The 1920-1960 period saw the creation of the conditions for a unification of disciplines in the area of evolutionary biology under a limited number of theoretical prescriptions: the evolutionary synthesis. Whereas the sociological dimension of this synthesis was fairly successful, it was surprisingly loose when it came to the interpretation of the evolutionary mechanisms per se, and completely lacking at the level of the foundational epistemological and metaphysical commitments. Key figures such as Huxley, Simpson, Dobzhansky, and Rensch only paid lip (...) service to the conceptual dimension of the evolutionary synthesis, as they eventually realized that a number of evolutionary phenomena could not be explained by its narrow theoretical corpus. Apparently, the evolutionary synthesis constituted a premature event in the development of evolutionary biology. Not only are the real achievements of the evolutionary synthesis in need of reevaluation, but this reassessment also has important implications for the historiography of Darwinism and the current debates about the darwinian movement. (shrink)

Theodosius Dobzhansky was one of the principal ‘founding fathers' of the modern ‘synthetic theory of evolution' and the ‘biological species' concept, first set forth in his classic book, Genetics and the Origin of Species (1937). Much of the discussion of Dobzhansky’s work by historians has focused on English-accessible sources, and has emphasized the roles of the Morgan School, and figures such as Sewall Wright, and Leslie C. Dunn. This article uses Dobzhansky’s Russian articles that are unknown to English-speaking readers, and (...) his late 1920s to early 1930s correspondence with colleagues and friends in the Soviet Union, to clarify some of the Russian influences on Dobzhansky’s evolving evolutionary views, particularly the development of his views on species and speciation. For Dobzhansky, as for Darwin, the problem of species and speciation was crucial for his theoretical explanation of evolution. (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)