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)

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)

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)

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)

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)

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)

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)

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)