1. RHYTHMS IN HUMAN NATURE
Presently only the day-length ‘circadian rhythms‘ have been studied for their evolutionary links to environmental time cues. Molecular biologists have found them in clock genes that undergird the sleep/waking cycle, body temperature regulation, blood pressure and many other functions across phyla.
Our very sense of ourselves is linked to the 24-hour day by internal clocks located in the super-chiasmic nucleus of the anterior hypothalamus. Certainly, the alternation between waking and sleep is the most telling existential expression of our rhythmicity. The contrasts between dream and waking life have long been subjects for philosophical inquiry.
However, circadian clocks are far from the only frequency driven processes in human physiology. Biologists have identified ultradian and infradian rhythms, biological oscillations moving faster and slower than a day respectively, working in animal life. The human menstrual cycle is an obvious example of a slower rhythm. Animal heart and breath rates move in the faster ultradian frequency bands. There are ultradian clock genes in the Saccharomysces cerevisiae yeast that orchestrate a 40-minute respiratory process that prepares the yeast for cell division.11 C. elegans, biologists’ favorite worm, has a 45-second defecation cycle controlled by an ultradian clock whose gene has been located. The fastest rhythms set the beat for biological processes on the smallest scale. They pervade our cellular chemistry and in some way must underlie our capacities for consciousness and through it for love and wisdom.
Biologists have calculated the rates and rhythms of many ultradian oscillators. They have studied the effects of perturbation on them. Nevertheless, the evolutionary sources of the ultradian rhythms and their perturbations, and the evolved responses we make to those perturbations, have rarely been sought.12 Researchers have paid very little attention to the larger ecological, behavioral and moral consequences of actually living in a resonant world.
Of the ultradian frequency clusters, I consider the following the most important in our study of human virtues and passions.
o The 90-minute rest/activation cycle, coordinated in the pontine reticular activating system in the brain, identified by Nathan Kleitman in the sixties, a cycle that runs continuously through the day and shapes the sleep stages and enters into REM sleep and dream life and so touches on the resources of human imagination. The same period is found in the somite deposition in vertebrate embryology.13
o The 20-minute cell division cycle conserved from prokaryotes and carried into more complex eukaryotic cell cycles as the M phase in mitosis. Rossi and Lippincott see this as a trigger or a latency period for the basic rest/activation cycle. According to their literature search, “A 20 minute building up period of mediating factors (maturation pro-moting factor and H1 kinase) is required to trigger the 90-120 minute process of genetic replication in the complete 24 hour circadian cell cycle in eukaryotes.”14 Murray, Solomon and Kirschner, quoted in Rossi and Lippincott tie the biology to behavior this way: “The neuroendocrine system is now well recognized as having prominent ultradian and circadian components related to a variety of psychobiological behaviors associated with mental and physical activity, nutrition, metabolism and reproduction. There are experimentally verifiable 20-minute couplings between peaks of associated hormones that are released in approximately 90-120 minute ultradian rhythms: luteinizing hormones peaks lead prolactin and testosterone peaks by 10-20 minutes (Veldhuis et al. 1987. Veldhuis and Johnson, 1988, Veldhuis, this volume); Glucose leads insulin by 15-20 minutes (van Cauter et al, 1989); cortisol leads B-endorphin by 20-30 minutes (Iranmanesh et al, 1989). These associations that extend from the molecular-genetic generation of these hormones at the cellular level to their expression at the neuroendocrinal level and their interaction with the mind-brain processes of memory, learning and behavior described below can hardly be accidental.”
o The interaction of heart and breath, rhythmically driven by the respiratory sinus arrhythmia (RSA) organized in the medulla of the brain. Though it shows a good deal of cycle to cycle variability, heart rate variability is important to our study because it feeds and drives emotional states, paces relaxation, pushes anxiety, and contributes enormously to a moment to moment sense of ourselves. It entrains other body rhythms related to blood flow, blood pressure, fluid shifts, vasomotor and kidney functions. A power spectrum analysis of heart rate variability shows the presence of all of these systems. Jerome Kagan treats these conditioned cardiac cycle patterns as formative factors in a child’s temperament.
o Calcium oscillations conserved across many phyla carry coded signals across cell membranes and bear instructions that start or stop or change the rate of reactions. Spontaneous calcium oscillations have been discovered in the astrocytes of human brain cells. Astrocytes respond to chemical, electrical and mechanical stimuli with transient increases in intracellular calcium concentration ([Ca2+](i)).15 Parri et al write that “astrocytes in situ display intrinsic [Ca2+](i) oscillations that are not driven by neuronal activity. These spontaneous astrocytic oscillations can propagate as waves to neighboring astrocytes and trigger slowly decaying NMDA receptor-mediated inward currents in neurons located along the wave path. These findings show that astrocytes in situ can act as a primary source for generating neuronal activity in the mammalian central nervous system." These rate-determining factors play a role in synaptic neurotransmitter release and reuptake and in the balances between the neurotransmitters themselves, and these balances have distinct emotional and behavioral consequences.
Fast calcium oscillations are found across all kingdoms of life. Jaffe and Creton, 1998, have been collecting and analyzing calcium wave traffic at a variety of frequencies.
Jaffe (1994)16 provides a good review of the possible rates and rhythms divided into four frequency bands. These closely fit the ultradian frequency bands we have been describing.
o Rhythm based motility. Organisms do not stay still. Their gliding, flying, twitching, swimming, walking and galloping gaits function rhythmically. The muscle contractions and relaxations behind them move rhythmically. Motility has been studied in organisms of many phyla. The rhythms of flagellated and ciliated locomotion in single celled organisms have been found in our own human bodies. The villi in our intestines and the cilia in our airways beat in tempos that are conserved across species. The molecular biology of actin-myosin is shared everywhere. So too with the biochemistry of the “movement molecules” actin, dynein, kinesin and others. The 9:2 rotors of flagellae and the coordinated movements of cilia of single-celled protista continue to function in the physiology of multicellular or-ganisms. The 9:2 flagellar motor drives our sperm cells.
o Many 8-12 Hz rhythms appear in human physiology, and may link together such divergent functions as theta brain waves, flagellar movements and the rhythm of muscle tone related to essential tremor. These frequencies recur all through the tree of life. We observe them in embryonic development. Rudolpho LLinas discuss these frequencies in primitive sea animal embryos, and notes “that intrinsic tremor in the musculature itself leads, via electrotonic coupling, to rhythmic, oscillatory movement, thus allowing water to flow through the gills and oxygen exchange with the external world and, so vital to life, throughout the egg sack. This form of motricity is “myogenic,” for it represents movement born purely from the intrinsic properties of the muscle cells.”17
Molecular biologists understand these intrinsic properties to involve the ratcheting movements in the actin and myosin motor molecules found even in primitive single celled organisms.
o Micromotion can sometimes entrain rhythms of the near environment. They are transmitted to the movement of air, to slight temperature changes, electrical potentials, to the wafting of pheromones and other chemotactic communications. These tremulous dance-like movements, small as they are, produce big changes when they are timed right. They move into resonant relationships with other body oscillators and to the rhythms in the near environment, including the micromotion of other persons. There is some evidence that mother/infant bonding works this way. With current digital video motion analysis technology, we will very likely view these rhythmic interactions in all kinds of social exchanges.
In their separate frequency bands, the rhythms of living nature carry on six major biological functions:
1) They carry materials inside single cells along the endoplasmic reticulum, the Golgi complex and by transport through endosomes and exosomes.
2) They move substances rhythmically in larger body systems (digestive peristaltic rhythms follow this pattern of operation).
3) They drive metabolism, producing and transmitting energy in the mitochondria of cells.
4) They communicate information directly in the nervous system and from one organism to another through rhythm driven sensorimotor pathways, as in the mating dances of animals.
5) They provide motility to the organism. The actin-myosin molecular reactions in single muscle fibers move rhythmically. Muscle tone is a frequency driven phenomenon.
6) They serve as carrier waves on which other information is transmitted through complex modulations of the carrier waveform.
Love and wisdom draw on all six functions, and as we shall see they do so in fundamental indispensible, coordinated ways .
In principle, the physiology of information exchange can be analyzed by power spectral analysis of carrier waves. We’re always encountering and deciphering carrier waves in our lived experience. The voice is a carrier wave. The rhythmicity, the pulses and beats generated by vocal cords, the writhing hairs in the cochlea of the ear that receive these compression waves, the rhythms in words, timbres, gestures, touches, the changes in all senses, resonating at cell membranes, require senders and receivers. Some of these communications, sent and received as carrier waves, are modulated by AM and FM and other transforming technology embedded in our physiology. In real life, every verbal and gestural communication has frequency, amplitude and phase characteristics that can be quantified.
Amplitude modulated carrier wave
Radio transmissions depend on carrier waves. The carrier wave, produced in the radio station, contains no information until it is modulated by another information-bearing wave. A piece of equipment called a modulator adds information to the carrier wave, usually voice or music, and turns it into a complex wave train. In AM radio transmission, the carrier wave is modulated by amplitude, as shown above. Its waves get taller or shorter while the frequency remains the same. The changes in amplitude encode information on the carrier wave.
FM radio works by frequency modulation of a carrier tone of constant amplitude. Your radio receiver is a demodulator. It extracts the signal from the carrier wave. You hear the music. Nature uses many other carrier techniques besides amplitude and frequency modulation.
They resonate in living cells in the molecular traffic across plasma membranes. Here biologically useful information is carried on very fast ultradian oscillators as modulations on their waveforms. Brain waves are information carriers. However, to be used as carrier waves, the neurons have to establish resonant relationships by entraining to each other.
In his studies of brain physiology, Rudolpho Llinas considers these rhythmic carriers basic to higher neural functioning.
“Studies indicate that 40hz coherent neuronal activity large enough to be detected from the scalp is generated during cognitive tasks… What does it mean? We are confronted with a system that addresses the external world not as a slumbering machine to be awoken by the entry of sensory information, but rather as a continuously humming brain, This active brain is willing to internalize and incorporate into its intimate activity an image of the external world, but always within the context of its own existence and its own intrinsic electrical activity.”18
The humming brain with its neural synchronies in the 40 Hz gamma range spanning wide areas of the cortex may be implicated in consciousness. The “binding problem” has been under active study by Gyorgy Buszaski, Francis Crick and others. Timothy J. Walter in REM Illumination applies it to memory consolidation. What researchers say of coherence in the brain applies to signal generation across living nature generally. Every organism hums at characteristic frequencies in the bands we have identified at least in some of its physiological sub-systems. Biosystems interact through harmonic and dissonant processes. Some rest on simple number ratios. Glass and Mackay in Clocks and Chaos explain that
“periodic stimulation of spontaneously oscillating physiological rhythms has powerful effects on the intrinsic rhythm. As the frequency and amplitude of the periodic stimulus are varied, a variety of different coupling patterns are set up between the stimulus and the spontaneous oscillator. In some situations the spontaneous oscillator is entrained or phase locked to the forcing stimulus so that for each N cycles of the stimulus there are M cycles of the spontaneous rhythm, and the spontaneous oscillation occurs at a fixed phase (or phases) of the periodic stimulus (N:M phase locking. )”19
The entrained ultradian oscillators commonly do double duty. They carry substances while they transmit the encoded instructions for their use.
Why these rates and not others? Where do they come from? What ties to nature do or did they express? Why are they so widely conserved? And crucial for our exploration: what do they tell us about love and wisdom and the other basic virtues? To make sense of the biological influences on human nature, we will have to speculate on their evolutionary origins.
Lynn Margulies suggests that many of the functions in eukaryotic cells (cells with nuclei and organelles) entered the stream of life when bacterial symbionts invaded or were ingested and were eventually co-opted by their host cells and lost their independence. They became the mitochondria, ribosomes, mictrotubules, and other organelles of primitive single celled life. “The descendants of the bacteria that swam in primeval seas breathing oxygen three billion years ago,” she wrote, “exist now in our bodies as mitochondria. At one time, the ancient bacteria had combined with other microorganisms. They took up residence inside, providing waste disposal and oxygen-derived energy in return for food and shelter.”20
Earlier still, horizontal gene transfers between bacterial microorganisms occurred. Carl Woese has done research on the rapid evolution this caused in the archea. We can guess that clock genes and rate-determining gene sequences were likely to have been among the transferred material. Later, Darwinian evolution carried them from species to species.
Margulies speculated that neuronal functioning itself might have been structured originally around the behaviors of imported bacterial spirochetes. She wrote:
“I continually play with an idea, the origin of thought and consciousness is cellular, owing its beginnings to the first courtship between unlikely bacterial bedfellows who became ancestors to our mind-brains… The microbes are not just metaphors; their remnants inhabit our brain, their needs and habits, histories and health status help determine our behavior.”21
By knowing the lineages of the conserved frequency bands, from horizontal gene transfers to bacterial endosymbiosis, – and by uncovering the primal functions of the ur-rhythms carried by them – we can learn more about ourselves. We can learn how we love and think.
But a crucial question remains: where did the first organisms get their rhythms?
Answer: from the sun, water and atmospheric electricity.