My current research focuses on a number of case studies designed to map the development of experimental genetics in Germany from the end of the 19th century to the middle of the 20th century. The general aim of the project is to look at the material characteristics of different experimental systems and related strategies of experimentation and to understand the impact they had on the historical shape and development of heredity research in Germany. These experimental systems and strategies of experimentation were rooted in many different disciplinary backgrounds of a number of researchers who, for various reasons and under widely different circumstances, came to contribute to a science in gestation that set the tone for the life sciences in the past century.
From an epistemological perspective, the current project aims at a characterization of what could be called a “landscape of experimentation.” Such landscapes or cultures of experimentation are broader than experimental systems and more circumscribed than disciplines. They are to be mapped out both in terms of the coherence of a domain of research, and in terms of the plurality of approaches they take for investigation. It is the balance between these two features - coherence and plurality - that determines the productivity of a particular domain of research at a given time.
One cluster of studies deals with the corn and pea hybridizations that led Carl Correns (1864-1933) to reformulate Mendel’s laws around 1900. A close study of his subsequent work shows that it was the strict pursuit of Mendelian genetics that eventually led Correns to substantiate the Mendelian inheritance of sex in plants and, through extended research on the phenomenon of variegation, to investigate extra-chromosomal phenomena of heredity. Correns’ strategies of experimentation are intimately linked to the material characteristics of the breeding systems he used. In contrast to Thomas Hunt Morgan’s Drosophila school of classical genetics, Correns did not concentrate on one particular organism around which a whole research community became organized. Instead he pursued a contrasting strategy of using many different model organisms according to the problems he pursued.
Another case study investigates the establishment of an experimental system that brought together transmission genetics and developmental physiology. It is devoted to a reconstruction of how Alfred Kühn (1885-1968) and his coworkers, in particular Ernst Caspari (1909-), came to conceptualize gene-action chains involved in pigment formation in the flour moth Ephestia between 1925 and 1945. In a parallel study, I have looked at Kühn’s investigations of hormones involved in insect metamorphosis. In contrast to his pigmentation studies, this project failed to become strongly linked to the genetics of its time, and institutionally, it was taken over by the laboratory of Adolf Butenandt (1903-1995) when Kühn moved from the University of Göttingen to the Kaiser Wilhelm Institute for Biology in the late 1930s.
Yet another case study is devoted to the establishment of tobacco mosaic virus (TMV) research in Germany. Georg Melchers (1906-1997), Gerhard Schramm (1910 - 1969), Gernot Bergold (*1911) and Rolf Danneel (1901-1982) are the major protagonists of the study. TMV served as a model of a combined physical, chemical, and biological approach to elucidate the structure of genetic material at the Kaiser Wilhelm Institutes for Biology and Biochemistry in Berlin-Dahlem around 1940.
Recently, I have begun to look at protozoological work on fertilization, reproduction, and sexuality, and its relation to genetic studies in the work of Max Hartmann (1876-1962). The field of protozoology plays a particular role in early twentieth history of heredity, which has not yet found wider scholarly attention. Beyond the focus on protists, Hartmann is particularly interesting for his reflections on the general structure of the life sciences and the role he attributed to genetics in this context.
Further studies will include the early, insect-based work of Richard Goldschmidt (1878-1958) on the mechanism and physiology of sex determination, as well as Fritz von Wettstein’s (1895-1945) research on cytoplasmic inheritance in mosses. The institutional background of all these works is the Kaiser Wilhelm Institute for Biology in Berlin-Dahlem, one of the first Kaiser Wilhelm Institutes founded in the years leading up to World War I.
A first cluster of these studies has recently been published as a book. See Hans-Jörg Rheinberger, Epistemologie des Konkreten. Studien zur Geschichte der modernen Biologie, Frankfurt am Main: Suhrkamp 2006. This book is available as an English version with Duke University Press 2010.