Although it has not been much noticed, reproduction is the central theme of François Jacob’s important history of biology, La logique du vivant (The Logic of Life). In a book ostensibly devoted to heredity, this molecular biologist had reproduction integrate levels of organization from organisms to molecules and play a major role in each historical transition between them, not just in the influential argument for a shift “from generation to reproduction.” Moreover, I claim, La logique was the first general history (...) of (research on) reproduction. Earlier histories had tackled only aspects of generation and reproduction; none historicized the latter. Jacob’s innovation came out of the rising prominence of reproduction in neo-Darwinist studies of populations and in his own field, the cellular genetics of bacteria and their viruses, and engagement with history and philosophy of science. The discovery of bacterial “sex” enabled microbial genetics but, ironically, led Jacob to a sexless concept of reproduction. This approach molded a history that reached across the living world but slighted sex and the complexities of reproduction in multicellular organisms. Readers can learn from its strength and limitations. (shrink)

In addition to his experiments on selection in pure lines, Wilhelm Johannsen performed less well-known hybridisation experiments with beans. This article describes these experiments and discusses Johannsen’s motivations and interpretations, in the context of developments in early genetics. I will show that Johannsen first presented the hybridisation experiments as an additional control for his selection experiments. The latter were dedicated to investigating heredity with respect to debates concerning the significance of natural selection of continuous variation for evolution. In the course (...) of the establishment of a Mendelian research program after 1900, the study of heredity gained increasing independence from questions of evolution, and focused more on the modes and mechanisms of heredity. Further to their role as control experiments, Johannsen also saw his hybridisation experiments as contributing to the Mendelian program, by extending the scope of the principles of Mendelian inheritance to quantitative characters. Towards the end of the first decade of genetics, Johannsen revisited his experiments to illustrate the many–many relationship between genes and characters, at a time when that relationship appeared increasingly complex, and the unit-character concept, accordingly, became inadequate. For the philosophy of science, the example shows that experiments can have multiple roles in a research programme, and can be interpreted in the light of questions other than those that motivated the experiments in the first place. (shrink)

The concept of plasticity has always been present in the history of developmental biology, both within the theory of epigenesis and within morphogenesis studies. However this tradition relies also upon a genetic conception of plasticity. Founded upon the concepts of ‘‘phenotypic plasticity’’ and ‘‘reaction norm,’’ this genetic conception focuses on the array of possible phenotypic change in relation to diversified environments. Another concept of plasticity can be found in recent publications by some developmental biologists (Gilbert, West-Eberhard). I argue that these (...) authors adopt a ‘‘broad conception of plasticity’’ that is closely related to a notion of development as something that is ongoing throughout an organism’s lifecycle, and has no clear-cut boundaries. However, I suggest that given a narrow conception of plasticity, one can define temporal boundaries for development that are linked to specific features of the morphological process, which are different from behavioral and physiological processes. (shrink)

This special issue of Biological Theory is focused on development; it raises the problem of the temporal and spatial boundaries of development. From a temporal point of view, when does development start and stop? From a spatial point of view, what is it exactly that "develops", and is it possible to delineate clearly the developing entity? This issue explores the possible answers to these questions, and thus sheds light on the definition of development itself.

Recently, the nature of science (NOS) has become recognized as an important element within the K-12 science curriculum. Despite differences in the ultimate lists of recommended aspects, a consensus is emerging on what specific NOS elements should be the focus of science instruction and inform textbook writers and curriculum developers. In this article, we suggest a contextualized, explicit approach addressing one core NOS aspect: the human aspects of science that include the domains of creativity, social influences and subjectivity. To illustrate (...) these ideas, we have focused on Charles Darwin, a scientist whose life, work and thought processes were particularly well recorded at the time and analyzed by scholars in the succeeding years. Historical facts are discussed and linked to core NOS ideas. Creativity is illustrated through the analogies between the struggle for existence in human societies and in nature, between artificial and natural selection, and between the division of labor in human societies and in nature. Social influences are represented by Darwin’s aversion of criticism of various kinds and by his response to the methodological requirements of the science of that time. Finally, subjectivity is discussed through Darwin’s development of a unique but incorrect source for the origin of variations within species. (shrink)

During the 1920s and 1930s geneticist L. C. Dunn of Columbia University cautioned Americans against endorsing eugenic policies and called attention to eugenicists' less than rigorous practices. Then, from the mid-1940s to early 1950s he attacked scientific racism and Nazi Rassenhygiene by co-authoring Heredity, Race and Society with Theodosius Dobzhansky and collaborating with members of UNESCO on their international campaign against racism. Even though shaking the foundations of scientific discrimination was Dunn's primary concern during the interwar and post-World War II (...) years, his campaigns had ancillary consequences for the discipline. He contributed to the professionalization of genetics during the 1920s and 1930s and sought respectability for human genetics in the 1940s and 1950s. My article aims to elucidate the activist scientist's role in undermining scientific discrimination by exploring aspects of Dunn's scientific work and political activism from the 1920s to 1950s. Definitions are provided for scientific discrimination and activist scientist. (shrink)