rhall at uvi.edu
Tue Mar 19 14:51:33 EST 1996
On 3/19/96 Zamanlf wrote a lot about the relevance of emf to the biological
process. And it was very interesting.
But why do you presume that of the four fundamental forces known in physics
only emf is significant? To be sure electromagnetic radiation as light
drives the entire food chain through photosynthetic pathways. Many
biological molecules absorb visible light, but does example hemoglobin
absorbion spectrum influence the function of hemoglobin to any significant
level? My hemoglobin molecules seem indifferent to the color of light.
In contrast, gravity has a profound effect on my hemoglobin molecule. At
sea level things are spiffy, but at 4,000 meters things change
dramatically. Temperature (heat) does not seem to figure into the four
fundamentals, but I can assure you tha Arrhenius was on to something when
he related reaction rates to thermal energies.
In neurosciences it electricity and consequently magnetism are obviously
important in two major areas:
1) the transmission of current to distant places.
2) the ability of current to alter charge densities at biological membranes
(ie capacitance) which then alters voltage. Many biological events are
influenced by either currents (eg., influx of calcium) or voltages (voltage
gated ion channels.)
In molecular biology, electrostatic fields play a role in DNA folding, but
so do hydrophobic:hydrophilic effects which are more temperature related.
Certainly we generate weak electromagnetic fields as a consequence of
biological activity and certainly electromagnetic fields may influence
neurological functions. We spend oodles of money monitoring
electromagnetic perturbations that have biological correlates: ecg, eeg,
impedance, extracellular and intracellular recordings of current and
voltage. But to turn the tables and say the tail wags the dog may not be
ying and yang. The presumption that biological activity can be reduced to
an electromagnetic common denominator seems a bit bold in every causal and
effect sense i know.
Anyway the mathematics of it all makes such thoughts beyond the reach of
most mortal biologists. Conversely, the diversity of life and its' frantic
efforts to avoid reduction into the cartesian sum of its parts can
certainly drive a physicist balmy.
Comparative Animal Physiologist
Division of Sciences and Mathematics
University of the Virgin Islands
St. Thomas, USVI 00802
rhall at uvi.edu
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