February 13th, 2002

How did humans get so intelligent? Why do we have such a big brain? Well, it didn’t happen overnight. The Earth is believed to have formed four and one-half billion years ago. Over the next one billion years, the Earth’s surface cooled forming the crust. Life stirred quickly on planet Earth. With an abundance of ultraviolet light, methane, ammonia, water, and hydrogen, the Earth’s seas soon had an abundance of amino acids. Life was soon to follow. Today we have found fossils from early living systems that are over 3 billion years old. What advantage emerging humanity had over the animals was not physical. The animals were bigger, stronger, and faster. The human advantage was intelligence. Time-binding is not a new physical form. Time-binding is a new way of “thinking”. And, understanding human intelligence understanding Time-binding will require us to understand the evolution of ourselves and of our human brain. To understand the evolution of our human intelligence­ which is to understand the roots of Time-binding, we need not go back three billion years. as A.T.W. Simenons writing in 1961 explained.

How Humans Got Big Brains

A.T.W. Simenons

 A good starting point is about two hundred million years ago. By then life had emerged from the sea. Some amphibians, having learned how to spend their whole life on the land, had already developed into reptiles. The reptiles were the first backboned animals that were able to breed on dry land. They had developed real lungs out of the simpler sacs with which amphibian’s breathe, their skin had become dry and scaly and their eggs had grown a tough protective shell. At that time the reptiles were already a great biological success. They had increased in size and were branching out into a large number of different species.

The Ruling reptiles produced the biggest animal that has every walked the Earth, Brachiosaurus, which could have looked over the roof of a three storied house and may have weighed fifty tons. There were huge flying dragons that conquered the air for the first time in the history of backboned animals. There were other forms that ran on two legs and had a long neck, somewhat resembling an enormous ostrich. Yet others looked like a rhinoceros, while some developed into ferocious, rampaging, flesh eaters that preyed on sluggishly browsing herbivora all of them often of gigantic size. Some of these early reptiles returned to an aquatic life, for instance, the marine turtles. However, turtles must still come ashore to lay their eggs. This single fact shows that they were originally landliving reptiles and not amphibians, because amphibians lay their eggs in water though much of their life is spent on the land. Thus the variety among these reptiles was as great as that of the present day mammals and their dominance over all other creatures of the Earth was undisputed. Among them lived the ancestors of our tortoises, snakes, lizards, crocodiles and alligators. These few forms have survived, but the whole crown of the repetilian famliy tree, the so called Ruling Reptiles vanished.

The beginning of the evolution of four-legged land living animals lies in the Carboniferous Age. Luxurious forests of gigantic ferns and towering trees, often reaching a height of one hundred feet, were piling up the vegetable matter that was later to become coal and oil. Just as the Ruling Reptiles were about to burst into their Garguntuan evolution, one small and still primitive retilian species broke away from the main stem. This aberrant species took to the trees of the Carboniferous Forest and became the first reptile to adopt an entirely tree-living mode of life. For a long time these animals continued to be reptiles, but life in the trees gradually brought about some remarkable bodily changes which were the rudimenary beginnings of typically mammalian features.

(Recall that the process of synergic evolution is continuously adapting every organism to its environment. Therefore changes in the environment must of course result in adaptive changes in the organism. –TKW) 

These small reptiles, destined to develop into mammals, found themselves faced with enumerable new problems. They  had to learn how to maintain a precarious balance in the branches and for this they needed quick muscular reactions in their limbs. Being defenseless, their survival depended on their ability to scutter away and hide when giant reptiles reared their heads into the trees or marauding winged dragons swooped down upon them from the skies. To detect these sudden dangers they needed good eyes and an acute sense of hearing, all attributes for which there was less need in the ponderous world of the earthbound creatures.

The working of a reptile’s brain is sluggish, and sight and hearing are poor. Only the sense of smell is highly developed. This arrangement of the senses and the working of the reptilian brain were not at all suitable for an agile and timid creature living in the trees. The speed with which the brain could translate messages from the senses into action was far too slow, and the high development of the sense of smell was almost useless to an animal living on insects, fruits and buds. Then as now, the reptilian brain was a highly organized central nervous system, in spite of its sluggishness. It was perfectly suited to control movement on the ground­feeding, mating, breeding and the internal functioning of the reptile’s body. It perfomed these many functions by the interaction of a large number of nerve centers finely tuned to each other and arranged in the brain with amazing compactness. Each of thse nerve centers had a very definite function to fulfill in the control of the body. For example, there was a center which controlled breathing, another that adjusted the blood circulation to momentary requirements and one which regulated sleep and waking. Such centers can by natural selection from suitable mutations increase or decrease their specific activity to meet evolutionary needs, but none of them can take over the function of any other center, nor can it change into a center governing a completely new bodily function.

The problems of quick muscular reaction, of feeding and breeding in the trees and the many other difficulties that confronted the reptile could never have been solved by the mere enlargement of its existing brain structure. Either the tree living reptile was doomed to die out for want of a suitable brain, or an entirely new trend in brain structure was needed to ensure the survival of the species. Man and all mammals owe their existence only to the fact that evolution adopted the latter alternative. This was one of the extremely rare instances in which evolution entered into a new phase to save an ill-adjusted species from extinction instead of sacrificing it.

In a reptile, the perception of smell is localized in two large bulbous outgrowths of the brain which we call the olfactory lobes. The olfactory lobes lie outside the rest of the brain, to which they are connected by a slender stalk. They are so far removed from all the the other centers of the brain that a new nervous function could originate in them­and in them alone­without structural alterations in the rest of the brain becoming necessary.

The reptilian brain is so organized that it must respond to all incoming messages from the senses. On the ground these messages lead to purposeful actions, for instance, burrowing for food or safety; but in the trees many of these actions become pointless. A reptiles’ behavior is governed entirely by automatic reflexes. It’s actions are not subject to reason. It does not have to make a choice between different ways of reacting. All its actions are due to sensory messages putting an ingrained reflex into operation, and over this process the reptile has no control.

A reptile, taking to the trees, carried with it all the ancient reflexes which it had acquired in the millions of years on the ground. These reflexes which the change of habitat rendered useless must have been a terrible harassment to an already overworked reptilian brain. In the slow course of evolution these reflexes would have gradually changed into more suitable ones, but so desperate was the situation of the tree-living reptile that it would have become extinct long before normal evolutionary trends could have brought about a better adjustment to the new environment. Some sort of evolutionary short cut was needed if the species was to survive.

The shortcut was biologically evolved out of just the right mutations occurring at this dramatic moment. It consisted of a mechanism which blocked useless messages from the nose and thus prevented them from reaching those centers of the brain which would have been obliged to react to them. In the olfactory lobes a few cells took over the function of a screening device, a sort of censorship or filter by which incoming olfactory messages were either suppressed or allowed to pass, according to their vital importance. This sorting or classifying of smells relieved the reptilian brain of the exhausting need to react to every message from the nose, and thus, in the trees, proved to be an efficient labor saving device.

The change in the olfactory lobe must have come about in the following way. Among the millions of individuals that lived through all of those ages, there occurred a mutation­a freakish change in the olfactory cells­which rendered such individuals able to withhold useless olfactory information. The freakish trait was inherited, and as the descendants of the mutated forms had a better chance of survival, those that had not inherited this new mechanism gradually died out, until only the forms that had the ability to censor smells survived.

An olfactory censorship that was able to prevent useless messages from reaching a nervous apparatus that would otherwise have been obliged to turn them into action gave the tree-living reptiles’ brain a new freedom from the tyranny of the sense of smell. It’s brain used this freedom to proceed rapidly with many other problems of adjustment. It was not forced to wait for a slow evolutionary weakening of the sense of smell.

Among the most pressing problems of adaptation was the improvement of sight and hearing. But as these senses widened their scope and came to furnish more finely detailed information, a point was reached at which they too began to harass the brain with messages that had no bearing on vital needs. And so once again the brain needed protection from the senses. The innovation in the olfactory lobes had proved to be outstandingly successful in achieving this end, but evidently the eyes and the ears were unable to evolve a screening mechanism of their own. They were in a upsurge of evolutionary progress and probably had no idle nerve cells which could be diverted to a new function. Moreover, the centers of seeing and hearing were structurally much closer to the central part of the brain than the olfactory lobes. Instead of evolving a censorship of their own, they made use of the one which was already in operation for the sense of smell. This evolved what may be called a complicated process of nervous rewiring and led to an enormous enlargement of those parts of the olfactory lobe that were performing the screening function.

Gradually the automatic reflexes which made the muscles contract or relax in movement came to be similarly supervised, calling for a further enlargement of censoring brain tissue. In higher mammals, finally, even the instincts themselves became subject to a process of censorship.

Out of such humble beginnings in the olfactory lobes of these first tree-living reptiles grew the cerebral hemispheres, the large domes which carry the cortex. These cerebral hemispheres have, in modern humans, reached so great a size that they now almost smother the original brain. In higher animals the original reptilian brain is called a brainstem in order to distinguish it from the much more recent cerebral hemispheres. In the human brain, the brainstem has come to look like a mere appendage hidden under and between the two hemispheres.

Had not this remarkable change in a tree-living reptiles’ sense of smell taken place it is doubtful whether mammals and their ultimate achievement, humans, could have evolved.

A. T. W.  Simeons, Man’s Presumptious Brain, E.P. Dutton & Co., New York, 1961, ( Dr. Simeons thanks and acknowledges Dr. Kenneth Oakley, D.S.C., F.B.A., of the British Museum of Natural History for his anthropological advice in writing this passage from the book.)

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