectories of alleles in a population that explores that space. The ‘body’ is scientific wealth that can be invested in studying every situation that happens to turn out suitable to be modeled as a Mendelian population, or as a modified Mendelian population, or as a population of continuously varying individuals with an underlying Mendelian basis. Mathematical tinkering and justification are two halves of the mutual adjustment between the body of theory and the new domain of culture. Some works in current literature overstate justification, misrepresenting the relationship between body of theory and domain, and hindering interdisciplinary dialogue. (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)

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. 1 Introduction2 Biological Population, Broad and Narrow3 Difficulties with Narrow Biological Population Conditions3.1 Against the genealogical condition3.2 Against the conspecificity condition3.3 Against the proximity condition3.4 Against the typology condition4 Causal Connectivity5 Massively Multidimensional Population Constructs6 Population Uniqueness and Natural Selection6.1 Statisticalism and its discontents6.2 Price at what price?7 Conclusion. (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)

This paper takes a close look at the role of behavior in the “major transitions” in evolution—events during which inheritance and development, and therefore the process of adaptation by natural selection, are reorganized at a new level of compositional hierarchy—and at the requirements for sufficiently explaining these important events in the history of life. I argue that behavior played a crucial role in driving at least some of the major transitions. Because behavioral interactions can become stably organized in novel ways (...) on timescales faster than the lifetime of an organism, behavior can lead the way into a transition—becoming organized at the new level prior to inheritance and development. It is widely acknowledged that behavioral plasticity can play an important role in evolution; environmental novelty can elicit novel behavior that may feed back on the evolutionary process through niche selection or cultural inheritance, for example (Jablonka and Lamb 2005). I argue here that not just novel behaviors but novel forms of behavioral organization (distributed or hierarchical control that produces functional coherence) can emerge, binding the evolutionary fates of a group of organisms which were previously independent in terms of behavior as well as reproduction, and leading the way into a transition to an aggregative or “higher-level” mode of reproduction. (shrink)

There are two competing interpretations of the modern synthesis theory of evolution: the dynamical (also know as ‘traditional’) and the statistical. The dynamical interpretation maintains that explanations offered under the auspices of the modern synthesis theory articulate the causes of evolution. It interprets selection and drift as causes of population change. The statistical interpretation holds that modern synthesis explanations merely cite the statistical structure of populations. This paper offers a defense of statisticalism. It argues that a change in trait frequencies (...) in a population can be attributed only to selection or drift against the background of a particular statistical description of the population. The traditionalist supposition that selection and drift are description‐independent causes of population change leads the dynamical interpretation into a dilemma: it must face a contradiction or accept the loss of explanatory power. (shrink)

We distinguish dynamical and statistical interpretations of evolutionary theory. We argue that only the statistical interpretation preserves the presumed relation between natural selection and drift. On these grounds we claim that the dynamical conception of evolutionary theory as a theory of forces is mistaken. Selection and drift are not forces. Nor do selection and drift explanations appeal to the (sub-population-level) causes of population level change. Instead they explain by appeal to the statistical structure of populations. We briefly discuss the implications (...) of the statistical interpretation of selection for various debates within the philosophy of biologythe `explananda of selection' debate and the `units of selection' debate. (shrink)

Essay review of 'Darwinian Populations and Natural Selection'.