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)

Julian Huxley’s eclipse of Darwinism narrative has cast a long shadow over the historiography of evolutionary theory around the turn of the nineteenth century. It has done so by limiting who could be thought of as Darwinian. Peter Bowler used the eclipse to draw attention to previously understudied alternatives to Darwinism, but maintained the same flaw. In his research on the Non-Darwinian Revolution, he extended this problematic element even further back in time. This paper explores how late nineteenth-century neo-Darwinian conceptualizations (...) of Darwinism were later utilized by several advocates and detractors of the Modern Synthesis. John Beatty has shown how this continuity hinges at least partly on the perceived importance of the creativity of natural selection. The paper provides a more thorough look at Darwin’s two conflicting accounts of variation, ascribed to struggles in explaining quantitative versus qualitative characters. In doing so, it suggests that other forms of Darwinism persisted, in both the non-Darwinian revolution and eclipse periods, because of tension between contingency and creativity in Darwin’s own work. This tension is traced out from Darwin’s conceptions of variation into the work of Alfred Russel Wallace, Hugo de Vries, and Thomas Henry Huxley. Based on this, the eclipse narrative is criticized for not considering the meaning of Darwinism in different geographical locations. Britain and the United States showed few signs of an eclipse. Rather, the rise of German debates about Haeckel’s vision of Darwinism have been mistaken for a universal decline in support. (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.

The distinction between discovery and justification is ambiguous. This obscures the debate over a logic of discovery. For the debate presupposes the distinction. Real discoveries are well established. What is well established is justified. The proper distinctions are three: initial thinking, plausibility, and acceptability. Logic is not essential to initial thinking. We do not need good supporting reasons to initially think of an hypothesis. Initial thoughts need be neither plausible nor acceptable. Logic is essential, as Hanson noted, to both plausibility (...) and acceptability. An hypothesis needs good supporting reasons to be either plausible or acceptable. Such reasons need not be relative to the particular scientific theory undergoing test at the time. There is no fundamental difference between reasons relevant to plausibility and acceptability. The difference is one of degree. Acceptability requires more than plausibility. (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)

Selection type theories solve adaptation problems. Natural selection, clonal selection for antibody production, and selective theories of higher brain function are examples. An abstract characterization of typical selection processes is generated by analyzing and extending previous work on the nature of natural selection. Once constructed, this abstraction provides a useful tool for analyzing the nature of other selection theories and may be of use in new instances of theory construction. This suggests the potential fruitfulness of research to find other theory (...) types and construct their abstractions. (shrink)

This note discusses lecture plates at the Hugo de Vries Laboratorium that may be relevant to Hugo de Vries's claim to have independently discovered Mendel's law of segregation. Dating when the plates were made is problematic.

It is argued that de Vries did not see Mendel's paper until 1900, and that, while his own theory of inheritance may have incorporated the notion of independent units, this pre-Mendelian formulation was not the same as Mendel's since it did not apply to paired hereditary units. Moreover, the way in which the term ‘segregation’ has been applied in the secondary literature has blurred the distinction between what is explained and the law which facilitates explanation.

A great deal is known about the technical issues surrounding the introduction of Hugo De Vries's mutation theory and the subsequent development of the modern genetical theory of natural selection. But so far little has been done to relate these events to the wider issues of the time. This article suggests that extra-scientific factors played a significant role, and substantiates this by comparing De Vries's respect for the original Darwinian spirit with Thomas Hunt Morgan's use of the mutation theory as (...) part of an attack on the whole philosophy of Darwinism. In particular, it is argued that Morgan's attitude was dictated by his moral objections to the picture of a world dominated by struggle. (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)