What It Is to Be Human

Starting from the recent discovery of one metre tall homo floresiensis on an Indonesian island, Margaret Ogden goes on to consider what it is to be human.

The recent discovery on an Indonesian island of Ebu, Homo floresiensis, reveals adaptation to a meagre food supply as a key feature of humans. Long after Neanderthal man had died out, there remained this group of marooned humans, of one metre stature and very limited brain size, subsisting on a low-calorie diet and seemingly with no large predators. With the bones from seven individuals there was evidence of stone-age tools, and fire-charred bones of small primitive elephants. The most complete skeleton was an 18,000 year old female, the others dating from just 13,000 years ago when they seem to have been wiped out by an earthquake. Twentieth-century humans living on nearby islands tell stories of amazing little hairy people they called "ebu gogo", meaning "grandmother who eats everything"! These Ebu and other early human species will have had gestures of recognition, limb signals relating to food sources and dangers, and early speech together with other basic attributes of mammals.

Let us now jump back to the Jurassic age of the Dinosaurs, when our early rat-sized placental and lactating mammalian ancestors were honing their survival strategies, alongside some larger badger-sized mammals preying on young dinosaurs. Among their attributes would have been curiosity, motivating searching for answers that would aid survival, a brain ability to map space and time sequences, with bravery in fighting for resources. Our forebears could have learned to hunt in packs like modern wolves, with marked territories for food and shelter, with shared child care, and competing for a pecking order that could provide the status for the most experienced to lead the troop, take the "lion"s" share of food, and raise most offspring. Within these social groups there would be signals and vocal sounds to express communication needs of hunger, fear, domination etc. Their brains would have forged pathways for these concepts, predating our later human labelling with words. Such pathways would form the basis in the brain for the Language Acquisition Device, L.A.D., postulated by Chomsky.

When Primate groups evolved, many lived in trees, developing prehensile thumbs and toes, tool use, and longer care of the newly born. Famous studies in the last century of Chimpanzees, Apes and Monkeys have revealed great advances in facial communication, tool use and cohesive group grooming. Individuals would need to know the characters of others in their troop, and differentiate friend and foe. One prominent feature of being human is an evolved and almost instinctive allegiance to our own social group, and a reluctance to share good fortune with "strangers". Present day chimps also show many other "human" characteristics, being able to learn sign language and teach this to their young. Jane Goodall reported from Gombe that some chimps showed signs of awe at waterfalls. It will be tragic if human wars in parts of Africa were to exterminate any of these remaining intelligent primate species. Hungry humans will be desperate for bush meat, and there are reports that the sexually friendly Bonobo monkeys may already be extinct.

During recurrent Ice Ages, requiring exploitation of extremely diverse habitats, humans needed to adapt in many ways simultaneously, trebling their brain size to cope with the overload of sensory information and the need to make relevant effective responses. Recent research by Professor Bruce Lahn at the University of Chicago (reported in The Guardian 29th December 2004) shows that the DNA of 214 genes involved in brain development had gone through an intense amount of evolution in a short time - a process that far outstripped the speed of evolution of genes affecting other body parts. The professor suggested that the development of human society may have stimulated brain growth because improved cognitive abilities became a key advantage. Only those parents who could think and plan survival strategies would be able to breed effectively and pass on their genes for larger brains to their offspring. Professor Lahn has written: "Even devoid of social context, as humans become more intelligent, it might create a situation where being a little smarter matters a lot."

Our own Homo genus moved out from the trees to the plains, with upright stature freeing the arms for improved tool use. Our human skills as marathon runners probably developed at this time. Loss of most body hair would help in cooling, but meant that infants had to be carried. Hands could wield more elaborate tools, and express more signals. The changes in diet and reduced jaw musculature left room for the enlarged brains that could enhance survival chances in successive generations Our brain size would also have enabled deliberate choices that would harm others (we humans indeed have a capacity for evil actions). It seems that larger brains are needed for deceit! The explosion in brain size enabled conversion of grunts into more meaningful words. Would these early species have been busy with survival tasks with no time for wonder at their world? Yet perhaps they had developed some inner spirituality that could help them endure hardship and survive.

For many thousands of years different human species continued to develop, with our Neanderthal "cousins" surviving until 30,000 years ago. So what are the most crucial additional special features of hunter-gatherer Homo sapiens compared with earlier humans? Principally the vastly larger and more complex brains enabled a quantum leap in brain inter-connectivity. Under each square mm of our convoluted human cortex there are 148,000 individual nerve cells - neurons. These branch out in networks to all other regions of the brain, some of which have become specialised for interpreting different senses, some for motor skills, some are concerned with language etc. Modern brain imaging techniques help scientists relate specific brain areas not only to specific motor and sensory stimuli, but also to reported "feelings" and images" from articulate experimentees. Our complex brains helped tribes of early humans to flourish and attain mastery over many other animal species, and then spread out over much of the globe. They could co-ordinate projects, submit to hierarchies in groups, and teach specialist skills to the young.

Matt Ridley [1] writes that one key way our brain differs from animals" is its capacity to exploit reciprocity, to trade favours and reap the benefits of social living. Steven Pinker [2] suggests that humans have intuitive knowledge of basic scientific mechanisms including psychology. Three year olds can be excellent manipulators! David Boulton [3] draws our attention to another human capacity, imagination, which prompts us to put ourselves in the place of others. This was demonstrated in the great sympathy and generosity following the Tsunami that struck on December 26th 2004.

When hunter-gathers began to live in farming settlements, with more reliable food sources, further specialised roles would increase, including herbal healers, builders, and spiritual leaders. Some leaders could tell stories to answer questions about the purpose of life and allay fears of death. They could gain power by predicting seasons, e.g. via stone circles, and could accept gifts to propitiate harmful spirits. Those tribes who had spiritual story-myths seem to have had the edge for survival, and any brain pathways that facilitated spiritual beliefs would have been inherited. I suggest that just as our brains have Chomsky"s facilitating L.A.D., so too our brains have evolved a R.A.D., a religious acquisition device, to aid survival. Different isolated human groups would have developed allegiance to different religious stories which could answer curiosity about origins, could give exemplars for moral conduct, and could also reduce fears of death via stories of heaven or reincarnation. Such stories can act as bribes for better conduct within the group.

Reflective techniques and neighbourly activities are part of most religions today, and should also be utilised by those who have discarded any evolved realist beliefs in external deities. Techniques of inner reflection can be learned via Yoga or other methods of meditation. Disciples of the 13th century Persian poet Rumi participated in a dancing "centring of consciousness", which aimed to join the body and soul together in a journey to a deeper psychic awareness. Moments of great wonder at Nature, Art, or Music, can achieve similar inner calm and joy. Our over-busy thinking minds can be refreshed, aiding survival skills and leading to greater empathy with fellow humans. David Sloan Wilson has written: "So religion acts as a biologically and culturally evolved adaptation that enables humans to function more effectively as a group rather than a mere collection of individuals." He advises us to "reflect and let your inner instincts contribute to your decisions." But will it ever be possible to enlarge the boundaries of our group empathies to become a more united world population?

Recent Consciousness Studies research have begun to give insights into that rather mysterious attribute- our sense of self. The fascinating book Radiant Cool [4] includes a detailed account of some current research using brain scans. Our complex brain structures lay down memories of events, linking the present with previous stored memories, and postulating forward scenarios for possible action.

During the many years of human evolution, our increase in brain size has stimulated us to spread out over our globe and to develop different technologies to fine-tune our lives to our enabling a few to achieve a more comfortable life style. Keith Ward [5] does not accept that Evolution has had this capacity to fine-tune living things to their environments, and considers that God as a first cause, with a capacity to influence events, has to be an essential postulate for our understanding of life on this planet, but ironically it is via Natural Selection itself that different religions have arisen to increase our chances of survival. However, theists can still maintain that a designer God would have planned our evolved spirituality!

Our inherited biases for particular concern for our own families, our own neighbourhoods, our own tribes or nations, our own life-spans, seem to blind us to the plight of other peoples and also to certain global consequences of our activities. The spectacular 2004 Tsunami disaster did cut through our complacency, and inspired generosity. Can future governments, or the Arts, inspire us to make sacrifices for the sake of future generations before it is too late?

The peoples of the world are limbs of one body,
sharing the essence.
When a single limb is oppressed, all the others
suffer agony. [6]

Those of us who no longer accept supernatural causation or interference in events should take due heed of the potential for contributions from our inner spirituality in guiding our choices of action, and the valuable contributions of organised religions in co-ordinating neighbourhood and national activities. It would be wise not to neglect this evolved capacity and to practise pausing reflectively before taking important decisions. Nor should we ignore the grave dangers posed by rival fundamentalist sects that can undermine local and national co-operative endeavours to work for the good of humanity as a whole. Neither any single religion, nor any agnostic or atheist group acting alone can hope to so influence global decisions made over the next fifty years as to ensure a longer term of survival for humans on this planet. Is the capacity to drift into our own destruction one inevitable result of what it means to be a very insapiens human?

Our natural evolved selfishness to protect kith and kin needs a vast expansion into care for all peoples of the world, including a determination to reduce certain emissions of air pollutants, and to approve regular government contributions from wealthy nations to support peoples scratching out subsistence livings. We need to be aware not only of our positive adaptive evolved attributes but also of the load of selfish luggage we carry selected during our struggles for survival in a past world that had ample resources for our small ancestral populations. Occasional generous charitable responses to disasters will not be enough to save our descendants from an increasingly uninhabitable world before human extinction cuts in, and natural selection enables, perhaps termites?, to conquer the globe. Will it ever be possible for us to channel our evolved selfish tribal attributes into a shared determination to do what it takes to conserve this planet for future generations?

Margaret Ogden

Margaret Ogden is a member of SoF Steering Committee. She had a superb student experience in the Zoology Department of University College, London, where she was taught by JBS Haldane, Peter Medawar, John Maynard Smith and others. This was followed by a teaching career in London.