6 - Mechanism and mechanical explanation in systems biology

Abstract

The chapter focuses on mechanisms and mechanical explanations in systems biology. Mechanistic explanations in cell biology provide a strong case for systems biology, because systems biology involves explaining the properties of cells in terms of the properties and interactions of their molecular constituents. Mechanistic explanations are essentially more detailed redescriptions and dynamic explanations of system behavior that treat cells (or organisms) as complex biochemical systems. In mechanistic models, higher level explanations are neither redundant nor eliminable. There is genuine explanatory work done at the higher level, reflecting systemic properties. The mechanistic model is applied to the regulation of diauxic growth of Escherichia coli and the involvement of the lac operon. The revolutionary aspect of the lac operon, within genetics, was that it introduced a distinctive class of genetic regulatory elements, governing the synthesis of enzymes and other products relevant to cell regulation.