Proteins, cells, organs: hierarchical structuring in modeling biological systems

To build mathematical models extending from gene expression through the full mathematics of cells, tissues, and organs to describe the behavior of an organism is clearly unachievable, but to build organ level models based on the underlying behavior of tissues, cells, and subcellular components is essential in order to make predictions of the results or changing environmental states or pharmaceutic or genomic intervention. The difficulty lies in maintaining the correctness of the representation or the smaller and faster elements of the systems in the face of the essential requirement to reduce computation. Strategies to do this involve modular simplification and mechanisms for maintaining adaptation of the module to changing conditions. This needs to be accomplished through roughly five levels of hierarchically structured components from gene to organ. Beginning results suggest that the strategy of modularization and simplification works over three levels.