Magnetoreception and Electromagnetic Field Effects: Sensory Perception of the Geomagnetic Field in Animals and Humans

This chapter reviews numerous discoveries that have been made during the past 15 years concerning the ability of living organisms to respond to the geomagnetic field. These include (1) the magnetotactic response of bacteria and protozoans, (2) magnetic effects on homing and navigational behavior by migrating animals, (3) the discovery of magnetically influenced signals in nerve fibers from the trigeminal system in birds and fish, and (4) the testing of two biophysical hypotheses for the magnetoreception mechanism (biogenic magnetite and optical pumping). A final discussion concerns possible biological effects of environmental electromagnetic fields on the basis of the energy required to rotate the small crystals of biogenic magnetite that have been discovered in various human tissues.