Three metascientific concepts that have been object of philosophical analysis are the concepts oflaw, model and theory. The aim ofthis article is to present the explication of these concepts, and of their relationships, made within the framework of Sneedean or Metatheoretical Structuralism (Balzer et al. 1987), and of their application to a case from the realm of biology: Population Dynamics. The analysis carried out will make it possible to support, contrary to what some philosophers of science in general and of (...) biology in particular hold, the following claims: a) there are "laws" in biological sciences, b) many of the heterogeneous and different "models" of biology can be accommodated under some "theory", and c) this is exactly what confers great unifying power to biological theories. (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)

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)

Filósofos e historiadores da ciência oferecem explicações para cientistas aceitarem ou rejeitaremuma dada hipótese ou teoria, mas, de um modo geral, não apresentam critérios que permitamdeterminar de maneira clara o que seja aceitação e o que seja rejeição. Com o intuitode contribuir para elucidar este problema, foi proposto um método de análise em Martinse Martins, exemplificado pelo posicionamento do naturalista inglês William Bateson diante da teoria cromossômica, no período compreendido entre 1902 e 1926.O objetivo deste artigo é aplicar o método (...) de análise acima mencionado para esclarecer aposição adotada pelo zoólogo Thomas Hunt Morgan diante da hipótese/teoriacromossômica, no período compreendido entre 1903 e 1910-1911. Nossa análise mostraque Morgan rejeitou a teoria cromossômica no período considerado e que sua mudançarepentina de opinião se deveu a uma estratégia profissional. (shrink)