Except for relatively few polarity reversals the magnitude of the magnetic dipole moment of the
earth has remained constant since life first began, allowing evolutionary processes to integrate
the geomagnetic field (GMF) into several biological functions. One of these, bearing the classical
signature of an ion cyclotron resonance (ICR)-like interaction, results in biological change associated
with enhanced proton transport. The wide range of cation masses over which this effect is
found suggest a fundamental biological dependence on the GMF, one that functions equally well
for electric as well as magnetic fields. Such generalization of ICR requires two things: transparency
of tissues to the GMF and suitably tuned ELF resonant magnetic or electric fields. To complement
the widely reported ICR responses to applied AC magnetic fields, we hypothesize the existence of
weak endogenous ICR electric field oscillations within the cell. This equivalence implies that even
in the absence of applied AC magnetic fields, biological systems will exhibit intrinsic GMFdependent
ion cyclotron resonance intracellular interactions. Many ICR effects that have been
reported appear as antagonist pairs suggesting that the characteristics of the GMF have not only
been incorporated into the genome but also appear to function in an endocrine-like manner.
ION Cyclotron Resonance: Geomagnetic Strategy For Living Systems?