Biological Cycles


The biologist is confronted with a bewildering variety of form, function and complexity in living things, from single-celled organisms such as amoebas to human beings. Beyond being composed of chemical compounds containing carbon and equipped with the capacity of self-replication, living things would appear to share few attributes. Over the past few decades however, it has become increasingly evident that all living things from the simplest plant to man possess an innate rhythmicity termed biological cycles. The sleep-wakefulness cycle is part of the human experience and superficially appears to be associated with the solar day, just as the human menstrual cycles seems to be correlated with the lunar month. However, the full complexity and richness of the living tides have only recently been recognized. Upon scientific examination, there is a surprising uniformity of rhythmicity which finds its counterpart in the tidal fluctuations in the earth's electromagnetic field. The study of these phenomena has become a scientific discipline in its own right. It is not the purpose of this section to study in detail all the complexities of modern chronobiology. Rather, we will hope to review the basic uniformity that underlies this general characteristic of living things and its relationship to the earth's normal electromagnetic field.

Much of our present understanding in this area is due to the patient and persistent work of one man, Dr. Frank Brown, Morrison Professor of Biology at Northwestern University. After a distinguished career in investigative endocrinology, he became interested in the relatively neglected field of biocycles in the mid-1950's. At that time the innate nature of these phenomena had been shown. It was common knowledge that organisms kept in the laboratory under constant conditions such as light and temperature maintained a basic rhythmicity, with a period close to 24 hours; hence the generic term, "circadian (about a day) rhythm."

This basic rhythm in the case of plants was strongly influenced by light and in the case of organisms living in the intertidal zone of the seashore, by the lunar tides. For example, oysters open their shells to feed as the tide comes in, covering them with water, and close them as the tide recedes. A seemingly simple observation with an obvious explanation-the depth of water determined the opening and closing. But this was not so. Oysters placed in the laboratory with a constant depth of water and constant light and temperature still continued to open and close their shells in synchrony with their fellows on the tidal flats. Somehow they received the timing signal or they had an internal clock mechanism.

In 1954 Brown performed an important experiment (10): he flew oysters in a light-tight box from the seashore at New Haven, Connecticut to Evanston, Illinois and installed them in the same controlled circumstances there. At first the oysters continued to open and close in synchrony with the tides at New Haven. However, gradually over a period of a few weeks the phase of the open-close cycle shifted to coincide with the tidal pattern at Evanston, were it on a seacoast! Devoid of all known positional cues, possessed of only the most rudimentary senses, the oysters somehow "knew" they had been displaced almost a thousand miles westward in space. This was probably the first scientific description of "jet lag!" What factor in the environment could possibly penetrate the laboratory and provide such precise positional information?

Many years before, at the close of the nineteenth century, it had been noted that the earth's normal magnetic field fluctuated with a lunar tidal pattern. This had led Arrhenius to postulate that somehow the cyclic pattern of living things was linked to this environmental parameter (11). Since then other studies have shown how complex and pervasive these rhythms are in the earth's geophysical environment. In particular, Konig had shown in 1959 that the magnitude of the 10 Hz frequency band in the ELF spectrum followed a precise diurnal variation (12 ) .

In his search for an organism and a biocycle pattern that could be studied in conjunction with magnetic fields, Brown turned to a seemingly unlikely animal, the mud snail Nassarius, a common global resident of the intertidal zone (13). He found that when these animals were placed under uniform illumination in an enclosure with an exit facing magnetic south, they would tum westward early in the morning, eastward at noon, and then back to the west in the early evening as they came out of the exit. Also, at new and full moons the snails would veer more to the west, and at the moon's quarters they turned more to the east. When fully analyzed, the data indicated that the animals possessed both a lunar day and a solar day "clock". By measurement, the earth's magnetic field at the test site averaged 0.17 gauss. Placing a bar magnet of 1.5 gauss beneath the exit oriented in a north-south direction to augment the natural field resulted in increasing the average angle of the turn but did not alter the basic rhythmicity. Turning the entire apparatus so that the exit pointed in a different direction resulted in the animals turning in different degrees. The same result could be obtained by leaving the apparatus stationary and rotating the bar magnet beneath the exit. According to Brown, "It seemed as if the snails possessed two directional antennae for detecting the magnetic field direction, and that these were turning, one with a solar day rhythm and the other with a lunar day one."

In addition to demonstrating that the biocyclic phenomenon was tied to variations in the earth's magnetic field, the experiment also indicated the subtlety of the interaction. It became evident that one could not expect to detect the same kind of dramatic, overt response to changes in the magnetic field as were associated with changes in the other environmental factors such as oxygen concentration or temperature. Within the next few years Brown and his associates established a similar sensitivity to electrostatic fields with responses in the same species of snail to fields of fractional microvolts per centimeter (14). During the same period of time the all-pervasive nature of the biological cycle phenomena became known. Living things as diverse as potatoes, mice, fruit flies and humans were found to demonstrate the same cyclic fluctuations, linked to the same variations in the earth's normal electromagnetic field. The same rhythms were demonstrated in the oxygen consumption of the potato and in the count of circulating Iymphocytes in the human blood stream. Clearly, we are dealing with as basic and all-encompassing a phenomenon as livings things exhibit.

Working at the Max Planck Institute over the past 15 years, Professor Rutger Wever has extended the research on biological cycles to the human, using a unique experimental facility. To produce an environment as free of external cues as possible, Wever constructed an underground experimental station consisting of two rooms. One room was completely isolated from normal variations such as light, noise, and temperature, but was not shielded from any electromagnetic fields. The other room was identical except that it was, in addition, completely shielded from both DC and AC electromagnetic fields. Extensive experimentation has been carried out with several hundred human subjects under various conditions with monitoring of such variables as: body temperature, sleep-activity cycles, and urinary excretion of sodium, potassium and calcium. Human subjects placed in both rooms soon demonstrated a "free running" rhythm. Those in the room not shielded from the electromagnetic environment had an essentially normal circadian rate, while those in the shielded room demonstrated a significantly longer cycle time (15). In the nonshielded room some subjects would, after the passage of 7 to 10 days, show an apparent desynchronization in some of the measured variables. In this situation one or more of the measured variables would maintain the normal circadian rate while others would show a gradual shift in cycle time away from this norm. However, these would eventually stabilize at some frequency which was directly related to the circadian rate (e.g. to two-to-one relationship). Subjects in the totally shielded room on the other hand, would demonstrate real desynchronization with several variables shifting away from the primary rate (which was not a normal circadian cycle to begin with) and stabilizing finally at a rate that had no harmonic relationship to the primary rate (16). All of these phenomena were statistically significant in a large series of subjects.

In an even more dramatic experiment Wever was able to introduce fully controlled electrical or magnetic fields into the completely shielded room (17). In this fashion he was able to study the effects of various parameters of these forces on the biological cycles. The fields introduced were imperceptible to the subjects and in fact the exact nature of the experiment was frequently not divulged to the subject. Static electrical fields of 300 v/m and static magnetic fields of 1.5 Oe. produced no measurable effect upon the cycle abnormalities exhibited by the experimental subjects. However, Wever found that the introduction of a 10-Hz electrical field (a square wave with a peak to peak field strength of 2.5 v/m) induced a return to normal cycle parameters. The abnormal lengthening in the "free running" period was promptly reduced; intersubject variability in the cycle patterns was also reduced as was the incidence of internal desynchronization. Wever interpreted these findings as indicating that the Io-Hz cyclic variations in the earth's normal electromagnetic field are probably the primary determinants of biological cycles. It is most interesting to consider this evidence in light of Cole and Graf's hypothesis regarding the 10-Hz component and the origin of life and the prominence of the 10-Hz component in the EEG common to all higher animals.

Chapter 3 Index