Textbook descriptions of the foundations of Genetics give the impression that besides Mendel’s no other research on heredity took place during the nineteenth century. However, the publication of the Origin of Species in 1859, and the criticism that it received, placed the study of heredity at the centre of biological thought. Consequently, Herbert Spencer, Charles Darwin himself, Francis Galton, William Keith Brooks, Carl von Nägeli, August Weismann, and Hugo de Vries attempted to develop theories of heredity under an evolutionary perspective, (...) and they were all influenced by each other in various ways. Nonetheless, only Nägeli became aware of Mendel’s experimental work; it has also been questioned whether Mendel even had the intention to develop a theory of heredity. In this article, a short presentation of these theories is made, based on the original writings. The major aim of this article is to suggest that Mendel was definitely not the only one studying heredity before 1900, if he even did this, as may be inferred by textbooks. Although his work had a major impact after 1900, it had no impact during the latter half of the nineteenth century when an active community of students of heredity emerged. Thus, textbooks should not only present the work of Mendel, but also provide a wider view of the actual history and a depiction of science as a social process. (shrink)

Twenty-first-century biology rejects genetic determinism, yet an exaggerated view of the power of genes in the making of bodies and minds remains a problem. What accounts for such tenacity? This article reports an exploratory study suggesting that the common reliance on Mendelian examples and concepts at the start of teaching in basic genetics is an eliminable source of support for determinism. Undergraduate students who attended a standard ‘Mendelian approach’ university course in introductory genetics on average showed no change in their (...) determinist views about genes. By contrast, students who attended an alternative course which, inspired by the work of a critic of early Mendelism, W. F. R. Weldon, replaced an emphasis on Mendel’s peas with an emphasis on developmental contexts and their role in bringing about phenotypic variability, were less determinist about genes by the end of teaching. Improvements in both the new Weldonian curriculum and the study design are in view for the future. (shrink)

Summary In 1979, Robert C. Olby published an article titled ?Mendel no Mendelian??, in which he questioned commonly held views that Gregor Mendel (1822?1884) laid the foundations for modern genetics. According to Olby, and other historians of science who have since followed him, Mendel worked within the tradition of so-called hybridists, who were interested in the evolutionary role of hybrids rather than in laws of inheritance. We propose instead to view the hybridist tradition as an experimental programme characterized by a (...) dynamic development that inadvertently led to a focus on the inheritance of individual traits. Through a careful analysis of publications on hybridization by Carl Linnaeus (1707?1778), Joseph Gottlieb Koelreuter (1733?1806), Carl Friedrich Gärtner (1772?1850), and finally Mendel himself, we will show that this development consisted in repeated reclassifications of hybrids to accommodate anomalies, which in the end allowed Mendel to draw analogies between whole organisms, individual traits, and ?elements? contained in reproductive cells. Mendel's achievement was a product of normal science, and yet a revolutionary step forward. This also explains why, in 1900, when the report he gave on his experiments was ?rediscovered?, Mendel could be read as a ?Mendelian? (shrink)

Lucas Matthews and I substantially revised my SEP entry on Heritability. This version includes discussion of the missing heritability problem and other issues that arise from the use of Genome Wide Association Studies by Behavioral Geneticists.

It has been widely received that one of Gregor Mendel’s most important contributions to the history of genetics is his novel work on developmental information (for example, the proposal of the famous Mendelian ratios like 1:2:1, 3:1, and 9:3:3:1). This view is well evidenced by the fact that much of early Mendelians’ work in the 1900s focuses on the retrodiction (viz. the re-analysis of the pre-exist data with Mendel’s approach). However, there is no consensus on what Mendel meant by development (...) (Entwicklung). Nor is there an agreement on the interpretation of Mendel’s laws of developmental series (Entwicklungsreihe). This chapter revisits Mendel’s notions of development and developmental series. Firstly, I argue that Mendel’s use of development is greatly influenced by Gärtner’s. Secondly, I show Mendel’s work on developmental series are novel and important for its new ways of experimentation, conceputalisation, and analysis. Thirdly, I argue that Mendel’s laws of developmental information were not about heredity. (shrink)

Prompted by recent recognitions of the omnipresence of horizontal gene transfer among microbial species and the associated emphasis on exchange, rather than isolation, as the driving force of evolution, this essay will reflect on hybridization as one of the central concerns of nineteenth-century biology. I will argue that an emphasis on horizontal exchange was already endorsed by ‘biology’ when it came into being around 1800 and was brought to full fruition with the emergence of genetics in 1900. The true revolution (...) in nineteenth-century life sciences, I maintain, consisted in a fundamental shift in ontology, which eroded the boundaries between individual and species, and allowed biologists to move up and down the scale of organic complexity. Life became a property extending both ‘downwards’, to the parts that organisms were composed of, as well as ‘upwards’, to the collective entities constituted by the relations of exchange and interaction that organisms engage in to reproduce. This mode of thinking was crystallized by Gregor Mendel and consolidated in the late nineteenth-century conjunction of biochemistry, microbiology and breeding in agro-industrial settings. This conjunction and its implications are especially exemplified by Wilhelm Johannsen’s and Martinus Beijerinck’s work on pure lines and cultures. An understanding of the subsequent constraints imposed by the evolutionary synthesis of the twentieth century on models of genetic systems may require us to rethink the history of biology and displace Darwin’s theory of natural selection from that history’s centre. (shrink)

The cell is not only the structural, physiological, and developmental unit of life, but also the reproductive one. So far, however, this aspect of the cell has received little attention from historians and philosophers of biology. I will argue that cell theory had far-reaching consequences for how biologists conceptualized the reproductive relationships between germs and adult organisms. Cell theory, as formulated by Theodor Schwann in 1839, implied that this relationship was a specific and lawful one, that is, that germs of (...) a certain kind, all else being equal, would produce adult organisms of the same kind, and vice versa. Questions of preformation and epigenesis took on a new meaning under this presupposition. The question then became one of whether cells could be considered as autonomous agents producing adult organisms of a given species, or whether they were the product of external, organizing forces and thus only a stage in the development of the whole organism. This question became an important issue for nineteenth-century biology. As I will demonstrate, it was the view of cells as autonomous agents which helped both Charles Darwin and Gregor Mendel to think of inheritance as a lawful process. (shrink)

According to the traditional account Mendel's paper on pea hybrids reported a study of inheritance and its laws. Hence, Mendel came to be known as The Father of Genetics. This paper demonstrates that, in fact, Mendel's objective in his research was finding the empirical laws which describe the formation of hybrids and the development of their offspring over several generations. Having found these laws (and not the laws of inheritance that he is generally credited with) he proposed a theoretical scheme (...) involving the formation of germinal and pollen cells in hybrids and their combination in fertilization competent to explain why his laws took the form that they did. Mendel's research shows a pattern of development closely paralleling the stages of empirical investigation beginning at the level of qualitative description in common language rising through four levels of increasing abstraction and culminating in a fifth level, his simple mechanical theory. This mechanism met all the tests that a theory of this type must pass. In that respect Mendel was highly successful and this success might be the reason why he did not push his theory to a higher level, a sixth level involving the use of particulate determiners; despite this fact, Mendel was credited with having taken exactly that step. (shrink)

SummaryIt is argued that Hugo de Vries's conversion to Mendelism did not agree with his previous theoretical framework. De Vries regarded the number of offspring expressing a certain character as a hereditary quality, intrinsic to the state of the pangene involved. His was a shortlived conversion since after the ‘rediscovery’ he failed to unify his older views with Mendelism. De Vries was never very much of a Mendelian. The usual stories of the Dutch ‘rediscovery’ need, therefore, a considerable reshaping.

This article presents a reconstruction of the so-called classical, formal or Mendelian genetics, which is intended to be more complete and adequate than existing reconstructions. This reconstruction has been carried out with the instruments, duly modified and extended with respect to the case under consideration, of the structuralist conception of theories. The so-called Mendel’s Laws, as well as linkage genetics and gene mapping are formulated in a precise manner while the global structure of genetics is represented as a theory-net. These (...) results are of methodological, philosophical and didactical relevance. (shrink)

In September 1950, the Genetics Society of America (GSA) dedicated its annual meeting to a "Golden Jubilee of Genetics" that celebrated the 50th anniversary of the rediscovery of Mendel's work. This program, originally intended as a small ceremony attached to the coattails of the American Institute of Biological Sciences (AIBS) meeting, turned into a publicity juggernaut that generated coverage on Mendel and the accomplishments of Western genetics in countless newspapers and radio broadcasts. The Golden Jubilee merits historical attention as both (...) an intriguing instance of scientific commemoration and as an early example of Cold War political theatre. Instead of condemning either Lysenko or Soviet genetics, the Golden Jubilee would celebrate Mendel – and, not coincidentally, the practical achievements in plant and animal breeding his work had made possible. The American geneticists' focus on the achievements of Western genetics as both practical and theoretical, international, and, above all, non-ideological and non-controversial, was fully intended to demonstrate the success of the Western model of science to both the American public and scientists abroad at a key transition point in the Cold War. An implicit part of this article's argument, therefore, is the pervasive impact of the Cold War in unanticipated corners of postwar scientific culture. (shrink)

This paper is concerned with the uses of history in science. It focuses in particular on Anglo-American genetics and on university textbooks—where the canon of a science is consolidated, as the heterogeneous approaches and controversies of its practice are rendered unified for its reproduction. Tracing the emergence and eventual standardization of geneticists’ use of a case-based method of teaching in the 1920s–1950s, this paper argues that geneticists created historical environments in their textbooks—spaces in which students developed an understanding of the (...) laws of genetics through simulations of their discovery and use. Witnessing the unfolding of Mendel’s and Morgan’s experiments and performing genetic crosses on paper, students learned not only the rules that were explicitly taught as such, but also the experientially-based, tacit skills needed to find and follow these rules. This didactic system taught them how to go on when confronting new situations, and in doing so, provided geneticists with an important disciplinary tool, freeing the first steps of their student’s enculturation from the physical infrastructure of the laboratory. (shrink)

In the late 1940s, a microanatomist from London Ontario, Murray Barr, discovered a mark of sex chromosome status in bodily tissues, what came to be known as the ‘Barr body’. This discovery offered an important diagnostic technology to the burgeoning clinical science community engaged with the medical interpretation and management of sexual anomalies. It seemed to offer a way to identify the true, underlying sex in those whose bodies or lives were sexually anomalous . The hypothesis that allowed the Barr (...) body to stand in for ‘chromosomal’ or ‘genetic’ sex was provisional, but it supported the expectation that genetic information established one’s primary identity, and the conviction that the animal world could be neatly divided into two, and only two, sexes. Ultimately, this provisional hypothesis, and its status as an unambiguous arbiter of true sex, was overturned. But during much of the 1950s, Barr’s thesis about the identity of the Barr body was consistent with a coherent set of theories and evidence explaining sexual development and sexual pathology. Though provisional, the scientific status of the sex chromatin within this system of knowledge was good enough to support a flourishing research enterprise in the clinical sciences. (shrink)

The earliest references to Darwin in China, which came by way of the network of Protestant missionaries, emerged in the early 1870s: the principle of general transformism and ideas about human origins were transmitted to the Chinese intellectual landscape. Only with the “evolutionary sensation” aroused by Yan Fu, in the mid-1890s, did Chinese readers begin to learn of Darwinian principles like the “struggle for existence” and “natural selection.” Translation of the Origin began much later, in 1902, and the initial effort (...) was misleading. In his translation of the first five chapters of the Origin, published before 1906, Ma Junwu used linguistic strategies to modify Darwin’s texts so as to reflect Yan’s progressive transformism. But in his 1920 translation of the book in its entirety, Ma redid his earlier work. The complete Chinese Origin did not generate a sensation in the biological community. Even so, the deliberate selection, absorption, and appropriation of Darwinian ideas by the Chinese over the next several decades assimilated the new evolution into their own cultural setting. The case of “Darwin in China” details a specific Chinese context that deepens our understanding of how audiences for new scientific theories can be actively involved in the processes of appropriation and universalizing, while also disseminating, modifying, and assimilating Darwinian ideas in local context. (shrink)

The theory of concepts advanced in the dissertation aims at accounting for a) how a concept makes successful practice possible, and b) how a scientific concept can be subject to rational change in the course of history. Traditional accounts in the philosophy of science have usually studied concepts in terms only of their reference; their concern is to establish a stability of reference in order to address the incommensurability problem. My discussion, in contrast, suggests that each scientific concept consists of (...) three components of content: 1) reference, 2) inferential role, and 3) the epistemic goal pursued with the concept's use. I argue that in the course of history a concept can change in any of these three components, and that change in one component—including change of reference—can be accounted for as being rational relative to other components, in particular a concept's epistemic goal.This semantic framework is applied to two cases from the history of biology: the homology concept as used in 19th and 20th century biology, and the gene concept as used in different parts of the 20th century. The homology case study argues that the advent of Darwinian evolutionary theory, despite introducing a new definition of homology, did not bring about a new homology concept (distinct from the pre-Darwinian concept) in the 19th century. Nowadays, however, distinct homology concepts are used in systematics/evolutionary biology, in evolutionary developmental biology, and in molecular biology. The emergence of these different homology concepts is explained as occurring in a rational fashion. The gene case study argues that conceptual progress occurred with the transition from the classical to the molecular gene concept, despite a change in reference. In the last two decades, change occurred internal to the molecular gene concept, so that nowadays this concept's usage and reference varies from context to context. I argue that this situation emerged rationally and that the current variation in usage and reference is conducive to biological practice.The dissertation uses ideas and methodological tools from the philosophy of mind and language, the philosophy of science, the history of science, and the psychology of concepts. (shrink)

‘History will be kind to me, for I intend to write it,’ Winston Churchill is famously said to have quipped. That he never seems to have actually made this comment is beside the point, since the message is important: past events never speak for themselves. Facts do not settle like rocks in a dry river, but are moved, displaced, and replaced by waters that continue to gush. The currents and their temperates are sensetative to mores, signs of their times. And (...) the keepers of the waters, more often than not, are historians. This special issue is devoted to new directions in the historiography of genetics, a field that has seen particularly lively drift, swirl, and surge in recent decades. (shrink)

This thesis aims to propose and defend a new way of analysing and understanding the origin of genetics (from Mendel to Bateson). Traditionally philosophers used to analyse the history of genetics in terms of theories. However, I will argue that this theory-based approach is highly problematic. In Chapter 1, I shall critically review the theory-driven approach to analysisng the history of genetics and diagnose its problems. In Chapter 2, inspired by Kuhn’s concept “exemplar”, I shall make a new interpretation of (...) exemplar and introduce an exemplar-based approach. Before introducing my exemplar-based analysis, I find it necessary to scrutinise the origin of genetics from Mendel to Bateson. In Chapter 3, I shall reinterpret Mendel’s work on Pisum by re-examining Mendel’s paper (1865) and its historical research context. In Chapter 4, by carefully examining the conceptual changes, I argue that the rediscovery event in 1900 should be better characterised as attempts of incorporating Mendel’s work with the work of “rediscoverers” (i.e. de Vries, Correns, Tschermak, and Bateson) rather than a mere reintroduction to Mendel’s work. In Chapter 5, I shall use the exemplar-based approach to analysing and interpreting the origin of genetics from Mendel to Bateson. In Chapter 6, I shall defend my exemplar-based characterisation of the origin of genetics by dismissing the potential responses from the theory-driven one, critically examining a potential mechanism-based analysis, and making the further notes on the implication of taking the exemplar-based approach to investigate scientific practice. (shrink)

The early decades of the twentieth century were marked by widespread optimism about biology and its ability to improve the world. A major catalyst for this enthusiasm was new theories about inheritance and evolution (particularly Hugo de Vries's mutation theory and Mendel's newly rediscovered ideas). In Britain and the USA particularly, an astonishingly diverse variety of writers (from elite scientists to journalists and writers of fiction) took up the task of interpreting these new biological ideas, using a wide range of (...) genres to help their fellow citizens make sense of biology's promise. From these miscellaneous writings a new and distinctive kind of utopianism emerged – the biotopia. Biotopias offered the dream of a perfect, post-natural world, or the nightmare of violated nature (often in the same text), but above all they conveyed a sense that biology was – for the first time – offering humanity unprecedented control over life. Biotopias often visualized the world as a garden perfected for human use, but this vision was tinged with gendered violence, as it became clear that realizing it entailed dispossessing, or even killing, ‘Mother Nature’. Biotopian themes are apparent in journalism, scientific reports and even textbooks, and these non-fiction sources shared many characteristics with intentionally prophetic or utopian fictions. Biotopian themes can be traced back and forth across the porous boundaries between popular and elite writing, showing how biology came to function as public culture. This analysis reveals not only how the historical significance of science is invariably determined outside the scientific world, but also that the ways in which biology was debated during this period continue to characterize today's debates over new biological breakthroughs. (shrink)

Peter Godfrey-Smith’s introduction to the philosophy of biology is excellent. This review questions one implication of his book, namely that Darwin’s case for the efficacy of natural selection was hampered by his ignorance of the particulate nature of inheritance. I suggest, instead, that Darwin was handicapped by an inability to effectively engage in quantitative population thinking. I also question Godfrey-Smith’s understanding of the role that Malthusian struggle plays in linking natural selection to the origination of new adaptive traits, and I (...) raise problems for his defence of apparently unproblematic conceptions of human nature. Finally, I highlight the welcome conception of a ‘philosophy of nature’ developed by Godfrey-Smith. (shrink)

Recent reinterpretations of Mendel's 1865 paper on Pisum as normal nineteenth-century science do not automatically solve the neglect issue. Those who argue that there were cognitive grounds for its neglect have only created a greater paradox, for if Mendel's work was not ahead of its time but was simply excellent normal science, then it should have been used by his contemporaries, as indeed was his work on Hieracium, which was average work. An examination of the nineteenth-century data in terms of (...) recent knowledge about scientific communication suggests that knowledge of Mendel's Pisum work never entered the informal communication network of nineteenth-century botany, and that very few individuals, either by chance or referral, located the Brünn Verhandlungen and read the paper. By this interpretation, Mendel's work was not neglected, it was not known. (shrink)

Traditionally genetics is said to be the science of heredity. At least this was how William Bateson defined it in 1906. Today this is no longer the case. Since about ten years ago. when biologists learned to extract genes from cells, to transfer them from cell to cell, to dissect them, to analyze them biochemically, in short to manipulate them, the term genetics has tended rather to designate the science of the action of genes in cells. (This is what was (...) formerly called physiological genetics). In any case this is the form of genetics which today is in the forefront of biological research. (This is also called molecular genetics). This kind of genetics is also in the forefront in the media, because of its present or potential applications, in the realms of biotechnology, genetic therapy and so on. (shrink)

The origin and development of Punnett’s Square for the enumeration and display of genotypes arising in a cross in Mendelian genetics is described. Due to R. C. Punnett, the idea evolved through the work of the ‘Cambridge geneticists’, including Punnett’s colleagues William Bateson, E. R. Saunders and R. H. Lock, soon after the rediscovery of Mendel’s paper in 1900. These geneticists were thoroughly familiar with Mendel’s paper, which itself contained a similar square diagram. A previously-unpublished three-factor diagram by Sir Francis (...) Galton existing in the Bateson correspondence in Cambridge University Library is then described. Finally the connection between Punnett’s Square and Venn Diagrams is emphasized, and it is pointed out that Punnett, Lock and John Venn overlapped as Fellows of Gonville and Caius College, Cambridge. Copious illustrations are given. (shrink)

The paper analyzes the early theory building process of Thomas Hunt Morgan from the 1910s to the 1930s and the introduction of the invisible gene as a main explanatory unit of heredity. Morgan’s work marks the transition between two different styles of thought. In the early 1900s, he shifted from an embryological study of the development of the organism to a study of the mechanism of genetic inheritance and gene action. According to his contemporaries as well as to historiography, Morgan (...) separated genetics from embryology, and the gene from the whole organism. Other scholars identified an underlying embryological focus in Morgan’s work throughout his career. Our paper aims to clarify the debate by concentrating on Morgan’s theory building—characterized by his confidence in the power of experimental methods, and carefully avoiding any ontological commitment towards the gene—and on the continuity of the questions to be addressed by both embryology and genetics. (shrink)

Taking as starting point Kuhn’s analysis of science textbooks and its application to Sinnott and Dunn’s (1925), it will be discussed the problem of the existence of laws in biology. In particular, it will be showed, in accordance with the proposals of Darden (1991) and Schaffner (1980, 1986, 1993), the relevance of the exemplars, diagrammatically or graphically represented, in the way in which is carried out the teaching and learning process of classical genetics, inasmuch as the information contained in them, (...) indispensable for the right development of that process, exceeds the information contained in the “laws” linguistically articulated and presented in the textbooks. However, it will be maintained that the information is implicit in the law that according to the structuralist concept of fundamental law and the reconstruction of genetics presented by Balzer & Dawe (1990), and later developed by Balzer & Lorenzano (1997) and Lorenzano (1995, 2000, 2002a) could be considered the fundamental law of classical genetics,the law of matching, clearly identified in this paper. (shrink)

In the history of genetics, the information-theoretical description of the gene, beginning in the early 1960s, had a significant effect on the concept of the gene. Information is a highly complex metaphor which is applicable in view of the description of substances, processes, and spatio-temporal organisation. Thus, information can be understood as a functional particle of many different language games (some of them belonging to subdisciplines of genetics, as the biochemical language game, some of them belonging to linguistics and informatics). (...) It is this wide covering of different language games that justifies the common description of genes x, y, z as containing information for the phenotypic traits X, Y, Z (or the genome as storage for the information of a whole organism). However, if information is taken as the explanans and phenotypic traits or organisms as the explananda, then a description of the explanandum is of prior importance before the explanans can be characterised. This way of thinking could be useful for future discussions on the strikingly dominant information -metaphor, and the different gene concepts as well. The article illustrates this in two steps. First, a condensed overview on the history of genetics is given, which can be divided into three parts: (1) genetics without genes, (2) genetics with genes, but without information, (3) genetics with genes and information. It is assumed that this provides not only some historical knowledge about the origin of genetics and the introduction of technical terms, but offers at least preliminary insight into the methodological structure of genetic descriptions. In a second step, we redraw Spemann’s disturbation experiments to discuss our thesis that genetic information is not a natural entity, but part of a causality-language game which is secondarily added to the descriptions of interventionalistic practices, viz. experimental approaches. (shrink)

This Ph.D. thesis provides a pilosophical account of the structure of the evolutionary synthesis of the 1930s and 40s. The first, more historical part analyses how classical genetics came to be integrated into evolutionary thinking, highlighting in particular the importance of chromosomal mapping of Drosophila strains collected in the wild by Dobzansky, but also the work of Goldschmidt, Sumners, Timofeeff-Ressovsky and others. The second, more philosophical part attempts to answer the question wherein the unity of the synthesis consisted. I argue (...) that it exemplifies a weak of form of explanatory unification. (shrink)

Mendel's work in hybridization is ipso facto a study in inheritance. He is explicit in his interest to formulate universal generalizations, and at least in the case of the independent segregation of traits, he formulated his conclusions in the form of a law. Mendel did not discern, however, the inheritance of traits from that of the potential for traits. Choosing to study discrete non-overlapping traits, this did not hamper his efforts.

My conclusion is that Mendel deliberately, though without any real falsification, tried to suggest to his audience and readers an unlikely and substantially wrong reconstruction of the first and most important phase of his research. In my book I offer many reasons for this strange and surprising behavior,53 but the main argument rests on the fact of linkage. Mendelian genetics cannot account for linkage because it was based on the idea of applying probability theory to the problem of species evolution. (...) Central to the theory is the law of probability according to which the chance occurrence of a combination of independent events is the product of their separate probabilities. This is the common basis of Mendel's first and second laws, but this is why Mendel's second law on independent assortment is enunciated in too general a way. From Morgan's work we now know that characters may not always be independent if their genes are located very close one to the other on the same chromosome. And this was also the basis of Mendel's personal drama: he surely observed the effects of linkage, but he had no theoretical tools with which to explain it. So he presented his results in a logical structure consistent with the central idea of his theory. Had he described the real course of his experiments he would have had to admit that his law worked for only a few of the hundreds of Pisum characters — and it would thus have been considered more of an exception than a rule. This is why he insisted on the necessity of testing the law on other plants, and this is why in his second letter to Carl Nägeli he admits that the publication of his data was untimely and dangerous.54.We can argue that already in 1866 Mendel was less confident that his so-called second law had the same general validity as the first — and that later he lost his confidence altogether. Contemporary testimony indicates that in the end he became as skeptical as all his contemporaries as to the scientific relevance of his theory.55 But he was wrong. His research is in no way the fruit of methodological mistakes or forgery, and it remains a landmark in the history of science. He was only the victim of a strange destiny in which the use of probability theory was responsible, at the same time, for the strength and for the weakness of his theory. We must still consider him the father and founder of genetics. (shrink)

In the 1940s and 1950s, British and American journals published a flood of papers by doctors, pathologists, geneticists and anthropologists debating the virtues of two competing nomenclatures used to denote the Rhesus blood groups. Accounts of this prolonged and often bitter episode have tended to focus on the main protagonists' personalities and theoretical commitments. Here I take a different approach and use the literature generated by the dispute to recover the practical and epistemic functions of nomenclatures in genetics. Drawing on (...) recent work that views inscriptions as part of the material culture of science, I use the Rhesus controversy to think about the ways in which geneticists visualized and negotiated their objects of research, and how they communicated and collaborated with workers in other settings. Extending recent studies of relations between different media, I consider the material forms of nomenclatures, as they were jotted in notebooks, printed in journals, scribbled on blackboards and spoken out loud. The competing Rhesus nomenclatures had different virtues as they were expressed in different media and made to embody commitments to laboratory practices. In exploring the varied practical and epistemic qualities of nomenclatures I also suggest a new understanding of the Rhesus controversy itself. (shrink)

In 1675, Burchard de Volder became the first university physics professor to introduce the demonstration of experiments into his lectures and to create a special university classroom, The Leiden Physics Theatre, for this specific purpose. This is surprising for two reasons: first, early pre-Newtonian experiment is commonly associated with Italy and England, and second, de Volder is committed to Cartesian philosophy, including the view that knowledge gathered through the senses is subject to doubt, while that deducted from first principles is (...) certain. On the surface, it is curious that such a man would bring experiments to university physics. After all, in demonstrating experiments to his students, he was teaching them through their senses, not reason. However, if we consider the institutional context of de Volder’s teaching, we come to see de Volder’s Cartesian experimentalism as representative of a certain form of pre-Newtonian Dutch Cartesian science, as well as part of a larger tradition of teaching through observation at the University of Leiden. Considering de Volder’s institutional context will help us see that de Volder’s experimentalism was not in spite of his Cartesianism, but motivated by it. This paper will describe de Volder’s physics curriculum, the Theatre in which it was taught and how his work predates similar efforts in other European Universities. The second part will consider three aspects of the culture at the University of Leiden: a tradition of teaching through observation, a particular reception of Cartesianism, and an eclectic approach to the New Philosophy. The concluding portion shows how de Volder would have understood his enterprise in Cartesian terms. (shrink)

The seventh section of Gregor Mendel’s famous 1866 paper contained a peculiar mathematical model, which predicted the expected ratios between the number of constant and hybrid types, assuming self-pollination continued throughout further generations. This model was significant for Mendel’s argumentation and was perceived as inseparable from his entire theory at the time. A close examination of this model reveals that it has several perplexing aspects which have not yet been systematically scrutinized. The paper analyzes those aspects, dispels some common misconceptions (...) regarding the interpretation of the model, and re-evaluates the role of this model for Mendel himself. In light of the resulting analysis, Mendel’s position between nineteenth-century hybridist tradition and twentieth-century population genetics is reassessed, and his sophisticated use of mathematics to legitimize his innovative theory is uncovered. (shrink)