Linkage (or genetic) maps are graphs, which are intended to represent the linear ordering of genes on the chromosomes. They are constructed on the basis of statistical data concerning the transmission of genes. The invention of this technique in 1913 was driven by Morgan's group's adoption of a set of hypotheses concerning the physical mechanism of heredity. These hypotheses were themselves grounded in Morgan's defense of the chromosome theory of heredity, according to which chromosomes are the physical basis of genes. (...) In this paper, I analyze the 1919 debate between William Castle and Morgan's group, about the construction of genetic maps. The official issue of the debate concerns the arrangement of genes on chromosomes. However, the disputants tend to carry out the discussions about how one should model the data in order to draw predictions concerning the transmission of genes; the debate does not bear on the data themselves, nor does it focus on the hypotheses explaining these data. The main criteria that are appealed to by the protagonists are simplicity and predictive efficacy. However, I show that both parties' assessments of the simplicity and predictive efficacy of different ways of modeling the data themselves depend on background theoretical positions. I aim at clarifying how preference for a given model and theoretical commitments articulate. (shrink)

T. H. Morgan (1866–1945), the founder of the Drosophila research group in genetics that established the chromosome theory of Mendelian inheritance, has been described as a radical empiricist in the historical literature. His empiricism, furthermore, is supposed to have prejudiced him against certain scientific conclusions. This paper aims to show two things: first, that the sense in which the term empiricism has been used by scholars is too weak to be illuminating. It is necessary to distinguish between empiricism as an (...) epistemological position and the so-called methodological empiricism. I will argue that the way the latter has been presented cannot distinguish an empiricist methodology from a non-empiricist one. Second, I will show that T. H. Morgan was not an epistemological empiricist as this term is usually defined in philosophy. The reason is that he believed in the existence of genes as material entities when they were unobservable entities when they were unobservable entities introduced to account for the phenotypic ratios found in breeding experiments. These two points, of course, are interrelated. If we were to water down the meaning of empiricis, perhaps we could call Morgan an empiricist. But then we would also fail to distinguish empiricism from realism. (shrink)

Laudan's thesis that conceptual problem solving is at least as important as empirical problem solving in scientific research is given support by a study of the relation between the chromosome theory and the Mendelian research program. It will be shown that there existed a conceptual tension between the chromosome theory and the Mendelian program. This tension was to be resolved by changing the constraints of the Mendelian program. The relation between the chromosome theory and the Mendelian program is shown to (...) be a good illustration of the influence of science itself on the rational standards governing scientific development. (shrink)

This article discusses the work of George Udny Yule in relation to the evolutionary synthesis and the biometric-Mendelian debate. It has generally been claimed that (i.) in 1902, Yule put forth the first account showing that the competing biometric and Mendelian programs could be synthesized. Furthermore, (ii.) the scientific figures who should have been most interested in this thesis (the biometricians W. F. Raphael Weldon and Karl Pearson, and the Mendelian William Bateson) were too blinded by personal animosity towards each (...) other to appreciate Yule's proposal. This essay provides a detailed account of (i.), maintaining that Yule's 1902 proposal is better understood as a reduction, not a synthesis of the two programs. The results of this analysis are then used to evaluate (ii.), where I will instead argue that Bateson and the biometricians had good reasons to avoid endorsing Yule's account. (shrink)

Humans can think about their conscious experiences using a special class of ?phenomenal? concepts. Psychophysical identity statements formulated using phenomenal concepts appear to be contingent. Kripke argued that this intuited contingency could not be explained away, in contrast to ordinary theoretical identities where it can. If the contingency is real, property dualism follows. Physicalists have attempted to answer this challenge by pointing to special features of phenomenal concepts that explain the intuition of contingency. However no physicalist account of their distinguishing (...) features has proven to be satisfactory. Leading accounts rely on there being a phenomenological difference between tokening a physical-functional concept and tokening a phenomenal concept. This paper shows that existing psychological data undermine that claim. The paper goes on to suggest that the recalcitrance of the intuition of contingency may instead by explained by the limited means people typically have for applying their phenomenal concepts. Ways of testing that suggestion empirically are proposed. (shrink)

William Bateson vigorously objected to the assumptions within the chromosome theory of heredity proposed by T. H. Morgan because he perceived inadequate experimental data that could substantiate the theory. Those objections were largely resolved by 1921, and Bateson reluctantly accepted the basic assumption that chromosomes carried the genetic factors from one generation to the next. Bateson's own research at that time on developmental genetics seemed out of touch with the general tone of the genetics field, and the chromosome theory did (...) not provide illuminating mechanisms that elucidated phenomena such as plant variegations or chimeras. Bateson imagined a general theory of heredity and development based on vortices and waves, concepts he borrowed from contemporary physics. For decades he sought to devise an intellectually and aesthetically satisfying theory to eventually explain evolution in genetic terms, but his aspirations remained unfulfilled when he died in 1926. (shrink)

In 1891 Cambridge biologist William Bateson (1861–1926) announced his idea that the symmetrical segmentation in living organisms resulted from energy peaks of some vibratory force acting on tissues during morphogenesis. He also demonstrated topographically how folding a radially symmetric organism could produce another with bilateral symmetry. Bateson attended many lectures at the Cambridge Philosophical Society and viewed mechanical models prepared by eminent physicists that illustrated how vibrations affected materials. In his subsequent research, Bateson utilized analogies and metaphors based upon his (...) observations of nature to build a thought model on the effects of vibrations on living tissue, because he realized that the chemistry and biology of his day lacked technologies to perform actual experiments on the subject. He concluded the production of organic segmentation was both a chemical and mechanical phenomenon. By the time of his death Bateson had incorporated new ideas about embryonic organizer regions to suggest a center from which a rhythmic force emanated and then produced the observed repetitive segmentation as a common feature in living organisms. (shrink)

Physics matters less than we once thought to the making of Mendel. But it matters more than we tend to recognize to the making of Mendelism. This paper charts the variety of ways in which diverse kinds of physics impinged upon the Galtonian tradition which formed Mendelism’s matrix. The work of three Galtonians in particular is considered: Francis Galton himself, W. F. R. Weldon and William Bateson. One aim is to suggest that tracking influence from physics can bring into focus (...) important but now little-remembered flexibilities in the Galtonian tradition. Another is to show by example why generalizations about what happens when ‘physics’ meets ‘biology’ require caution. Even for a single research tradition in Britain in the decades around 1900, these categories were large, containing multitudes. (shrink)

There are two motivations commonly ascribed to historical actors for taking up statistics: to reduce complicated data to a mean value (e.g., Quetelet), and to take account of diversity (e.g., Galton). Different motivations will, it is assumed, lead to different methodological decisions in the practice of the statistical sciences. Karl Pearson and W. F. R. Weldon are generally seen as following directly in Galton’s footsteps. I argue for two related theses in light of this standard interpretation, based on a reading (...) of several sources in which Weldon, independently of Pearson, reflects on his own motivations. First, while Pearson does approach statistics from this "Galtonian" perspective, he is, consistent with his positivist philosophy of science, utilizing statistics to simplify the highly variable data of biology. Weldon, on the other hand, is brought to statistics by a rich empiricism and a desire to preserve the diversity of biological data. Secondly, we have here a counterexample to the claim that divergence in motivation will lead to a corresponding separation in methodology. Pearson and Weldon, despite embracing biometry for different reasons, settled on precisely the same set of statistical tools for the investigation of evolution. (shrink)

The recognition of Gregor Mendel's achievement in his study of hybridization was signalled by the ‘rediscovery’ papers of Hugo de Vries, Carl Correns and Erich Tschermak. The dates on which these papers were published are given in Table 1. The first of these—De Vries ‘Comptes renduspaper—was in French and made no mention of Mendel or his paper. The rest, led by De Vries’Berichtepaper, were in German and mentioned Mendel, giving the location of his paper. It has long been accepted that (...) the first account of Mendel's work in English was given by the Cambridge zoologist, William Bateson, to an audience of Fellows of the Royal Horticultural Society in London on 8 May, 1900. This is based on two sources: the paper ‘Problems of Heredity as a Subject for Horticultural Investigation’, published in the Society's journal later that year and stated as ‘Read 8 May, 1900’, and Beatrice Bateson's account of the event over a quarter of a century later. Of the paper which her husband gave on that occasion she wrote:He had already prepared this paper, but in the train on his way to town to deliver it, he read Mendel's actual paper on peas for the first time. As a lecturer he was always cautious, suggesting rather than affirming his own convictions. So ready was he however for the simple Mendelian law that he at once incorporated it into his lecture. (shrink)

This article scrutinizes in detail much of the extant historiography on the controversy between biometricians and Mendelians, considering in particular how this controversy is related to the evolutionary synthesis. While the historiographic critique concentrates on William Provine’s standard account, it also extends to the proposal by Donald MacKenzie and Barry Barnes. What Provine and these sociologists of scientific knowledge have in common is a set of unquestioned assumptions about the nature of Darwinism, about William Bateson’s anti-Darwinism, and about the very (...) idea of an evolutionary “synthesis.” While these assumptions make for a compelling history of the synthesis, they engender an endemically asymmetrical perspective and bias historiography toward the mere confirmation of antecedent expectations, which renders the years from 1859 to 1929 an age of ignorance and misunderstanding. In contrast, a return to what was probably the original meaning of evolutionary “synthesis” allows for a symmetrical account. It yields an appreciation of the positive contributions made both by Mendelians and biometricians to the gradual development of Darwinism. The article concludes with a synopsis of this alternative account. (shrink)

The controversy between Biometricians and Mendelians has been called an inexplicable embarrassment since it revolved around the mistaken identification of Mendelian genetics with non-Darwinian saltationism, a mistake traced back to the non-Darwinian William Bateson, who introduced Mendelian analysis to British science. The following paper beings to unravel this standard account of the controversy by raising a simple question: Given that Bateson embraced evolution by natural selection and that he studied the causes of variation within a broadly Darwinian framework of problems (...) and questions, how are we to understand the claim that he was a non-Darwinian? A brief survey of possible responses to this question is followed by an alternative proposal: the controversy will be considered as a struggle among Darwinians about the future course of Darwinism. On this account, Darwin's own work led to the juncture at which Mendelians and Biometricians parted company, indeed, the Origin itself prepared the divergent methodological stances subsequently adopted by Bateson and his antagonists. The inexplicable embarrassment is dissolved through the parsimonious reconstruction of the profound substantive conflict between Biometricians and Mendelians as a chapter in the articulation and differentiation of the Darwinian research programme. (shrink)

The debate between the Mendelians and the (largely Darwinian) biometricians has been referred to by R. A. Fisher as ‘one of the most needless controversies in the history of science’ and by David Hull as ‘an explicable embarrassment’. The literature on this topic consists mainly of explaining why the controversy occurred and what factors prevented it from being resolved. Regrettably, little or no mention is made of the issues that figured in its resolution. This paper deals with the latter topic (...) and in doing so reorients the focus of the debate as one between Karl Pearson and R. A. Fisher rather than between the biometricians and the Mendelians. One reason for this reorientation is that Pearson's own work in 1904 and 1909 suggested that Mendelism and biometry could, to some extent, be made compatible, yet he remained steadfast in his rejection of Mendelism. The interesting question then is why Fisher, who was also a proponent of biometric methods, was able to synthesise the two traditions in a way that Pearson either could not or would not. My answer to this question involves an analysis of the ways in which different kinds of assumptions were used in modelling Mendelian populations. I argue that it is these assumptions, which lay behind the statistical techniques of Pearson and Fisher, that can be isolated as the source of Pearson's rejection of Mendelism and Fisher's success in the synthesis. (shrink)

Bateson's belated acceptance of the chromosome theory came in two main stages, and was permanent, although he retained to the end reservations about some implications and extensions of the theory. Coleman's attempt to explain Bateson's resistance in terms of his conservative mode of thought is critically examined, and rejected: the attributes Coleman assigns to Bateson are all either inappropriate, or irrelevant to chromosome theory, or both. Instead, the diverse factors which contributed to Bateson's resistance are enumerated and discussed. These include (...) deficiencies in the evidence then available to support the theory; embryological difficulties; Bateson's aversion to microscopy combined with the lack of a close colleague skilled in cytology; his iconoclastic temperament, and the fact that he found T. H. Morgan, the leader of the Drosophila school, an uncongenial personality. Taken together, these factors suffice to account for his resistance. Bateson's position is contrasted with that of the other most eminent opponent, W. Johannsen, whose organismic outlook was the main obstacle to acceptance. (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)

Laudan's thesis that conceptual problem solving is at least as important as empirical problem solving in scientific research is given support by a study of the relation between the chromosome theory and the Mendelian research program. It will be shown that there existed a conceptual tension between the chromosome theory and the Mendelian program. This tension was to be resolved by changing the constraints of the Mendelian program. The relation between the chromosome theory and the Mendelian program is shown to (...) be a good illustration of the influence of science itself on the rational standards governing scientific development. (shrink)

The so-called "biometric-Mendelian controversy" has received much attention from science studies scholars. This paper focuses on one scientist involved in this debate, Arthur Dukinfield Darbishire, who performed a series of hybridization experiments with mice beginning in 1901. Previous historical work on Darbishire's experiments and his later attempt to reconcile Mendelian and biometric views describe Darbishire as eventually being "converted" to Mendelism. I provide a new analysis of this episode in the context of Darbishire's experimental results, his underlying epistemology, and his (...) influence on the broader debate surrounding the rediscovery and acceptance of Mendelism. I investigate various historiographical issues raised by this episode in order to reflect on the idea of "conversion" to a scientific theory. Darbishire was an influential figure who resisted strong forces compelling him to convert prematurely due to his requirements that the new theory account for particularly important anomalous facts and answer the most pressing questions in the field. (shrink)

Richard Goldschmidt famously rejected the notion of atomic and corpuscular genes, arranged on the chromosome like beads-on-a-string. I provide an exegesis of Goldschmidt’s intuition by analyzing his repeated and extensive use of metaphorical language and analogies in his attempts to convey his notion of the nature of the genetic material and specifically the significance of chromosomal pattern. The paper concentrates on Goldschmidt’s use of metaphors in publications spanning 1940-1955. -/- .