Explaining in Contemporary Molecular Biology: Beyond Mechanisms

Abstract

Over the past decade, the concept of mechanism has drawn considerable attention in the philosophy of biology. This interest stemmed from the recognition that mechanistic explanations are central to the practice of biologists. So far, most discussions have aimed at defining the mechanism and characterizing mechanistic explanations, rather than assessing the genuine significance of these explanations in the overall explanatory activity of biologists. This reinforced the view that in functional biology, and in particular in molecular biology, explaining a phenomenon mostly consists in showing how this phenomenon is produced by its causes, by describing the mechanisms that maintain and underlie it. From this perspective, mechanistic explanations appear to be the most relevant causal explanatory scheme in functional biology. However, in this chapter, I argue that causal explanations have been mistakenly reduced to mechanistic explanations. I focus on current research on the regulation of genetic expression by microRNAs to suggest that in contemporary molecular biology, explanations increasingly describe some features of causal processes that mechanistic explanations are not meant to grasp. Given this, I characterize two types of explanations – namely, quantitative explanations and systemic explanations – that do not rely on the concept of mechanism. Altogether, these considerations prompt the reconsideration of the status of the concept of mechanism in biological practice, as well as the development of a pluralistic approach of explanations in molecular biology.