Like all our organs,the brain evolved over millions of years,increasing in complexity and information content.The brain has evolved from inside out.Deep inside is the oldest part,the brainstem,which conducts the basic functions of biological sustainance,including the 2 intrinsic rhythms of life-heartbeat and respiration.
The higher functions of the brain seem to have evolved in 3 successive phases:
1.Capping the brainstem is the R-Complex,the seat of aggression,ritual,territoriality and social hierarchy,which evolved hundreds of millions of years ago in our reptilian ancestors.Deep inside the skull of every one of us lies something like the brain of a crocodile.
2.Surrounding the R-Complex is the limbic system,the mammalicn brain,which evolved tens of millions of years ago in our ancestors who were mammals but not yet primates.It is the major source of our moods and emotions,our concern and care for the young.
3.And finally,living in uneasy truce with the more primitive brains beneath,is the cerebral cortex,which evolved millions of years ago,in our primate ancestors.The cerebral cortex,where matter is transformed into consciousness,is the point of our embarkation for all our cosmic voyages.Comprising more than 70% of the brain mass,it is the realm of intuition and critical analysis.It is here that we have ideas and inspirations,read and write,do mathematics and compose music.The cortex regulates our conscious lives.Civilization,in a way,is a product of the cerebral cortex,the world of Thought.
The world of thought is divided,roughly,into 2 hemispheres.The right hemisphere is mainly responsible for pattern recognition,intuition,sensitivity,creative insights.The left hemisphere presides over man's rational,analytical and critical thinking.These are the dual strengths,opposite in essence,that characterize human consciousness and cognition.Together,they seem to provide the means both for generating ideas and testing their validity.Simply speaking,these 2 hemispheres are engaged in a continuous and lifelong dialogue,channeled through an immense bundle of nerves,the corpus callosum,the bridge between creativity and analysis-both being so necessary to understand our surrounding world,immediate and remote.
The language of the brain is not the DNA language of our genes.Rather,what we 'know' is encoded in cells called neurons,essentially microscopic electrochemical switching elements.Even during sleep,the brain is active,pulsing and flashing with the complex existential functions of man-dreaming,remembering,figuring things out.Our thoughts,visions and fantasies have a physical reality.A "Thought" is made of hundreds of electrochemical impulses.
The information content of the human brain expressed in bits probably comparable to the total number of connections among the neurons,roughly about a hundred trillion bits.On the other hand,the information content in our DNA double helix need 5 billion bits.
The brain does much more than recollect.It compares,synthesizes,analyses,generates abstractions.For our supreme survival,we must figure out much more than our genes can know.That is why the brain 'library' is approximately a 10,000 times larger than our genetic library.Our passion for learning,evident in the behaviour of a toddler,is The Tool for our survival.Emotions and ritualised behaviour patterns are built deeply into us.They are part of our humanity.Yet they are not 'characteristically human',as many other animals have Feelings too.
What distinguishes our species from all others in this planet is Thought.The cerebral cortex,figuratively speaking,represents Existential Liberation.We need no longer be trapped in the genetically inherited behaviourial patterns of reptiles or non-human primates.Man is largely responsible for what permeates into his brain from the external world,and for what man,as a responsible adult winds up caring for and knowing about.No longer in the mercy of his reptilian brain,man can change himself.
(Having said that,I would like to mention here a favourite 'thought' of mine which I love to muse over and over again.There is a remote chance that someone who shall be reading this one day,might agree with me,however inconsequential it might seem to be,as far as existential practicality is concerned.)
Were our Earth to be started all over again with all its physical features and its ontological history remaining identical,I strongly doubt that anything closely resembling a human being would ever emerge.(I would love to be corrected or contradicted on this by dependable teleologic contemplations that learned reader might like to put forward.)
As our learned ancestors dabbling with philosophy and science have proceeded to unravel,layer by layer,the mysteries of the subatomic world and macrocosmic grandeur of the fascinatingly 'endless' of the universe that we see,one common yet prominent scheme seems to stand out-That there is a powerful random character to the process of evolution.A cosmic ray striking a different gene to produce a different mutation,can potentially have small immediate consequences but profound late implications.Happenstance have played a powerful role not only in history but evolutionary biology too.The farther back these hypothetic critical events occur in time,the more powerfully and diversely can they influence the present.One does not need to go far searching for proofs of contextual affirmation of this when a simple example seems to lie 'at hand'.
The human hand has 5 fingers including an opposable thumb which serves us quite well.But I think we would have been served equally well if the hand had 6 fingers including the thumb,or 4 fingers and 2 thumbs. There is nothing intrinsically best about the particular configuration of the fingers our hands have,which one might think to be naturally inevitable.
We have 5 fingers because we have descended from a Devonian fish that had 5 phalanges in its fins.Had we descended from a fish with 4 or 6 phalangesin its fins,we would have had 4 or 6 fingers which we would have thought to be perfectly natural. One profound consequence of this evolutionary specificity is that we use Base Ten Arithmetic because we have 10 fingers in 2 hands(arithmetic started in ancient Greece by counting with fingers).Had the arrangement been otherwise,we would have ended up with 'Base Eight' or 'Base Twelve' arithmetic.
The same point,I believe,applies to more essential aspects of our existence-our hereditary material,our biophysiology,our form and stature,passions and dispairs,tenderness and aggression,or even our cognitive and analytical processes.It is sheer bewilderment which fills one's senses to think that all these intrinsic factors are,at least partially,a result of apparently minor accidents in our long evolutionary history.The pattern of evolutionary causality is a web of astonishing complexity,and the incompleteners of our knowledge humbles us.
Man has come a long way.Furry little mammals hid in caves from the giant dinosaurs,colonized treetops,scampered down to domesticate fire,invented language and writing,constructed space observatories and harnessed nuclear energy.And in the process he has destroyed ecosystems and abused the pain-stakingly gathered knowledge of the subatomic world to build weapons of mass genocide.Today the world faces a great threat in Terrorism which has its seeds in fanatic ideologies and which tries to find justification through tennets of organized religion.
Here I would like to breeze through an academic endeavour which,unfortunately,did not find much peer review due to extreme polarisation of world politics which prevailed as The Cold War. Almost 4 decades back,neuropsychologist James W Prescott performed a startling cross-cultural statistical analysis of 400 pre-industrial societies and found that lavish physical affection on infants tend to be disinclined in violence.Prescott believed that cultures with a predisposition for violence are composed of individuals who have been deprived,during infancy and adolescence,of the pleasures of the body.Where physical affection is encouraged,theft,organized religion and invidious displays of wealth are inconspicuous;where infants are physically punished,there tends to be slavery,frequent killing,torturing and mutilation of enemies,a devotion to the inferiority of women,and a belief in one or more supernatural beings who intervene in daily life.
We do not understand human behaviour grossly better than what we did during the times of Prescott,to be sure of the mechanisms underlying these relationships,although we can conjecture.Yet I mentioned Prescott as I find these correlations significant today.All I want to point out that we inhabit a universe where atoms are made in the centres of the stars,where life is sparked by sunlight and lightning in the airs and waters of beautiful planets,where the raw material for biological evolution is sometimes made by the explosion of a star halfway across the Milky Way.And how pallid by comparison are the pretensions of Superstition and Pseudoscience,distortion of ideologies which take life in our planet.When shall man see Sense and understand the importance to pursue Knowledge and understand Science,that characterises human endeavour.
Human history can be viewed as a slowly dawning awareness that we are members of a larger group.Initially our loyalties were to ourselves and our immediate family,next,to bands of wandering hunter-gatherers,then to tribes,small settlements,city-states and nations.We have broadened the circle of those we love.We have now organized what are modestly described as superpowers,which include groups of people from divergent ethnic and cultural backgrounds working,in some sense,together-surely a humanizing and character-building experience.
If we are to survive the crises that threaten our sheer existence today,we have to broaden our loyalties further,to include the whole human community,and the entire planet Earth.People who run the superpowers will find this idea unpleasant,fearing loss of power.And perhaps one will hear much about treason and disloyalty.Rich nations will have to share their wealth with poor ones.But the choice is stark and ironic.It is clearly existence or nothing.
Reference:
Prescott,James W. "Body Pleasure and the Origins of Violence."-Bulletin of the Atomic Scientists,page-10,November,1975.
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