"A FUNCTION-BASED Approach to Systems Biology"
Systems biology research is currently dominated by multidisciplinary approaches that attempt to integrate the interactions of biological entities through modeling to create an understanding of system-level functions. Although important, these approaches cannot relate the higher-level functions to the behavior of lower-level molecular interactions. We describe here the use of the Axiomatic Design approach and a complexity theory to system modeling and illustrate their utility in the study of biological systems. Axiomatic Design relates functions at all levels to the behavior of biological molecules and uses a Design Matrix to understand these relationships. Such a modeling and analysis reveals that robustness in many biological systems is achieved through the maintenance of functional independence of numerous subsystems. When the interlinking (coupling) of systems is required, biological systems impose a functional period in order to maximize successful operation of the system, which reduces the complexity of the biological system. Ultimately, the application of Axiomatic Design methods and the complexity theory to the study of biological systems will allow the establishment of the biological functions to molecular level across many scales, identifying control points, and predicting system-wide effects of pharmacological agents.