The field of the philosophy of biology is flourishing in its aim to evaluate and rethink the view inherited from the previous century ---the Modern Synthesis. Different research areas and theories have come to the fore in the last decades in order to account for different biological phenomena that, in the first instance, fall beyond the explanatory scope of the Modern Synthesis. This thesis is anchored and motivated by this revolt in the philosophy of biology. -/- The central target in (...) this context is the possibility of naturalizing teleology, a classical nightmare for the history of biology itself. This requires, principally, understanding the causes of teleological explanations without assuming an unfashioned backward causation of sorts. As the riddles of teleological explanations are about their temporal dimension, I analyze different temporal scales of biological processes: evolutionary, developmental, and physiological. -/- The first one is the one defended in the context of the Modern Synthesis. As expected, one of the aims of this thesis is to evaluate the adequacy of an evolutionary account of teleological explanation. The scrutiny is negative. Evolutionary explanations in the context of the Modern Synthesis lack the necessary causal roots to naturalize teleology. Concerning the physiological scale, a long tradition pushed up by Kant and the organicist movement in the 20th century allows us to better understand how teleological explanations can be naturalized in physiological process. The key notions in this temporal scale are self-organization and the recursive, looped character of physiological process. While the physiological scale may be suitably accounted by contemporaries views, such as Autonomous Systems Theory, different central teleological phenomena remain unexplained from a purely physiological perspective. In particular, different issues concerning the (adaptive) construction of organism ---such as plasticity, robustness, variation, novelty, inheritance--- deserve an ontogenetic analysis. -/- The principal aim of this thesis is to provide a theory of teleological development that falls beyond the Modern Synthesis' framework and is prompted by different insights from the history of biology. I call it Agential Teleosemantics. It rests on two central pillars. First, that developmental processes, beyond any gene-centered stance, can be understood in informational terms; i.e. developmental processes are about the interaction of developmental resources conveying biological information. The second ingredient is agentivity, namely the idea that development is regulated by an agentive system according to the adaptiveness of the phenotypic outcomes produced. The role of agency in Agential Teleosemantic is equivalent to the role of genes in the Modern Synthesis: it is responsible for explaining the order and the adaptive complexity in the living realm. -/- The second target of this thesis regards the possibility of naturalizing intentional explanations in cognitive science. The central project involved in such an aim is known as teleosemantics. Classical teleosemantics however is etiological: it explains the teleofunctions of representational systems in terms of evolutionary processes. The different disputes in the contemporary philosophy of biology provide two insights to analyze teleosemantics in cognitive science. First, the challenges against the Modern Synthesis must be extended to the evolutionary approach of etiological teleosemantics. Second, as Agential Teleosemantics suggests an alternative source for teleofunctions ---ontogeny, I offer an attempt to integrate Agential Teleosemantics into cognitive science in order to provide an alternative teleosemantic project to understand intentional explanations in cognitive science. (shrink)

By linking the concepts of homology and morphological organization to evolvability, this paper attempts to (1) bridge the gap between developmental and phylogenetic approaches to homology and to (2) show that developmental constraints and natural selection are compatible and in fact complementary. I conceive of a homologue as a unit of morphological evolvability, i.e., as a part of an organism that can exhibit heritable phenotypic variation independently of the organism’s other homologues. An account of homology therefore consists in explaining how (...) an organism’s developmental constitution results in different homologues/characters as units that can evolve independently of each other. The explanans of an account of homology is developmental, yet the very explanandum is an evolutionary phenomenon: evolvability in a character-by-character fashion, which manifests itself in phylogenetic patterns as recognized by phylogenetic approaches to homology. While developmental constraints and selection have often been viewed as antagonistic forces, I argue that both are complementary as they concern different parts of the evolutionary process. Developmental constraints, conceived of as the presence of the same set of homologues across phenotypic change, pertain to how heritable variation can be generated in the first place (evolvability), while natural selection operates subsequently on the produced variation. (shrink)

In recent years, the concept of evolvability has been gaining in prominence both within evolutionary developmental biology (evo-devo) and the broader field of evolutionary biology. Despite this, there remains considerable disagreement about what evolvability is. This article offers a solution to this problem. I argue that, in focusing too closely on the role played by evolvability as an explanandum in evo-devo, existing philosophical attempts to clarify the evolvability concept have been overly narrow. Within evolutionary biology more broadly, evolvability offers a (...) robust explanation for the evolutionary trajectories of populations. Evolvability is an abstract, robust, dispositional property of populations, which captures the joint causal influence of their internal features on the outcomes of evolution (as opposed to the causal influence of selection, which is often characterized as external). When considering the nature of the physical basis of this disposition, it becomes clear that the many existing definitions of evolvability at play within evo-devo should be understood as capturing only aspects of a much broader phenomenon. 1 Introduction2 The Problem of Evolvability3 The Theoretical Role of Evolvability in Evolutionary Biology3.1 The explanatory targets of evolutionary biology3.2 Selection-based explanations3.3 Lineage explanations3.4 Evolvability-based explanations3.5 What properties must evolvability have?4 What Evolvability Really Is4.1 Making sense of ft4.2 Making sense of x and b5 What of the Limbs? The Power of E6 Conclusion. (shrink)

Godfrey-Smith ( 2001 ) has distinguished three types of adaptationism. This article builds on his analysis, and revises it in places, by distinguishing seven varieties of adaptationism. This taxonomy allows us to clarify what is at stake in debates over adaptationism, and it also helps to cement the importance of Gould and Lewontin’s ‘Spandrels’ essay. Some adaptationists have suggested that their essay does not offer any coherent alternative to the adaptationist programme: it consists only in an exhortation to test adaptationist (...) hypotheses more thoroughly than was usual in the 1970s. Here it is argued that the ‘Spandrels’ paper points towards a genuinely non-adaptationist methodology implicit in much evolutionary developmental biology. This conclusion helps to expose the links between older debates over adaptationism and more recent questions about the property of evolvability. (shrink)

Mayr’s proximate–ultimate distinction has received renewed interest in recent years. Here we discuss its role in arguments about the relevance of developmental to evolutionary biology. We show that two recent critiques of the proximate–ultimate distinction fail to explain why developmental processes in particular should be of interest to evolutionary biologists. We trace these failures to a common problem: both critiques take the proximate–ultimate distinction to neglect specific causal interactions in nature. We argue that this is implausible, and that the distinction (...) should instead be understood in the context of explanatory abstractions in complete causal models of evolutionary change. Once the debate is reframed in this way, the proximate–ultimate distinction’s role in arguments against the theoretical significance of evo-devo is seen to rely on a generally implicit premise: that the variation produced by development is abundant, small and undirected. We show that a “lean version” of the proximate–ultimate distinction can be maintained even when this isotropy assumption does not hold. Finally, we connect these considerations to biological practice. We show that the investigation of developmental constraints in evolutionary transitions has long relied on a methodology which foregrounds the explanatory role of developmental processes. It is, however, entirely compatible with the lean version of the proximate–ultimate distinction. (shrink)

One foundational question in contemporarybiology is how to `rejoin evolution anddevelopment. The emerging research program(evolutionary developmental biology or`evo-devo) requires a meshing of disciplines,concepts, and explanations that have beendeveloped largely in independence over the pastcentury. In the attempt to comprehend thepresent separation between evolution anddevelopment much attention has been paid to thesplit between genetics and embryology in theearly part of the 20th century with itscodification in the exclusion of embryologyfrom the Modern Synthesis. This encourages acharacterization of evolutionary developmentalbiology as the marriage (...) of evolutionary theoryand embryology via developmental genetics. Butthere remains a largely untold story about thesignificance of morphology and comparativeanatomy (also minimized in the ModernSynthesis). Functional and evolutionarymorphology are critical for understanding thedevelopment of a concept central toevolutionary developmental biology,evolutionary innovation. Highlighting thediscipline of morphology and the concepts ofinnovation and novelty provides an alternativeway of conceptualizing the `evo and the `devoto be synthesized. (shrink)

Kevin Laland and colleagues have put forward a number of arguments motivating an extended evolutionary synthesis. Here I examine Laland et al.'s central concept of reciprocal causation. Reciprocal causation features in many arguments supporting an expanded evolutionary framework, yet few of these arguments are clearly delineated. Here I clarify the concept and make explicit three arguments in which it features. I identify where skeptics can—and are—pushing back against these arguments, and highlight what I see as the empirical, explanatory, and methodological (...) issues at stake. (shrink)

A number of biologists and philosophers have noted the diversity of interpretations of evolvability in contemporary evolutionary research. Different clusters of research defined by co-citation patterns or shared methodological orientation sometimes concentrate on distinct conceptions of evolvability. We examine five different activities where the notion of evolvability plays conceptual roles in evolutionary biological investigation: setting a research agenda, characterization, explanation, prediction, and control. Our analysis of representative examples demonstrates how different conceptual roles of evolvability are quasi-independent and yet exhibit important (...) relationships across scientific activities. It also provides us with the resources to detail two distinct strategies for how evolvability can help to synthesize disparate areas of research and thereby potentially serve as a unifying concept in evolutionary biology. (shrink)

In recent years, the concept of evolvability has been gaining in prominence both within evolutionary developmental biology (evo-devo) and the broader field of evolutionary biology. Despite this, there remains considerable disagreement about what evolvability is. This article offers a solution to this problem. I argue that, in focusing too closely on the role played by evolvability as an explanandum in evo-devo, existing philosophical attempts to clarify the evolvability concept have been overly narrow. Within evolutionary biology more broadly, evolvability offers a (...) robust explanation for the evolutionary trajectories of populations. Evolvability is an abstract, robust, dispositional property of populations, which captures the joint causal influence of their internal features on the outcomes of evolution (as opposed to the causal influence of selection, which is often characterized as external). When considering the nature of the physical basis of this disposition, it becomes clear that the many existing definitions of evolvability at play within evo-devo should be understood as capturing only aspects of a much broader phenomenon. 1 Introduction2 The Problem of Evolvability3 The Theoretical Role of Evolvability in Evolutionary Biology 3.1 The explanatory targets of evolutionary biology 3.2 Selection-based explanations 3.3 Lineage explanations 3.4 Evolvability-based explanations 3.5 What properties must evolvability have?4 What Evolvability Really Is 4.1 Making sense of ft 4.2 Making sense of x and b5 What of the Limbs? The Power of E6 Conclusion. (shrink)

There is long-standing conflict between genealogical and developmental accounts of homology. This paper provides a general framework that shows that these accounts are compatible and clarifies precisely how they are related. According to this framework, understanding homology requires both an abstract genealogical account that unifies the application of the term to all types of characters used in phylogenetic systematics and locally enriched accounts that apply only to specific types of characters. The genealogical account serves this unifying role by relying on (...) abstract notions of ‘descent’ and ‘character’. As a result, it takes for granted the existence of such characters. This requires theoretical justification that is provided by enriched accounts, which incorporate the details by which characters are inherited. These enriched accounts apply to limited domains, providing the needed theoretical justification for recognizing characters within that domain. Though connected to the genealogical account of homology in this way, enriched accounts include phenomena that fall outside the scope of the genealogical account. They therefore overlap, but are not nested within, the genealogical account. Developmental accounts of homology are to be understood as enriched accounts of body part homology. Once they are seen in this light, the conflict with the genealogical account vanishes. It is only by understanding the fine conceptual structure undergirding the many uses of the term ‘homology’ that we can understand how these uses hang together. (shrink)

The concept of developmental constraint was at the heart of developmental approaches to evolution of the 1980s. While this idea was widely used to criticize neo-Darwinian evolutionary theory, critique does not yield an alternative framework that offers evolutionary explanations. In current Evo-devo the concept of constraint is of minor importance, whereas notions as evolvability are at the center of attention. The latter clearly defines an explanatory agenda for evolutionary research, so that one could view the historical shift from ‘developmental constraint’ (...) towards ‘evolvability’ as the move from a concept that is a mere tool of criticism to a concept that establishes a positive explanatory project. However, by taking a look at how the concept of constraint was employed in the 1980s, I argue that developmental constraint was not just seen as restricting possibilities (‘constraining’), but also as facilitating morphological change in several ways. Accounting for macroevolutionary transformation and the origin of novel form was an aim of these developmental approaches to evolution. Thus, the concept of developmental constraint was part of a positive explanatory agenda long before the advent of Evo-devo as a genuine scientific discipline. In the 1980s, despite the lack of a clear disciplinary identity, this concept coordinated research among paleontologists, morphologists, and developmentally inclined evolutionary biologists. I discuss the different functions that scientific concepts can have, highlighting that instead of classifying or explaining natural phenomena, concepts such as ‘developmental constraint’ and ‘evolvability’ are more important in setting explanatory agendas so as to provide intellectual coherence to scientific approaches. The essay concludes with a puzzle about how to conceptually distinguish evolvability and selection. (shrink)

Due to the variation, contingency and complexity of living systems, biology is often taken to be a science without fundamental theories, laws or general principles. I revisit this question in light of the quest for design principles in systems biology and show that different views can be reconciled if we distinguish between different types of generality. The philosophical literature has primarily focused on generality of specific models or explanations, or on the heuristic role of abstraction. This paper takes a different (...) approach in emphasizing a theory-constituting role of general principles. Design principles signify general dependency-relations between structures and functions, given a set of formally defined constraints. I contend that design principles increase our understanding of living systems by relating specific models to general types. The categorization of types is based on a delineation of the scope of biological possibilities, which serves to identify and define the generic features of classes of systems. To characterize the basis for general principles through generic abstraction and reasoning about possibility spaces, I coin the term constraint-based generality. I show that constraint-based generality is distinct from other types of generality in biology, and argue that general principles play a unifying role that does not entail theory reduction. (shrink)

Stephen Jay Gould argued that replaying the ‘tape of life’ would result in radically different evolutionary outcomes. Recently, biologists and philosophers of science have paid increasing attention to the theoretical importance of convergent evolution—the independent origination of similar biological forms and functions—which many interpret as evidence against Gould’s thesis. In this paper, we examine the evidentiary relevance of convergent evolution for the radical contingency debate. We show that under the right conditions, episodes of convergent evolution can constitute valid natural experiments (...) that support inferences regarding the deep counterfactual stability of macroevolutionary outcomes. However, we argue that proponents of convergence have problematically lumped causally heterogeneous phenomena into a single evidentiary basket, in effect treating all convergent events as if they are of equivalent theoretical import. As a result, the ‘critique from convergent evolution’ fails to engage with key claims of the radical contingency thesis. To remedy this, we develop ways to break down the heterogeneous set of convergent events based on the nature of the generalizations they support. Adopting this more nuanced approach to convergent evolution allows us to differentiate iterated evolutionary outcomes that are probably common among alternative evolutionary histories and subject to law-like generalizations, from those that do little to undermine and may even support, the Gouldian view of life. (shrink)

Recent historiography of 19th century biology supports the revision of two traditional doctrines about the history of biology. First, the most important and widespread biological debate around the time of Darwin was not evolution versus creation, but biological functionalism versus structuralism. Second, the idealist and typological structuralist theories of the time were not particularly anti-evolutionary. Typological theories provided argumentation and evidence that was crucial to the refutation of Natural Theological creationism. The contrast between functionalist and structuralist approaches to biology continues (...) today, and the historical misunderstanding of 19th century typological biology may be one of its effects. This historical case can shed light on current controversies regarding the relevance of developmental biology to evolution. (shrink)

Evolutionary systems biology (ESB) aims to integrate methods from systems biology and evolutionary biology to go beyond the current limitations in both fields. This article clarifies some conceptual difficulties of this integration project, and shows how they can be overcome. The main challenge we consider involves the integration of evolutionary biology with developmental dynamics, illustrated with two examples. First, we examine historical tensions between efforts to define general evolutionary principles and articulation of detailed mechanistic explanations of specific traits. Next, these (...) tensions are further clarified by considering a recent case from another field focused on developmental dynamics: stem cell biology. In the stem cell case, incompatible explanatory aims block integration. Experimental approaches aim at mechanistic explanation while dynamical system models offer explanation in terms of general principles. We then discuss an ESB case in which integration succeeds: search for general attractors using a dynamical systems framework synergizes with the experimental search for detailed mechanisms. Contrasts between the positive and negative cases suggest general lessons for achieving an integrated understanding of developmental and evolutionary dynamics. The key integrative move is to acknowledge two complementary aims, both relevant to explanation: identifying the space of possible dynamic states and trajectories, and mechanistic understanding of causal interactions underlying a specific phenomenon of interest. These two aims can support one another in a joint project characterizing dynamic aspects of evolving lineages. This more inclusive project can lead to insights that cannot be reached by either approach in isolation. (shrink)

This volume explores questions about conceptual change from both scientific and philosophical viewpoints by analyzing the recent history of evolutionary developmental biology. It features revised papers that originated from the workshop "Conceptual Change in Biological Science: Evolutionary Developmental Biology, 1981-2011" held at the Max Planck Institute for the History of Science in Berlin in July 2010. The Preface has been written by Ron Amundson. In these papers, philosophers and biologists compare and contrast key concepts in evolutionary developmental biology and their (...) development since the original, seminal Dahlem conference on evolution and development held in Berlin in 1981. Many of the original scientific participants from the 1981 conference are also contributors to this new volume and, in conjunction with other expert biologists and philosophers specializing on these topics, provide an authoritative, comprehensive view on the subject. Taken together, the papers supply novel perspectives on how and why the conceptual landscape has shifted and stabilized in particular ways, yielding insights into the dynamic epistemic changes that have occurred over the past three decades. This volume will appeal to philosophers of biology studying conceptual change, evolutionary developmental biologists focused on comprehending the genesis of their field and evaluating its future directions, and historians of biology examining this period when the intersection of evolution and development rose again to prominence in biological science. (shrink)

In this paper I develop three conceptions of the relationship between evolutionary and developmental biology. I further argue that: (a) the choice between them largely turns on as yet unresolved empirical considerations; (b) none of these conceptions demand a fundamental conceptual reevaluation of evolutionary biology; and (c) while developmental systems theorists have constructed an important and innovative alternative to the standard view of the genotype/phenotype relations, in considering the general issue of the relationship between evolutionary and developmental biology, we can (...) remain neutral on this debate. (shrink)

Darwinists classify biological traits either by their ancestry (homology) or by their adaptive role. Only the latter can provide traditional natural kinds, but only the former is practicable. Process structuralists exploit this embarrassment to argue for non-Darwinian classifications in terms of underlying developmental mechanisms. This new taxonomy will also explain phylogenetic inertia and developmental constraint. I argue that Darwinian homologies are natural kinds despite having historical essences and being spatio-temporally restricted. Furthermore, process structuralist explanations of biological form require an unwarranted (...) assumption about the space of developmental possibility. (shrink)

Stephen Jay Gould argued that replaying the “tape of life” would result in a radically different evolutionary outcome. Some biologists and philosophers, however, have pointed to convergent evolution as evidence for robust replicability in macroevolution. These authors interpret homoplasy, or the independent origination of similar biological forms, as evidence for the power of natural selection to guide form toward certain morphological attractors, notwithstanding the diversionary tendencies of drift and the constraints of phylogenetic inertia. In this paper, I consider the implications (...) of homoplasy for the debate over the nature of macroevolution. I argue that once the concepts of contingency and convergence are fleshed out, it becomes clear that many instances of homoplasy fail to negate Gould’s overarching thesis, and may in fact support a Gouldian view of life. My argument rests on the distinction between parallelism and convergence, which I defend against a recent challenge from developmental biology. I conclude that despite the difficulties in defining and identifying parallelism, the concept remains useful and relevant to the contingency controversy insofar as it underscores the common developmental origins of iterated evolution. (shrink)

Evo-Devo exhibits a plurality of scientific “cultures” of practice and theory. When are the cultures acting—individually or collectively—in ways that actually move research forward, empirically, theoretically, and ethically? When do they become imperialistic, in the sense of excluding and subordinating other cultures? This chapter identifies six cultures – three /styles/ (mathematical modeling, mechanism, and history) and three /paradigms/ (adaptationism, structuralism, and cladism). The key assumptions standing behind, under, or within each of these cultures are explored. Characterizing the internal structure of (...) the cultures is necessary for understanding how they collaborate or compete, and how they are fragmented or integrated, in the rich interdisciplinary /trading zone/ (Galison 1997) of Evo-Devo. Evo-Devo is an important example of how science can progress through a radical plurality of perspectives and cultures. (shrink)

Evolutionary developmental biology (Evo-devo) is a vibrant area of contemporary life science that should be (and is) increasingly incorporated into teaching curricula. Although the inclusion of this content is important for biological pedagogy at multiple levels of instruction, there are also philosophical lessons that can be drawn from the scientific practices found in Evo-devo. One feature of particular significance is the interdisciplinary nature of Evo-devo investigations and their resulting explanations. Instead of a single disciplinary approach being the most explanatory or (...) fundamental, different methodologies from biological disciplines must be synthesized to generate empirically adequate explanations. Thus, Evo-devo points toward a non-reductionist epistemology in biology. I review three areas where these synthetic efforts become manifest as a result of Evo-devo’s practices (form versus function reasoning styles; problem-structured investigations; idealizations related to studying model organisms), and then sketch some possible applications to teaching biology. These philosophical considerations provide resources for life science educators to address (and challenge) key aspects of the National Science Education Standards and Benchmarks for Scientific Literacy. (shrink)

What gets integrated in integrative scientific practices has been a topic of much discussion. Traditional views focus on theories and explanations, with ideas of reduction and unification dominating the conversation. More recent ideas focus on disciplines, fields, or specialties; models, mechanisms, or methods; phenomena, problems. How integration works looks different on each of these views since the objects of integration are ontologically and epistemically various: statements, boundary conditions, practices, protocols, methods, variables, parameters, domains, laboratories, and questions all have their own (...) structures, functions and logics. I focus on one particular kind of scientific practice, integration of “approaches” in the context of a research system operating on a special kind of “platform.” Rather than trace a network of interactions among people, practices, and theoretical entities to be integrated, in this essay I focus on the work of a single investigator, David Wake. I describe Wake’s practice of integrative evolutionary biology and how his integration of approaches among biological specialties worked in tandem with his development of the salamanders as a model taxon, which he used as a platform to solve, re-work and update problems that would not have been solved so well by non-integrative approaches. The larger goal of the project to which this paper contributes is a counter-narrative to the story of 20th century life sciences as the rise and march of the model organisms and decline of natural history. (shrink)

The traditional practice of establishing morphological types and investigating morphological organization has found new support from evolutionary developmental biology (evo-devo), especially with respect to the notion of body plans. Despite recurring claims that typology is at odds with evolutionary thinking, evo-devo offers mechanistic explanations of the evolutionary origin, transformation, and evolvability of morphological organization. In parallel, philosophers have developed non-essentialist conceptions of natural kinds that permit kinds to exhibit variation and undergo change. This not only facilitates a construal of species (...) and higher taxa as natural kinds, but also broadens our perspective on the diversity of kinds found in biology. There are many different natural kinds relevant to the investigative and explanatory aims of evo-devo, including homologues and developmental modules. (shrink)

Evolutionary developmental biology (evo-devo) offers both an account of developmental processes and also new integrative frameworks for analyzing interactions between development and evolution. Biologists and philosophers are keen on evo-devo in part because it appears to offer a comfort zone between, on the one hand, what some take to be the relative inability of mainstream evolutionary biology to integrate a developmental perspective; and, on the other hand, what some take to be more intractable syntheses of development and evolution. In this (...) article, I outline core concerns of evo-devo, distinguish theoretical and practical variants, and counter Sterelny's recent argument that evo-devo's attention to development, while important, offers no significant challenge to evolutionary theory as we know it. (shrink)

A growing number of linguistic attempts to explain how languages change use cultural-evolutionary models involving selection or drift. Developmental constraints and biases, which take center stage in evolutionary developmental biology or evo-devo, seem to be absent within this framework, even though linguistics is home to numerous notions of constraint. In this paper, we show how these evo-devo concepts could be applied to linguistic change and why they should. This requires some conceptual groundwork, due to important differences between linguistic and biotic (...) evolution. In biological evolution, development generates the organism's variable traits on which selection and drift act. In linguistic evolution by analogy, we say development generates the linguistic variants on which selection and drift can act. “Linguistic development” then picks out how individual speakers produce and comprehend language. It involves much more than just learning. Using this broad notion of development, we distinguish between different types of bias that could operate in the processes of linguistic innovation and transmission, which correspond to genetic mutation and biological reproduction, respectively. Having thus sharpened our conceptual toolbox, we then reanalyze two well-documented cases of linguistic change and show that, in both these cases, linguists have only considered Neo-Darwinian evolutionary explanations, falsely deploying an exclusive disjunction of selection and drift. We show that there is at least a third relevant alternative in these examples, namely developmental constraint or bias in the sense we explicate here. (shrink)

Much philosophical progress has been made in elucidating the idea of evolutionary contingency in a recent re-burgeoning of the debate. However, additional progress has been impaired on three fronts. The first relates to its characterisation: the under-specification of various contingency claims has made it difficult to conceptually pinpoint the scope to which ‘contingency’ allegedly extends, as well as which biological forms are in contention. That is—there appears to be no systematic means with which to fully specify contingency claims which has (...) led to a tendency for authors to talk past each other. Secondly, on the matter of evidence, recent research has focused on the evidential import of convergent evolution which is taken to disconfirm the evolutionary contingency thesis. However, there has been a neglect of convergent evolution’s converse: ‘evolutionary idiosyncrasies’ or the singular evolution of certain forms, which I argue is evidentially supportive of evolutionary contingency. Thirdly, evolutionary contingency has often been claimed to vary in degrees and that the debate, itself, is a matter of ‘relative significance’. However, there has been no formal method of evaluating the strength of contingency and its relative significance in a particular domain. In this paper, I address all three issues by proposing a systematic means of fully specifying contingency theses with the concept of the modal range. Secondly, I propose an account of evolutionary idiosyncrasies, investigate the explanations for their occurrences, and, subsequently, spell out their significance with respect to the evolutionary contingency thesis. Finally, having been equipped with the evidential counterpart to convergent evolution, I shall sketch a likelihood framework for evaluating, precisely on the basis of a sequence of opposing data, the strength and relative significance of evolutionary contingency in a particular domain. With this in hand, the relative observations of idiosyncrasies and convergences can be informative of the strength and relative significance of contingency in any particular domain. (shrink)

Evolution in its contemporary meaning in biology typically refers to the changes in the proportions of biological types in a population over time (see the entry on the concept of evolution to 1872 for earlier meanings). As evolution is too large of a topic to address thoroughly in one entry, the primary goal of this entry is to serve as a broad overview of contemporary issues in evolution with links to other entries where more in-depth discussion can be found. The (...) entry begins with a brief survey of definitions of evolution, followed by a discussion of the different modes of evolution and related philosophical issues, and ends with a summary of other topics in the philosophy of evolution focusing particularly on topics covered in this encyclopedia. (shrink)

Living organisms are currently most often seen as complex dynamical systems that develop and evolve in relation to complex environments. Reflections on the meaning of the complex dynamical nature of living systems show an overwhelming multiplicity in approaches, descriptions, definitions and methodologies. Instead of sustaining an epistemic pluralism, which often functions as a philosophical armistice in which tolerance and so-called neutrality discharge proponents of the burden to clarify the sources and conditions of agreement and disagreement, this paper aims at analysing: (...) (i) what has been Kant's original conceptualisation of living organisms as natural purposes; (ii) how the current perspectives are to be related to Kant's viewpoint; (iii) what are the main trends in current complexity thinking. One of the basic ideas is that the attention for structure and its epistemological consequences witness to a great extent of Kant's viewpoint, and that the idea of organisational stratification today constitutes a different breeding ground within which complexity issues are raised. The various approaches of complexity in biological systems are captured in terms of two different styles, universalism and (weak and strong) constructivism, between which hybrid forms exist. (shrink)

A number of authors have pointed to “convergent evolution” as evidence for the central role of natural selection in shaping predictable trajectories of macroevolution. However, there are numerous conceptual and empirical difficulties that arise in broadly appealing to the frequency of homoplasy as evidence for a non-contingently constrained adaptational design space. Most important is the need to distinguish between convergent (externally constrained) and parallel (internally constrained) evolution, and to consider how the respective frequencies of these significantly different sources of homoplasy (...) affect a strong adaptationist view of life. In this paper, I critically evaluate Simon Conway Morris’s use of the homoplasy literature to support his argument for a non-contingent, counterfactually stable account of macroevolutionary pattern. In so doing, I offer a conception of parallelism which avoids the charge that it differs from convergence merely in degree and not in kind. I argue that although organisms sharing a homoplastic trait will also share varying degrees of homology, it is the underlying developmental homology with respect to the generators directly causally responsible for the homoplastic event that defines parallel evolution and non-arbitrarily distinguishes it from convergence. The notion of “screening-off” is used to distinguish the proximal generators of a homoplastic trait from its more distal genetic causes (such as a master control gene). (shrink)

This paper surveys recent philosophy of biology. It aims to introduce outsiders to the field to the recent literature (which is reviewed in the footnotes) and the main recent debates. I concentrate on three of these: recent critiques of the replicator/vehicle distinction and its application to the idea of the gene as the unit of section; the recent defences of group selection and the idea that standard alternatives to group selection are in fact no more than a disguised form of (...) group selection; and recent ideas on the role of selection in evolution, especially the role of selection in structuring the large-scale history of life. The paper connects philosophy of biology to some more general problems in the philosophy of science, and concludes with a few suggestions about unfinished business. (shrink)

This contribution to the adaptationism debate elaborates the nature of constraints and their importance in evolutionary explanation and argues that the adaptationism debate should be limited to the issue of how to privilege causes in evolutionary explanation. I argue that adaptationist explanations are deeply conceptually dependent on developmental constraints, and explanations that appeal to constraints are dependant on the results of natural selection. I suggest these explanations should be integrated into the framework of historical causal explanation. Each strategy explicitly appeals (...) to some aspect of the evolutionary process, while implicitly appealing to others. Thus, adaptationists and anti-adaptationists can offer complementary causal explanations of the same explanandum. This eliminates much of the adaptationism debate and explains why its adversaries regularly agree with each other more than they would like. The adaptationism issue that remains is a species of the general issue of how to privilege causes in explanation. I show how a proposed solution to this general problem might be brought to bear on evolutionary explanations, and investigate some difficulties that might arise due to the nature of the evolutionary process. (shrink)

The 1981 Dahlem conference was a catalyst for contemporary evolutionary developmental biology (Evo-devo). This introductory chapter rehearses some of the details of the history surrounding the original conference and its associated edited volume, explicates the philosophical problem of conceptual change that provided the rationale for a workshop devoted to evaluating the epistemic revisions and transformations that occurred in the interim, explores conceptual change with respect to the concept of evolutionary novelty, and highlights some of the themes and patterns in the (...) different contributions to the present volume, Conceptual Change in Biology: Scientific and Philosophical Perspectives on Evolution and Development. (shrink)

Some methodological adaptationists hijacked the term “exaptation,” and took an occasion of Stephen Jay Gould’s misspeaking as confirmation that it possessed an evolutionarily “designed” function and was a version of an adaptation, something it was decidedly not. Others provided a standard of evidence for exaptation that was inappropriate, and based on an adaptationist worldview. This article is intended to serve as both an analysis of and correction to those situations. Gould and Elisabeth Vrba’s terms, “exaptation” and “aptation,” as originally introduced, (...) are very useful, unlike the faded adaptationist echo of “exaptation” devised by the methodological adaptationists, which has made the term incoherent. We will discuss how exaptation relates to function, to aptation, and to adaptation, both primary and secondary. These ideas have been rendered practically useless through their mistaken definitions and misapplications by evolutionary psychologists. (shrink)

Adaptationism has for decades been the topic of sophisticated debates in philosophy of biology but methodological adaptationism has not received as much attention as the empirical and explanatory issues. In addition, adaptationism has mainly been discussed in the context of evolutionary biology and not in fields such as zoophysiology and systems biology where this heuristic is also used in design analyses of physiological traits and molecular structures. This paper draws on case studies from these fields to discuss the productive and (...) problematic aspects of this heuristic in different research practices, in functional as well as evolutionary studies on different levels of biological organization. Gould and Lewontin’s Spandrels-paper famously criticized adaptationist methodology for implying the risk of generating ‘blind spots’ with respect to non-selective effects on evolution. Some have claimed that this bias can be accommodated through the testing of evolutionary hypotheses. Although this is an important aspect of overcoming naïve adaptationism, I argue that the issue of methodological biases is broader than the question of testability. I demonstrate the productivity of adaptationist heuristics but also discuss the deeper problematic aspects associated with the methodological imperialism that is part of the strong adaptationist position. (shrink)

Pere Alberch played a pivotal role in shaping the field of evolutionary developmental biology during the 1980s and 1990s. Whereas initially his contributions were sidelined by the empirical advancements of the molecular revolution in developmental and evolutionary biology, his theoretical insights have left a lasting impact on the discipline. This article provides a comprehensive review of the legacy and evolvability of Alberch's ideas in contemporary evo-devo, which included the study of morphogenesis as the proper level of developmental causation, the interplay (...) between developmental constraints and natural selection, the epistemic role of teratologies, the origin of evolutionary novelties and the concept of evolvability. (shrink)

There is still a great deal of debate over what counts as a constraint and about how to assess experimentally the relative importance of constraints and selection in evolutionary history. I will argue that the notion of a constraint on variation, and thus the selection-constraint distinction, depends on two specifications: (1) what counts as a variant -- constraints limit or bias the production of what? and (2) range of assessment -- over what range of times or conditions is the variation (...) assessed? Specifications 1 and 2 help us to understand empirical work on the relative importance of constraint and selection in evolution. (shrink)

Evolutionary psychologists attempt to infer our evolved psychology from the selection pressures present in our ancestral environments. Their use of this inference strategy—often called “adaptive thinking”—is thought to be justified by way of appeal to a rather modest form of adaptationism, according to which the mind's adaptive complexity reveals it to be a product of selection. I argue, on the contrary, that the mind's being an adaptation is only a necessary and not a sufficient condition for the validity of adaptive (...) thinking, and that evolutionary psychology's predictive project is in fact committed to an extremely strong and highly implausible form of adaptationism. According to this “strong adaptationism,” the macroevolutionary trajectory of a population is determined by, and therefore predictable on the basis of, the selection pressures acting upon it. Not only is this form of adaptationism prima facie highly implausible, it requires making a number of naïve and likely false assumptions concerning the nature of heritable phenotypic variation in natural populations. In particular, it assumes that phenotypic variation is inevitably small in its extent, unbiased in its direction, and copious in its quantity. Because it is unlikely that these conditions obtain as a general rule, and even more unlikely that they obtained in early human populations, I conclude that there is little reason to believe that adaptive thinking can be used to infer the current structure of our minds from evidence of past selection pressures. (shrink)

Explanatory Externalism states that the only adaptive force in evolution is natural selection. Explanatory Externalism is a central thesis of the Modern Evolutionary Synthesis. The etiological theory of natural selected-effect functions also advocates Explanatory Externalism. According to this theory, natural selection is the process responsible for determining the proper natural functions of traits. However, I will point out several challenges to Explanatory Externalism that are proposed primarily by developmental biology and its various subfields. Based on these challenges, this paper will (...) argue why biological functions cannot be fully explained by the selected-effect theory, i.e., that a theory of biological functions must adopt some kind of Explanatory Internalism. At the end of this paper, I will discuss whether or not Explanatory Internalism entails a pluralistic view of biological functions, and how this discussion is related to the different explanations of fit and diversity found in evolutionary biology. (shrink)

While the notion of chance has been central in discussions over the probabilistic nature of natural selection and genetic drift, its role in the production of variants on which populational sampling takes place has received much less philosophical attention. This article discusses the concept of chance in evolution in the light of contemporary work in evo-devo. We distinguish different levels at which randomness and chance can be defined in this context, and argue that recent research on variability and evolvability demands (...) a causal understanding of variational probabilities under which development acquires a creative, rather than a constraining role in evolution. We then provide a propensity interpretation of variational probabilities that solves a conceptual confusion between causal properties, variational probabilities and extant variation present in the literature, and explore some metaphysical consequences that follow from our interpretation, specifically with regards to the nature of developmental types. (shrink)

Recently some philosophers have emphasized a potentially irreconcilable conceptual antagonism between the statistical characterization of natural selection and the standard scientific discussion of natural selection in terms of forces and causes. Other philosophers have developed an account of the causal character of selectionist statements represented in terms of counterfactuals. I examine the compatibility between such statisticalism and counterfactually based causal accounts of natural selection by distinguishing two distinct statisticalist claims: firstly the suggested impossibility for natural selection to be a cause (...) acting upon populations and secondly the conceptualization that all evolutionary causes occur at the level of interactions between individual organisms. I argue that deriving the latter from the former involves supplementary assumptions concerning precisely what causation is. I critically examine two of these assumptions purportedly preventing natural selection being regarded as a cause: the locality claim and the modularity claim. I conclude that justifying the strongest version of statisticalism—i.e. evolutionary causation only occurs at the level of individual interactions between organisms—would require further metaphysical arguments that are likely to be deemed highly problematic. Additionally, I argue that such a metaphysical position would be considered incongruous with both our scientific and ordinary use of the concepts of causality and explanation as employed within our everyday epistemological framework. (shrink)

Some adaptationist explanations are regarded as maximally solid and others fanciful just-so stories. Just-so stories are explanations based on very little evidence. Lack of evidence leads to circular-sounding reasoning: “this trait was shaped by selection in unseen ancestral populations and this selection must have occurred because the trait is present.” Well-supported adaptationist explanations include evidence that is not only abundant but selected from comparative, populational, and optimality perspectives, the three adaptationist subdisciplines. Each subdiscipline obtains its broad relevance in evolutionary biology (...) via assumptions that can only be tested with the methods of the other subdisciplines. However, even in the best-supported explanations, assumptions regarding variation, heritability, and fitness in unseen ancestral populations are always present. These assumptions are accepted given how well they would explain the data if they were true. This means that some degree of “circularity” is present in all evolutionary explanations. Evolutionary explanation corresponds not to a deductive structure, as biologists usually assert, but instead to ones such as abduction or induction. With these structures in mind, we show the way to a healthier view of “circularity” in evolutionary biology, and why integration across the comparative, populational, and optimality approaches is necessary. (shrink)

Is it possible, and in the first place is it even desirable, to define what "development" means and to determine the scope of the field called "developmental biology"? Though these questions appeared crucial for the founders of "developmental biology" in the 1950s, there seems to be no consensus today about the need to address them. Here, in a combined biological, philosophical, and historical approach, we ask whether it is possible and useful to define biological development, and, if such a definition (...) is indeed possible and useful, which definition can be considered as the most satisfactory. (shrink)

The Darwinian theory of evolution is itself evolving and this book presents the details of the core of modern Darwinism and its latest developmental directions. The authors present current scientific work addressing theoretical problems and challenges in four sections, beginning with the concepts of evolution theory, its processes of variation, heredity, selection, adaptation and function, and its patterns of character, species, descent and life. The second part of this book scrutinizes Darwinism in the philosophy of science and its usefulness in (...) understanding ecosystems, whilst the third section deals with its application in disciplines beyond the biological sciences, including evolutionary psychology and evolutionary economics, Darwinian morality and phylolinguistics. The final section addresses anti-Darwinism, the creationist view and issues around teaching evolution in secondary schools. The reader learns how current experimental biology is opening important perspectives on the sources of variation, and thus of the very power of natural selection. This work examines numerous examples of the extension of the principle of natural selection and provides the opportunity to critically reflect on a rich theory, on the methodological rigour that presides in its extensions and exportations, and on the necessity to measure its advantages and also its limits. Scholars interested in modern Darwinism and scientific research, its concepts, research programs and controversies will find this book an excellent read, and those considering how Darwinism might evolve, how it can apply to the human sciences and other disciplines beyond its origins will find it particularly valuable. Originally produced in French (Les Mondes Darwiniens), the scope and usefulness of the book have led to the production of this English text, to reach a wider audience. This book is a milestone in the impressive penetration by Francophone scholars into the world of Darwinian science, its historiography and philosophy over the last two decades. Alex Rosenberg, R. Taylor Cole Professor of Philosophy, Duke University Until now this useful and comprehensive handbook has only been available to francophones. Thanks to this invaluable new translation, this collection of insightful and original essays can reach the global audience it deserves. Tim Lewens, University of Cambridge. (shrink)

The Gouldian argument for evolutionary contingency found in Wonderful Life can be dissected into three premises: palaeontological, macro-evolutionary, and developmental. Discussions of evolutionary contingency have revolved primarily around the developmental. However, a shift in methodological practice and new palaeontological evidence subsequent to the book’s publication appears to threaten the palaeontological premise that asserts high Cambrian disparity, or, roughly, that morphological differences between the Cambrian species were high. This presents a prima facie problem: Did the Cambrian consist of enough anatomical variety (...) to fuel a different outcome upon a replay of the tape of life? I investigate the role that disparity plays in the Gouldian argument for evolutionary contingency and conclude that the reduced disparity view does not undermine the argument, per se. As for the macro-evolutionary premise, Gould never offers any explicit justification for the idea that species sorting was indiscriminate or ‘lottery-like’ (though he certainly gestures at it). Putting aside the exegetical, I consider certain empirical avenues for underwriting the macro-evolutionary premise and argue that the most plausible route is to appeal to the special status of mass extinctions, a move that is not entirely unfamiliar to macro-evolutionists. That is, mass extinctions can be good sources of contingency due to their being ‘chancy’ in at least three respects. In sum, I update the palaeontological and macro-evolutionary premises as to reconstrue the Gouldian argument for evolutionary contingency in its strongest form. (shrink)

In this brief commentary I compare and contrast two different views of evolution: one of limited (convergent) evolution and mathematical predictability, and one of unbounded diversity and no entailing laws. Clearly these opposing views cannot both be true at the same time. Their disagreement seems to rest on different underlying assumptions, and the challenge is to see if they can be reconciled.

One current version of the internalism/externalism debate in evolutionary theory focuses on the relative importance of developmental constraints in evolutionary explanation. The received view of developmental constraints sees them as an internalist concept that tend to be shared across related species as opposed to selective pressures that are not. Thus, to the extent that constraints can explain anything, they can better explain similarity across species, while natural selection is better able to explain their differences. I challenge both of these aspects (...) of the received view and propose a hierarchical view of constraints. (shrink)