Browse Papers

Review essay of Richard Owen's On the Nature of Limbs: A Discourse edited by Ron Amundson, University of Chicago Press, 2007. This article reviews the recent reissuing of Richard Owen’s On the Nature of Limbs and its three novel, introductory essays. These essays make Owen’s 1849 text very accessible by discussing the historical context of his work and explaining how Owen’s ideas relate to his larger intellectual framework. In addition to the ways in which the essays point to Owen’s relevance for contemporary biology, I discuss how Owen’s unity of type theory and his homology claims about fins and limbs compare with modern views. While the phenomena studied by Owen are nowadays of major interest to evolutionary developmental biology, research in evo-devo has largely shifted from homology (which was Owen’s concern) towards evolutionary novelty, e.g., accounting for fins as a novelty. Still, I argue that questions about homology are important and raise challenges even for explanations of novelty.

Recent discussion of mechanism has suggested new approaches to several issues in the philosophy of science, including theory structure, causal explanation, and reductionism. Here, I apply what I take to be the fruits of the 'new mechanical philosophy' to an analysis of a contemporary debate in evolutionary biology about the role of natural selection in speciation. Traditional accounts of that debate focus on the geographic context of genetic divergence--namely, whether divergence in the absence of geographic isolation is possible (or significant). Those accounts are at best incomplete, I argue, because they ignore the mechanisms producing divergence and miss what is at stake in the biological debate. I argue that the biological debate instead concerns the scope of particular speciation mechanisms which assign different roles to natural selection at various stages of divergence. The upshot is a new interpretation of the crux of that debate--namely, whether divergence with gene flow is possible (or significant) and whether the isolating mechanisms producing it are adaptive.

The present paper discusses Kitcher’s framework for studying conceptual change and progress. Kitcher’s core notion of reference potential is hard to apply to concrete cases. In addition, an account of conceptual change as change in reference potential misses some important aspects of conceptual change and conceptual progress. I propose an alternative framework that focuses on the inferences and explanations supported by scientific concepts. The application of my approach to the history of the gene concept offers a better account of the conceptual progress that occurred in the transition from the Mendelian to the molecular gene than Kitcher’s theory.

Bayle's article on Rorarius, author of a work purporting to demonstrate that animals reason better than humans, describes and rejects all but one of the current opinions concerning the souls of animals. That survivor is Leibniz's theory of monads, but Bayle cannot accept pre-established harmony, and so Leibniz goes by the wayside too. Bayle exhibits clearly the consequences of Cartesianism for attempts to distinguish us from the animals. The alternatives are reduced to two: either we do not have an immortal soul, or animals do. Both are untenable on moral grounds. The result for Bayle is that no opinion on animal souls can be stably maintained.

The paper works towards an account of explanatory integration in biology, using as a case study explanations of the evolutionary origin of novelties—a problem requiring the integration of several biological fields and approaches. In contrast to the idea that fields studying lower level phenomena are always more fundamental in explanations, I argue that the particular combination of disciplines and theoretical approaches needed to address a complex biological problem and which among them is explanatorily more fundamental varies with the problem pursued. Solving a complex problem need not require theoretical unification or the stable synthesis of different biological fields, as items of knowledge from traditional disciplines can be related solely for the purposes of a specific problem. Apart from the development of genuine interfield theories, successful integration can be effected by smaller epistemic units (concepts, methods, explanations) being linked. Unification or integration is not an aim in itself, but needed for the aim of solving a particular scientific problem, where the problem’s nature determines the kind of intellectual integration required.

Over these last few years once again the relationship between biology and information has been debated with great liveliness. The crucial points concern the meaning of the term ‘information’ and whether the so-called “information talk” is really necessary inside biology.I will proceed by first commenting on some points of the debate (§ 2), then showing that a biophysical account of the process from the nucleotide sequences to the correlated amino acid sequences is possible (§ 3). In this way, I will suggest that a satisfying account of that process can be offered without entering the quicksand of information.

The philosophy of our proposal are as follows: (1) Various ideas of life and death, including that of objecting to brain death as human death, should be guaranteed. We would like to maintain the idea of pluralism of human death; and (2) We should respect a child’s view of life and death. We should provide him/her with an opportunity to think and express their own ideas about life and death.

Darwinian theories of culture need to show that they improve upon the commonsense view that cultural change is explained by humans� skillful pursuit of their conscious goals. In order for meme theory to pull its weight, it is not enough to show that the development and spread of an idea is, broadly speaking, Darwinian, in the sense that it proceeds by the accumulation of change through the differential survival and transmission of varying elements. It could still be the case that the best explanation of why the idea has developed and spread is the conscious pursuit of human goals. Meme theory has the potential to do explanatory work in diverse ways. It can challenge the goal-based account of cultural change directly. Other possibilities for meme theory include explaining the acquisition of our goals and showing that memes and genes evolve together, each affecting the selective forces acting on the other. Raising the question of meme theory�s explanatory payoff brings out the importance of the �selfish-meme� idea and the idea of non-content biases. Both have the potential to challenge the claim that our goals are in the driver�s seat. In order to show that a Darwinian theory of culture is more than an idle redescription, however, it is necessary to make the case that it offers explanatory gain over its competitors, in particular over the common sense goal-based account.

Homology is a natural kind term and a precise account of what homology is has to come out of theories about the role of homologues in evolution and development. Definitions of homology are discussed with respect to the question as to whether they are able to give a non-circular account of the correspondence or sameness referred to by homology. It is argued that standard accounts tie homology to operational criteria or specific research projects, but are not yet able to offer a concept of homology that does not presuppose a version of homology or a comparable notion of sameness. This is the case for phylogenetic definitions that trace structures back to the common ancestor as well as for developmental approaches such as Wagner’s biological homology concept. In contrast, molecular homology is able to offer a definition of homology in genes and proteins that explicates homology by reference to more basic notions. Molecular correspondence originates by means of specific features of causal processes. It is speculated that further understanding of morphogenesis might enable biologists to give a theoretically deeper definition of homology along similar lines: an account which makes reference to the concrete mechanisms that operate in organisms.

The present paper analyzes the use and understanding of the homology concept across different biological disciplines. It is argued that in its history, the homology concept underwent a sort of adaptive radiation. Once it migrated from comparative anatomy into new biological fields, the homology concept changed in accordance with the theoretical aims and interests of these disciplines. The paper gives a case study of the theoretical role that homology plays in comparative and evolutionary biology, in molecular biology, and in evolutionary developmental biology. It is shown that the concept or variant of homology preferred by a particular biological field is used to bring about items of biological knowledge that are characteristic for this field. A particular branch of biology uses its homology concept to pursue its specific theoretical goals.