Biological clocks: endogenous cycles synchronized by subtle geophysical rhythms.

Organismic sensitivity to atmospheric electromagnetic forces, together with usually asymmetrical phase-response systems, have enabled a simple unified explanation of the biological clocks and their timed rhythms. The clocks, endogenous cycles synchronized by subtle geophysical Zeitgeber, are always accurate. The rhythms, freely phase labile, autophase in "constant conditions" to generate a host of overt frequencies.