This editorial introduces a series of review articles concerning the ways in which recent work on microbial evolution has both deepened and challenged the modern synthesis. The authors develop a framework for thinking about theory change in biology.

Since its origin in the early 20th century, the modern synthesis theory of evolution has grown to represent the orthodox view on the process of organic evolution. It is a powerful and successful theory. Its defining features include the prominence it accords to genes in the explanation of development and inheritance, and the role of natural selection as the cause of adaptation. Since the advent of the 21st century, however, the modern synthesis has been (...) subject to repeated and sustained challenges. In the last two decades, evolutionary biology has witnessed unprecedented growth in the understanding of those processes that underwrite the development of organisms and the inheritance of characters. The empirical advances usher in challenges to the conceptual foundations of evolutionary theory. Many current commentators charge that the new biology of the 21st century calls for a revision, extension, or wholesale rejection of the modern synthesis theory of evolution. Defenders of the modern synthesis maintain that the theory can accommodate the exciting new advances in biology, without forfeiting its central precepts. The original essays collected in this volume—by evolutionary biologists, philosophers of science, and historians of biology—survey and assess the various challenges to the modern synthesis arising from the new biology of the 21st century. Taken together, the essays cover a spectrum of views, from those that contend that the modern synthesis can rise to the challenges of the new biology, with little or no revision required, to those that call for the abandonment of the modern synthesis. (shrink)

Huxley coined the phrase, the “evolutionary synthesis” to refer to the acceptance by a vast majority of biologists in the mid-20th Century of a “synthetic” view of evolution. According to this view, natural selection acting on minor hereditary variation was the primary cause of both adaptive change within populations and major changes, such as speciation and the evolution of higher taxa, such as families and genera. This was, roughly, a synthesis of Mendelian genetics and Darwinian evolutionary (...) theory; it was a demonstration that prior barriers to understanding between various subdisciplines in the life sciences could be removed. The relevance of different domains in biology to one another was established under a common research program. The evolutionary synthesis may be broken down into two periods, the “early” synthesis from 1918 through 1932, and what is more often called the “modern synthesis” from 1936-1947. The authors most commonly associated with the early synthesis are J.B.S. Haldane, R.A. Fisher, and S. Wright. These three figures authored a number of important synthetic advances; first, they demonstrated the compatibility of a Mendelian, particulate theory of inheritance with the results of Biometry, a study of the correlations of measures of traits between relatives. Second, they developed the theoretical framework for evolutionary biology, classical population genetics. This is a family of mathematical models representing evolution as change in genotype frequencies, from one generation to the next, as a product of selection, mutation, migration, and drift, or chance. Third, there was a broader synthesis of population genetics with cytology, genetics, and biochemistry, as well as both empirical and mathematical demonstrations to the effect that very small selective forces acting over a relatively long time were able to generate substantial evolutionary change, a novel and surprising result to many skeptics of Darwinian gradualist views. The later “modern” synthesis is most often identified with the work of Mayr, Dobzhansky and Simpson. There was a major institutional change in biology at this stage, insofar as different subdisciplines formerly housed in different departments, and with different methodologies were united under the same institutional umbrella of “evolutionary biology.” Mayr played an important role as a community architect, in founding the Society for the Study of Evolution, and the journal Evolution, which drew together work in systematics, biogeography, paleontology, and theoretical population genetics. (shrink)

A common criticism of punctuated equilibria as an evolutionary theory is that it erects a straw man by characterizing the modern synthesis as being devoid of mechanisms that bring about rapid speciation and abrupt changes in morphology. Thompson supports this view and argues that the modern synthesis does not entail gradualism, all-pervasive adaptationism, or extrapolationism and that punctuationists have mischaracterized the theory on all these points; properly understood the synthetic theory is hierarchical (...) and able to explain phenomena at all levels of the hierarchy, thus rendering macroevolutionary theories, such as punctuated equilibria, unnecessary. I argue in this paper that Thompson's approach is overly dependent upon rational reconstruction in the style of the logical empiricists, and as such ignores important sociological and historical factors that when taken into account justify punctuational criticism of the synthetic theory. (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)

Darwin proposed that evolutionary novelties are environmentally induced in organisms “constitutionally” sensitive to environmental change, with selection effective owing to the inheritance of constitutional responses. A molecular theory of inheritance, pangenesis , explained the cross‐generational transmission of environmentally induced traits, as required for evolution by natural selection. The twentieth‐century evolutionary synthesis featured mutation as the source of novelty, neglecting the role of environmental induction. But current knowledge of environmentally sensitive gene expression, combined with the idea of (...) genetic accommodation of mutationally and environmentally induced change, supports a revival of Darwin's original theory that is consistent with modern molecular and population genetics. †To contact the author, please write to: Smithsonian Tropical Research Institute, c/o Escuela de Biología, Universidad de Costa Rica, Costa Rica; e‐mail: [email protected]. (shrink)

Evolutionary epistemology has experienced a continuous rise over the last decades. Important new theoretical considerations and novel empirical findings have been integrated into the existing framework. In this paper, I would like to suggest three lines of research that I believe will significantly contribute to further advance EE: ontogenetic considerations, key ideas from cognitive biology, and the framework of the Extended Evolutionary Synthesis. EE, in particular the program of the evolution of epistemological mechanisms, seeks to provide a (...) phylogenetic account of the generation of cognitive processes underlying knowledge creation. Traditionally, EE and EEM have been oriented towards an account of evolutionary theory that mainly drew from the tenets of the Modern Synthesis. The Modern Synthesis largely dismisses ontogenetic processes and considers them irrelevant for evolutionary explanations. If anything, the role of development in evolution is believed to be that of a constraint. There is, however, ample evidence for a tight intertwinement of developmental and evolutionary processes. Organisms employ their cognitive apparatus to interact with the environment in order to achieve a fully functioning perceptual and cognitive nervous system. Also, ontogeny provides generative potentials to enable variations that natural selection can act upon. EEM’s agenda may, therefore, strongly benefit from bringing together ontogenetic and phylogenetic approaches. To grapple with this challenge, an alternative vision of the evolutionary theory termed Extended Evolutionary Synthesis could be used. This extended evolutionary theory explores relationships between the processes of individual development and phenotypic change during evolution and can provide a more suitable framework for EEM to draw from. In recent years, cognitive biology has gained momentum as an independent research field. Cognitive biology builds on the concepts of EEM and understands knowledge as a biogenic phenomenon. Its main objective is also the formulation of substantiated interrelations between cognition and evolution but it focuses on cognitive functionality at all levels of biological organization. It thus employs a “vertical” approach that encompasses nested hierarchies which span from single molecules, cells, and tissues to the organismal level, communities, and societies. In contrast to cognitive biology, EEM is here understood to adopt a “horizontal” approach that focuses on phylogenetic explanations of cognition and knowledge acquisition. Linking EEM with the key ideas of cognitive biology could make EEM’s research program stronger as it can more easily accommodate phylogenetic and ontogenetic questions within a hierarchical, multilevel perspective. This is of particular importance for a more comprehensive account of cognition since living systems are subject to context-dependent causal influences from different organizational levels. In addition to EEM, there is a second program of EE. This program has been labeled evolutionary epistemology of theories and understands the increase in human knowledge, such as scientific theories, as naturalistic accounts of evolution. Both, EEM and EET initially drew from the core concepts of the Modern Synthesis. Several scholars have severely criticized the analogies made between EET and the Neo-Darwinian key processes of evolution. In particular processes of random mutation, the rate of variation, natural selection as the unique driving force, and the adaptationist agenda are believed to reveal disanalogies. In contrast to the Modern Synthesis, the Extended Evolutionary Synthesis not only recognizes developmental processes but also ecological interactions and systems dynamics as well as social and cultural evolutionary reciprocity as important evolutionary processes. Concepts of the Extended Evolutionary Synthesis are therefore expected to be more fruitful for re-conceptualizing parallels between scientific theorizing and biological evolution. (shrink)

I propose we abandon the unit concept of "the evolutionary synthesis". There was much more to evolutionary studies in the 1920s and 1930s than is suggested in our commonplace narratives of this object in history. Instead, four organising threads capture much of evolutionary studies at this time. First, the nature of species and the process of speciation were dominating, unifying subjects. Second, research into these subjects developed along four main lines, or problem complexes: variation, divergence, isolation, (...) and selection. Some calls for 'synthesis' focused on these problem complexes (sometimes on one of these; other times, all). In these calls, comprehensive and pluralist compendia of plausibly relevant elements were preferred over reaching consensus about the value of particular formulae. Third, increasing confidence in the study of common problems coincided with methodological and epistemic changes associated with experimental taxonomy. Finally, the surge of interest in species problems and speciation in the 1930s is intimately tied to larger trends, especially a shifting balance in the life sciences towards process-based biologies and away from object-based naturalist disciplines. Advocates of synthesis in evolution supported, and were adapting to, these larger trends. (shrink)

One central tenet of the Modern Evolutionary Synthesis , and the consensus view among biologists until now, is that all genetic mutations occur by “chance” or at “random” with respect to adaptation. However, the discovery of some molecular mechanisms enhancing mutation rate in response to environmental conditions has given rise to discussions among biologists, historians and philosophers of biology about the “chance” vs “directed” character of mutations . In fact, some argue that mutations due to a particular (...) kind of mutator mechanisms challenge the Modern Synthesis because they are produced when and where needed by the organisms concerned. This paper provides a defense of the Modern Synthesis’ consensus view about the chance nature of all genetic mutations by reacting to Jablonka and Lamb’s analysis of genetic mutations and the explicit Lamarckian flavor of their arguments. I argue that biologists can continue to talk about chance mutations according to what I call and define as the notion of “evolutionary chance,” which I claim is the Modern Synthesis’ consensus view and a reformulation of Darwin’s most influential idea of “chance” variation. Advances in molecular genetics are therefore significant but not revolutionary with respect to the Modern Synthesis’ paradigm. (shrink)

The Extended Evolutionary Synthesis (EES) debate is gaining ground in contemporary evolutionary biology. In parallel, a number of philosophical standpoints have emerged in an attempt to clarify what exactly is represented by the EES. For Massimo Pigliucci, we are in the wake of the newest instantiation of a persisting Kuhnian paradigm; in contrast, Telmo Pievani has contended that the transition to an EES could be best represented as a progressive reformation of a prior Lakatosian scientific research program, (...) with the extension of its Neo-Darwinian core and the addition of a brand-new protective belt of assumptions and auxiliary hypotheses. Here, we argue that those philosophical vantage points are not the only ways to interpret what current proposals to ‘extend’ the Modern Synthesis-derived ‘standard evolutionary theory’ (SET) entail in terms of theoretical change in evolutionary biology. We specifically propose the image of the emergent EES as a vast network of models and interweaved representations that, instantiated in diverse practices, are connected and related in multiple ways. Under that assumption, the EES could be articulated around a paraconsistent network of evolutionary theories (including some elements of the SET), as well as models, practices and representation systems of contemporary evolutionary biology, with edges and nodes that change their position and centrality as a consequence of the co-construction and stabilization of facts and historical discussions revolving around the epistemic goals of this area of the life sciences. We then critically examine the purported structure of the EES—published by Laland and collaborators in 2015—in light of our own network-based proposal. Finally, we consider which epistemic units of Evo-Devo are present or still missing from the EES, in preparation for further analyses of the topic of explanatory integration in this conceptual framework. (shrink)

In the six decades since the publication of Julian Huxley's Evolution: The Modern Synthesis, spectacular empirical advances in the biological sciences have been accompanied by equally significant developments within the core theoretical framework of the discipline. As a result, evolutionary theory today includes concepts and even entire new fields that were not part of the foundational structure of the Modern Synthesis. In this volume, sixteen leading evolutionary biologists and philosophers of science survey the (...) conceptual changes that have emerged since Huxley's landmark publication, not only in such traditional domains of evolutionary biology as quantitative genetics and paleontology but also in such new fields of research as genomics and EvoDevo. Most of the contributors to Evolution—The Extended Synthesis accept many of the tenets of the classical framework but want to relax some of its assumptions and introduce significant conceptual augmentations of the basic Modern Synthesis structure—just as the architects of the Modern Synthesis themselves expanded and modulated previous versions of Darwinism. This continuing revision of a theoretical edifice the foundations of which were laid in the middle of the nineteenth century—the reexamination of old ideas, proposals of new ones, and the synthesis of the most suitable—shows us how science works, and how scientists have painstakingly built a solid set of explanations for what Darwin called the "grandeur" of life. (shrink)

According to a classical narrative, early geneticists, failing to see how Mendelism provides the missing pieces of Darwin’s theory, rejected gradual changes and advocated an implausible yet briefly popular view of evolution-by-mutation; after decades of delay (in which synthesis was prevented by personal conflicts, disciplinary rivalries, and anti-Darwinian animus), Darwinism emerged on a new Mendelian basis. Based on the works of four influential early geneticists – Bateson, de Vries, Morgan and Punnett –, and drawing on recent scholarship, we (...) offer an alternative that turns the classical view on its head. For early geneticists, embracing discrete inheritance and the mutation theory (for the origin of hereditary variation) did not entail rejection of selection, but rejection of Darwin’s non-Mendelian views of heredity and variation, his doctrine of natura non facit saltum, and his conception of “natural selection” as a creative force that shapes features out of masses of infinitesimal differences. We find no evidence of a delay in synthesizing mutation, rules of discrete inheritance, and selection in a Mendelian-Mutationist Synthesis. Instead, before 1918, early geneticists had conceptualized allelic selection, the Hardy–Weinberg equilibrium, the evolution of a quantitative trait under selection, the probability of fixation of a new mutation, and other key innovations. Contemporary evolutionary thinking seems closer to their more ecumenical view than to the restrictive mid-twentieth-century consensus known as the Modern Synthesis. (shrink)

In this paper, we analyze the debate between the Modern Synthesis and the Extended Evolutionary Synthesis in light of the concept of incommensurability developed by Thomas Kuhn. In order to do so, first we briefly present both the Modern Synthesis and the Extended Evolutionary Synthesis. Then, we clarify the meaning and interpretations of incommensurability throughout Kuhn’s works, concluding that the version of this concept deployed in The Structure of Scientific Revolutions is the (...) best suited to the analysis of scientific disputes. After discussing incommensurability in Kuhn’s works, we address the question of whether the Modern Synthesis and the Extended Evolutionary Synthesis can be considered semantically, methodologically, and ontologically incommensurable, concluding that they can. Finally, we discuss three problems that arise from such a conclusion: firstly, what are the consequences of incommensurability; secondly, which mode of scientific change better explains this current dispute in evolutionary biology; and thirdly, whether rational theory comparison is possible given incommensurability. We suggest that the main consequence of incommensurability is profound disagreement, that the kind of scientific change that better explains the current dispute between the MS and the EES may be scientific specialization, and that incommensurability does not preclude rational theory comparison. (shrink)

This paper uses formal Darwinism as elaborated by Alan Grafen to articulate an explanatory pluralism that casts light upon two strands of controversies running across evolutionary biology, viz., the place of organisms versus genes, and the role of adaptation. Formal Darwinism shows that natural selection can be viewed either physics-style, as a dynamics of alleles, or in the style of economics as an optimizing process. After presenting such pluralism, I argue first that whereas population genetics does not support optimization, (...) optimality can still be taken as a default hypothesis when modeling evolutionary processes; and second, that organisms have an explanatory role in evolutionary theory, since they are involved in the economic perspective of optimization. Finally, in order to ask whether the Modern Synthesis can indeed provide a theory of organisms, I apply a Kantian-inspired theoretical view of organisms (underlying much developmental modeling), according to which they are both designed entities and subjects of intrinsic circular processes involving the whole organism and its parts. I first show that the design aspect is accountable for in terms of the Modern Synthesis understood in the formal Darwinism framework. I then question whether the latter aspect of organisms can also be ultimately captured in the same framework, and to this purpose devise an empirical test relying on an assessment of the relative weight of genetic elements in developmental and functional gene regulatory networks. (shrink)

ABSTRACTMetaphors are a genuinely human construction. They are used to improve communication and they are a very powerful tool that might have an influence in human evolution. In this article I argue that metaphors, transformed in powerful memes, adapt to a new communicative niche and contribute to transform it. In order to prove this hypothesis, I study 319 cartoons published in the wake of the Germanwings air crash, where I inventory 144 metaphors. The study shows the conceptual metaphor evolution for (...) a period of 2 weeks, and how the metaphors changed as a result of the variations in the communicative niche, becoming much more efficient communicatively. (shrink)

Evolutionary biology is a field currently animated by much discussion concerning its conceptual foundations. On the one hand, we have supporters of a classical view of evolutionary theory, whose backbone is provided by population genetics and the so-called Modern Synthesis (MS). On the other hand, a number of researchers are calling for an Extended Synthe- sis (ES) that takes seriously both the limitations of the MS (such as its inability to incorporate developmental biology) and recent (...) empirical and theoretical research on issues such as evolvability, modularity, and self-organization. In this article, I engage in an in-depth commentary of an influential paper by population geneticist Michael Lynch, which I take to be the best defense of the MS-population genetics position published so far. I show why I think that Lynch’s arguments are wanting and propose a modification of evolutionary theory that retains but greatly expands on population genetics. (shrink)

Ernst Mayr (1980) provided an influential picture of the nature of the Modern Evolutionary Synthesis and of the debate and changes occurring prior to its completion. Mayr intended his account to be applicable to comparable cases. Sociobiology should be evaluated both as a comparable case, an attempt to produce a synthesis which undergoes development of the sort Mayr described, and as an extension of the Modern Synthesis itself. Examination of what the explanatory goals and (...) development of the New Sociobiological Synthesis would be, if it is to achieve a fruitful synthesis which fits Mayr's account, undermines Richard Lewontin's critique of sociobiology. Although Lewontin speaks for many in viewing sociobiology as the latest historical manifestation of social Darwinism, genetic determinism, biological reductionism, and vulgar adaptationism, sociobiology's effort to produce a synthesis does not entail commitment to those positions. (shrink)

Since the 1940s, microbiologists, biochemists and population geneticists have experimented with the genetic mechanisms of microorganisms in order to investigate evolutionary processes. These evolutionary studies of bacteria and other microorganisms gained some recognition from the standard-bearers of the modern synthesis of evolutionary biology, especially Theodosius Dobzhansky and Ledyard Stebbins. A further period of post-synthesis bacterial evolutionary research occurred between the 1950s and 1980s. These experimental analyses focused on the evolution of population and genetic (...) structure, the adaptive gain of new functions, and the evolutionary consequences of competition dynamics. This large body of research aimed to make evolutionary theory testable and predictive, by giving it mechanistic underpinnings. Although evolutionary microbiologists promoted bacterial experiments as methodologically advantageous and a source of general insight into evolution, they also acknowledged the biological differences of bacteria. My historical overview concludes with reflections on what bacterial evolutionary research achieved in this period, and its implications for the still-developing modern synthesis. (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 recent years, several prominent biologists have pointed to the relatively new field of evolutionary developmental biology (EvoDevo) as evidence of an Extended Synthesis in evolutionary biology. More particularly, these biologists claim that theoretical and empirical EvoDevo research is extending the Modern Synthesis framework of evolutionary theory through investigation of evolutionarily important concepts that are not part of the framework developed during the 20th century. To describe the current changes in evolutionary biology (...) as an Extended Synthesis, however, is incorrect. Through review of Extended Synthesis arguments and analysis of the same biological concepts used to support these arguments, I argue that the foundation of the Modern Synthesis framework, theoretical population genetics, faces significant, perhaps insurmountable challenges from the concepts highlighted by EvoDevo research. As the foundation of the Modern Synthesis framework will require considerable remodeling—if possible—in light of the concepts emphasized by EvoDevo, it is incorrect to describe the ongoing changes in evolutionary biology as an Extended Synthesis. (shrink)

In recent years, several prominent biologists have pointed to the relatively new field of evolutionary developmental biology as evidence of an Extended Synthesis in evolutionary biology. More particularly, these biologists claim that theoretical and empirical EvoDevo research is extending the Modern Synthesis framework of evolutionary theory through investigation of evolutionarily important concepts that are not part of the framework developed during the 20th century. To describe the current changes in evolutionary biology as (...) an Extended Synthesis, however, is incorrect. Through review of Extended Synthesis arguments and analysis of the same biological concepts used to support these arguments, I argue that the foundation of the Modern Synthesis framework, theoretical population genetics, faces significant, perhaps insurmountable challenges from the concepts highlighted by EvoDevo research. As the foundation of the Modern Synthesis framework will require considerable remodeling—if possible—in light of the concepts emphasized by EvoDevo, it is incorrect to describe the ongoing changes in evolutionary biology as an Extended Synthesis. (shrink)

The Modern Synthesis has been receiving bad press for some time now. Back in 1983, in an article entitled “The Hardening of the Modern Synthesis” Stephen Jay Gould criticized the way the Modern Synthesis had developed since its inception in the 1930s and early 1940s (Gould 1983). Back then, those who would later become known as ‘architects’ of the synthesis were united in their call for explaining evolution at all levels in terms of (...) causation at one level: genetics. What drove changes in gene frequency remained an open question. It could be mainly selection, or drift, or some (other) form of constraint. But in the two decades that followed, the synthesis underwent a major change. By the late 1940s the synthesis had ‘hardened’ around adaptationism, according to Gould. Influential contributors like Dobzhansky, Simpson and Wright had increasingly expressed adaptationist views in the later editions of their landmark books. Not because evidence had piled up, showing that selection was in fact pervasive. Instead, Gould argued, adaptationist tendencies had been preserved by some kind of cultural inertia, and were now being revived. “Certain ‘national styles’ persisted from the eighteenth century, through Darwin’s era, and into our own time. Views on adaptation provide a good example” (Gould 1983). Gould did not just argue that some form of adaptationism had resurfaced. He became well-known for his efforts to intervene on this status quo by attempting to make evolutionary biology more ‘pluralistic’. In collaborative work with Richard Lewontin (Gould and Lewontin 1979), Elisabeth Vrba (Gould and Vrba 1982; Vrba and Gould 1986) and Niles Eldredge (Eldredge and Gould 1972; Gould and Eldredge 1977) he criticized the synthesis for its adaptationism and its lack of appreciation for hierarchical perspectives. Gould exerted his influence in a different way as well. Together with Eldredge, he had facsimiles reprinted of the first editions of two books that had shaped synthesis, but with their own critical introductions (Eldredge 1982; Gould 1982). Dobzhansky’s Genetics and the Origin of Species and Mayr’s Systematics and the Origin of Species appeared as reprints in the ‘Columbia Classics in Evolution’ series, sending an unambiguous message to the readers: these are foundational works, but they have been superseded. In the summer of 2008, some 25 years after Gould made his point about the hardening of the Modern Synthesis, a group of sixteen biologists and philosophers gathered at the Konrad Lorenz Institute for Evolution and Cognition Research (KLI) near Vienna, Austria, to discuss cutting-edge research that reaches beyond the synthesis framework. Before it even started, this workshop on the ‘Extended Synthesis’ had already attracted a fair share of attention in the blogosphere and had resulted in a news feature in Science (Pennisi 2008). After the meeting, Nature weighed in on the matter (Whitfield 2008). The results of over 3 days of presentations and extensive discussion have now been published as Evolution—The Extended Synthesis. 1 The publication of this collection of sixteen essays is accompanied by the republication of Julian Huxley’s Evolution: The Modern Synthesis; the book that introduced the term ‘Modern Synthesis’. Both books are introduced by the organizers of the KLI workshop, Massimo Pigliucci and Gerd Müller. Like Gould and Eldredge before them, Pigliucci and Müller did not reissue one of the canons of the Modern Synthesis without giving the readers some ‘guidance’. Starting with the cover, the editors proclaim boldly that this is ‘the definitive edition’ of Huxley’s book. In a new foreword, they sketch the context in which the book was written and assess some of its features. They voice some mild criticism of alleged ‘adaptationism’. But their tone is different from that of Gould and Eldredge. Pigliucci and Müller praise Huxley for his pluralistic outlook, which has again become essential in the forging of an Extended Synthesis. That makes Huxley’s book more than just an interesting but obsolete classic. Instead, it can teach valuable lessons about how to ‘soften up’ a synthesis that has become hardened over time. (shrink)

In this paper, I present an argument that quantitative behavioural analysis can be used in zoosemiotic studies to advance the field of biosemiotics. The premise is that signs and signals form patterns in space and time, which can be measured and analysed mathematically. Whole organism sign processing is an important component of the semiosphere, with individual organisms in their Umwelten deriving signs from, and contributing to, the semiosphere, and vice versa. Moreover, there is a wealth of data available in the (...) traditional ethology literature which can be reinterpreted semiotically and drawn together to make a cohesive biosemiotic whole. For example, isolated signals, such as structural elements of birdsong, are attributed meaning by an interpreter, thus generating new ideas and hypotheses in both biology and semiotics. Furthermore, animal behaviour science has developed numerous test paradigms that with careful adaptation, could be suitable for use within a Peircean tripartite model, and thus give valuable insights into Umwelten of other species. In my conclusion, I suggest that by bringing together traditional ethology and biosemiotics, it is possible to use the Modern Synthesis to provide context to biosemiosis, thus pragmatic meaning to animal signals. On this basis, I propose updating the Modern Synthesis to a Semiotic Modern Synthesis, which focuses on whole-organism signals and their contexts, the latter being derived from neo-Darwinian theory and the ‘Umwelt’. Thus, there need be no dichotomy; the Modern Synthesis can successfully be integrated with biosemiotics. (shrink)

Evolutionary anthropology has focused on the origins of war, or rather ethnocentricity, because it epitomizes the problem of group selection, and because war may itself have been the main agent of group selection. The neo-Darwinian synthesis in biology has explained how ethnocentricity might evolve by group selection, and the distinction between evoked culture and adopted culture, suggested by the emerging synthesis in evolutionary psychology, has explained how it might be transmitted. Ethnocentric mechanisms could have evolved by (...) genetic selection in ancestral hominids, or through the interaction of genetic and cultural selection in modern humans, or both. The existence of similar behaviors in chimpanzees and the parallel development of early human societies around the globe are arguments for such inherited mechanisms. There may have been some adaptive breakthroughs in purely cultural evolution, but this process does not seem likely to produce long-term Darwinian adaptations because of the prolificity of cultural traits. Warfare may once have been a major agent of group selection, but the rates of extinction among human groups are so slow as to render this improbable since the rise of state-level societies, whose warfare tends to become a cyclical balance-of-power situation. Perhaps the most serious implication of current evolutionary thought is that the individualistic model of culture common in the social sciences and humanities is outmoded, and should be replaced by a new model that recognizes the organismic nature of human societies. (shrink)

Today a change is imperative in approaching global problems: what is needed is not arm-twisting and power politics, but searching for ways of co-evolution in the complex social and geopolitical systems of the world. The modern theory of self-organization of complex systems provides us with an understanding of the possible forms of coexistence of heterogeneous social and geopolitical structures at different stages of development regarding the different paths of their sustainable co-evolutionary development. The theory argues that (...) the evolutionary channel to the observed increasing complexity is extremely narrow and only certain discrete spectra of relatively stable self-maintained structures are feasible in complex systems. There exists a restricted set of ways of assembling a complex evolutionary whole from diverse parts. The law of nonlinear synthesis of complex structures reads: the integration of structures in more complex ones occurs due to the establishment of a common tempo of their evolution. On the basis of the theory, we can see not only desirable but also attainable futures. (shrink)

A central reason that undergirds the significance of evo-devo is the claim that development was left out of the Modern synthesis. This claim turns out to be quite complicated, both in terms of whether development was genuinely excluded and how to understand the different kinds of embryological research that might have contributed. The present paper reevaluates this central claim by focusing on the practice of model organism choice. Through a survey of examples utilized in the literature of the (...) Modern synthesis, I identify a previously overlooked feature: exclusion of research on marine invertebrates. Understanding the import of this pattern requires interpreting it in terms of two epistemic values operating in biological research: theoretical generality and explanatory completeness. In tandem, these values clarify and enhance the significance of this exclusion. The absence of marine invertebrates implied both a lack of generality in the resulting theory and a lack of completeness with respect to particular evolutionary problems, such as evolvability and the origin of novelty. These problems were salient to embryological researchers aware of the variation and diversity of larval forms in marine invertebrates. In closing, I apply this analysis to model organism choice in evo-devo and discuss its relevance for an extended evolutionary synthesis. (shrink)

I argue that Darwinian evolutionary theory has a rhetorical dimension and that rhetorical criticism plays a role in how evolutionary science acquires knowledge. I define what I mean by rhetoric by considering Darwin’s Origin. I use the Modern Evolutionary Synthesis to show how rhetoric conceived as situated and addressed argumentation enters into evolutionary theorizing. Finally, I argue that rhetorical criticism helps judge the success, limits, and failures of these theories.

Evolutionary theory is undergoing an intense period of discussion and reevaluation. This, contrary to the misleading claims of creationists and other pseudoscientists, is no harbinger of a crisis but rather the opposite: the field is expanding dramatically in terms of both empirical discoveries and new ideas. In this essay I briefly trace the conceptual history of evolutionary theory from Darwinism to neo-Darwinism, and from the Modern Synthesis to what I refer to as the Extended (...) Synthesis, a more inclusive conceptual framework containing among others evo–devo, an expanded theory of heredity, elements of complexity theory, ideas about evolvability, and a reevaluation of levels of selection. I argue that evolutionary biology has never seen a paradigm shift, in the philosophical sense of the term, except when it moved from natural theology to empirical science in the middle of the 19th century. The Extended Synthesis, accordingly, is an expansion of the Modern Synthesis of the 1930s and 1940s, and one that—like its predecessor—will probably take decades to complete. (shrink)

In this paper, I will conduct three interrelated analyses. First, I will develop an analysis of various concepts in the history of biology that used to refer to individual-level phenomena but were then reinterpreted by the Modern Synthesis in terms of populations. Second, I argue that a similar situation can be found in contemporary biological theory. While different approaches reflect on the causal role of developing organisms in evolution, proponents of the Modern Synthesis avoid any (...) substantial change by reinterpreting and explaining individual-level phenomena from a population perspective. Finally, I will approach this debate by advocating the statistical reading of natural selection, which holds that explanations by natural selection are statistical. I will argue that the above historical conceptual reinterpretations belong to a new explanatory strategy developed by the Modern Synthesis based on population thinking. The reinterpretation of concepts at the individual level is part of the explanatory framework of the Modern Synthesis and the empty role of development within this framework. Moreover, the statistical perspective adopted here allows for the integration of two explanatory models: population-statistical and individual-causal. Finally, I will argue that this pluralistic framework can help to define the explanatory scope of the different biological approaches in order to achieve a coherent integration of development into evolution without rejecting population thinking. (shrink)

Represents the most comprehensive and current survey of the various challenges to the Modern Synthesis theory of evolution. Incorporates a variety of theoretical and disciplinary perspectives, from evolutionary biologists, historians and philosophers of science. These essays constitute the state of the art in the current debate on the status of the Modern Synthesis.

The theory of punctuated equilibrium has been proposed as a challenge to the modern synthesis of evolutionary theory. Two important issues are raised. The first is scientific: whether morphological change as observed in the paleontological record is essentially always associated with speciation events. This paper argues that there is at present no empirical support for this claim: the alleged evidence is based on a definitional fallacy. The second issue is epistemological: whether macroevolution is an autonomous (...) field of study, independent from microevolutionary knowledge. It is herein argued that macroevolution and microevolution are not decoupled in two senses: identity at the level of events and compatibility of theories. But macroevolution is autonomous in the epistemologically important sense: macroevolutionary theories are not reducible to microevolutionary principles. It is finally pointed out that the discipline of macroevolution is notoriously lacking in theoretical constructs of great import and generality. (shrink)

Two welcome extensions of evolutionary thinking have come to prominence over the last thirty years: the so-called ’extended evolutionary synthesis’ (EES) and debate about biological kinds and individuals. These two agendas have, however, remained orthogonal to one another. The EES has mostly restricted itself to widening the explanations of adaptation offered by the preceding ’modern evolutionary synthesis’ by including additional mechanisms of inheritance and variation; while discussion of biological kinds has turned toward philosophical questions (...) of essential vs. contingent properties of life forms and realist vs. epistemological approaches to categorization and classification. Here we attempt to broaden the explanatory scope of evolutionary theory by linking these two agendas. We expand on the mechanistic orientation of the EES, using new understandings of networked systems of components in order to engage the distinct intellectual challenge of the origination of “historical kinds”. With this phrase we designate a subset of natural kinds that acquires, through evolutionary processes, a quasi-independent lineage-history. Such kinds emerge in both biology and culture, and we enlarge the limited number of historical kinds that have thus far been recognized in evolutionary biology in a series of paradigmatic exemplars, from genes and cell types to rituals and music. For each exemplar we discern specific mechanisms by which it arose and persists; comparing these, we suggest a general unity in the ways in which diverse historical kinds originate. (shrink)

This paper examines the history of animal behavior studies after the synthesis period. Three episodes are considered: the adoption of the theory of natural selection, the mathematization of ideas, and the spread of molecular methods in behavior studies. In these three episodes, students of behavior adopted practices and standards developed in population ecology and population genetics. While they borrowed tools and methods from these fields, they made distinct uses that set them relatively apart and led them to contribute, (...) in their own way, to evolutionary theory. These episodes also highlight some limitations of “conjunction narratives” centered on the relation between a discipline and the modern synthesis. A trend in conjunction narratives is to interpret any development related to evolution in a discipline as an “extension,” an “integration,” or as a “delayed” synthesis. I here suggest that this can lead to underestimate discontinuities in the history of evolutionary biology. (shrink)

Joseph Persky's excellent book, The Political Economy of Progress: John Stuart Mill and Modern Radicalism, shows that J. S. Mill's support for socialism is a carefully considered element of his political and economic reform agenda. The key thought underlying Persky's argument is that Mill has an ‘evolutionary theory of justice’, according to which the set of institutions and practices that are appropriate to one state of society should give way to a new set of institutions as circumstances (...) change and the people themselves improve. However, Persky does not spend a great deal of time discussing Mill's theory of reform, in particular the principles he believes should guide our reform efforts. Reflecting on these principles – notably his principle of impartiality or equal treatment – shows the consistency of Mill's thought over time. (shrink)

This is the first volume to address directly the question of the speciation of modern Homo sapiens. The subject raises profound questions about the nature of the species, our defining characteristic (it is suggested it is language), and the brain changes and their genetic basis that make us distinct. The British Academy and the Academy of Medical Sciences have brought together experts from palaeontology, archaeology, linguistics, psychology, genetics and evolutionary theory to present evidence and theories at the (...) cutting edge of our understanding of these issues. Palaeontological and genetic work suggests that the transition from a precursor hominid species to modern man took place between 100,000 and 150,000 years ago. Some contributors discuss what is most characteristic of the species, focussing on language and its possible basis in brain lateralization. This work is placed in the context of speciation theory, which has remained a subject of considerable debate since the evolutionary synthesis of Mendelian genetics and Darwinian theory. The timing of specific transitions in hominid evolution is discussed, as also is the question of the neural basis of language. Other contributors address the possible genetic nature of the transition, with reference to changes on the X and Y chromosomes that may account for sex differences in lateralization and verbal ability. These differences are discussed in terms of the theory of sexual selection, and with reference to the mechanisms of speciation. These essays will be vital reading for anyone interested in the nature and origins of the species, and specifically human abilities. (shrink)

This is the first volume to address directly the question of the speciation of modern Homo sapiens. The subject raises profound questions about the nature of the species, our defining characteristic, and the brain changes and their genetic basis that make us distinct. The British Academy and the Academy of Medical Sciences have brought together experts from palaeontology, archaeology, linguistics, psychology, genetics and evolutionary theory to present evidence and theories at the cutting edge of our understanding of (...) these issues.Palaeontological and genetic work suggests that the transition from a precursor hominid species to modern man took place between 100,000 and 150,000 years ago. Some contributors discuss what is most characteristic of the species, focussing on language and its possible basis in brain lateralization. This work is placed in the context of speciation theory, which has remained a subject of considerable debate since the evolutionary synthesis of Mendelian genetics and Darwinian theory. The timing of specific transitions in hominid evolution is discussed, as also is the question of the neural basis of language. Other contributors address the possible genetic nature of the transition, with reference to changes on the X and Y chromosomes that may account for sex differences in lateralization and verbal ability. These differences are discussed in terms of the theory of sexual selection, and with reference to the mechanisms of speciation.These essays will be vital reading for anyone interested in the nature and origins of the species, and specifically human abilities. (shrink)

We trace the history of the Modern Evolutionary Synthesis, and of genetic Darwinism generally, with a view to showing why, even in its current versions, it can no longer serve as a general framework for evolutionary theory. The main reason is empirical. Genetical Darwinism cannot accommodate the role of development (and of genes in development) in many evolutionary processes. We go on to discuss two conceptual issues: whether natural selection can be the “creative factor” (...) in a new, more general framework for evolutionary theorizing; and whether in such a framework organisms must be conceived as self-organizing systems embedded in self-organizing ecological systems. (shrink)

A new conceptual essay introducing one of the classics of the evolutionary biological literature.

The Rise of Chance in Evolutionary Theory: A Pompous Parade of Arithmetic explores a pivotal conceptual moment in the history of evolutionary theory: the development of its extensive reliance on a wide array of concepts of chance. It tells the history of a methodological and conceptual development that reshaped our approach to natural selection over a century, ranging from Darwin’s earliest notebooks in the 1830s to the early years of the Modern Synthesis in the (...) 1930s. Far from being a “pompous parade of arithmetic,” as one early critic argued, evolution transformed during this period to make these conceptual and technical tools indispensable. This book charts the role of chance in evolutionary theory from its beginnings to the earliest days of modern evolutionary theory, making it an ideal resource for evolutionary biologists, historians, philosophers, and researchers in science studies or biological statistics. (shrink)

Joseph Persky's excellent book, The Political Economy of Progress: John Stuart Mill and Modern Radicalism, shows that J. S. Mill's support for socialism is a carefully considered element of his political and economic reform agenda. The key thought underlying Persky's argument is that Mill has an ‘evolutionary theory of justice’, according to which the set of institutions and practices that are appropriate to one state of society should give way to a new set of institutions as circumstances (...) change and the people themselves improve. However, Persky does not spend a great deal of time discussing Mill's theory of reform, in particular the principles he believes should guide our reform efforts. Reflecting on these principles – notably his principle of impartiality or equal treatment – shows the consistency of Mill's thought over time. (shrink)

The Modern Synthesis was based on Darwin’s gradualist view of evolution and early twentieth Century Mendelian and population genetics. Although early results in microbial and molecular genetics seemed to solidify MS views through the Central Dogma of Molecular Biology, accepting their basic concepts as permanent truths blinded MS proponents to the importance of incompatible discoveries in the second half of the 20th and early 21st Centuries. Discoveries based largely on the DNA record have provided a radically different view (...) of genome complexity and biologically-mediated evolutionary change. (shrink)

In this commentary on Denis Noble’s “The Illusions of the Modern Synthesis,” I discuss three illusions he argues exist within the Modern Synthesis. These illusions have the common theme of attempting to identify the correct way of understanding and describing biological systems. I agree with much of Noble’s claims, but offer the language of developmental systems theory as a friendly tool for moving the project forward.

The Modern Synthesis (MS) is the current paradigm in evolutionary biology. It was actually built by expanding on the conceptual foundations laid out by its predecessors, Darwinism and neo-Darwinism. For sometime now there has been talk of a new Extended Evolutionary Synthesis (EES), and this article begins to outline why we may need such an extension, and how it may come about. As philosopher Karl Popper has noticed, the current evolutionary theory is a (...) theory of genes, and we still lack a theory of forms. The field began, in fact, as a theory of forms in Darwin’s days, and the major goal that an EES will aim for is a unification of our theories of genes and of forms. This may be achieved through an organic grafting of novel concepts onto the foundational structure of the MS, particularly evolvability, phenotypic plasticity, epigenetic inheritance, complexity theory, and the theory of evolution in highly dimensional adaptive landscapes. (shrink)

Chance has been a focus of attention ever since the beginning of population genetics, but neutrality has not, as natural selection once appeared to be the only worthwhile issue. Neutral change became a major source of interest during the neutralist–selectionist debate, 1970–1980. It retained interest beyond this period for two reasons that contributed to its becoming foundational for evolutionary reasoning. On the one hand, neutral evolution was the first mathematical prediction to emerge from Mendelian inheritance: until then evolution by (...) natural selection was considered the alternative to the fixity of species; now it appears to be the alternative to continuous change. Second, neutral change generated a set of clear predictions on standing variation. These could be used as a reference for detecting more elusive alternative mechanisms of evolution including natural selection. In the wake of the transition from Mendelism to genomics, the combination of coalescent theory, DNA sequence variation, and numerical analysis made it possible to integrate contingent aspects of the history of species into a new null model, thus opening a new dimension in the concept of population that the Modern Synthesis formerly considered as a mere gene pool. (shrink)

There is a conceptual crisis in the biomedical sciences that is particularly salient in psychopathology research. Underlying the crisis is a controversy that pertains to the current medical model of disease that largely draws from causal-mechanistic explanations. The bedrock of this model is the analysis of biological part-dysfunctions that aims at unequivocally defining a pathological condition and demarcating it from its neighboring entities. This endeavor has led to a quest for physiological, biochemical, and genetic signatures. Yet, so far there is (...) little evidence for reliable biomarkers for any mental disorder. The contemporary biomedical paradigm largely ignores historical, dynamic, and system-level aspects—a view that has contributed much to the conceptual disjunction of the patient as a person from his/her disease. Notwithstanding the impressive progress in the biomedical sciences, increasingly more critics question whether the constituting framework is sufficient to convey a comprehensive understanding of illnesses, especially mental illnesses. Thus, the medical model urgently requires an update. But rather than revamping it by methodological advancements, it will be necessary to critically review its philosophical roots. The most problematic issues that require reworking are: the preponderance of the biostatistical theory; the undue decoupling of physiological from evolutionary explanations of function; the clinging to the Modern Synthesis ; and the neglect of dynamic and system-level properties. The proposed overhaul requires the heeding of historical explanations that draw from the Extended Evolutionary Synthesis as well as systems biology approaches for tackling multilevel and dynamic phenomena of complex systems. (shrink)

Advocates of an ‘extended evolutionary synthesis’ have claimed that standard evolutionary theory fails to accommodate epigenetic inheritance. The opponents of the extended synthesis argue that the evidence for epigenetic inheritance causing adaptive evolution in nature is insufficient. We suggest that the ambiguity surrounding the conception of the gene represents a background semantic issue in the debate. Starting from Haig’s gene-selectionist framework and Griffiths and Neumann-Held’s notion of the evolutionary gene, we define senses of ‘gene’, (...) ‘environment’, and ‘phenotype’ in a way that makes them consistent with gene-centric evolutionary theory. We argue that the evolutionary gene, when being materialized, need not be restricted to nucleic acids but can encompass other heritable units such as epialleles. If the evolutionary gene is understood more broadly, and the notions of environment and phenotype are defined accordingly, current evolutionary theory does not require a major conceptual change in order to incorporate the mechanisms of epigenetic inheritance. _1_ Introduction _2_ The Gene-centric Evolutionary Theory and the ‘Evolutionary Gene’ _2.1_ The evolutionary gene _2.2_ Genes, phenotypes, and environments _3_ Epigenetic Inheritance and the Gene-Centred Framework _3.1_ Treating the gene as the sole heritable material? _3.2_ Epigenetics and phenotypic plasticity _4_ Conclusion. (shrink)

In this paper, I will briefly summarize the history and current accounts of Evolutionary Medicine (EM). I will show that EM, in its current forms, is using an evolutionary understanding that carries the explanatory framework, as well as explanatory limits, of the Modern Synthesis (MS). I will then point out some essential elements that need to be seen as limiting factors within EM and analyze the limitations that are brought about by the MS understanding of it. (...) On this basis, I will argue that if the latest developments in evolutionary theory are considered – in particular, those pertaining to the inheritance mechanisms highlighted by the Extended Evolutionary Synthesis (EES), and the newly introduced evolutionary entities – EM will have a much broader explanatory scope and increased explanatory power in addition to greater relevance, which will enable its application in medical explanations. (shrink)

Jean Gayon’s encounters with American evolutionary biologists and philosophers of biology affected his project of justifying the Darwinian research tradition. He challenged entrenched views about evolution in France by showing how the population-genetic theory of natural selectionSelection removed conceptual blockages that had thwarted the Darwinian research tradition. He taught his American colleagues how important French physiological genetics was to the DarwinismDarwinism of the modern evolutionary synthesis and, with Richard BurianBurian, Richard, stressed the compatibility of the (...) Synthesis with postwar French molecular geneticsMolecular genetics. His seamless integration of history and philosophy of biology helped create an international learned society in which historians and philosophers of biology work together (ISSHSPB). (shrink)