This session considers three cases in the development of evolutionary thinking in the first part of the 20th century, each at the intersection of various disciplines. The first case concerns the emergence of agricultural research on the evolution of insecticide resistance (1914-mid 1940s) and its subsequent influence on Dobzhansky's genetics. The second case considers the effort of Richard Goldschmidt and others to integrate development and evolution through the study of homeotic mutants. The third case focuses on alternative approaches to evolution and behavior ó the neoDarwinian reduction championed by David Lack and the emphasis on populations pioneered by Wynne-Edwards. The work in separate fields, each related to evolutionóand not always successfulóhelps reframe our understanding of the Evolutionary Synthesis, as conventionally portrayed in folk histories by biologists.

Mark Borello, Indiana University
"Synthesis and Selection"

V.C. Wynne-Edwards and David Lack were two renown British ornithologists, working during the period of the Modern Synthesis, who had contrasting explanations of various bird behaviors and alternative interpretations of the Modern Synthesis. Lack became the chief advocate of the Neo-Darwinian synthesis with respect to avian ecology. On the other hand, Wynne-Edwards developed his theory of group selection viewing the new emphasis on populations as the most important development provided by the Modern Synthesis. In this paper I will present the early development of these two positions and expose their roots in the literature of the synthesis.

Michael Dietrich, Dartmouth College "Homeotic Mutants and the Failure of the First Developmental Synthesis Authors: Michael Dietrich, David Jacobs, and Gregory Davis"

From the 1930s throught the 1950s, homoetic mutants were a significant object of inquiry for Drosophila geneticists interested in questions of development. In this paper, we seek to recover this history and its distinctive evolutionary interpretation by Richard Goldschmidt and others. It is our contention that this research on homoeotic mutants represents an attempt to create a synthesis between developmental genetics and evolutionary biology. Ultimately this developmental synthesis failed, however, because of the way in which it was advocated as well as, difficulties with the developmental and evolutoinary interpretation of homeotic mutants.

John Cecatti, University of Basel "Natural Selection in the Field: Insecticide Resistance, Genetic Explanations, and the Evolutionary Synthesis, 1914-1944"

In his influential Genetics and the Origin of Species (1937), Theodosius Dobzhansky cited insect resistance to insecticides as "probably the best proof of the effectiveness of natural selection yet obtained" (p. 161), a claim upon which he expanded in subsequent editions. Insect resistance was first described by entomologists working at agricultural field stations in Washington state and California in the 1910s. But research on the subject was limited to specialists in economic entomology until the late 1940s when the widespread commercial use of DDT transformed insect resistance from a local agricultural concern into a global public health problem. The goal of this paper will be to trace the development of research on insect resistance to insecticides from the initial report in 1914 until the mid 1940s. The primary focus will be to analyze the kinds of explanations researchers gave to understand this phenomenon. An attempt will be made to delineate the influence that applied entomological research at agricultural research stations had on Dobzhansky's formulation of natural selection and the evolutionary synthesis.