The Centre for Fortean Zoology was founded in the UK in 1992 - nearly 20 years ago. Over the past two decades it has expanded to become a truly global organisation. We opened our American office in 2001, our Australian office in 2009, and now - in our 19th year - we are proud to welcome CFZ Canada to the CFZ global family.

Thursday 7 June 2012

Bigfoot from the Bottom Up part 7: Head of the Class

My apologies for the lengthy absence.  I’ve had some health issues.  Here is the final segment of this series.

So much research (mine included) is based in the assumption that Bigfoot is immediately related to primates.  Until we have some sort of evidence to the contrary, because of the reported behavior and physical description it would seem logical to continue that path.  In light of that, this last entry on researching Bigfoot From the Bottom Up discusses the Bigfoot brain.

The brain is the center of the nervous system. This is the structure of all mammals.  In primates, the similarities are many.  The brain controls all bodily functions and in some magical way also provides “thought” and “behavior”.  How the brain produces these is not understood, but science is quickly getting a handle on how mechanisms in the brain alter both.  Putting aside the brain function for ordinary activities such as walking, breathing, and basically physically existing, we’re going to look at the comparisons between human and other primate brains with a goal of perhaps better identifying what sort of brain our Sasquatch may have.

The human brain has the same general structure as the brains of others, but is larger than it should be compared to body size.  Larger primates have brains that are sized basically like their body—larger apes having larger brains, smaller monkeys having smaller brains.  The adult human brain weighs on average about 3 lbs. (1.5 kg) with a volume of  about  1130-1260 cubic centimetres.  Neanderthals, now extinct so far as we know, had larger brains at adulthood than present-day humans. In the course of evolution of the Homininae, the human brain has grown in volume from about 600 cc in Homo habilis to about 1500 cc in Homo sapiens neanderthalensis.   Then over the past 28,000 years the brain has been shrinking.   For comparison, Homo erectus, a relative of humans, had a brain size of 1,100 cc. However, the little Homo floresiensis, often called "hobbits", had a brain size about a third of that of their ancestor H. erectus even though they are known to have used fire, hunted, and made stone tools as well. The section of the brain called the cerebellum, a pair of bun-like mounds at the base of the brain, plays an important role in coordinated muscle movement. Consistently across all mammals this is about 13 percent by volume, regardless of total brain size.  

Species that eat fruit tend to have larger brains than species that dine mainly on leaves. Although leaf-eating howler monkeys are closely related to fruit-eating spider monkeys, the latter possess much larger brains. Leaves are easily found but fruit resources are less available. Successful harvesting of fruit requires animals to remember where fruit-bearing trees are located and anticipate when they will be in season. Larger brains may have helped fruit eaters deal with environmental variation and patterning.  Because of this, it is important to understand the diet of the Sasquatch with an eye toward anticipating the size, and therefore functionality, of his brain.

A large brain requires greater energy use.  Our brains at rest use about 25% of our energy but the brains of other primates use only about 9 percent.  The larger brain also uses a greater amount of the basic brain “building blocks” like fatty acids and DHA. Physiologist Loren Cordain suggests that  our ancestors overcame the issue of increased energy use by the brain by getting rid of a roughly equal amount of intestinal tissue. Humans have less intestinal tissue than great apes, which require more in order to extract nutrients from a poorer diet. Our ancient ancestors likely fed on richer foods (animal fat and bone marrow) and the essential fatty acids.

Although the first primates had great availability of AA and DHA in thier diet, it was necessary for evolution to give larger brains more time to develop. Slower development meant longer gestation, slower childhood growth, and a later sexual maturity.  These longer development times allowed our hominid ancestors more time to accumulate those essential brain nutritives.   Humans have taken advantage  of this and are the slowest primates to mature.  We are also the most carnivorous primate. Our hominid ancestors would have needed a varied diet of freshwater fish and shellfish; the liver, brain, and muscle of large game; as well as wild nuts, roots, tubers, and vegetation.

The progressive enlargement of the hominid brain has resulted in a three hundred percent increase in endocranial volume. By charting the expansion of the brain from one species of human ancestor to the next,  scientists may be able to show changes in the shape and size of neocortex structures as they appeared over the course of time. These can then be compared with the activity of a modern human brain.  Scientists study MRIs (magnetic resonance imaging) of shapes in bone structure of skulls of these human precursors in hopes of understanding when certain intellectual capabilities developed during human evolution.
Using this technique, changes within the brains of Australopithecines, human ancestors that lived one to three and a half million years ago, have been documented.  Australopithecus africanus had features in its frontal lobes that had evolved beyond the great apes and along the road to humans. The cerebral cortex of this species was unlike that of any living primate. This part of the frontal lobe is important for focusing on and completing tasks, and for highly abstract thinking and planning.

Brain size by itself doesn’t explain why we are intelligent. The brain of a horse is more than six times bigger than that of a rhesus monkey. But if the two animals were the same size, the monkey brain would be 20 times larger. And let’s face it, horses aren’t exactly genius material.  Primate evolution has shown dramatic expansion of the neocortex (the outer shell of the brain). The percentage of neocortex in humans is, for example, four times the percentage in size of the neocortex of a shrew. 

Neocortex varies widely across species. Fish, reptiles, birds, and amphibians, all precursors to mammals, lack a neocortex entirely.  One particular feature of the neocortex makes it ideal for supporting flexible behavior.  Science considers this plasticity to be the hallmark of intelligence.   The ability of the brain to change in response to stimulation occurs in this part of the brain.

All mammals are born with more connections between neurons than they will ever use. As we explore and learn, even as babies, we stimulate these neurons.  The ones that are stimulated grow stronger and the ones that are not are eventually lost.  This is what learning is all about.  Primates have an longer period of development into adulthood and during this time wiring of their big neocortex is established through learning.  If we assume Bigfoot is a primate, then he would have a large neocortex, and the greater ability to learn.  Behaviors reported by witnesses support the idea that this species, whether human or other primate, does have a great capacity to learn.  The imprint for the Skookum Meadow cast was made when investigators located a probable Sasquatch area, set a fruit trap in mud, and attracted a purported living Sasquatch. Demonstrating a typical Sasquatch aversion to leaving tracks, the subject lay across the mud to reach the fruit. The implication is that he was smarter than an ape (avoiding making footprints) but not as smart as a human (leaving a big body imprint). Random vocalizing in the vicinity of tape recorders but avoiding video cameras implies they have some sort of understanding of what these machines do, beyond simply that they are foreign to their environment.

As mammal brains are shaped by interactions, different parts of the neocortex become specialized to perform different functions. The more important the function, the larger the area of neocortex devoted to it. Bats that rely on echolocation have an expansive portion of the neocortex devoted to hearing, for example. Significant areas of the human neocortex are devoted to the face and lips, reflecting the importance of communication through spoken language and facial expression.  Once in the possession of a Sasquatch skull, MRI testing of the bone impressions where the neocortex was present will show what amount of neocortex was committed to these functions and we will be better able to know if they do in fact have speech communication, and even possibly writing.

Primates have sensory maps in their neocortecies.  These maps correspond to visual and touch input.  A great deal of the brain of primates, sometimes as much as 50 percent, is devoted to visual processing.  If a human is born blind, however, parts of the visual   cortex may be developed to support hearing instead.  In the visual cortex there are many little maps that correspond to things like color, shape, and movement.  That Bigfoot is able to subsist on virtually any terrain in the world and to evade detection most of the time is a good indicator that he has a highly developed neocortex, especially where vision is concerned.  This does not,  however, rule out his being an ape.  Apes have a greater area devoted to visual mapping.   Solid visual mapping is necessary to facilitate eye-hand coordination, to locate food, and to be social.  In humans, and in apes, good vision is used to measure emotional expressions and assessing whether friend or foe.

The frontal neocortex is involved in mental manipulation of information. It may also be involved in the use of visual information to plan and execute fine motor movements. During EEG studies on monkeys, when the animal  performs an action like reaching out and grasping an object with its fingers, neurons in a certain part of the frontal neocortex fire.  These same neurons fire when the monkey simply observes another monkey, or even a human, performing the same action. Neurophysiologist Giacomo Rizzolatti dubbed them “mirror cells” and suggests they may play a role in imitative behavior and learning.

Primatologist Jane Goodall reported that juvenile chimpanzees at Gombe National Park (Tanzania) watch their mothers break off branches and poke them into holes, looking for termites. The young chimps then make  attempts to copy their mothers.  Ergo, “monkey see, monkey do.”

The same area where mirror cells are found in the monkeys neocortex is called Brocas area in humans and is involved in speech production. People with brain damage in this area have a very difficult time speaking. Imaging studies have shown that this area is also activate when people make or observe hand gestures. It is suggested that observing and repeating gestures may have been a precursor to gesture-based communication, which eventually evolves into vocal language, at least in humans.   Not surprisingly, all types of Sasquatch are reported worldwide to be very vocal, far beyond the screams, chattering and roars of apes. They are reported to moo, whistle, cry and imitate human speech.  They also make other noises, presumably to communicate, like wood pounding and rock pounding. We also know that Neanderthals had the brain structures associated with speech but that their mouth and jaw construction was not suitable for what we think of as speaking.

Most speculative, is the notion that mirror cells are precursors of the ability to take the mental perspective of others.  The ability of primates to show empathy, for example, and to anticipate what someone would do next would involve these mirror cell functions   This also gives the ability to deceive or manipulate.  Perhaps the Saskquatch ability to elude researchers (and a few hunters) is because of a well-developed set of mirror cells. Yet Darwin first suggested more than a century ago that the evolution of intelligence is linked with living in social groups.  Does this imply that Sasquatch, given what seems to be intelligence, lives in a social group as well?

Primates are predominantly social animals. Although many live solitarily, most all monkey and apes live in social groups. Survival in social groups invokes its own selection pressures, requiring the evolution of social problem solving skills and other adaptations.  Anatomically this means that the prefrontal and temporal cortices have been implicated in social interactions, so the degree of development of these areas in different species might reflect different levels of sociality.  Studying that oft wished for Bigfoot Skull would again give us an idea of how much of the general area is devoted to these functions and give us an idea of whether or not the Sasquatch is a primarily social animal.  The cerebral cortex is involved in many complex functions in both humans and other primates, including memory, attentiveness, thought processes and language.

The Machiavellian intelligence hypothesis is an group of speculations,), about the unique complexity of primate social interactions. It proposes that increased coordination between social actions reflects a flexible feeding strategy involving the manipulation of tool use and the ability to use other individuals as tools, manipulating the social environment in order to meet preconceived goals.  Descriptions generally fall into three subcategories: (1) transmission of novel behaviors ; (2) deception; and (3) alliance formation. Alliance formation implies that primates have a knowledge of rank relations beyond knowing who is above or below them. Additionally,  all three may involve altruistic interactions like objects being exchanged.  Social alliance formation and maintenance requires an animal to analyze a significant amount of information, including the relations between individuals involved   as well as their relations to other individuals.  Evidence of nested levels of alliances within a population of bottlenose dolphins in Shark Bay, Australia suggests that because, like primates, they have relatively large brains, there may be a relationship between brain size and social complexity. However, primates, more than non-primates, choose their allies based on competitive ability, not necessarily on kin relations as other mammals appear to do.

In another interesting primate brain study, Drs. Clutton-Brock and Harvey found that brain size correlated with home range size in the cercopithecines (a subfamily of the Old World monkeys, that includes in its 71 species the baboons, the macaques and the vervet monkeys) and that monogamous species have significantly smaller brains than polygamous ones. Home range varies with troop size, and monogamous species have smaller troops than polygamous ones. Does this suggest that Sasquatch, because they appear to be in small troop sizes, are monogamous creatures?

Results suggest that the factors controlling primate neocortical expansion are not uniform across the order and vary in their strength according to the nature of the animal's environment. It may be this factor that makes the bigfoot so difficult to label.  Perhaps because of the widely varied environments these creatures have been reported to inhabit, each group evolves a bit differently.

Differences between humans and other primates aren’t as black and white as once was thought. Intelligence appears more a matter of degree, developing gradually throughout the primate lineage rather than sprouting magically when humans first arrived on the scene. Many of the features of our brain that support higher cognitive functions, such as language and mathematics, or at least their precursors, may well be present in ape and monkey brains, and in the brains of long-extinct ancestors like the Australopithecus.

The study of the evolution of primate intelligence is still in its infancy. Not enough is known about the functioning and interconnections of areas within the brains of various species to allow for accurate measures of the differences.  Additionally, techniques used for probing the human brain (e.g. fast-NMR, PET) may not work on animals.  There is also no reason to expect that brain evolution has proceeded regularly without reorganization.   An understanding of the functioning of the brains of different species is essential for making accurate comparisons. The studies have not been done, and may not get done for a long time, so we have to choose assume regularity in brain evolution. Researchers have, however, uncovered trends that are accurate on a gross level.

Understanding the relationship between the brain and the mind is a challenge. It is difficult to imagine how thoughts and emotions could be implemented by physical entities (neurons and synapses).  This difficulty was expressed by Gottfried Leibniz in an analogy known as Leibniz's Mill:

One is obliged to admit that perception and what depends upon it is inexplicable on mechanical principles, that is, by figures and motions. In imagining that there is a machine whose construction would enable it to think, to sense, and to have perception, one could conceive it enlarged while retaining the same proportions, so that one could enter into it, just like into a windmill. Supposing this, one should, when visiting within it, find only parts pushing one another, and never anything by which to explain a perception.
— Leibniz, Monadology

The human brain is also susceptible to degenerative disorders, such as Parkinson's disease, multiple sclerosis, and Alzheimer's disease.  We also have a whole host of psychiatric conditions.  Could Sasquatch suffer these as well? If this is the case, then the study of how the animals think expands exponentially.  Certainly physical deformities of various kinds exist in all animal species, and mental deformities and diseases are numerous in humans, so it would follow that whether human or ape, Sasquatch may be crazier than those of us who believe in him

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