Hugo de Vries (1848–1935) would without doubt turn in his grave if he could be told about the various perspectives from which historians have studied his ideas and works. His would not be an exceptional case, of course, for many before and after him have fallen victim to the irony of history. Still, I am inclined to grant de Vries that he would have some reason for his distress, for the irony has hit him particularly hard. In 1922, de Vries (...) was invited to attend the Mendel centennial celebrations at Brünn (Brno). He declined the invitation, suspecting, among other things, that the tenor of the commemoration would be pro-Mendel and anti-Darwin, and he heartily refused to share in either sentiment. Now contrast this with de Vries' imputed role in the historiography of genetics and evolutionary theory as ‘rediscoverer’ of Mendelism and as co-executor of the ‘eclipse of Darwinism’, and the irony will be clear. (shrink)

This paper describes the historical background and early formation of Wilhelm Johannsen's distinction between genotype and phenotype. It is argued that contrary to a widely accepted interpretation his concepts referred primarily to properties of individual organisms and not to statistical averages. Johannsen's concept of genotype was derived from the idea of species in the tradition of biological systematics from Linnaeus to de Vries: An individual belonged to a group - species, subspecies, elementary species - by representing a certain underlying type. (...) Johannsen sharpened this idea theoretically in the light of recent biological discoveries, not least those of cytology. He tested and confirmed it experimentally combining the methods of biometry, as developed by Francis Galton, with the individual selection method and pedigree analysis, as developed for instance by Louis Vilmorin. The term "genotype" was introduced in W. Johannsen's 1909 treatise, but the idea of a stable underlying biological "type" distinct from observable properties was the core idea of his classical bean selection experiment published 6 years earlier. The individual ontological foundation of population analysis was a self-evident presupposition in Johannsen's studies of heredity in populations from their start in the early 1890s till his death in 1927. The claim that there was a "substantial but cautious modification of Johannsen's phenotype-genotype distinction" from a statistical to an individual ontological perspective derives from a misreading of the 1903 and 1909 texts. The immediate purpose of this paper is to correct this reading of the 1903 monograph by showing how its problems and results grow out of Johannsen's earlier work in heredity and plant breeding. Johannsen presented his famous selection experiment as the culmination of a line of criticism of orthodox Darwinism by William Bateson, Hugo de Vries, and others. They had argued that evolution is based on stepwise rather than continuous change in heredity. Johannsen's paradigmatic experiment showed how stepwise variation in heredity could be operationally distinguished from the observable, continuous morphological variation. To test Galton's law of partial regression, Johannsen deliberately chose pure lines of self-fertilizing plants, a pure line being the descendants in successive generations of one single individual. Such a population could be assumed to be highly homogeneous with respect to hereditary type, and Johannsen found that selection produced no change in this type. Galton, he explained, had experimented with populations composed of a number of stable hereditary types. The partial regression which Galton found was simply an effect of selection between types, increasing the proportion of some types at the expense of others. (shrink)

This paper describes the historical background and early formation of Wilhelm Johannsen's distinction between genotype and phenotype. It is argued that contrary to a widely accepted interpretation his concepts referred primarily to properties of individual organisms and not to statistical averages. Johannsen's concept of genotype was derived from the idea of species in the tradition of biological systematics from Linnaeus to de Vries: An individual belonged to a group - species, subspecies, elementary species - by representing a certain underlying type. (...) Johannsen sharpened this idea theoretically in the light of recent biological discoveries, not least those of cytology. He tested and confirmed it experimentally combining the methods of biometry, as developed by Francis Galton, with the individual selection method and pedigree analysis, as developed for instance by Louis Vilmorin. The term "genotype" was introduced in W. Johannsen's 1909 treatise, but the idea of a stable underlying biological "type" distinct from observable properties was the core idea of his classical bean selection experiment published 6 years earlier. The individual ontological foundation of population analysis was a self-evident presupposition in Johannsen's studies of heredity in populations from their start in the early 1890s till his death in 1927. The claim that there was a "substantial but cautious modification of Johannsen's phenotype-genotype distinction" from a statistical to an individual ontological perspective derives from a misreading of the 1903 and 1909 texts. The immediate purpose of this paper is to correct this reading of the 1903 monograph by showing how its problems and results grow out of Johannsen's earlier work in heredity and plant breeding. Johannsen presented his famous selection experiment as the culmination of a line of criticism of orthodox Darwinism by William Bateson, Hugo de Vries, and others. They had argued that evolution is based on stepwise rather than continuous change in heredity. Johannsen's paradigmatic experiment showed how stepwise variation in heredity could be operationally distinguished from the observable, continuous morphological variation. To test Galton's law of partial regression, Johannsen deliberately chose pure lines of self-fertilizing plants, a pure line being the descendants in successive generations of one single individual. Such a population could be assumed to be highly homogeneous with respect to hereditary type, and Johannsen found that selection produced no change in this type. Galton, he explained, had experimented with populations composed of a number of stable hereditary types. The partial regression which Galton found was simply an effect of selection between types, increasing the proportion of some types at the expense of others. (shrink)

The general problem around which this Special Issue revolves is that the way in which science is organized into specialties can have negative consequences on the progress of knowledge [...].

This paper focuses on the structural development of institution-based interest in genetics in Anglo-North American medicine after 1930 concomitantly with an analysis of the changes through which ideas about heredity and the hereditary transmission of diseases in families have passed. It maintains that the unfolding relationship between medicine and genetics can best be understood against the background of the shift in emphasis in conceptualisations of recurring patterns of disease in families from ‘biological relatedness’ to ‘related to chromosomes and genes’. The (...) paper begins with brief considerations of the historical confluences of, first, heredity and medicine and, second, genetics and medicine which, in a third section, leads to a discussion about a uniquely ‘genetics-based approach’ to medicine in the second half of the twentieth century. (shrink)

One area of genetics particularly dominated by German-speaking geneticists (Brücher, Correns, Lehmann, Michaelis, Oehlkers, Renner, von Wettstein) during the interwar period was research in the field of cytoplasmic inheritance (Plasmon-Theory). The controversy between the botanists Lehmann (Tübingen) and Brücher (Jena, Tübingen) about the function of “supressor genes” in Epilobium cell division was central to debates about cytoplasmic inheritance. The failure of Brücher, Michaelis and Oehlkers to replicate Lehmann's Epilobium experiments ultimately forced Lehmann to admit his error.

Bernard Norton's friends in the history of science have had many reasons for commemorating, with admiration and affection, not only his research and teaching but no less his conversation and his company. One of his most estimable traits was his refusal to beat about the bush in raising the questions he thought worthwhile pursuing. I still remember discoursing at Pittsburgh on Darwin's route to his theory of natural selection, and being asked at the end by Bernard what were Darwin's views (...) on heredity. I answered with the conventional waffle to the effect that the theory concerned the populational fate rather than the individual production and transmission of heritable variation, so that whatever views Darwin had on heredity had only a subsidiary place in his theorizing. Bernard was not fooled. ‘I would have thought’, he said, ‘that in order to understand anyone's theorising about evolution it would be necessary to look at his views on heredity’. (shrink)

We present two case studies from contemporary biology in which we observe conflicts between established and emerging approaches. The first case study discusses the relation between molecular biology and systems biology regarding the explanation of cellular processes, while the second deals with phylogenetic systematics and the challenge posed by recent network approaches to established ideas of evolutionary processes. We show that the emergence of new fields is in both cases driven by the development of high-throughput data generation technologies and the (...) transfer of modeling techniques from other fields. New and emerging views are characterized by different philosophies of nature, i.e. by different ontological and methodological assumptions and epistemic values and virtues. This results in a kind of conflict we call “epistemic competition” that manifests in two ways: On the one hand, opponents engage in mutual critique and defense of their fundamental assumptions. On the other hand, they compete for the acceptance and integration of the knowledge they provide by a broader scientific community. Despite an initial rhetoric of replacement, the views as well as the respective audiences come to be seen as more clearly distinct during the course of the debate. Hence, we observe—contrary to many other accounts of scientific change—that conflict results in the formation of new niches of research, leading to co-existence and perceived complementarity of approaches. Our model thus contributes to the understanding of the pluralization of the scientific landscape. (shrink)

The technique of nuclear transplantation – popularly known as cloning – has been integrated into several different histories of twentieth century biology. Historians and science scholars have situated nuclear transplantation within narratives of scientific practice, biotechnology, bioethics, biomedicine, and changing views of life. However, nuclear transplantation has never been the focus of analysis. In this article, I examine the development of nuclear transplantation techniques, focusing on the people, motivations, and institutions associated with the first successful nuclear transfer in metazoans in (...) 1952. The conflict between embryologists and geneticists over the mechanisms of differentiation motivated Robert Briggs to pursue nuclear transplantation experiments as a way to resolve the debate. Briggs worked at the Lankenau Hospital Research Institute, a research facility devoted to the study of cancer. The goal of understanding cancer would play a role in the development of the technique, and the story of nuclear transplantation sheds light on the role that biomedical contexts play in biological research in the second half of the twentieth century. (shrink)

Advocates of “Mendelism” early on stressed the usefulness of Mendelian principles for breeders. Ever since, that usefulness—and the favourable opinion of Mendelism it supposedly engendered among breeders—has featured in explanations of the rapid rise of Mendelian genetics. An important counter-tradition of commentary, however, has emphasized the ways in which early Mendelian theory in fact fell short of breeders’ needs. Attention to intellectual property, narrowly and broadly construed, makes possible an approach that takes both the tradition and the counter-tradition seriously, by (...) enabling a more complete description of the theory-reality shortfall and a better understanding of how changing practices, on and off the Mendelians’ experimental farms, functioned to render that shortfall unproblematic. In the case of plant breeding in Britain, a perennial source of lost profits and disputes over ownership was the appearance of individual plants departing from their varietal types—so-called “rogues.” Mendelian plant varieties acquired a reputation for being rogue-free, and so for demonstrating the correctness of Mendelian principles , at a time when Mendelians were gradually taking control of the means for distributing their varieties. Mendelian breeders protected their products physically from rogue-inducing contamination in such a way that when rogues did appear, the default explanation—that contamination had somehow occurred—ensured that there was no threat to Mendelian principles. (shrink)

T. H. Morgan, A. H. Sturtevant, H. J. Muller and C. B. Bridges published their comprehensive treatise "The Mechanism of Mendelian Heredity" in 1915. By 1920 Morgan 's "Chromosome Theory of Heredity" was generally accepted by geneticists in the United States, and by British geneticists by 1925. By 1930 it had been incorporated into most general biology, botany, and zoology textbooks as established knowledge. In this paper, I examine the reasons why it was accepted as part of a series of (...) comparative studies of theory-acceptance in the sciences. In this context it is of interest to look at the persuasiveness of confirmed novel predictions, a factor often regarded by philosophers of science as the most important way to justify a theory. Here it turns out to play a role in the decision of some geneticists to accept the theory, but is generally less important than the CTH's ability to explain Mendelian inheritance, sex-linked inheritance, non-disjunction, and the connection between linkage groups and the number of chromosome pairs; in other words, to establish a firm connection between genetics and cytology. It is remarkable that geneticists were willing to accept the CTH as applicable to all organisms at a time when it had been confirmed only for Drosophila. The construction of maps showing the location on the chromosomes of genes for specific characters was especially convincing for non-geneticists. (shrink)

In the early twentieth century, Wilhelm Johannsen proposed his pure line theory and the genotype/phenotype distinction, work that is prized as one of the most important founding contributions to genetics and Mendelian plant breeding. Most historians have already concluded that pure line theory did not change breeding practices directly. Instead, breeding became more orderly as a consequence of pure line theory, which structured breeding programmes and eliminated external heritable influences. This incremental change then explains how and why the large multi-national (...) seed companies that we know today were created; pure lines invited standardisation and economies of scale that the latter were designed to exploit. Rather than focus on breeding practice, this paper examines the plant varietal market itself. It focusses upon work conducted by the National Institute of Agricultural Botany during the interwar years, and in doing so demonstrates that, on the contrary, the pure line was actually only partially accepted by the industry. Moreover, claims that contradicted the logic of the pure line were not merely tolerated by the agricultural geneticists affiliated with NIAB, but were acknowledged and legitimised by them. The history of how and why the plant breeding industry was transformed remains to be written. (shrink)