In introgressive hybridization (the repeated backcrossing of hybrids with parental populations), Edgar Anderson found a source for variation upon which natural selection could work. In his 1953 review article “Introgressive Hybridization,” he asserted that he was “bringing taxonomy to the service of genetics” whereas distinguished colleagues such as Theodosius Dobzhansky and Ernst Mayr did the precise opposite. His work as a geneticist particularly focused on linkage and recombination and was enriched by collaborations with Missouri Botanical Garden colleagues interested in taxonomy (...) as well as with cytologists C.D. Darlington and Karl Sax. As the culmination of a biosystemtatic research program, Anderson’s views challenged the mainstream of the Evolutionary Synthesis. -/- . (shrink)

The twentieth century witnessed a dramatic increase in the use of statistics by biologists, including systematists. The modern synthesis and new systematics stimulated this development, particularly after World War II. The rise of "the statistical frame of mind " resulted in a rethinking of the relationship between biological and mathematical points of view, the roles of objectivity and subjectivity in systematic research, the implications of new computing technologies, and the place of systematics among the biological disciplines.

During the 1930s, Aleksandr Promptov—a student of the founder of Russian population genetics Sergei Chetverikov—developed an elaborate concept of speciation in birds. He conducted field investigations aimed at giving a naturalistic content to the theoretical formulations and laboratory models of evolutionary processes advanced within the framework of population genetics, placing particular emphasis on the evolutionary role of bird behavior. Yet, although highly synthetic in combining biogeographical, taxonomic, genetic, ecological, and behavioral studies, Promptov's speciation concept was ignored by the architects of (...) the 1930s and 1940s evolutionary synthesis, including Theodosius Dobzhnasky, Ernst Mayr, and Julian Huxley. In this article, I argue that the story of Promptov's concept and its reception by other evolutionists challenges the traditional presentation of the synthesis as a singular, international process of the unification of biology, which led to the creation of a universal synthetic theory of evolution. It suggests that during the same time period, within largely the same theoretical framework, there were multiple, intrinsically local, attempts at creating synthetic evolutionary concepts. These concepts were often quite particular—in their taxonomic applicability, in their explanations of various evolutionary factors, and in the range of disciplines unified in the synthesis. Apparently, these concepts ran contrary to the universal aspirations of the synthesis architects, and as a result, they were disregarded, first by the architects and later by historians of the evolutionary synthesis. (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)

The Committee on Common Problems of Genetics, Paleontology, and Systematics (United States National Research Council) marks part of a critical transition in American evolutionary studies. Launched in 1942 to facilitate cross-training between genetics and paleontology, the Committee was also designed to amplify paleontologist voices in modern studies of evolutionary processes. During coincidental absences of founders George Gaylord Simpson and Theodosius Dobzhansky, an opportunistic Ernst Mayr moved into the project's leadership. Mayr used the opportunity for programmatic reforms he had been pursuing (...) elsewhere for more than a decade. These are evident in the Bulletins he distributed under Committee auspices. In his brief tenure as Committee leader, Mayr gained his first substantial foothold within the coalescing community infrastructure of evolutionary studies. Carrying this momentum forward led Mayr directly into the project to launch the journal Evolution. The sociology of interdisciplinary activity provides useful tools for understanding the Committee's value in the broad sweep of change in evolutionary studies during the synthesis period. (shrink)

This paper clarifies the chronology surrounding the population geneticist Theodosius Dobzhansky's 1937 book, "Genetics and the Origin of Species." Most historians assume (a) Dobzhansky's book began as a series of 'Jesup lectures,' sponsored by the Department of Zoology at Columbia University in 1936, and (b) before these lectures were given, Dobzhansky knew he would produce a volume for the Columbia Biological Series (CBS). Archival evidence forces a rejection of both assumptions. Dobzhansky's 1936 Columbia lectures were not Jesup lectures. The book (...) he intended to write from his lectures began as a stand-alone text in evolutionary genetics; the CBS had been defunct since 1910. In May 1937 -- seven months after Dobzhansky's Columbia lectures -- Leslie Dunn lobbied Columbia University to revive the CBS and the Jesup lecture series. He then quietly back dated, naming Dobzhansky a Jesup lecturer and co-opting his book manuscript as the first volume in the revived CBS. A detailed chronology of this 1936-1937 period is provided. This relocates the CBS and Jesup revivals within the narrow context of zoology at Columbia University. These helped Dunn and colleagues define cutting edges and define themselves as managers and promoters of those edges. (shrink)

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)