The extended evolutionary synthesis intends to offer a new framework for understanding evolution based mainly on empirical and theoretical findings of current studies, including heredity and evolutionary developmental biology. In this essay, we present and develop the following objections about the terminology associated with the EES literature: despite using the term "extension," EES protagonists claim new evolutionary processes, reformulate conceptual networks, and modify central assumptions of the evolutionary synthesis. Therefore, the difference between ES and EES should not be described in (...) terms of a set-subset relationship ; despite using the term "synthesis," the EES leads, at least in the short term, to a pluralism of approaches in evolutionary biology. Thus, we argue that the EES should not be described as a synthesis, but as a broad and plural interpretative framework encompassing different approaches. These objections are not directed to the proposed changes, but to the interpretation of these changes as a mere expansion of the previous evolutionary framework, as well as to the interpretation of the EES as a synthesis. Based on these objections, we seek to present some explanations for the use of the term "extended synthesis" among its protagonists. (shrink)

Synthesising arguments motivate changes to the conceptual tools, theoretical structure, and evaluatory framework employed in a given scientific domain. Recently, a broad coalition of researchers has put forward a synthesising argument in favour of an Extended Evolutionary Synthesis (‘EES’). Often this synthesising argument is evaluated using a virtue-based approach, which construes the EES as a wholesale alternative to prevailing practice. Here I argue this virtue-based approach is not fit for purpose. Taking the central concept of niche construction as a case (...) study, I show that an agenda-based approach better captures the pragmatic and epistemological goals of the EES synthesising argument and diagnoses areas of empirical disagreement with prevailing practice. (shrink)

In this paper I take evolutionary biology as an example to reflect on the role of philosophy and on the transformations that philosophy is constantly stimulated to do in its own approach when dealing with science. I consider that some intellectual movements within evolutionary biology (more specifically, the various calls for 'synthesis') express metascientific views, i.e., claims about 'what it is to do research' in evolutionary biology at different times. In the construction of metascientific views I see a fundamental role (...) to be played by philosophy, and, at the same time, a need to complement the philosophical methods with many more methods coming from other sciences. What leads philosophy out of itself is its own attention to scientific practice. My humble methodological suggestions are, at this stage, only meant to help us imagine metascientific views that are built with a more scientific, interdisciplinary approach, in order to attenuate partiality, subjectivity and impressionism in describing the scientific community. And yet, we should not be naïve and imbued with the myth of 'datadriven' research, especially in this field: other complex issues about metascientific views call for a serious, constant philosophical reflection on scientific practice. (shrink)

The dichotomy between ‘typological thinking’ and ‘population thinking’ features in a range of debates in contemporary and historical biology. The origins of this dichotomy are often traced to Ernst Mayr, who is said to have coined it in the 1950s as a rhetorical device that could be used to shield the Modern Synthesis from attacks by the opponents of population biology. In this two-part essay, I argue that the origins of the typology/population dichotomy are considerably more complicated and more interesting (...) than is commonly thought. In the first part, I argued that Mayr's dichotomy was based on two distinct type/population contrasts that had been articulated much earlier by George Gaylord Simpson and Theodosius Dobzhansky. Their distinctions made eminent sense in their own, isolated contexts. In this second part, I will show how Mayr conflated these type/population distinctions and blended in some of his own, unrelated concerns with ‘types’ of a rather different sort. Although Mayr told his early critics that he was merely making “a temporary oversimplification,” he ended up burdening the history and philosophy of biology with a troubled dichotomy. (shrink)

Julian Huxley’s eclipse of Darwinism narrative has cast a long shadow over the historiography of evolutionary theory around the turn of the nineteenth century. It has done so by limiting who could be thought of as Darwinian. Peter Bowler used the eclipse to draw attention to previously understudied alternatives to Darwinism, but maintained the same flaw. In his research on the Non-Darwinian Revolution, he extended this problematic element even further back in time. This paper explores how late nineteenth-century neo-Darwinian conceptualizations (...) of Darwinism were later utilized by several advocates and detractors of the Modern Synthesis. John Beatty has shown how this continuity hinges at least partly on the perceived importance of the creativity of natural selection. The paper provides a more thorough look at Darwin’s two conflicting accounts of variation, ascribed to struggles in explaining quantitative versus qualitative characters. In doing so, it suggests that other forms of Darwinism persisted, in both the non-Darwinian revolution and eclipse periods, because of tension between contingency and creativity in Darwin’s own work. This tension is traced out from Darwin’s conceptions of variation into the work of Alfred Russel Wallace, Hugo de Vries, and Thomas Henry Huxley. Based on this, the eclipse narrative is criticized for not considering the meaning of Darwinism in different geographical locations. Britain and the United States showed few signs of an eclipse. Rather, the rise of German debates about Haeckel’s vision of Darwinism have been mistaken for a universal decline in support. (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)

This paper surveys questions about the nature of the Modern Synthesis as a historical event : was it rather theoretical than institutional? When and where did it actually happen? Who was involved? It argues that all answers to these questions are interrelated, and that systematic sets of answers define specific perspectives on the Modern Synthesis that are all complementary.

During its centennial celebrations in 2008, the Museum of Vertebrate Zoology (MVZ) at the University of California, Berkeley paid homage to its founding director, Joseph Grinnell. Recognized as a leading scientific institution, the MVZ managed to grow throughout the twentieth century, a period often characterized by the decline of natural history. To understand how and why research flourished at the MVZ, this paper looks closely at Grinnell's undergraduate course, the Natural History of the Vertebrates (NHV). Taught by MVZ affiliates since (...) 1914, the NHV offers an important window on Grinnell's approach and legacy. This paper argues that the NHV contributed to the MVZ's long-term success by acting as, first, a gateway to natural history; second, a vector for the MVZ's research programme; and third, a shared faculty responsibility. Grinnell's significance in the history of science is understated, in part because his writing style de-emphasized the importance of his theoretical contributions, including his development of the niche concept, his emphasis on population thinking and geographic isolation in studies of evolution, and his effort to integrate speciation questions and genetics. Studying the NHV highlights these contributions because Grinnell freely communicated his ideas to his students. An analysis of Grinnell's course material shows that his theoretical and methodological approach pre-dated the evolutionary synthesis and inspired natural-history research throughout the past century. (shrink)

The role of paleontology in evolutionary biology between the publication of The Origin of Species in 1859 and the Evolutionary Synthesis of the 1940s is frequently described as mostly misguided failure. However, a significant number of American and British PDPS invertebrate paleontologists of this period did devote considerable attention to evolution, and their evolutionary theories and conclusions were a good deal more diverse and nuanced than previous histories have suggested. This paper brings into focus a number of important but underrecognized (...) aspects of the history of paleontology within the history of biology, including that PDPS paleontologists were not all as theoretically backward as they have been portrayed; that the post-Synthesis narrative of the history of evolution should be continually reevaluated, in part to decouple historical understanding from the agendas of authors who have used history to advance particular views of evolution; and that there is a much richer story to be told about the history of evolutionary biology in both the pre- and post-Synthesis eras. (shrink)

The use of ‘race’ as a proxy for population structure in the genetic mapping of complex traits has provoked controversy about its legitimacy as a category for biomedical research, given its social and political connotations. The controversy has reignited debates among scientists and philosophers of science about whether there is a legitimate biological concept of race. This paper examines the genetic race concept as it developed historically in the work of Theodosius Dobzhansky from the 1930s to 1950s. Dobzhansky’s definitions of (...) race changed over this time from races as ‘arrays of forms’ or ‘clusters’ in 1933–1939, to races as genetically distinct geographical populations in 1940–1946, to races as genetically distinct ‘Mendelian populations’ in 1947–1955. Dobzhansky responded to nominalist challenges by appealing to the biological reality of race as a process. This response came into tension with the object ontology of race that was implied by Dobzhansky’s increasingly holistic treatment of Mendelian populations, a tension, the paper argues, he failed to appreciate or resolve. (shrink)

Historians of science have long been agreeing: what many textbooks of evolutionary biology say, about the histories of Darwinism and the New Synthesis, is just too simple to do justice to the complexities revealed to critical scholarship and historiography. There is no current consensus, however, on what grand narratives should replace those textbook histories. The present paper does not offer to contribute directly to any grand, consensual, narrational goals; but it does seek to do so indirectly by showing how, in (...) just one individual case, details of intellectual biography connect with big picture issues. To this end, I examine here how very diverse scientific and metaphysical commitments were integrated in Sewall Wright’s own personal synthesis of biology and philosophy. Taking as the decisive text the short final section of Wright’s long 1931 paper on ‘Evolution in Mendelian populations,’ I examine how his shifting balance theory related to his optimum breeding strategy research, his physiological genetics, his general theory of homogenising and heterogenesing causation and his panpsychist view of mind and matter; and I discuss how understanding these relations can clarify Wright’s place in the longue durée of evolutionary thought. (shrink)

The term “genetic load” first emerged in a paper written in 1950 by the geneticist H. Muller. It is a mathematical model based on biological, social, political and ethical arguments describing the dramatic accumulation of disadvantageous mutations in human populations that will occur in modern societies if eugenic measures are not taken. The model describes how the combined actions of medical and social progress will supposedly impede natural selection and make genes of inferior quality likely to spread across populations – (...) a process which in fine loads their progress. Genetic load is based on optimal fitness and emerges from a “typological view” of evolution. This model of evolution had previously, however, been invalidated by Robert Wright and Theodosius Dobzhansky who, as early as 1946, showed that polymorphism was the rule in natural populations. The blooming and persistence of the concept of genetic load, after its theoretical basis had already expired, are a historical puzzle. This persistence reveals the intricacy of science and policy-making in eugenic matters. The Canguilhemian concept of ‘scientific ideology’ is used along with the concept of ‘immutable mobile’ and compared with the concept of ‘co-production’, to provide complementary perspectives on this complex phenomenon. (shrink)

The dichotomy between ‘typological thinking’ and ‘population thinking’ features in a range of debates in contemporary and historical biology. The origins of this dichotomy are often traced to Ernst Mayr, who is said to have coined it in the 1950s as a rhetorical device that could be used to shield the Modern Synthesis from attacks by the opponents of population biology. In this two-part essay I argue that the origins of the typology/population dichotomy are considerably more complicated and more interesting (...) than is commonly thought. In this first part, I will argue that Mayr's dichotomy was based on two distinct type/population contrasts that had been articulated much earlier by George Gaylord Simpson and Theodosius Dobzhansky. Their distinctions made eminent sense in their own, isolated contexts. In the second part, I will show how Mayr conflated these type/population distinctions and blended in some of his own, unrelated concerns with ‘types’ of a rather different sort. Although Mayr told his early critics that he was merely making “a temporary oversimplification,” he ended up burdening the history and philosophy of biology with a troubled dichotomy. (shrink)

Ernst Mayr’s influence on philosophy of biology has given the field a particular perspective on evolution, phylogeny and life in general. Using debates about the tree of life as a guide, I show how Mayrian evolutionary biology excludes numerous forms of life and many important evolutionary processes. Hybridization and lateral gene transfer are two of these processes, and they occur frequently, with important outcomes in all domains of life. Eukaryotes appear to have a more tree-like history because successful lateral events (...) tend to occur among more closely related species, or at a lower frequency, than in prokaryotes, but this is a difference of degree rather than kind. Although the tree of life is especially problematic as a representation of the evolutionary history of prokaryotes, it can function more generally as an illustration of the limitations of a standard evolutionary perspective. Moreover, for philosophers, questions about the tree of life can be applied to the Mayrian inheritance in philosophy of biology. These questions make clear that the dichotomy of life Mayr suggested is based on too narrow a perspective. An alternative to this dichotomy is a multidimensional continuum in which different strategies of genetic exchange bestow greater adaptiveness and evolvability on prokaryotes and eukaryotes. (shrink)

Ecology in principle is tied to evolution, since communities and ecosystems result from evolution and ecological conditions determine fitness values. Yet the two disciplines of evolution and ecology were not unified in the twentieth-century. The architects of the Modern Synthesis, and especially Julian Huxley, constantly pushed for such integration, but the major ideas of the Synthesis—namely, the privileged role of selection and the key role of gene frequencies in evolution—did not directly or immediately translate into ecological science. In this paper (...) I consider five stages through which the Synthesis was integrated into ecology and distinguish between various ways in which a possible integration was gained. I start with Elton’s animal ecology, then consider successively Ford’s ecological genetics in the 1940s, the major textbook Principles of animal ecology edited by Allee et al., and the debates over the role of competition in population regulation in the 1950s, ending with Hutchinson’s niche concept and McArthur and Wilson’s Principles of Island Biogeography viewed as a formal transposition of Modern Synthesis explanatory schemes. I will emphasize the key role of founders of the Synthesis at each stage of this very nonlinear history. (shrink)

The correspondence between Edgar Anderson and Ernst Mayr leading into their 1941 Jesup Lectures on “Systematics and the Origin of Species” addressed population thinking, the nature of species, the relationship of microevolution to macroevolution, and the evolutionary dynamics of plants and animals, all central issues in what came to be known as the Evolutionary Synthesis. On some points, they found ready agreement; for others they forged only a short term consensus. They brought two different working styles to this project reflecting (...) their different appreciations of what was possible at this point in evolutionary studies. For Mayr, it was a focused project with definitive short term conclusions imminent while Anderson viewed it as an episode in an ongoing historical process that, while exciting and suggestive, remained openended. Thus, Mayr and Anderson represent two distinct perspectives on the Evolutionary Synthesis in formation; by understanding both of their points of view, we can grasp more fully the state of evolutionary theory at this key moment. (shrink)

During the decades following World War II diverse groups of American biologists established a variety of distinctive approaches to organismal biology. Rhetorically, organismal biology could be used defensively to distinguish established research traditions from perceived threats from newly emerging fields such as molecular biology. But, organismal biologists were also interested in integrating biological disciplines and using a focus on organisms to synthesize levels of organization from molecules and cells to populations and communities. Part of this broad movement was the development (...) of an area of research variously referred to as physiological ecology, environmental physiology, or ecophysiology. This area of research was distinctive in its self-conscious blend of field and laboratory practices and its explicit integration with other areas of biology such as ecology, animal behavior, and evolution in order to study adaptation. Comparing the intersecting careers of Knut Schmidt-Nielsen and George Bartholomew highlights two strikingly different approaches to physiological ecology. These alternative approaches to studying the interactions of organisms and environments also differed in important ways from the organismal biology championed by leading figures in the modern synthesis. (shrink)

This paper extends previous arguments against the assumption that the study of variation at the molecular level was instigated with a view to solving an internal conflict between the balance and classical schools of population genetics. It does so by focusing on the intersection of basic research in protein chemistry and the molecular approach to disease with the enactment of global health campaigns during the Cold War period. The paper connects advances in research on protein structure and function as reflected (...) in Christian Anfinsen’s The molecular basis of evolution, with a political reading of Emilé Zuckerkandl and Linus Pauling’s identification of molecular disease and evolution. Beyond atomic fallout, these advances constituted a rationale for the promotion of genetic surveys of human populations in the Third World, in connection with international health programs. Light is shed not only on the experimental roots of the molecular challenge but on the broader geopolitical context where the rising role of biomedicine and public health had an impact on evolutionary biology. (shrink)

Berichte zur Wissenschaftsgeschichte, Volume 45, Issue 3, Page 468-486, September 2022.

Speciation—the origin of new species—has been one of the most active areas of research in evolutionary biology, both during, and since the Modern Synthesis. While the Modern Synthesis certainly shaped research on speciation in significant ways, providing a core framework, and set of categories and methods to work with, the history of work on speciation since the mid-twentieth century is a history of divergence and diversification. This piece traces this divergence, through both theoretical advances, and empirical insights into how different (...) lineages, with different genetics and ecological conditions, are shaped by very different modes of diversification. (shrink)

Fisher recognized that the evolution of social insect colonies needed explaining, a point which Charles Darwin had avoided discussing in detail. Fisher, in his 1930 book The Genetical Theory of Natural Selection, outlined in detail how eusociality could evolve, and developed a verbal model by connecting selection on fecundity with the sterility of workers. Fisher saw social insect colonies as harmonious units, in contrast to human societies that exhibit intra-communal conflict. Fisher’s development of the model was strongly influenced by his (...) correspondence with Leonard Darwin, and so I call it the Fisher-Darwin model. However, Fisher was not influenced by Lamarckian views on the evolution of social insects that were common at that time. The Fisher-Darwin model presages almost exactly the mathematical model recently proposed by Nowak and colleagues. (shrink)

In Fall 1939, as war engulfed Europe, the author of one of the most influential texts on genetics and evolution, Theodosius Dobzhansky, wrote a letter to curator of insects at the United States National Museum, Edward Albert Chapin. Dobzhansky wished to know what Chapin thought about his pursuing some taxonomic work on an old fascination of his: lady-bird beetles. This paper examines the resulting correspondence as a window into Dobzhansky’s attitude toward taxonomy, the different pressures on geneticists and taxonomists when (...) wrestling with how to name species, the relation between biological theory and taxonomic practice, and how claims regarding human races may have motivated Dobzhansky’s continued interest in the work of beetle taxonomists. In doing so, this article builds on the work of Paul Farber and others to highlight the importance of including museums, taxonomy, and the naturalist tradition within the history of twentieth-century biology. (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)