Experimental taxonomy was a diverse area of research, and botanists who helped develop it were motivated by a variety of concerns. While experimental taxonomy was never totally a taxonomic enterprise, improvement in classification was certainly one major motivation behind the research. Hall's and Clements' belief that experimental methods added more objectivity to classification was almost universally accepted by experimental taxonomists. Such methods did add a new dimension to taxonomy — a dimension that field and herbarium studies, however rigorous, could not (...) duplicate. Nonetheless, experimental techniques were never completely divorced from traditional taxonomic methods. In practice, all experimental taxonomists employed a combination of descriptive and experimental methods. Most researchers freely acknowledged a debt to traditional taxonomy. Furthermore, the greater rigor of twentieth-century taxonomy was not due entirely to experimentalism. Both the experimental and descriptive aspects of taxonomy were improved by the increased use of quantitative methods, particularly statistics.52From the beginning, a number of experimental taxonomists were interested primarily in classification. But many approached their research from fields other than taxonomy. These botanists were concerned primarily with ecological and genetic problems rather than with classification. There is little indication that they drew a sharp distinction: for example, taxonomic and cytogenetic conclusions were interwoven in Babcock and Stebbins' 1938 study of Crepis 53 (this was even more true of Babcock's final mongraph on the genus, published in 1947). Similarly, the extensive series of monographs, “Experimental Studies on the Nature of Species,” initiated by the Carnegie Institution group in 1940 combined ecological, cytogenetic, and taxonomic conclusions. Indeed, the significance of the major projects completed by experimental taxonomists was largely due to the fact that they were comprehensive studies rather than strictly taxonomic or cytogenetic.In a general sense, the primary motivation behind much of experimental taxonomy was evolutionary. Beginning in the second decade of the century Hall and Clements exhorted taxonomists to take an explicitly evolutionary perspective on research. Hall undoubtedly spoke for the majority of experimental taxonomists when he stated, “If there be anything at all to organic evolution, then taxonomy is dealing with the products of evolution and it is this that gives to taxonomy both its highest mission and its greatest responsibility.”54Aside from a common interest in evolution, however, the theoretical orientations of experimental taxonomists were varied. This diversity is strikingly illustrated by the evolutionary views of members of the Carnegie Institution research group. Experimental taxonomy was initiated by Clements as one aspect of his Lamarckian study of adaptation and speciation. In contrast, Hall's research was inspired by a broad concern for evolutionary problems. Hall rarely referred to specific evolutionary mechanisms; rather, he applied a general conception of evolutionary processes to deduce phylogenetic relationships. His later associates at the Carnegie Institution explicitly dissociated themselves from Clements' theoretical framework. The neo-Darwinian interpretations of adaptation and speciation presented by Clausen, Keck, and Hiesey could hardly have been more different than those of Clements. However, this major shift in theoretical orientation should not obscure significant similarities between the research of Clements and later Carnegie workers. In terms of research problems and methodology, the first volume of “Experimental Studies on the Nature of Species” was an extension of the Clementsian research program. Clausen, Keck, and Hiesey's monograph was the mature discussion of transplant experimentation that Clements had very tentatively initiated during the first decades of the twentieth century. The bond that linked the members of the Carnegie Institution research group to experimental taxonomists in general was one of shared methodology rather than common theoretical orientation. While Clements' evolutionary views were eventually repudiated, his enthusiasm for innovative experimental methods was shared by later workers.The development of experimental taxonomy faced significant problems. During the period 1920–1950 this area of botanical research remained a hybrid discipline. The aims and scope of experimental taxonomy were never articulated in a completely unified manner. Consequently, even among experimental taxonomists, there were disagreements over the relation of their research to other botanical endeavors. Even though experimental taxonomy had close ties with general taxonomy, a number of experimental taxonomists questioned the “taxonomic” nature of their research55. Even to the extent that this hybrid discipline could be identified as a branch of taxonomy, problems arose. Taxonomists, as we have seen, were justifiably skeptical of what appeared to be a rapid influx of untested methods and ideas. Experimental taxonomists were not merely incorporating well-accepted methods from ecology and cytogenetics; during the period 1920–1950 the fields from which experimental taxonomists borrowed were themselves undergoing major theoretical and methodological changes. Despite problems and conflicts, experimental taxonomists did contribute improvements to classification. Furthermore, they made significant contributions to plant ecology and evolutionary genetics.The development of experimental taxonomy indicates that twentieth-century botanists were not necessarily isolated in naturalist and experimentalist camps. The joint session of taxonomists, cytologists, and geneticists at the 1926 International Congress of Plant Sciences indicates communication among specialists fairly early in the century. The papers and commentaries presented during this session do not reveal the hostility and intolerance that supposedly characterized encounters between experimentalists and naturalists. Nor do they suggest incompatible conceptual worlds separating geneticists and taxonomists.Discussions between taxonomists and other specialists were not limited to a single international congress. Particularly during the 1930s discussions among specialists appear to have been fairly widespread. Groups such as the Biosystematists and the Society for the Study of Systematics in Relation to General Biology served as forums for discussion among biologists from a variety of disciplines. The naturalist-experimentalist dichotomy tends to obscure the broad research interests of a number of prominent twentieth-century botanists. Most of the experimental taxonomists cannot be characterized adequately as either naturalists or experimentalists. Traditionally trained taxonomists such as Hall, Keck, and Turrill throughout their careers participated in both experimental and herbarium research. And a number of specialists in fields other than taxonomy took an active interest in taxonomic problems, not necessarily limited to experimental aspects. For example, Anderson suggested a number of innovations to make herbarium collections more amenable to statistical analysis.This historical study of experimental taxonomy indicates a different relationship between experimentalism and taxonomy than that portrayed by the naturalist-versus-experimentalist dichotomy. F. E. Clements originated experimental taxonomy as a revolt against descriptive botany. In retrospect, this revolution was not vigorously waged and was not successfully completed. Experimental taxonomy was never an entirely experimental approach to botanical research. Even the most ardent advocates of experimentalism relied heavily on methods inherited from traditional taxonomy. Moderate exponents of experimental taxonomy stressed the compatibility of experimental methods, field observation, and herbarium techniques. Attempts to fuse cytogenetics, ecology, and taxonomy during the period 1920–1950 resulted in an impressive body of research. However, this fusion constituted neither a repudiation of descriptive botany nor a complete revision of taxonomic theory of practice. (shrink)

Tracing the contributions of Edgar Anderson (1897-1969) of the Missouri Botanical Garden to the important discussions in evolutionary biology in the 1940s, this paper argues that Anderson turned to corn research rather than play a more prominent role in what is now known as the Evolutionary Synthesis. His biosystematic studies of Iris and Tradescantia in the 1930s reflected such Synthesis concerns as the species question and population thinking. He shared the 1941 Jesup Lectures with Ernst Mayr. But rather than preparing (...) his lectures as a potentially key text in the Synthesis, Anderson began researching Zea mays -- its taxonomy, its origin, and its agronomic role. In this study, Anderson drew on the disciplines of taxonomy, morphology, genetics, geography, anthropology, archaeology, and agronomy among others in his own creative synthesis. Though his maize research in the 1940s represented the most sustained work of his career, Anderson was also drawn in many directions during his professional life. For example, he enjoyed teaching, working with amateurs, and popular writing. (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)

WE HAVE LEARNED in the preceding chapter that a revolutionary change of the species concept is in the making, a change which not only affects taxonomic procedure, but which also contributes considerably toward a better understanding of ...

This paper explores the complex relationship between the plant evolutionist G. Ledyard Stebbins and the animal evolutionist Theodosius Dobzhansky. The manner in which the plant evolution was brought into line, synthesized, or rendered consistent with the understanding of animal evolution (and especially insect evolution) is explored, especially as it culminated with the publication of Stebbins's 1950 book Variation and Evolution in Plants. The paper explores the multi-directional traffic of influence between Stebbins and Dobzhansky, but also their social and professional networks (...) that linked plant evolutionists like Stebbins with Edgar Anderson, Carl Epling, and the 'Carnegie team' of Jens Clausen, David Keck, and William Hiesey with collaborators on the animal side like I. Michael Lerner, Sewall Wright and L.C. Dunn and other 'architects' of the synthesis like Ernst Mayr, Julian Huxley and George Gaylord Simpson. The compatibility in training, work styles, methodologies, goals, field sites, levels of analysis, and even choice of organismic systems is explored between Stebbins and Dobzhansky. Finally, the extent to which coevolution between plants and insects is reflected in the relationship is explored, as is the power dynamic in the relationship between two of the most visible figures associated with the evolutionary synthesis. (shrink)