The Prodigal Genetics Returns: Integrating Gene Regulatory Network Theory Into Evolutionary Theory

[摘要] The aim of this dissertation is to show how gene regulatory network (GRN) theory can be integrated into evolutionary theory. GRN theory, which lies at the core of evolutionary-developmental biology (evo-devo), concerns the role of gene regulation in driving developmental processes, covering both how these networks function and how they evolve. Evolutionary and developmental biology, however, have long had an uneasy relationship. Developmental biology played little role in the establishment of a genetic theory evolution during the modern synthesis of the early to mid 20th century. As a result, the body of evolutionary theory that descends from the synthesis period largely lacks obvious loci for integrating the information provided by GRN theory. Indeed, the relationship between the two has commonly been perceived, by both scientists and philosophers, as one of conflict. By combining historical and philosophical analysis, I consider four sources of tension between evo-devo and synthesis-derived evolutionary theorizing in order to show how those tensions can be resolved. I present a picture of the conceptual foundations of evo-devo that reveals the potential for integrating it with existing evolutionary theorizing. In chapter two, I argue that a major historical source of tension between evolutionary and developmental biology was the debates, in the first half of the 20th century, about the possibility of explaining development in terms of gene action. I show that the successes of GRN theory put these worries to bed. In chapter three, I argue that, rather than conceive of evo-devo as typological, we should see it as resting on Cuvieran functionalism. I argue that Cuvi-eran functionalism complements the Darwinian functionalism of the modern synthesis. In chapter four, I present a picture of the fine structure of the concept 'homology’. This picture shows how accounts of homology that have traditionally been taken to conflict are in fact compatible and complementary. In chapter five, I analyze the nature of structure/function disputes in terms of types of answers to contrastive why-questions. On the basis of this analysis, I show how the structure of evolutionary theory requires both structuralist and functionalist approaches.

[发布机构] the University of Pittsburgh