Elements of a unifying theory of biology.

To discover a unifying theory of biology, it is necessary first to believe in its existence and second to seek its elements. Such a theory would explain the regulation of the cell cycle, differentiation and the origin of life. Some elements of the theory may be obtained by considering both eukaryotic and prokaryotic cell cycles. These elements include cytoskeletal proteins, calcium, cyclins, protein kinase C, phosphorylation, transcriptional sensing, autocatalytic gene expression and the physical properties of lipids. Other more exotic candidate elements include the dynamic enzoskeleton, ATP generation, mechanotransduction, the piezoelectric effect and resonance. Bringing these disparate elements together--and discovering others--will require extensive collaborations between specialists from different sciences. This can only be achieved within the context of an integrated approach to biology.