It is clear that it was known more than a hundred years ago that the fusion of the spermatozoa and the oocyte begins the life of a new individual human being. In embryology, the terms understood are integral. In the common sense there is human, being, persona, individual, human being, life and human life. It is unfortunate that every one of these terms have been corrupted, by scientists and the lay audience alike, to mean something that it does not.
This is made evident in the corruption of the term individual into individuation. There are other problems, that is, when the early embryo split, does the ‘soul’ also split? And, if until that time, how could there be, then, a person. By soul, in the scientific context, one refers to the ‘animated essence.’ This is not an issue for theology alone, but theologians always muddle the waters of this very issue when it comes to abortion.
Some would certainly say, however, that this is a question for theology. I disagree for the simple expedient that the science has been there for over a hundred years. As a point of fact, it should be clear that when human life does begin there is no relationship to religion. The pro-life opponents to abortion are arguing about the undifferentiated tissue of a fertilized ovum without a developed brain or conscience; a cluster of cells, to be precise. Many embryologists agree that fertilization is the beginning of a new human life. I disagree on two points. First, not all fertilized eggs make it to term and never develop a neocortex or frontal lobe by the end of the first trimester. Second, the word human itself is associated with identity and feeling, something that a fetus does not develop in the womb.
It is certain that scientists will continue to manipulate biological organisms and the various elements that constitute an organism. There have been and are proposals for gene selectionism, gene deletion, and gene insertion. The first gene therapy took place in 1990 on a four year old with an inherited disorder. Jesse Gelsinger underwent a gene therapy in 1999 at the university of Pennsylvania and died.
A chimera is an organism composed of chromosomes from two different organisms. There are human animal chimera already in the form of the SCID mouse. The mouse is born without an immune system. It is called SCID because of Severe Combined Immunodeficiency. One of the SCID mice received a transplant from a human fetus. Without an immune system, the transplant is not rejected, as it would be if the animal had an immune system.
Transplants from animals to humans seem to be on the horizon. They have been proposed and are discussed amongst geneticists, as have been human to human chimeras. Do these situations call for ethical assessment? The science is clearly manipulating life. The geneticist Arthur Caplan has said: these forms, will they be human life or a genetically programmed embryo, a flawed human being or a improperly formed non-embryo? Caplan is on the side of caution when it comes to issues of manipulating chromosomes and embryos. But it is unreasonable to think that this science is without value.
Are transplants from animal to human likely? They certainly have been proposed and discussed in scientific circles, as have been human – human chimeras. These situations will call for bioethical assessment; the science being involved is clear that what we normally agree to be life is being manipulated. This has caused the bioethicist, Arthur Caplan, to state: will these forms be a human life or “a genetically misprogrammed embryo, a flawed human being or simply a non – properly formed non – embryo”.
In Mary Shelley’s ghost novel, Frankenstein said: “I had worked hard for nearly two years for the sole purpose of infusing life into an inanimate body.” But when he witnessed the first signs of life in his creation: “the beauty of the dream vanished, and breathless horror and disgust filled my heart.”
In 1979 Clifford Grobstein, a frog embryologist, invented the term “preembryo” in his publication in Scientific American entitled: “External Human Fertilization” [7]. He boldly admitted that this term was conceived in order to reduce “the status” of the early human embryo. At this time the Secretary of Health, Education and Welfare, Joseph Califano, Jr., had publicly called for an evaluation of the early human embryo because of the proliferation of in-vitro fertilization clinics and laboratories and he was worried about the moral status of what was essentially experimentation on the early human being.
Grobstein accomodated; he presented the term preembryo as a pre-person. The justification to Grobstein was the fact that these terms were predicted in artificial human embryology. It was in the same article that [Grobstein] invented another term: ‘individuation.’ He also declared that, because of the early embryo could divide into (perhaps more) ‘indivudals.’ This related to identical twins (monozygotic twins.) For fourteen days prior, before this, post fertilization, individuation had not occurred. The reasoning is this: the ‘individual’ was not present, ergo, the human being, as Grobstein claimed, in terms of scientific differentiation, was not a human being or, as he put it, a “person” was not present.
This type of reasoning has formed the belief by many that no human life is present prior to mitosis, prior to fourteen days. The term ‘human’ at the core is vague and undefined and, its humanity, or lack thereof, has been, for many centuries, left open to interpretation. When does life begin in embryology? I will return to this in a later chapter.
Grobstein’s contributions are still being applied today, published wide and by many; the pundits and the scientists too have favored this view. First of all, those who devalue the early embryo based on Grobstein’s reasoning seldom comments on what takes place in the developing embryo. Monozygotic twinning is unlikely and rare, this means that, by Grobstein’s logic, we are individuated during embryology. When [he] applies this concept to all human embryos, he is in error.
Pre-embryo and individuation has been unequivocally been refuted, no exception to embryologists, and discredited further by Nomenclature and the Association of Anatomists, who have excluded the concepts in respect to the official lexicon of anatomical terminology (Terminologia embryologica.) These terms have not been used in any book on human embryology.
Professor Lee Silver, the president of molecular biology at Princeton penned a paper, published by the Washington Post, in which he declased that a human embryo is not a human life, that it was ambiguous in terminology, the words ’embryo’ and ‘life’ have several meanings.
A professor of neuroscience at Dartmouth College, and member of the President’s Council on Bioethics, Michael Gazzaniga authored an article in 2002 entitled: ‘Zygotes and People Aren’t Quite the Same.’ He believed that cloning was a question of ethics, best fit for moralists and theologians. The early embryo is a cluster of cells, no more, and has no conceptualization of space, time, self, or pain. I don’t think that the direction of scientific study should fall under the domain of layman theologians who, for the most part, shun new discoveries that aren’t tailored to their scripture. One need only to read of Galileo to see the dogmatic triumphing over inconvenient truths. And, since then, science has been allowed its baby steps into the acceptance of an increasingly large number of apologists. A human embryo is not a living thing in the sense that we classify living things. It is a clump of cells, about the size of the dot in an i. Should the value of human life be reduced according to size?
There is an obstinately ignorant streak in those biologists whose tautology is a perverted and an uninspired one, as they relate to irrelevant size. The argument against the secular scientist, in classifying the embryo as not [yet] human life, goes like this: The value of human life is according to size! Does this mean that small people are less significant or less human?
This is an ignorant line of questioning from the outset. A human being, having been born, is not restricted in humanity based on size, and the embryo of a human being is only referred to in size during the earliest days of conception. When a mass of cells coalesce from the spermatozoa fertilizing the ovum, there is still much time yet for it to become life at all, much less human life. A sapling, from a flower, may have a full trunk and be in good condition; would it be a dead plant if it had no leaves? Is the seed alive? Certainly not. It can become life (by being watered and being exposed to sunlight) but a seed, on its own, does not constitute a form of life no more than the early human embryo.
Human pregnancy begins when the sperm fuses with the egg. This is, to some extent, a plausible acknowledgement of life. This is true for well understood biological reasons. The concern of embryology, a particular branch of science. Bruce Carlson, in a 1994 textbook may have led to the erroneous conclusion that pregnancy, whether it be in the fallopian tube, uterus, ectopically, or in a petri dish. This is a fundamental error and often a Christian one.
Human pregnancy does not always follow that the embryo, once fertilized, will ever predictably lead to a full term pregnancy. Fertilized eggs, along with other unused eggs, are flushed out during menstruation. With this line of thinking, human pregnancy does not begin with the sperm fertilizes the egg: it begins to divide by mitosis.
Because there are substances which prevent the sperm from penetrating and fertilizing the ovum, the classic definition of conception, they are not strictly contraceptives. This prevents the fertilized egg from implanting itself in the uterus. The inference, since it comes after conception, has been, by some, considered a form of abortion. It has been suggested, What they do is prevent the newly fertilized egg from implanting itself in the uterus. Since the interference occurs after conception, some embryologists choose implantation instead of fertilization as a constituent of developing mind.



Of all of nature, with its myriad of animals, it is the mammalian brain that has proven most adaptive. It adapts during the postnatal period, and continues to adapt, learning from new experiences. In the 60’s, a series of studies demonstrated that rats, when placed in different, more complex environments, grew thicker brains and new synapses. This study showed that the once popular belief that learning and memory are additive processes involved in the formation of new synaptic connections and the strengthening of existing connections.
It has also been suggested that there is more than just additive synapses in learning. J. Z. Young, in 1964, posited that learning could be the result of eliminated neuronal connections. Years later, J. S. Albus suggested that pattern storage was accomplished by weakening synaptic weights rather than strengthening them. Richard Dawkins, the famous evolutionary biologist, speculated that the death of neurons could underlie the storage of memory.
This brings us to an intriguing, but surprising, question. How can the elimination of neurons be involved in learning and memory? One would surely think the contrary: new knowledge being stored in ever increasing cabinets of information, categorized by the sensory impression the idea or memory primarily influenced. Memories are often associative: as we saw with Little Albert, fear was created by association with a startling noise. It is difficult to imagine that the learning of a new skill, roller skating, or speaking a foreign language, the formation of new memory, such as learning the words to a song, could be made possible by the loss of synapses.
But how could a subtractive process of neuron elimination be involved in learning and memory? It is particularly difficult to understand how the learning of a new skill, such as riding a bicycle or speaking a foreign language, or acquisition of new memories, such as learning the words to a poem or song, could be made possible by loss of synapses.
We have seen that, in the development and maturation of the brain, connections are rarely used and are weakened, or eliminated, whereas those in active neural pathways are retained and strengthened. Subtractive processes make sense when one deals with an overwired, immature brain, a brain that may have twice the amount of synapses than an adult. How can this subtractive process work for a mature adult–the adult brain–that has already undergone synaptic pruning?
It is, more than likely, a process involving the addition of new synapses, in the case of learning language, or at least the reorganization of current ones, which would be necessary for the learning to take place. In dealing with this subject, there is another problem we must reconcile; (humans are quite fond of ‘how’ and ‘why’ questions) Can we understand how the brain knows which new synapse to add or modify?
There has to be some sort of synaptic change when someone attempts to learn a foreign language and many adults learn English and other languages, and this kind of learning must be the result of changes in the synaptic connections of the brain. Which synapses, or combination of synapses, will do the trick? It would appear that the brain would sort out, or try a number of new combinations and select the best. To select the best, that is, the most fit, implies a source of variation. Perhaps it works in the same manner as the initial variation of synaptic connections present in an immature brain.
A possible solution, one to which I’ve already alluded to, was proposed by Jean-Pierre Changeux in 1983 in his book, ‘L’homme Neuronal’ (Neuronal Man.) In it, Changeux suggested a type of natural selection, a ‘Darwinism’ of the synapses to account for the developing mind and what it undergoes within its cultural environment. In this manner, culture makes a progressive impression. There are 10,000, give or take, synapses per cortical neuron which are not established immediately. They propagate in different waves during periods of development: from birth to puberty. In each stage there is ‘transient’ redundancy.
He was suggesting that changes in the adaptive brain, or those occurring between birth and puberty in humans, involve the elimination of preexisting pathways, although these preexisting synapses were not necessarily all present at the same time. He hypothesized that, from birth to puberty, waves of synaptic growth would occur, in essence eliminating a useless and redundant synapse. Waves of synaptic overproduction provided variation on which ‘synaptic selection’ could operate. This learning has resulted in an absolute increase in synaptic growth and numbers over time. The growth isn’t constant, but was envisioned as analogous, repeatedly taking two steps forward, two steps back, randomly adding new synapses.
Changeux had little evidence for this hypothesis, the hypothesis that synaptic variation in the form of overproduction would ensure the elimination of synapses as part of the brain’s restructuring to permit the learning of new skills and acquisition of knowledge. Such evidence was found a few years after the publication of his book.
William Greenough and his associates, whose work on the development of the maturing rat brain, noted earlier, also conducted research on changes within the brain induced by placing adult specimens in special, enriched environments. In one study this resulted in a 20% increase in the number of synapses per neuron in the upper layers of the visual cortex. Further research demonstrated such dramatic increases were not limited to the rat’s visual cortex.
These discoveries, amid others, led Greenough’s group to suggest that waves of synapse proliferation, first demonstrated by Changeux, could be elicited by the complex demands on the adult brain in new, challenging environments. This process is referred to as ‘experience dependent’ development. It depends on the environment, and more especially, triggering the formation of new synaptic growth on which the selection pressure can act.
Greenough’s conception of the adult brain’s ability to learn and form new memories offer an appealing solution to problems concerning the additive and subtractive process. The additive component results in the blooming of new synapses in response to the animal’s attempt to control new and complex environment. The brain appears to know what part of itself is involved in synapse-construction. It need not, indeed it could not, know which connections to make.
Forming a large variety of new connections, the brain can select the combinations that work best, in the same way that the immature, developing brain retains useful connections from the initial oversaturation of unfit synapses. The long-term result is overall addition to the number of synapses. The selection process fine-tunes the connections are ‘selected’ and retained, while less useful ones are eliminated.
Clear evidence exists for synaptic increase in learning, however, there is no such evidence in mature learning for an overproduction of synapses, those to be pruned away. However, research has found evidence for an overproduction of dendrites in mature rats, when healing from a brain injury, suggests synaptic overproduction may be involved. These findings correlate nicely with subtractive synapse finding on brain maturation and provide a solution for how the brain could know exactly which new synaptic connections to establish to enable it to acquire new knowledge, skills, and memories.
There are few neuroscientists who have opted for the selectionist approach to their research and theorizing. Changeux and Greenough, and their associates are not the only ones whose research suggests that the adult brain develops, learns, and does this through a cumulative process of neural variation and selection. This theory has been embraced and given support by several neuroscientists. William Calvin refers to the brain as a ‘Darwin machine’ that follows the general constituents of natural selection on a neuronal level: ‘The brain makes lots of random variants by brute force, bashing about and then select the good ones.’
Gerald Edelman, awarded the Nobel prize in 1972 for his research on the chemical structure of antibodies in the immune system. His remarkable output, having written several books describing the aspects of his, ‘Neuronal group selection theory’ of brain development and learning, a selectionist process he refers to as ‘Neural Darwinism.’ Noted psychologist and neuroscientist Michael Gazzaniga, who is best known for his ground-breaking research on humans with split brains, recently embraced a selectionist account of brain functioning and development.
Current research is under way to determine whether unambiguous physical evidence can be found for the overproduction and elimination of newly formed synapses in the adult brain in response to environmental changes. Such a finding would place the brain alongside the immune system as another striking example of how cumulative variation and selection processes during the lifetime of an organism make it possible to adapt to complex, changing environments.
We have seen that understanding the adapted complexity of the human brain involves three questions: how did the brain become a biological organ? How does it developed from a fertilized egg into a mature brain? And how is it able, when mature, to rewrite itself to form and adapt to environmental changes?
A lot of work must first be done before we have the detail answers to these questions. Substantial progress, however, has already been made; we are living in an age where scientists are spending more and more work on the brain and much more time on defining its methodology of function. To a large extent, progress has consisted of rejecting providential and instructionist explanations for these puzzles to fit, and finding evidence in favor for selectionist explanations. The process of cumulative blind variation and selection working over millions of years is not only the only reasonable theory for the biological evolution of the brain, yet we find it has surfaced again and again in different but recognizable forms as a working theory for the brain’s embryonic growth and continued development during its–relativity brief–lifetime.
It is here that the ‘Darwinism of the synapses’ replaces the ‘Darwinism of genes.’ To close the circle, it should be noted, that a consequence of joint effects among-organism genetics and within-organism synaptic selection is the brain’s understanding of itself and the selection pressures responsible for its extraordinary abilities.


We have seen that normal development of the brain depends on interaction between genetic inheritance and environmental experience. The genome provides a general structure of the nervous system. Nervous system activity and sensory stimulation refine the mode of operation. This ‘fine-tuning’ doesn’t mean the addition of new components or connections. It is achieved by eliminating
We thus see that the normal development of the brain depends on a critical interaction between genetic inheritance and environmental experience. The genome provides the general structure of the central nervous system, and nervous system activity and sensory stimulation provide the means by which the system is fine-tuned and made operational. But this fine-tuning does not depend on adding new components. It is achieved by discarding much of what was originally present. It is as if the radio arrived on the assembly line with twice as many electrical components and connections as necessary to work.
The process by which the brain connections change over time has been the result of mature animals interacting with their environments. Using sophisticated techniques for determining the numbers and densities of neurons and synapses in specific regions of the rat’s brain, a group of scientists found that, during the first months of the rat’s life, a rapid spurt in the growth of synapses occur, regardless of the amount, or type, of sensory experience.
This is called ‘synaptic blooming’ and it is always followed by a sharp decline in synapses. That is to say, there is an element of pruning, a pruning of synapses that takes place based on the activity and stimulation (sensory) in the brain. It ultimately results in the configuration of characteristic connections of the adult rat’s brain.
This period of synaptic “blooming” is followed by a sharp decline in the number of synapses. That is, an elimination or “pruning” of synapses then takes place based on the activity and sensory stimulation of the brain, and ultimately results in the configuration of connections characteristic of the mature rat’s brain. This initial blooming and ‘pruning’ of synapses are experience-expectant learning; the initial synaptic overproduction appears to be independent of the animal’s experiences. It is as though the mind expects important things to happen during the first week and first few months of life and, prepared for these experiences, possess an overabundance of synapses, to which a fraction of the initial set are selected. It is as though the brain is expecting important things to be happening during the first weeks and months of life, and is prepared for these experiences with an overabundance of synapses, only a fraction of which, however, will be selectively retained.
In synaptic density, and the expansion of cortical volume, leave no doubt that the postnatal period is one of rapid development in the frontal cortex (human, that is.) By the age of two, synaptic density is at its height; and, at the same time, when other components of the cerebral cortex, also cease growing as brain weight approaches that of the adult. Synaptic density declines subsequently, reaching, by adolescence, an adult value of 60%.
This over-abundance of synapses is thought to be responsible for the striking plasticity of the immature brain that leads to the learning of skills that can be, in childhood, learned with relative ease, and, in adulthood, is more difficult. We have seen how immature animals and children are unable to develop normal vision if they’re not exposed to a vivid, visual world during the period of brain development. It has, in fact, been repeatedly observed that, although many adults can rapidly learn a language, young children have an advantage in the sounds of language.
At age twelve, children begin to lose the ability to differentiate contrasting sounds they are unaccustomed to. Whereas normal infants can distinguish between two related but distinct sounds represented by the letter T in Hindi, those who hear, through their childhood, only English, lose this ability although Hindi speaking children retain it. Recent work has provided important human behavioral evidence consistent with the view that normal brain development involves the loss of synaptic connections, which, inevitably, result in the loss of certain skills as the brain approaches maturity.
These findings paint a picture of a developing brain that contrasts sharply from ‘genetic providentialism.’ Instead of the brain unfolding according to a specified blueprint, we see, instead, a process of selection by which abundant neuronal connections are eliminated, leaving only the connections that permit the animal to interact with its environment. Taken together, these findings paint a picture of the developing brain that contrasts sharply from the genetic providentialism favored by Sperry. Instead of the brain unfolding according to a genetically specified blueprint, we see instead a process of selection by which overly abundant neuronal connections are eliminated through a weeding-out process, leaving only those connections that permit the animal to interact successfully with its environment.


It is not directly possible to know the exact circumstances, or selection pressures, that favored the development of the human brain. Consideration of its structural evolution, and comparative research, on human and nonhumans (other members of the primate order) have provided insights into the early ‘drafts’ of the modern mind. It is believed that, during the evolution of our mind, the nervous system changed in a number of manners, four to be precise. The arrangement of organs first became centralized in architecture, being the next step of evolution from a loose connection of nerve cells, as in jellyfish, to a spinal column and complex brain with impressive swellings at the hindbrain and forebrain. Centralized architecture led to hierarchy amongst structure and it appears that newer ‘drafts’ of the brain overtook the earlier additions and in effect became the Operator, the master of the domain of evaluating sensations.
Initiation of voluntary behavior, alongside the ability to foresee, plan, and engage in complex thought, along with the usage of language, depends on the neocortical structures. The human neocortex can actually destroy itself, and, this form of death is rare amongst the species of the Earth, as human beings, in the throes of a depression, can subdue the natural Will to Life and end their own existence, a rebellion against their genes.
This absurdism was put eloquently in the philosophy of Albert Camus, especially in The Myth of Sisyphus. And the existentialist view point, though it has its merit, must not always give rise to feelings of powerlessness amid the populated world of sight and sound; it doesn’t have to result in Sartre’s Nausea or Dostoyevsky’s Underground Man. Living in a universe without true purpose is not to say that life is without meaning. It is to say that there can be meaning, you just have to work it out for yourself.
There has for the last few thousand years been a trend towards encephalization; a concentration of sense organs and neurons at one end of the organism. Concentrated neural and sensory input in one location, transmission time from sense organs to the brain was minimized. Third, the size and variety of elements within the brain have increased. There has also been an increase in what is known as plasticity; the brains ability to modify itself as a result of experience. By self modification the brain is storing memories of what has been learned of new perceptual constructs and abilities.
One way to understand the evolution of the human brain is to see it as the elevated ability of control. Function of the animal and human behavior can be understood as the control of perceptions, with perceptions corresponding to aspects of the environment in which the organism was selected for and ostensibly adapted to. The very base drives of the animal is to find food, mate, and sleep. The human being must have had other challenges throughout evolutionary history: avoiding enemies, enduring drought, fighting other tribal chiefs for mating, and, as a result, the mind became more complex due to the increasing number of competing organisms. A considerable advantage, one has to agree, is to be able to perceive and control complex aspects of the environment. Bacterium, such as E. coli, can control its sensing of food and toxins in a primitive manner. However, organisms with more complex brains are able to sense and control much more complex aspects of their environment.
Nowhere in the biological world is environmental control more striking than in our species. We use advanced perceptual and behavioral capacities together with a culturally evolved knowledge of science, and of technology, and it is with this technology that we have expanded our view of space and the inner-workings of the Earth. It is interesting to note, on human character, it is not necessary that these things be done out of pride; it is the microcosm of the human being in that party climbing Everest, and each member in that party can be compared, metaphorically, to those who scale the highest peaks of human understanding.
It is this daring, this consummation of wonder and ability, that marks the human race. It is the impossible odds, it is the challenge, and that innate desire to overcome has, most certainly, played a role in our evolutionary history.
It is all beyond doubt that the role of language has had an evolutionary impact on the function of the human mind. Instead of thinking in abstracts, whose wording would be nonsense, the role of language allowed for the formation of thought, comparison, image association, mathematics, and foresight.
It is an intriguing question to put forth: can the most elaborate and complex of human abilities, art and music and science, and morality–could that be a product of natural selection? Our brain has certainly not changed appreciably over the last couple of hundred years, and yet we can solve mathematical, scientific, technological, and artistic problems that did not even exist a hundred years ago. So how could natural selection be responsible for the striking abilities of today’s scientists, engineers, and artists?
This problem also troubled the independent co-discoverer of natural selection, Mr. Wallace and, it should be remembered, that Wallace, despite being a discover of natural selection, didn’t believe it could be powerful enough to select among certain abilities, namely the ability of African’s to sing and perform European music, since nothing in their environment could have selected such an ability. This, to me, brings about the universal nature of mankind. Disparate parts of the world may engender different races and castes of people, when it comes down to ability, those, save for the mentally impaired, are as capable as the next when it comes to learning and remembering. We now know that in his embrace of this providential explanation, Wallace failed to realize that natural selection can lead to new abilities unrelated to those that were originally selected.
A classic example of this phenomenon of functional shift in biological evolution is the transformation of stubby appendages for thermoregulation in insects and birds into wings for flight. In the same way, selection pressure was undoubtedly exerted on early hominids to become better hunters. The ability to understand the behavior of other animals and organize hunting expeditions must have been very important in the evolution of our species.
And the increasingly complex and adapted brain thus selected would have made other skills possible, such as making tools and using language, traits that in turn could become targets for continued natural selection. This transformation of biological structures and behaviors from one use to another was given the unfortunate name of preadaptation by Darwin, unfortunate since it can too easily be misunderstood to imply that somehow evolution “knows” what structures will be useful for future descendants of the current organisms.
From this perspective, it would be easy to conclude that our brain and all of its complexity are an inherited legacy, a direct transmission of genes that affect the growth of the brain in utero. Once evolved, it, thereafter, is coded by specified inherited parameters in the fine print detail of the genome, immortal cells, as it were, marching through the generations, from body to body until it runs into a dead-end, extinction being the result. During its life, however, any one species can branch off into different evolutionary directions. Such as the common ancestry we share with chimpanzees; the common ancestor, which we share, has gone extinct.
Richard Dawkins, in The Ancestor’s Tale, puts this date around 5 to 6 million years ago. The progeny of this ancestor, though an evolutionary dead end, diverged. One of its descendents was h. sapiens and p. trogrolytes, the chimpanzee. So, in a sense, the replicator, that was once the product of our common ancestor, has lived on through the coded information in the genome of human beings and chimpanzees. Looking at evolution this way, there aren’t as many ‘total’ dead ends. An evolutionary dead-end does not necessarily mean that the information of an ancestor is lost, it simply need to mean that the inheritance is being passed through different species of common descent.
Despite all we’ve learned about the brain so far, the question will not go away. I don’t know if mankind is inclined, by nature, to an infinite regress of why, and this infinite regress is part of the process by which we differentiate ourselves from other animals, but in this, this infinite regress, behind every fact there exists a why, when behind every fact there should instead be how. So, how was the brain assembled? Is it just a miasma of tangled wires from synapse to neuron, from signal to function? Is that what thinking is–bioelectric charges along the neocortex? How does a neuron know which muscle fiber to connect with? How are sensory neurons able to join with the correct cell in the visual cortex in the occipital lobe? If this detailed mass of staggering complexity, this neuron-to-neuron connection system, is not in our genes. Where does it come from?
The first clue to solving this puzzle go back to 1906 when it was first observed, in embryonic nerve tissue, that some neurons didn’t ‘stain’ well and, not only did they degenerate, the neurons died. It had long been assumed that, in a developing embryo, nerve cells should be increasing, not dying off, and this discovery was a bit surprising. In the developing nervous system, nerve cell death has been, since then, thoroughly observed.
Despite his name, which I’m sure the English speaking world would chuckle upon hearing it, Viktor Hamburger found that a certain area of the spinal cord of a chicken embryo, over 20,000 neurons were present. However, the adult chicken, much to his bewilderment, had little over half, or 60% of the remaining cells, as neuronal death occurs in the earliest days of the embryo’s existence. Nerve cells continue to die off later in development, but at a slower pace.
The death of obviously useless brain cells cannot account for the specific connections that are achieved by the remaining neurons. For example, the visual cortex of cats and monkeys has what are called ocular dominance columns within a specific region known as cortical layer 4. In any one column of this brain area in the adult animal we find only axons that are connected to the right eye, while in the neighboring column are located only axons with signals originating from the left eye. So not only must the axons find their way to a specific region of the brain, which can be quite far from where their cell bodies are located, they must also find a specific address within a certain neighborhood.
Axons, and their ability to connect to appropriate regions of the brain during development, has been carefully studied since the beginning of the 21st century. Axons grow in the brain like a stem of a plant. At the end of the growing axon is a growth cone. It has been described as, ‘a sort of club or battering ram, possessing an exquisite chemical sensitivity, rapid amoeboid movements, and a driving force which permits it to push aside, or cross, obstacles in its way–until it reaches its destination.
The exact mechanisms by which this occurs are still speculative, it does appear that the growth cone is sensitive to certain chemicals along its path, to be released by its target region. Visual systems, in function, involve axons which originate in the lateral geniculate nucleus and find their way to ‘cortical layer 4’ in the occipital lobe. The way in which they find their way could be represented by a sleuthhound is able to sniff our an escaped prisoner hiding out in some Americana cornfield.
Although growth cones lead axons to the proper region of the brain, or the muscle in the case of motor neurons, they don’t lead them to the target address. For a particular growth cone, it appears that any type of cell can serve as a target. This has been demonstrated on other animals. In a newborn kitten, ocular columns receive axons from both eyes, not just from each other as it is in the adult brain. This ‘tuning’ is achieves many of the original, though terminal connection of the eliminated axon. This is what affords stereoscopic vision. In vision, axonal connections from the ‘wrong eye’ are eliminated. The axonal connections from the ‘correct eye’ are retained.
When it comes to motor systems, which initially have many connections between motor neurons (the spinal column) and muscle fibers (motor neuron axons connected to muscle fibers). Many muscle fibers are connected to the axon. The mature animal has a more acute ocular receptive capacity as the system is more ‘ordered’ as each muscle fiber is enervated by only one motor neuron.
In mammals, the nervous system changes during embryology and from birth to maturity. From a redundant and disordered system to a more accurate apparatus. This makes complex behavior possible, along with stereoscopic vision. The question still bulks large. How does the nervous system differentiate between the necessary connections to retain and which to eliminate? So now the question naturally arises, how does the nervous system know which connections to retain and which to eliminate? Research conducted amongst newborn kittens. For one week an eyelid was closed. The experiment showed that a week without sight altered the connection of the eyes to layer 4 of the occipital cortex.
This showed that axons carrying nervous signal from the closed eye made fewer connections with the cortex. Axons from the open eye made many more connections than was normal, to compensate, as it were. This showed that axons in the visual system compete for space in the visual cortex.
This suggested that visual system axons compete for space in the visual cortex, and this depends on the amount and type of sensory information carried by the axons. Subsequent research, using drugs to block the firing of visual system neurons, as well as artificial stimulation of these neurons, showed that it is not only neural activity that results in the selective elimination of synapses. Only certain types of neural activity result in the retention of certain synapses. Others lose receptibility and ‘short out’ — that is to say, they are eliminated and no longer send responses to the visual motor cortex.
Cells that fire together wire together. Timing of the action-potential activity is critical as it determines which synaptic connections are strengthened and those, the less fit (a nod to natural selection) are abandoned and are gradually discarded. Vision itself correlates the activity of retinal ganglion cells. This is because the cells receive input from the same parts of the visual world.
Dependence on the development of the visual system, via sensory simulation, indicates that ‘fine-tuning’ of connections take place once the animal has been delivered from its warm and comfortable womb into the cold sterility of artificial light. Recent evidence, however, suggests that this process of visual development is done in utero. Prenatal development depends on firings of retinal cells that don’t require the stimulation of light. Endogenous activity, it is thought, may also exist in the spinal cord and may, turn, refine synaptic connections between motor systems.


In mammals, there are three major components of the mind with two new structures, or subroutines. Neocerebellum, added to the cerebellum, looks like a growth at the base of the brain. The neocortex, therefore, is a product of the forebrain. Most mammals, though they have a neocortex, the additions are not large as relative to the brain stem. In the primate order, of which we are a part, they are larger; in humans, the neocortex is so large that the brain stem is hidden by a complicated mass of gray, neural matter. This remarkable increase of neocerebellar activity and neocortical tissue, gives humans the highest ratio of brain to body of all of nature’s children.

The mind, that noble faculty, that lavishes our exaltation is an organ made of different subset systems for differing mental processes. It contains millions of neurons and nerve cells, which transmit signals within the brain and to the body. Neurons connect through cellular junctions, the synapses, which allow neurons to transmit chemical signals across the active mind. When a cell receives a chemical signal, it changes. This leads to the bioelectrical signal through the cell. The mechanism of action relies on elemental activity sending bioelectric signals.
Sodium is a key element within a nerve cell. Dissolved sodium ions can be found in water and around nerve cells and pass in and out of the cell through proteins at the cell surface–the protein ion-channels. Before the initiation of action potential, the area surrounding the nerve cell contains a higher concentration of sodium than the cell itself. When chemical signals are interpreted by a nerve, sodium channels in the receiving nerve began to open as sodium enters the nerve cell. Sodium signals are the beginning of the active potential and starts with bioelectric signals within the cell. This mechanism is called depolarization.
The second part of the active / action potential is carried out by potassium. At the beginning of the action motive, potassium becomes high in concentration relative to the nerve cell and then allows it to return to its natural state. Depolarization and repolarization involves the occurrence of sodium and potassium at several times along the length of a receptive neuron, when the signal reaches the cell body and triggers a nerve response.
The third part of this abstract is the role of calcium in bioelectrical signals, signals which play a role in releasing chemicals into nerve synapses. This allows for chemical signals to be translated to the actuated potentiality. Calcium, like sodium, is another type of ion. It controls the release of chemical signals into the synapse; this activates the action potentiality; this allows calcium ions to enter the cell and, in doing so, causes chemicals, the neurotransmitters, to be released into a synapse wherein they behind to the receptive neuron and invoke bioelectric potentiality. Calcium is an ion, and controls the release of signals into the synapse to initiate active potentiality. Calcium ion channels transmit chemical signal on the surface of an open neuron. This allows calcium to enter the cell.
This addition of calcium causes neurotransmitters to be released into the synapse where they bind to the receptive neuron and initiate a bioelectric active potentiality. In addition, calcium plays a significant role in signaling long chains of nerve cells. When a cell begins as an active potential, the release of calcium produces chemical signals to neighboring cells. This leads transmission of bioelectric signals from one cell to another and, eventually, links to millions of cells to allow for the brain’s bioelectrical current.
In defining chemical elements of the mind, one would be remiss to dismiss dopamine, so I will describe the mechanism and its action among pathways. There are three primary corridors for transmission. The first is the mesolimbic pathway. This is how dopamine is translated from the ventral legmental area to the nucleus accumbens in the limbic system. This is, in essence, the reason for some, but not all, emotions, responses to joy, and fondness of pleasurable memories. It is this chemical Sigmund Freud referred to as the ‘Pleasure Principle.’ Therefore, through the passageway, it becomes more active in extroverts than introverts and cautious people. It is in the pathways of the limbic system where our memory takes shape; it achieves this by the integration of strong emotion (favorable) and memories of physical sensations, the mental simulation of a prior event. The simulation of coming events.
The mesocortical pathway transmits dopamine from the ventral legmental area to the frontal cortext. Dysfunctions of dopamine receptors in the prefrontal lobe can lead to schizophrenia. The third method, associated with the nigrostrital pathway, transmits dopamine from the substantia nigra to the stratum. This pathway is associated with motor control, right and left handedness, and builds the mind’s image of its carrier body. There are many people, since this is quite common, have, after losing a limb, the feeling of the limb still being there, the ‘phantom limb.’ It’s not that they imagine that it’s there and it’s not, it’s part of the architectural map the mind makes based on feedback from the nerve endings along the body that gives the ghostly feeling.
The final pathway is called the tuberoinfundibular pathway and it transmits dopamine from the hypothalamus to the pituitary gland and influences the secretion of certain hormones, hormones such as prolactin. The amount of this chemical directly influences mood, the growth of hair, and even weight. These four operating mechanisms of dopamine transmissions are closely intertwined with the subsystems of motivation and cognitive functions. The mesolimbic pathway is directly related to dopamine receptor transmission.
Body cells are different from neurons in the way that makes them suited for a specified role, the role of signal processing and communication. It is not too difficult to see how the mind could have evolved. There are a number of less specialized cells throughout the length of the body and in the nervous system, all specialized to carry out bioelectric function. All cells are surrounded by a membrane. This separates it from chemical composition of its interior and exterior. Chemical composition differentiation results in electrical potentiality and this causes depolarizations along the cell membrane. In most cells this depolarization doesn’t spread, but changes in the shape and arrangement of cells allows depolarization to propagate from one neuron to another, allowing quick and efficient electrochemical signals from one end of an animal to the other.
The nervous system in other animals, such as jellyfish, forms undifferentiated networks and coordinates the animals physical motion. The ‘skirt’ of a jellyfish opens and contracts in a coordinated manner. This allows the animal to move through the water. The nervous system in the Medusa jellyfish is relatively simple, a communication network which makes it possible for parts of the ‘skirt’ to open and contract.
The most simple organism with a specialized nervous system is the humble worm. It includes in its composition of distinction between the brain and the groups of nervous codons running along the length of the worm’s body. This kind of nervous system affords more complex behavior. Anterior brains connected to the nerve cord is the basic design for all organisms, from jellyfish to man, with central nervous systems. Although we can differentiate between a separate brain in these worms, it is not the case that its brain is the Operator–a concept we will come to in a later chapter. The Operator is not the Field Marshal presiding over actions of the central nervous system and body of the worm. With its brain removed, the worm is still capable of common biological functions; locomotion, burrowing, area mapping, burrowing, and mating. The same could be said of Creationists.
Ethologists, those who study animal behavior, have discovered an increased complexity in aspects of the brain and nervous system in respect to more ‘primitive’ assemblies. Giant fiber systems (found to some extent in the worms and jellyfish) allow conduction of nervous impulses which connect parts of the mind to specific appendages and muscles. These connections, or to be more precise, the genes, has influenced the evolution of the cockroaches and its understanding, by sensing movement in the air, are able to quickly escape the slowly hovering foot above them. To a roach, our movement is much slower than we perceive it. For example, if one were to look at the clouds, it seems they are barely moving. That’s based on a ‘relative’ perspective. The roach, in viewing us, sees us as barely moving–hence their ability to so ably escape our lumbering feet.
The insect mind is divided into specialized segments–again a topic we will come to later–three segments: the protocerebrum, the deutocerebrum, and the tritocerbrum. Among other organisms, insects display a wider variety of sensory receptors, more so than any other group of organisms, including vertebrates, which are sensitive to sound, odor, patterns, pressure, temperature, patterns of light, and the chemical composition of their surroundings.
These sensory organs allow for rapid communication within the tiny, capable brain located within.
Small by primate standards, abilities made possible by the insect brains are impressive. The insects are capable of a wide variety of complex behavior and movement. Locomotion, mating, aiding the survival of their progeny; they crawl, swim, fly, hop, burrow and even walk on water. Take for example the strategy of a female wasp when hunting for a host body. First it paralyzes the caterpillar with its venom and lays its eggs inside of the catatonic caterpillar. This is done so the offspring, ass thy grow, they will have plenty of food after hatching. The larvae eats all the muscles and fatty tissue, but saves the heart and lungs for last, when the wasp reaches maturity, it abandons the dead caterpillar. This relationship, in nature, is called symbiosis. It is another topic we will return to.
A species known as the Leafcutter ant harvest leaves. The leaves are brought into the nest and are used to cultivate gardens of fungus. The interesting thing about the Leafcutter ants is its metabolism; the food that it does it, is indigestible and the ants lack the enzyme in their stomach to process it. The way they get around this is by harvesting the mushrooms that grow on their dung. These ants aren’t the only species to have learned and exploited this trait.
Honeybees are social animals. There are different castes of society, workers, food gatherers, and soldier ants whose purpose is to protect the queen. When a spot of abundant food is found, the bees perform a kind of dance that signals to the other ants a location wherein there is a richness of food. This is the evolution of their brains, with complementary evolution of other body parts (phyla), and this has made insects the most numerous multicellular organism on planet Earth.
The brain is much larger and complex in vertebrates such as reptiles and amphibians. The spinal cord is protected within the vertebrae of the backbone. This has become a servant to the brain, a type of two-way highway of communication with different electrical connections separated in descending motor pathways and ascending sensory input differentiation. The brain, in vertebrates, is composed of a swelling of the anterior end of the spinal cord, the brain stem, the three major ones make up the three major parts of the vertebrae brain: the hindbrain, midbrain, and forebrain. The cerebellum is a distinct structure attached to the hindbrain.
Once a nerve cell has become differentiated it does not divide anymore. A single nucleus, with the same DNA, must serve an entire lifetime for the formation and maintenance of tens of thousands of synapses. It seems difficult to imagine a differential distribution of genetic material from a single nucleus to each of these tens of thousands of synapses unless we conjure up a mysterious “demon” who selectively channels this material to each synapse according to a pre-established code! The differential expression of genes cannot alone explain the extreme diversity and specificity of connections between neurons.
Additional understanding of the relation between the genome and the nervous system can be gained by considering Daphnia magna. Commonly referred to as the water flea or daphnid, this small fresh-water crustacean is familiar to many aquarium owners since it is relished by tropical fish. But what makes the daphnid interesting for our current purposes is that when the female is isolated from males, she can most conveniently reproduce by the asexual process of parthenogenesis, giving birth to genetically identical clones. In addition, the daphnid has a relatively simple nervous system that facilitates its study.
If its genome completely controlled the development of its nervous system, it should be the case that genetically identical daphnids should have structurally identical nervous systems. However, examination of daphnid eyes using the electron microscope reveals that although genetically identical clones all have the same number of neurons, considerable variation exists in the exact number of synapses and in the configurations of connections leading to and away from the cell body of each neuron, that is, the dendritic and axonal branches. As we move to more complex organisms, the variability of their nervous systems increases. This provides clear evidence that the structure and wiring of the nervous system are not the result of following a detailed construction program provided by the genes.
A particularly striking example of neuronal elimination in development involves the death of an entire group of brain cells: Most frequently, neuron death affects only some of the neurons in a given category. However, in one case a whole category of cells died. These particular neurons of layer I, the most superficial layer of the cerebral cortex, characteristically have axons and dendrites oriented parallel to the cortical surface rather than perpendicular to it, like the pyramidal cells. These cells were first observed in the human fetus but have since been found in other mammals. Purely and simply, they disappear in the adult.


How complex is the mind? Will we ever find a complete and working model to describe and explain our emotions and physical sensations? We have deciphered the human genome; sent a man to the moon, and invented the drive-through pharmacy. Yet the mind is still a source with many unexplored frontiers. How do we know what we know? What can we learn about thought and its formation? Can we understand what is called thinking?
Among the amazing discoveries we have made as a species, things we have began to understand, such as the theories of relativity, the uncertainty principle, natural selection, the creations of planets and stars–all of these discoveries have had an enormous impact on our view of the natural world. Now, we are beginning to understand the mechanics of thought and concept of identity, intrinsic properties and structure, and other mechanisms of the brain.
We have mapped the parts of the mind responsible for happiness, anger, and even the lobe (the occipital parietal) that affords our cognizance of time and space. This was discovered by studying people undergoing ‘religious experiences.’ In each case, a Buddhist monk, while in deep contemplation, was seen to have a dramatic decrease in activity in the occipital parietal. Those familiar with Buddhism could tell you, when one meditates, the concept of space and time, and to some degree, identity, washes away. By the simple expedient of mapping patterns of the brain of people in meditation, we were shown the areas of the brain that contain the concept of self, of space, and time.
This is something we should be genuinely proud of. However, it must be acknowledged, that, the most intricate and complex object we have yet to encounter is the brain, an organ weighing three to four pounds and found everywhere in nature. It is with this mechanism that we form our picture of the world.
Martin Heideggar, a German philosopher, in his treatise, What is Called Thinking?, concluded, in one of his lectures: ‘…Still, any such remarks will take us step by step, sentence by sentence, into a difficult landscape which is remote, however, from the almost airless spaces of dead concepts and luxuriant abstractions. This landscape is in a land on whose grounds all movements of our modern age take place. The fact that we do not see or rather do not wish to see these grounds, much less this land, is no proof that they aren’t there.’
There are vast landscapes of the mind, full of odd and ridiculous concepts, luxuriant abstractions. And it is this difficulty of which Heideggar speaks that keeps us at arm’s length when we come to the brain. It may be a difficult landscape to travel through, but at the end of it is understanding. We should embrace what we as of yet can’t understand on the grounds that someday we will. We shouldn’t be so eager to toss away an unknown under any circumstances, religious or scientific. We should see Heideggar’s difficult landscape of airless space and view, in their physical manifestations, these delightful forms of dead concepts and the movements of our modern age.
I will give reference to the different segments of the brain in passing, and later develop the more complex concepts of their interaction. The brainstem, at the top of the spinal column, controls your heartbeat, your breathing, swallowing, and mostly involuntary, rash reactions. Beside it is the cerebellum and under its protection we are afforded coordination. Sitting on top of the cerebellum is the temporal lobe: the temporal lobe is responsible for intellectual and emotional abstractions. This is the part of the mind that is active when you hear your inner voice.
Above it is the frontal lobe, and, this is one I think that, by now in our evolutionary development we could do without, as it responds to smells. Broca’s area is one of the most fascinating areas of the brain. It’s primary function is speech; but that’s not all that happens there. Speech that is processed by Broca’s area, remains there. In a sense, it ‘echoes’ within it. This is memory, space, and time. Above this is something that is often lacking in graduate students: the frontal lobe: with it there is foresight, voluntary movement, and analytical judgment.
Above is the motor cortex (movement) and in between the motor cortex and the cerebrum is the sensory cortex (pain, heat, cold; physical sensations.) There is the parietal lobe, which is to be labeled that of a comprehending mechanism, though it’s comprehension is specialized as we’ve already discussed. There remains Wernicke’s area, and it is responsible for speech comprehension.
This is what I believed Heideggar was alluding to. There’s a lot going on inside this four pound mass between our ears. There are concepts we weren’t programmed to understand. This landscape is highly populated. Within the brain there are billions of nerve cells, called neurons, and these neurons are receptive of electrochemical signals, signals which the neurons relay to other parts of the brain, it is these signals that our thoughts, feelings, and concept of the physical self depend.
These neurons signal to various parts of the body chemical signals which provoke stimulus based response. The amount of neurons which can be found within the brain isn’t as interesting is how they are organized; how neurons communicate depends on structure.
There are different types of neurons but most of them share features, (See figure 5.1) The cell body contains the nucleus of the neuron; this nucleus, containing the complete set of genetic information, is surrounded by cytoplasm. The cell also contains organelles; this is essential to the functioning of the neuron and metabolism; in this manner, neurons are similar to different types of cells, the difference between neurons and other cells is that they seldom divide and therefore rarely reproduce.
Neurons are specialized to carry out communicative function. This is made evident by the appendages they sport, their dendrites and axons. Dendrites are, in a manner of speaking, rather like a disorganized antenna receptive of signals from other neurons. Dendrites, when stimulated in a certain way, causes the neuron to which it is attached will change
its electrical polarity and fire a signal along its axon to be picked up by the dendrites of other neurons. The neuron is relatively small, although the length of an axon can be considerable; the firing of a neuron can influence the firing of another despite its distance.
One neurons influence over another is dependent on their connection; these connective junctions are called synapses (figure 5.2) Synaptic junctions connect the axon of a neuron with the dendrites of another, a neuron in the cortex of the brain, having near 10,000 synapses, constitute a complicated system of interconnection within the skull, the complexity of which is far beyond the most advanced supercomputers. The humble earthworm has a computative capacity beyond that of the modern computer.
The organization of connections within the skull, and to distant sense organs and muscles, give the brain its baffling ability. Neuroscientists and psychologists, even philosophers, now believe that of all the knowledge our brain contains–from being able to walk erect, perform complicated mathematics and daydream–is a function, all of the functions in essence, is the result of connections existing between neurons.
This organization allows us to interpret stimuli, behave, feel, think, and use our abilities to interact with our environment. To come to terms with this outstanding complexity, not to retreat to the non-answer of ‘intelligent design,’ we must look to the long history, millions of years, to the primitive nervous systems present in our ancestors which, over time, evolved into a complicated organ that has made it possible for our species to adapt to almost any natural condition–from the snowcapped mountains, to the most arid deserts, savannahs, marshes, even in space–we have become the most successful expression of organism evolution; we can live, thrive, and subdue, physically, mentally, or through our technology, the environments which we live in and explore.    How is it possible for such an unlikely structure of the brain, especially in maturity, to be able to continue to, not only modify the worlds around us, we are now venturing, through medicine and genetic engineering–we are beginning to see a clear horizon of self-modification through technology. What reasons would necessitate the modification of something that has brought us to where we are now, a conscious, sentient, intelligent being, to consider altering the work of our planet’s potter, Natural Selection? Some believe that the structure of our minds can be changed to learn new skills and better process information.


A zygote is a diploid cell that fuses haploid gametes into a fertilized ovum. The question for our purpose is how the fertilized egg develops from a single cell into a living organism.
As castles are made of brick and stone, organisms are constructed by cells. The animal can be unicellular (one cell) or multicellular (many cells.) In addition to the two types of cells, there are two types of organisms. There are the ancient prokaryotes and the (relatively) new eukaryotic organisms. I’d like to take a moment to note the differences between the two fundamental cells of living systems. I’ll start where nature started–with the prokaryotes.
Prokaryotic cells are not as complex as eukaryotic cells. They have no stable nucleus and the DNA is not contained within a membrane or separated from the rest of the cell. It is confined to a region of the cytoplasm called the nucleoid. Using bacteria as an example, I will attempt to describe the anatomy of the prokaryotic cell:
The obvious starting point is the capsule, that, when found in some bacterial cells, acts as an additional layer that protects the cell from other organisms. The capsule also helps the cell bind to surfaces and take in nutrients. The cell wall consists of a covering of cells that protect the bacteria and give it shape. The plasma membrane surrounds the cytoplasm and the cell and allows for substances to pass into and out of the cell. The Pili, a rare word to come across for sure, is a hair-like structure on the surface of the cell. It attaches to other bacterial cells. The short pili (fimbriae) allows bacteria to attach to surfaces and spread.
The flagella, the creationist’s wet dream, has a long protrusion that affords cellular movement. The ribosomes are cells responsible for metabolizing proteins. The plasmids are circular structures of DNA, although they are not involved in reproduction. Finally there is the nucleoid region, where the cytoplasm contains a single DNA (and bacterial) molecule. Prokaryotes also reproduce asexually by means of binary fission.
Binary fission begins with the single DNA molecule replicating both copies attaching to the cell membrane. Then, the cell membrane begins to grow between two DNA molecules. The bacterium, once it has doubled in size, the cell membrane begins to pinch inward. A cell wall forms between the two DNA molecules dividing the original cell into identical daughter cells.
The most notable feature that differentiates these complex cells from prokaryotes is the presence of a nucleus, a double membrane-bound control center separating the genetic ‘material,’ DNA (Deoxyribonucleic Acid), from the rest of the cell. In addition to the plasma membrane, eukaryotic cells contain internal membrane-bound structures called organelles. Organelles, such as mitochondria and chloroplasts, are both believed to have evolved from prokaryotes that began living symbiotically (we’ll discuss symbiosis itself later on) within eukaryotic cells. These organelles are involved in metabolism and energy conversion within the cell. Other cellular organelles within eukaryotic cell structure carry out the many additional functions required for the cell to survive and reproduce. Eukaryotic cells can reproduce in one of two ways: meiosis (sexual reproduction) and mitosis (cell division in producing identical daughter cells as within asexual species.)
Both eukaryotic and prokaryotic cells have a plasma membrane, a membrane that surrounds the cell. However, only eukaryotic cells have an endomembrane system, a collection of intracellular membrane-bound organelles (such as vesicles, lysosomes, endoplasmic reticlum, a golgi apparatus, and mitochondria.
This system of organelles functions to transport material into and out of the cells; everything inside the plasma membrane is floating around in cytoplasm. I feel that it would be proper to treat the eukaryotic cell, and define its functions, as thoroughly as possible. All of the animals and human beings are eukaryotes. Men, kittens, and dandelion puffs.
Eukaryotic cells are so called because they house a nucleus. This nucleus houses genes (DNA) and is contained within a membrane. This separates it from other cellular structures. As I’ve mentioned, prokaryotes have no true nucleus. In the prokaryotic cell, the DNA is not separated from the rest of the cell; it is bound within the nucleoid.
Eukaryotes grow and reproduce in a quite different manner than the prokaryotes; they reproduce through a process called mitosis. Reproducing sexually causes cell division. This process is called meiosis. Despite their differences, both types get their energy to grow, and maintain, normal cellular function by means of cellular restoration.
Cellular respiration has three distinct stages: glycolysis, citric acid cyde, and electron transport. Most cellular respiration takes place with mitochondria, another organelle. In prokaryotes this happens in the cytoplasm within the cell membrane. This brings us to the organism.
Biological organisms can be explained in four ways: morphological structure, function, chemistry, and biochemistry. Chemistry, in living systems, shows us what they’re made of. The scientists of our time know a lot about this type of chemistry—it is a chemical constituent on which living systems depend. There are, as well, chemical species: when an organism takes in nutrients, the organism is taking, from the smallest of cells, thousands of chemical species.
Biochemistry defines a set of chemical reactions in living systems. This allows organisms to synthesize a large number of chemicals. Structure is the phylogeny of the organism, what we see with our eyes, with x-rays—the shape of the organism. Function of a living system is a description of that organism’s capabilities. The ability to respond to the environment is a function.
Today we know that life evolved on our planet between 3.5 billion to 4 billion years ago. The operative element on which life is based, carbon, perhaps, under specific conditions, could variate between forms. Darwinian selection was only possible once there was true heredity and inheritability. Selection amongst the earliest replicators led to the various species that inhabited our planet, today and in the past.
The evolution of an organism begins at the chromosome. There are slots along the chromosomes, call loci. Genes compete with alternate forms of genes, their alleles, for slots along the genetic locus. This gives rise to different phenotypic traits. The competition for genes for spots along the chromosome allow for mutation. These mutations are the essence of natural selection. As species don’t add to their genetic information during their lifetime, it is present within the gene pool and inherited upon birth. Changes in the conditions of the environment allow for animals of the same species to be ‘selected’ for survival. By selected I intend to mean that those with the genetic predisposition to survive the environmental change are born with the genetic basis for that survival and thus out propagate their contemporaries.
As we shall later see, our ancestors, far from ignorant, recognized the unity of all life–even of the non-living and the living–but did not, until much later, understand the manifold complexities of evolution under natural selection. The last generalization, having emerged in modern biology, I would like to give some mention, is all aspects of living phenomena, without exception, have a physiochemical basis. All properties of life can be understood by explicable laws of physics and chemistry. The earliest biologists didn’t recognize this, as Einstein didn’t prove the existence of the atom until 1906, a thought to which the ancient philosopher Democritus had given serious thought. Along with Boltzmann, in passing, the possibility of one constituent making up existing physical constructs of the universe.
We know, now, that living and non-living worlds are a part of a material continuum of physics, chemistry, and biology. The living world is still subject to the laws of physics and these same rules hold true in the non-living world. To the ancient philosophers, the relationship between the inanimate and the animate was ambivalent. One mode of thought, ‘Dust thou art to dust return,’ and it would seem, that such a remark, implies that living objects are related to non-living objects. Then there is the ‘pervasive element’ which was an early constituent of the metaphysical soul, and it was this that made living things different from inanimate matter. This is a concept incompatible with modern biology.
It would be unfair to blame our ancestors for their ambivalence. To understand living systems, we needed, first of all, the type of chemistry developed after the Renaissance. It did not, however, touch our science until this century. It would be pardonable to doubt if anyone could have done better during the ancient and early medieval period than in ancient India. It is disappointing for the biologist to see the uncritical reception of absurdities. Respecting the past ideals is admirable as they give perspective to our development as a species, but, to do them service, we must honor the spirit of their inquiry; we should not, by any means, discard contradictory, modern, testable knowledge for the ancient systems of religious tautology.
Despite occasional relapses into religious dogma, many of our ancestors were extremely accurate and perceptive people. It is this acuity of observation that provided the foundation for ancient Indian sciences. Nowhere is this capacity so explicit as, as observed, that relate to the structure of biological systems.
There is detailed knowledge of internal and external organs during the Vedic period. In Atharaveda, there is knowledge of the fallopian tubes, testicles, and semen. They knew more about the skeletal structure than just the bones; they knew about cartilage and ligaments. In the Caraka Samhita, we find that the number of bones in the human body amount to 360; we know, today, the number of bones in the human body are 206. It is more than likely that all of them were identified by Caraka’s time.
Susruta’s description, before the time of Caraka, of the anatomy of the human body, within the limitations of the human eye, is extraordinarily complex and analytical. The difference between vertebrates and invertebrates was, by Susruta’s time, widely known; ‘Some stand with the support of bone, others with muscles.’
Parasara, in the first century BC, added details to the understanding of the internal structure of a leaf. The description refers to ever smaller compartments, sap, and possibly the cell ‘wall.’ In ancient Hindu literature, the Brhadaranyakopanishad, for example, compares the human being with a tree; ‘A man, indeed, is likened unto a tree. His hairs are leaves, his skin the outer bark. His blood flows as does the sap from the wounded tree. Flesh corresponds to the inner-bark, his nerves are tough as inner fibers; bones behind the flesh are as the wood behind the tissue. The marrow of the bone resembles the pith.’
There is an element of realism in this kind of early poetry and makes for fascinating reading for students of ancient biology and the Vedic mythology from which it came. Susura systemized the classification of plants and animals into strict categories; categorical thinking is inherent in human thought, as one experience prepares one for another experience, and the recollection of each experience is put into a sort of recall-able category for when a situation demands it.
This is a human instinct, to categorize, and arrange into categories, as Susura did with the classification of plants and animals. 700 (plus) plants and 300 (or thereabouts) animals were referred to in the ancient Hindu literature (the biological history of which I am most familiar). They were classified in different ways: the basis of medicinal properties, utility, and morphology. Another attempt to classify animals in a systematic way can be found in one of the Upanishads; in the Chandogya, the designation was based on origin and development.
By these means of classification, there was as well a group comprising organisms born out of the moisture of the earth, such as gnats, lice, flies, bugs. It is of interest to think that, despite the size of these creatures, ancient biologists believed them to be menacing and dangerous, a scourge upon the Earth. It would be later on before the theory of ‘spontaneous generation’ was buried, once and for all, by Louis Pasteur, before we understood parasites and symbiosis, though not directly or immediately.
Taking this under consideration, our ancestor’s didn’t stray too far away from the mark in their attempts to understand and classify the living world. An elaborate classification of plants was made by Parasara; it was largely based on morphology and floral characteristics. Plants were classified into families and some of them mirror the families of today. Take for example: Leguminosea, the Crustacea, Cruciferae, Kapucynacea, Cucurbitacea, and Compositae. It is a tragedy that such classifications were not improved upon. The relationship, at that point in time, between various classes and orders was not analyzed. Had that been done, perhaps a more elegant and systematic classification could have emerged centuries ahead of Linnaeus.
It is a testament to the importance of dealing within many parameters at a time when classification is not a universally acknowledged subset of biological division, such as the groups, the phyla, the clade; and thus they never chanced upon the formation of variation, the cousinship between man and other animals, but they did well and, for their time, they were influential enough to bring more and more people into the biological sciences. We have these early teachers to thank for the likes of Charles Darwin and Gregor Mendel.
Combined, these two men, one a Victorian naturalist and the other a monk, transformed the way in which people looked at the animal world. It is through these glasses that I hope the reader will see. Knowledge of the universe is not beyond us; it may be ahead of us, but not impossible. Reverting to an adamant refutation of tested scientific truths does little for the instructor, other than annoy them, but does great damage to the person who, in adamant refusal, cannot see how grandiose and splendid nature truly is. I repeat this in a type of frustration. It’s like asking a blind child what his favorite color is.
We must not forever sweep that which we as of yet don’t understand under a comfortable carpet labeled, ‘God.’ This is not an answer; it is an admission of not knowing the answer. The answer, how it is formed and computed and synthesized, is the subject of the next chapter.


The way most human beings form their thoughts are based on sensory input: the eyes, the ears, the nose, taste and touch; these senses report information to the mind. In this chapter, despite brief digressions, I will describe the eye–the evolving window–and the way it allows us to form our image of the world. I will attempt to detail, among other things, the various ways that animals, with different faculties, have adapted to their environments.
I’ll start with something that is widely known, though I feel I should include it: there is a particular species of dolphin with eyes atop their head. They live in turbid water and ‘see’ by echolocation. This is a unique sensory input, denied to most humans, but flourishes in bats, the platypus, and other monotremes.
Echolocation has been known to develop in human beings to compensate for blindness. I am reminded of watching a video of a blind young man riding a bicycle, playing basketball, and being able to describe the way he mapped out objects. He emitted tiny clicks as he walked and, when they reverberated, appeared as a three dimensional green image inside his head. It lacked subtle definition, but he could play ball and, amazingly, could play video games, of which he was very fond.
Likewise, bats see by projecting high pitch sound waves that vibrate in such a manner that works like sonar imaging, as used on submarines. There is another, special case, the star nose mole. It ‘sees’ with it’s nose, mapping three dimensional structures by measuring the closeness and distance of faint and robust smells.
To human acuity, we rely most deeply upon our eyes. When we lose our sight, the other sensory organs become refined. It is not always enough to be favored in your genetic makeup; human beings are most adept at meeting most of nature’s challenges. Since no genetic information is changed mid-life, adaptation throughout life is a type of natural selection, but a conscious one.
There is a lot of evolutionary baggage, however, that we, as a species, carry around. Our prefrontal lobe is too small; our adrenal glands too big; and our awe is usually misled by ‘faery fancy’ as Richard Dawkins called it in his extremely provocative book Unweaving the Rainbow.
Science represents the way in which we strive to understand a world of amazing complexity and beauty. A Christian ethologist, would, perhaps, have a greater sense of humility toward nature and our natural heritage. This field of research leads, inexorably, to the abandonment of the insipid idiom ‘intelligent design.’ But to listen to the televangelists, one sees the sales pitch of the used car dealer, lip service to a dead doctrine fleecing money from the gullible and dying.
Science doesn’t sell it’s information. It is available and observable and for the entire world. It is not a religion to say one is humbly awed at the mechanisms of life.
It is through this process that theories live and die. How could one look at Moses’s burning bush and then look at the Helix Nebula and be more impressed by the shrubs? The Hubble Deep Field, a portrait of thousands, and thousands of galaxy is so staggeringly beautiful, it is hard to see the aversion to these discoveries and their understanding.
As for Dr. Dawkins, to whom this book is dedicated, he changed the way I looked at the natural world–reading The Extended Phenotype was somewhat of a revelation. It changed the way I viewed the behavior of different organisms and, in the by lines, the behavior of human beings, especially those repulsed by their natural heritage. I hope to settle this issue presently.
Galileo was imprisoned for the heresy (fact) of a Heliocentric Solar System; he was so imprisoned because, not for the information he was spreading, but for the egos he was wounding. It was not in accordance with a tribal book cobbled together by nomads who wandered through the deserts of Judea two thousand years ago. Galileo’s eyes were wrong.
It was a wound to pride; to think oneself to be the reason for all creation, at the center of the universe, and made in the image of God–all of these are real conceits. When the theory of evolution (I say theory out of habit; it is scientific orthodoxy and, at this point, indisputable) came about, the ego was again affronted.
To deny the great white males their place on the pulpit, to suggest we evolved from more brutish, less intelligent ancestors, couldn’t be true. It was an affront to the ego of man and that is at the core of the issue. To a man, having descended from Australopithecus, (the famous Lucy comes to mind) a creature on the cusp ‘tween man and ape, down through the generations having given spark to daughter fires: a. forensis, Africanus, the Cro-Magnon, and the Neanderthal. There are no gaps. It was a gradual gradation.
To me, the religious wonder is misplaced: to see that we are all children of the Earth, connected and having grown and diverged one amongst another; I think this is a grand and beautiful account of life, much more so than a ‘let there be light’ tautology.
The true story of light and how it behaves will play a prominent part of the later segments of this book. To continue the apologist mode of ‘this meant that’ is, in this day and age, untenable. It can’t be both. Religiosos (from the Latin batshit crazy) pick and choose what they will allow to science, to allow what science says. If carbon dating confirmed that Jesus lived, I guarantee you they would have no issue with the ‘inability to date fossils.’ It is an offense to that which made us human to begin with.
To question, to seek answers, to ask why, to find meaning, that is human nature. Having meaning and answers given to you, from someone who says they are infallible, is missing out on a richer, broader perspective of the natural world–it is the self denial of humanity.
And the pious themselves, though having benefited greatly from the minds of scientists, denounce that which affronts their delusions of importance. To trace the variety of life since the constitution of the eukaryotic cell takes you through millions of years: through the Cambrian (where many of the first phyla and fossils and eyes are found) into the Permian (and it’s great extinction) through the Carboniferous to the Cretaceous (another mass extinction) and find that, through it all, the will, the very drive of life, the force that still permeates us, the same eyes we share with long dead animals, our noses and our mouths, our diets, we are living the same way.
We are all children of the Earth, no species no more special than the other, and to equate intelligence with superiority is a crude method of approximating self worth. Competence is not inherited. Not by race, not by species, not by man. Evolution shapes and molds the natural world in a way that allows for organisms to be tuned. It is not the way around; nature found the statue under the block of marble in shaping us.
Throughout evolutionary history, along with our barbaric tendencies (one need only think of the genocide, slavery, infanticide, and wholesale slaughters of women and children in the old testament to see this–and this is where apologists say we should derive our morals) we have evolved a finer nature: a nature less accusatory and suspicious, less covetous and more serene, more appreciative of the world, and deeply interested in what science allows us to understand.
Like the other animals, we care for our children. We teach them how to learn and feed them. For my money, teaching a child how to learn on their own would be a most gracious favor, as there could be no bias. We follow the herds for food, we depend on the fruits of the trees. The world is truly our mother; having made us does she plant the fruits that we may live and bring more of our kind. We are another step in a very long slideshow of life and, having made it to where we are, I think constitutes more of a miracle than any parting of the seas.
This is a grand view of life, a sprawling tree with many fruits, and there is, to me, more wonder and awe before the laws of nature than for the obscurantist morality tales of primitive people. The common argument against evolution is not an argument against evolution. We did not evolve from monkeys. Evidence shows we are much further along than the old world monkeys (and the new world monkeys) but, if you were to go backwards in evolutionary time, you would encounter our common ancestor with our closest animal relative: the chimpanzee. One volume alone, compared to the massive genome, divides us from these animals.
I sometimes find myself thinking of a particular parrot; it was mentioned by Douglas Adams a few days before his heart attack (We miss you Douglas; you showed us how to laugh and love) and it was a story of a particular type of parrot living in isolation. He goes into convergent evolution briefly (something we will come to later) and tells a charming story of one of his favorite animals.
The animal was a flightless bird, a peekapoo, with really small wings, but it had still not evolved the understanding that it long ago abandoned flight because there were no natural predators. It was easy to eat more and more and fly less and less and they, over many generations, became flightless.
What I found most endearing about his story, and its poignancy in human evolution, is the strange way the animal mimicked long dead evolutionary change. Despite not being able to fly, these birds, so determined, often climbed up trees and jumped off. They fly exactly like bricks don’t, said Douglas.
There are evolutionary stable strategies that once were efficient and, because of some ecological change or displacement, rendered them inefficient. They will gradually be tuned by nature, blindly they will be selected. This same argument can be made of man.
We ascribe petty feelings to the Gods; jealousy, a demand to be worshiped; a demand for us to constantly beg; the vanity of such a being is detestable. I don’t see how, seeing the myriad of problems in the world (famine, disease, genocide, murder, the suffering of innocent children, etc) this being, if it were actually there, one should not through pomp ceremony celebrate his love; they should collude against him before he wipes out life again.
The crime of religion is the uncanny fortification they instill in their children. They teach them to believe a book of uncertain origin over the tests and proofs of a million or more scientists of our modern times and instead rely on a book whose authorship can not be attributed whose construction is cobbled together and contradictory and, of course, there’s no need for proof of that.
Somebody you never heard of is telling you how you should live your life (which most of the Bible does not) and, the opponents of evolution who demand its proof, demand no proof of their own creed. They don’t need proof that it’s a book of uncertain authorship. The most brilliant minds of our generation have explained things once in the realm of religion. And those who didn’t agree, whose opinions were different on some of the subtleties of thought, they weren’t burned at the stake; imprisoned; or tortured. The debates were settled with reason, logic, and experimental truth. As Douglas Adams famously said, isn’t a garden beautiful enough without having to believe there are fairies at the bottom of it?
I think this religious baggage is the same bird trying to fly after having lost its wings. The Jesuit taunt: ‘Give me the boy and I’ll give you the man,’ should righteously be called child abuse. The joy of wondering, of discovery, to understand what once we only guessed at, an entire generation of kids are going to grow up thinking themselves to be superior to people who eat pork or don’t wear funny hats on Saturdays. to another of their holy book and see secular humanists as arrogant materialists.
I use the term to describe a pejorative levied at me when writing for our journal in my senior year at high school. The paper was a call for people to stop worrying about what created the world, if there was an afterlife, and just be kind to human beings, and make the most of the only life we’re sure we’ll ever have. In the American South–this is tantamount to blasphemy. Being an atheist has, throughout my life, meant the end of relationships and friendships. I was once forced to leave a man’s house for writing with my left hand. I don’t know what the cosmic bogeyman has against lefties, or pigs, but there has to be a point when logic kicks in and you go, ‘Why do we believe these things said to have happened thousands of years ago, when we surely wouldn’t believe them if they were reported today?’
Why do modern people still, in the face of insuperable odds, still favor their delusions over what they can see with their own eyes? We see stars dying and coming together every day. Does this mean that God didn’t create all the stars in one day or decided to get up after the 7th day and make more stars? I think this has survived from the days where people believed that, if they didn’t dance for the rain or sacrifice a human being on an altar, the Gods would be unappeased and the sun wouldn’t come up.
These tendencies are still with our species. They just have more elegant forms. One would imagine a Mayan, perhaps an Einstein of their people, daring to wonder if the sun would return anyway, that it obeyed fundamental laws, and it didn’t require the still beating heart of a slaughtered man to do its job.
Today it is an amalgamation of superstition and statistics. I’m sure that many naturalists, myself included, have a lucky shirt, or a lucky tie. My brother has a special type of superstition when it comes to college football. If he wakes up and his team is winning, he goes back to sleep. If he wakes up and they’re losing, he watches the game. If his team wins the game, it reinforces the statistical likelihood matched to superstitions of this kind.
I’d like to introduce an animal parallel. In experiments done at Kings College, a particular type of flightless pigeon was placed into a box. Every time it pressed against a button, a small portion of food would come out. So after days of having lived under this condition the bird is certain that to press the button will bring food. However, the experiment has changed to deliver, at random, the food once brought by the button.
The way this pigeon coped with this has particular significance to psychiatrists studying ritualistic behavior. The pigeons developed certain eccentricities once they realized that the fruit was being dispensed at random. Some of them even developed rituals, rituals based on what they were doing the last time they were fed. Some would tuck their head under their wing and wobble their head back and forth, presumably it had worked, at one point, to bring them food. This type of experiment has shown that animals adapt superstitions in cases where there is no other explanation, beyond statistics and probability. This has been seen in man, also.
If knowledge begins in understanding how little you know, where does knowledge go–what is the price of this endowment? Knowledge is a bitten apple, and we so endowed, are, from the start, limited. It has been speculated that there is, ultimately, a limit as to what a person can know. The Uncertainty Principle is one such theory. I’ll give you an example.
We see a limited portion of the color spectrum, for instance, and do not see a flower in the manner that a humble bee is able. They can see into the ultraviolet and this we humans are incapable of doing without technology. Nor are we able to see into the infrared. There are pitches of sound which our ears are incapable of perceiving. Faculties in possession by other animals, as in sound waves, are heard only by whales and elephants.
Flowers rely on bees for pollination and, it has been said, without bees, if bees were to go extinct that is, the human race would join them in extinction four years later. Seeing the world in their peculiar manner, they are guided to the flower’s nectar.
Without bees to pollinate the flowers, the flowers would not be able to derive energy from the sun, and would be incapable of photosynthesis. Photosynthesis is the process where by plants convert sunrays (photons) into breathable oxygen. Look at it this way, if not for bees, we could not survive as a species. This is a testament to the beauty of the interconnected species of this world.
Another fact about the way we perceive the world lies in the finite speed of light. Because light travels at a finite speed, it takes time for it to reach your eye. It might be less than a Planck second, but it is still a moment in the past. How did eyes evolve? Which animal was the first to see the stars? I shall endeavor to answer some of these questions.
A creature, in the early oceans, capable of seeing, was surely more likely to either catch prey or escape from being it. There are periods in evolution called arms races; it is this process by which each animal adapts based upon the higher functioning of the other animal.
The best way to explain this is by illustrating the speed of the cheetah, one of the many delights of the animal world. The cheetah, before its present form, was part of the family Canidae; to begin with, it probably didn’t rush out of the gates at 60 miles per hour. However, by slow gradation, the prey became faster and faster, as only the fastest of the prey were being able to survive to reproductive age. This in turn influenced the evolution of speed in the cheetah. The cheetahs incapable of catching the fastest of the prey died out, allowing for the ever faster cheetahs to out propagate their slower relatives.
The evolution of the eye has been a heavily debated study since the publication of perhaps the most profound scientific work ever published by a human being, On the Origin of Species by Charles Darwin. As Darwin himself wrote, ‘…that the evolution of the eye by natural selection at first glance seemed “absurd in the highest possible degree”. However, he went on to explain that despite the difficulty in imagining it, it was perfectly feasible:
‘…if numerous gradations from a perfect and complex eye to one very imperfect and simple, each grade being useful to its possessor, can be shown to exist; if further, the eye does vary ever so slightly, and the variations be inherited, which is certainly the case; and if any variation or modification in the organ be ever useful to an animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could be formed by natural selection, though insuperable by our imagination, can hardly be considered real.’
Today scientists have come up with explanations through which the first eye-like structure, a light-sensitive pigmented spot on the skin, could have gone through changes and complexities to form the human eye. Complex eyes appear to have first evolved within a few million years, in the rapid burst of evolution known as the Cambrian explosion. There is no evidence of eyes before the Cambrian, but a wide range of diversity is evident in the Middle Cambrian Burgess shale.
If you take a look at different morphology of eyes and photoreceptor cell types observed in various animals, this would give us an impression that animal eyes evolved multiple times independently. Interestingly ,the entire animal kingdom is dependent on function of the pax6 gene (a sort of master control gene) for the development of eyes and not only this, but the genes that interact with the pax6 gene to form the photoreceptor cells are also highly conserved in evolution providing strong evidence supporting one time evolution of animal eyes but modified on many occasion to suit the requirements of the organisms that bear it. Therefore, as it was previously thought that eyes formed independently many different times, we now know that each type of eye is nothing but a variation on a common theme evolved from a common, simple precursor called which could be called “the proto-eye”.
The proto-eye can be reconstructed by the structural and molecular comparison of extant eyes such as the insect compound eye, the vertebrate camera eye, and the simple pigment-cup eyes found in many invertebrate groups. Its common to believe that all animals do have eyes but a significant part of animal species lack eyes completely or have rudimentary looking eyes in the form of spots e.g.,: Sea urchins, Sponges, Ctenophores, flatworms etc. Eye spots in simple animals spots can sense whether it’s night or day or whether a shadow is passing closely, but fail to form any kind of image like the ones of jelly fishes and bilaterians.
The animal group that exhibit true eyes are a ensemble of multicellular organisms including jellyfish ,arthropods, molluscs, annelid worms, onychophora (velvet worms), and chordates. This list is rather strange (if one look at the phylogeny tree) giving us an impression that eyes appeared in scattered lineages and mixed up with groups that lack them. This was one reason of the hypothesis that animal eyes evolved multiple times but this is not true as we have seen earlier.
One of the important aspect of natural selection is that it favors an organism which has slight advantage over others on the planet, which tends to survive and produce offspring for the next generation. According to many scientists from the field, the simple light-sensitive spot on the skin of some ancestral creature gave it some tiny survival advantage, which afforded it the ability to better evade predators and further subsequent changes by natural selection. This led to changes then created a depression in the light-sensitive patch, a deepening pit that made vision a little sharper. Later, the pit’s opening gradually narrowed, so light entered through a small aperture, like a pinhole camera. every little change counts, where the light-sensitive spot evolved into a retina and the magnificence of the human eye today.
For us the eye has been a window to the world. This has psychological ramifications. A child, having a familial bond with his / her mother, can be calmed by the sight of its mother. The child can be appeased when the lights are on, though unsure with the lights off and scared. The child reacts favorably to warmth and companionship. This inheritance, presumably, dates back to the Great Leap Forward (which we shall come to.)
From a psychological view, this childhood behavior can be explained by evolutionary inheritance: it can be understood by the way in which our ancestors lived. Think about the parrot, whose ability to fly has been stilted (though still they try) and the way this could relate to the issues of a developing child.
Today they may be irrational fears, like our dopey parrot, but the fear of the dark, for our ancestors, was a matter of life and death, real fear; a period of anxiety in the east African steppe.
The warmth of the mother could be seen as the calming influence of a group of ancestors round a fire, their happiness with their clan and mother have all been passed to us.
And to see ones mother is to know that, if the mother be a good one, that these necessities will be taken care of. The youngest eyes delight the child, for food, for milk and warmth. The eyes recoil from a darkness left as an evolutionary imprint on our psyche. One must remember the movie Jaws and, it is famously known, that the shark was scarier before one saw it. In this sense, this beautiful organ, homologous and present in many animals, from reptiles to mammals, attenuates our understanding of what first brought humans face to face with a world not yet understood. They had their senses, their eyes, and their brains. However, there is more than one type of life on Earth. That will be the focus of the next chapter.


The Jatakas are a collection of ancient Buddhist stories intended for children. They consists of a number of fables, many of which concern the past lives and incarnation of the Buddha–Siddhartha Gautama. The Jatakas are associated with the Theravada tradition (as opposed to the Mahayanas) and were written in the third century, B. C. There is one story in particular that I would like to share. It is known as the Mahakapi Jataka (The Great Monkey King.)
The historicity of such stories is unimportant. According to tradition–which is important–the Buddha was sitting around a fire with a group of Bhikkus. (Bhikkus are Buddhist aspirants and ascetics.) Upon hearing a tale of kindness and sacrifice of a nobleman, the Buddha entreated them to repeat their story. After hearing the tale again, the Buddha said: “That is not the only time the Tathagata has done well for another’s keep. I would like to share a story with you.”
The attentive Bhikkus fell silent and the Buddha spoke: “Once there was a Great King, a King of the Monkeys of the Himalayas–wise in mind, and noble in character. He was a most respected King, adored by all his subjects and like them in his manner, solemn and humble. He was a much adored leader with thousands of monkeys committed to his charge.
“Along the bank of the Ganges River (where the historical Buddha is said to have wandered) there grew a magnificent mango tree with massive branches. The fruit was ripe and sweet and spread across the bank. The King, keen in awareness and perceptive, knew this could be disastrous, as the King of men, and all his knights behind him, could find the tree and subdue it, as men were known to do.
“He ordered, therefore, his foresters, to pick all the mango flowers and fruit from the tree. However, there was one fruit hidden and fell into the river where a king was bathing. So fond of the taste, he ordered his soldiers to find the giant tree. The king, with guards on either side, sent his soldiers out to find the mango tree. Finding it the King rejoiced and picked as many as he could eat. When night came they went to sleep, warm, with their bellies full.
“With his own troops, the Monkey King arrived at midnight as the men below them slept. They went from branch to branch collecting the mangoes. In the stillness of the night, the King of men awoke, and seeing all the monkeys in the tree above, he ordered his finest archers to kill the monkeys.
“They saw no way to escape and they feared for their lives. They gathered with their children and their families around the Great Monkey King and asked. “What can we do? They’re going to kill us.”
“The King showed no fear in speech or manner and told him not to fear, for he would save their lives. He climbed onto a branch that stretched across the river. He sprung from the base of it, up the trunk, and then across the river Ganges. sprung from the end of it, and then jumped onto the other side of the Ganges.
“He hurriedly judged the distance and thought of how far he had come. Then he found a long vine to fasten to the tree and allow the rest of the monkeys to cross in safety. First he tied the vine to a tree. Then he tied the vine around his waist and leapt across the river. The Great Monkey King had made a mistake. however; he had been too quick in his judgment; he forgot to include the amount of rope to be tied around his waist. He would be unable to reach the trunk of the mango tree. Even though the Monkey King had made a mistake, he refused to give up, and managed to grab a branch. He signaled to the frightened monkeys; he would allow them to step on his back and then run along the vine to safety, to the other side of the Ganges. He wished them all good luck as they passed. Each of his eighty thousand subjects made it to the other side.
“The last of the monkeys to cross was very bitter, desirous to be king, desirous for glory. And seeing the Great Monkey King prostrate between the trunk and the other shore, he jumped on the Monkey King’s back and clawed at his eyes. Then he laughed and made his way to the other side.
“The King of men, seeing this, felt empathy, and a great sense of humility came over him. “This Great King of monkeys, he has sacrificed his life for the safety of his subjects.” Being moved to tears the King of men ordered his soldiers to bring the Monkey King ashore and take care of him. As order, the Monkey King was brought ashore and washed. He was anointed with perfumes and treated with great respect. They covered him in noble robes and gave him sugar water to drink. Bowed before him, the King of men asked, “What were the other monkeys to you? What made their life worth more than your own?”
“The Monkey King replied: “Great king, I guard the herd. I am their lord, I am their chief, and when they are filled with fear, I will be there to assure them. They know I will do anything to spare them pain, and give my life for theirs. I tied the vine around my waste and returned to the tree with half my strength, barely enough to hold the branch for my friends to pass. I could save them, and, because of that, I had no fear of death. To be a great King, and ruler, I had to guarantee the happiness and safety over those I reigned. Sire, you must understand this, if you wish to be a righteous ruler, the happiness of your people must be very dear to you; they must be more dear than your life.”
“Speaking thus, the Great Monkey King closed his eyes and died in peace. He was given a royal burial. The women carried torches. The ministers sent wood. The skull was taken to the King of men after the ceremony was over. A noble shrine was built to do him honor, to honor his noble sacrifice. His skull, inlaid with gold, was raised upon a spear in front of the royal court. It was placed at the gate, at the height of honor, and adorned with lotus flowers. The King of men himself would forever revere the skull and it would remain a treasure relic for the rest of his life.”
His story finished, the Buddha said, “At that time, the great King of men was Ananda, the monkeys were this assembly, and I myself was the Monkey King.”