Ute Deichmann

Avery’s et al. ’s 1944 paper provides the first direct evidence of DNA having gene-like properties and marks the beginning of a new phase in early molecular genetics (with a strong focus on chemistry and DNA). The study of its reception shows that on the whole, Avery’s results were immediately appreciated and motivated new research on transformation, the chemical nature of DNA’s biological specificity and bacteria genetics. It shows, too, that initial problems of transferring transformation to other systems and prominent criticism of its results nurtured skepticism. Avery’s experiment was downplayed and neglected particularly by many of those scientists who worked in the new fields of biochemical and biophysical genetics, genetic phage, and TMV research. This was not due to the fact that the implications of the paper could not be connected to generally accepted knowledge. Contrary to a widespread belief, the assumed uniformity of DNA as opposed to proteins was not used as an argument against the validity of Avery’s et al.’s finding. The indifference rather reflected, among other things, the disciplinary gap between the chemically oriented microbiologists and the old and new geneticists who remained committed to genetic and physical methods (in particular x-ray studies) and clung to the assumption that proteins were the sole carriers of biological specificity. The responses to Avery’s et al.’s paper show how different research interests in the areas between microbiology, genetics, and biochemistry interacted with the prejudices, dogmas, individual farsightedness or short-sightedness, and scientific authority during a pivotal period of early molecular biology.

Dissatisfied with the descriptive and speculative methods of evolutionary biology of his time, the physiologist Jacques Loeb , best known for his “engineering” approach to biology, reflected on the possibilities of artificially creating life in the laboratory. With the objective of experimentally tackling one of the crucial questions of organic evolution, i.e., the origin of life from inanimate matter, he rejected claims made by contemporary scientists of having produced artificial life through osmotic growth processes in inorganic salt solutions. According to Loeb, the answer to the question of whether or not life could be created artificially had to come from macro-molecular chemistry, in particular from the research on the recently discovered DNA. He was convinced that a prerequisite for making living matter from inanimate substances was the chemical synthesis of nuclear material capable of self-replication. Moreover, Loeb, experimentally refuting some vitalistic explanations as well as colloidal chemists’ far-reaching claims that biologically relevant macromolecules follow colloidal rather than chemical laws, pioneered research on the physical and chemical explanations of biological phenomena

Three early 20th-century attempts at unifying separate areas of biology, in particular development, genetics, physiology, and evolution, are compared in regard to their success and fruitfulness for further research: Jacques Loeb’s reductionist project of unifying approaches by physico-chemical explanations; Richard Goldschmidt’s anti-reductionist attempts to unify by integration; and Sewall Wright’s combination of reductionist research and vision of hierarchical genetic systems. Loeb’s program, demanding that all aspects of biology, including evolution, be studied by the methods of the experimental sciences, proved highly successful and indispensible for higher level investigations, even though evolutionary change and properties of biological systems up to now cannot be fully explained on the molecular level alone. Goldschmidt has been appraised as pioneer of physiological and developmental genetics and of a new evolutionary synthesis which transcended neo-Darwinism. However, this study concludes that his anti-reductionist attempts to integrate genetics, development and evolution have to be regarded as failures or dead ends. His grand speculations were based on the one hand on concepts and experimental systems that were too vague in order to stimulate further research, and on the other on experiments which in their core parts turned out not to be reproducible. In contrast, Sewall Wright, apart from being one of the architects of the neo-Darwinian synthesis of the 1930s, opened up new paths of testable quantitative developmental genetic investigations. He placed his research within a framework of logical reasoning, which resulted in the farsighted speculation that examinations of biological systems should be related to the regulation of hierarchical genetic subsystems, possibly providing a mechanism for development and evolution. I argue that his suggestion of basing the study of systems on clearly defined properties of the components has proved superior to Goldschmidt’s approach of studying systems as a whole, and that attempts to integrate different fields at a too early stage may prove futile or worse. © 2011 Elsevier Inc.

In Goethe's Faust, the poet refers to alchemists' widespread ideas on artificial creation of life in the laboratory. In Faust, such an attempt was not successful: the little man,Homunculus, created by the scholar Wagner through crystallization, was a pure spirit; his form and light disappeared in an attempt to become real life. According to Goethe, life was obviously not a crystal, and he pointed to decisive differences between crystals and organic beings, the latter for example elaborating their food into clear-cut organs and unable to be reconstituted from their ingredients, once destroyed. Thus Goethe's "sensitivity to the 'Gestalt' of the entire complicated organism and his general philosophical attitude ..

The encounter between two fundamentally different approaches in seminal research in molecular biology-the problems, aims, methods and metaphysics - is delineated and analyzed. They are exemplified by the microbiologist Oswald T. Avery who, in line with the reductionist mechanistic metaphysics of Jacques Loeb, attempted to explain basic life phenomena through chemistry; and the theoretical physicist Max Delbrück who, influenced by Bohr’s antimechanistic views, preferred to explain these phenomena without chemistry. Avery’s and Delbrück’s most important studies took place concurrently. Thus analysis of their contrasting approaches lends itself to examination of the Weltanschauungen view concerning the role of fundamental (metaphysical) assumptions in scientific change, that is, the view that empirical research cannot be neutral in regard to the worldviews of the researchers. This study shows that the initial ostensible disparity (non-integratibility) of the two approaches lasted for just a short time. Ironically it was a student of Delbrück’s school, James Watson, who (with Crick) proposed a chemical model, the DNA double helix, as a solution to Delbrück’s problem. The structure of DNA has not been seriously challenged over the past half century. Moreover, Watson’s and Crick’s work did not call into question the validity of Delbrück’s research, but opened it up to entirely new approaches. The case of Avery and Delbrück demonstrates that after initial obstacles were overcome the different fundamental attitudes and the resulting research practices were capable of integration. © 2008 Stazione Zoologica Anton Dohrn.

: In contrast to anti-Jewish campaigns at German universities in the 19th century, which met with opposition from liberal scholars, among them prominent chemists, there was no public reaction to the dismissals in 1933. Germany had been an international leader in (bio-)chemistry until the 1930s. Due to a high proportion of Jewish physicists, (bio-)chemistry was strongly affected by the expulsion of scientists. Organic and inorganic chemistry were least affected, while biochemistry suffered most. Polymer chemistry and quantum chemistry, of minor importance among the majority of academic chemists (despite pioneering work by German physicists) was further weakened by the expulsion of renowned scientists. However, a look at the research carried out in Nazi Germany shows that no field of research "emigrated" as such, except research into molecular beams. The reception of emigré (bio-)chemists differed with respect to their field of research and the degree of competition in the host countries. Thus biochemists and physical chemists were accepted at American universities, whereas organic chemists were not. In contrast, they received high positions in Turkey, Palestine/Israel, and Egypt. After WWII, few emigrés were asked to come back. The delay of the resumption of international contacts by German (bio-)chemists contributed to the delay in rebuilding in particular German biochemistry, the physical chemistry of polymers, and physical organic chemistry.

Inheritance and variation were a major focus of Charles Darwin’s studies. Small inherited variations were at the core of his theory of organic evolution by means of natural selection. He put forward a developmental theory of heredity (pangenesis) based on the assumption of the existence of material hereditary particles. However, unlike his proposition of natural selection as a new mechanism for evolutionary change, Darwin’s highly speculative and contradictory hypotheses on heredity were unfruitful for further research. They attempted to explain many complex biological phenomena at the same time, disregarded the then modern developments in cell theory, and were, moreover, faithful to the widespread conceptions of blending and so-called Lamarckian inheritance. In contrast, Mendel’s approaches, despite the fact that features of his ideas were later not found to be tenable, proved successful as the basis for the development of modern genetics. Mendel took the study of the transmission of traits and its causes (genetics) out of natural history; by reducing complexity to simple particulate models, he transformed it into a scientific field of research. His scientific approach and concept of discrete elements (which later gave rise to the notion of discrete genes) also contributed crucially to the explanation of the existence of stable variations as the basis for natural selection. © Springer Science+Business Media B.V. 2010

For centuries the question of the origin of life had focused on the question of the spontaneous generation of life, at least primitive forms of life, from inanimate matter, an idea that had been promoted most prominently by Aristotle. The widespread belief in spontaneous generation, which had been adopted by the Church, too, was finally abandoned at the beginning of the twentieth century, when the question of the origin of life became related to that of the artificial generation of life in the laboratory. This paper examines the role of social authorities, researchers’ basic beliefs, crucial experiments, and scientific advance in the controversies about spontaneous generation from the seventeenth to the nineteenth centuries and analyzes the subsequent debates about the synthesis of artificial life in the changing scientific contexts of the nineteenth and early-twentieth centuries. It shows that despite the importance of social authorities, basic beliefs, and crucial experiments scientific advances, especially those in microbiology, were the single most important factor in the stepwise abandoning of the doctrine of spontaneous generation. Research on the origin of life and the artificial synthesis of life became scientifically addressed only when it got rid of the idea of constant smooth transitions between inanimate matter and life and explored possible chemical and physical mechanisms of the specificity of basic molecules and processes of life.

Until the 1930s Germany had been the international leader in biochemistry, chemistry, and areas of biology. After WWII, however, molecular biology as a new interdisciplinary scientific enterprise was scarcely represented in Germany for almost 20 years. Three major reasons for the low performance of molecular biology are discussed: first, the forced emigration of Jewish scientists after 1933, which not only led to the expulsion of future distinguished molecular biologists, but also to a strong decline of ''dynamic biochemistry'', a field which contributed greatly to molecular biology. Second, German university structures that strongly impeded interdisciplinary research. Third, the international isolation and self-isolation of German scientists that was a major obstacle to the implementation of new fields of research developed elsewhere. Despite the fact that there was no official boycott against Germany as there had been after WWI and despite the Cold War policy of integrating Germans into the West, as a consequence of National Socialism and WWI for many years only very few German scientists gained access to the international community of molecular biologists. Max Delbruck played an important role in helping the Germans establish modern, mostly molecular, biology because he retained strong connections to Germany. Most importantly, it required a new generation of young scientists who had received part of their training in the US to establish modern molecular biology at German universities and Max Planck Institutes.