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)

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 article discusses the contribution to evolutionary theory of Leonard Darwin, the eighth child of Charles Darwin. By analysing the correspondence Leonard Darwin maintained with Ronald Aylmer Fisher in conjunction with an assessment of his books and other written works between the 1910s and 1930s, this article argues for a more prominent role played by him than the previously recognised in the literature as an informal mentor of Fisher. The paper discusses Leonard’s efforts to amalgamate Mendelism with both Eugenics and (...) Darwinism in order for the first to base their policies on new scientific developments and to help the second in finding a target for natural selection. Without a formal qualification in biological sciences and as such mistrusted by some “formal” scientists, Leonard Darwin engaged with key themes of Darwinism such as mimicry, the role of mutations on speciation and the process of genetic variability, arriving at important conclusions concerning the usefulness of Mendelian genetics for his father’s theory. (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)

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)

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)