ABSTRACT
Discovery of the clockworks of living organisms has required more detective work. The human pacemaker is likely in the suprachiasmatic nuclei, and the human circadian system is a hierarchy of oscillators including the pineal and pituitary and adrenal glands. Scientists treated the biological clock mechanism as a black box and attempted to create clockworks using what they knew about the properties of measured rhythms, rules of science, and biological components. The method that has been successfully used to locate pacemakers and photoreceptors has been ablation. Removing a suspected area can be done many ways, with surgery or lesions, with chemicals, and sometimes with mechanical means, such as a hood to block light from reaching a photoreceptor. A chronon model for the circadian clock makes use of the sequence of events by which proteins are synthesized in cells. A membrane model is based on the structures of cell membranes, potassium ions, and the circadian Q10 evidence for a diffusion process.
