evolution


Hoatzins-ecuador

The Hoatzin

They were all over the path and on the field beside it. There must have been about 50 of them scampering about, twittering to each other and occasionally bending forwards to peck at some insect or seed. They were Japanese pheasants, slightly smaller and much duller than our own magnificent pheasants, which we regard as indigenous but were actually imported by the Romans from their natural range to the east of the Black Sea. I ran closer and they scattered and ran away, behaving not so much like birds but like little dinosaurs. It reminded me of a scene from ‘Jurassic Park’. Flying is a last resort for pheasants; with their small wings and large bodies they can only make it to the next copse or area of scrub. Other ground nesting birds, the American Road Runner, which is actually a type of Cuckoo, the Stone Curlew, and the Great Bustard, also seem to resemble dinosaurs more than they do birds.

So have birds evolved from dinosaurs? Our notion of dinosaurs, large lumpen grey-green reptiles that roamed through swamps or terrifying blood thirsty monsters as large as a double decker bus would seem to make that highly unlikely.  Nevertheless, the discovery of the Archaeopteryx is Southern Germany in 1861 shortly after the publication of The Origin of Species, seemed to settle the question beyond any doubt. This strange creature, which was about the size of a pigeon, but had a skeleton like a lizard and wings with flight feathers, was heralded as the missing link between dinosaurs and birds. Only a few specimens were discovered, but deep in Amazonia there is a strange bird that sort-of resembles Archaeopteryx. This is the Hoatzin. I spotted one once while travelling up Rio Negro beyond Manaus in a small motor boat. It was about the size of large pheasant, with a bald face, big maroon eye, punk-like spiky crest and the most striking rufous red wing and tail feathers which it displayed frequently. The Hoatzin is the sole member of the family, Opisthocomidae, which is thought to have split off from the evolutionary trajectory of other birds after the extinction of the dinosaurs. This weird chimera eats fruits and leaves, which it ferments in its chambered crop like a cow. For this reason, it is also called ‘the stink bird’. Hoatzins are too heavy to fly far, preferring to spend most of their time eating and calling noisily to each other. The chicks have one other curious atavistic feature, claws on the first two digits of their developing wings, which, together with the claws on their feet, help them climb trees. So that was it: the evolution of birds from dinosaurs rested on the Archaeopteryx, a strange bird living in the Amazon basin that resembles the  Archaeopteryx, and few other strange creatures, such as the Hesperornithes, large seabirds that resembled divers but had teeth, and the flightless ratites (Ostriches, Emus, Rheas, Cassowaries, Kiwis and Moas).

Nevertheless, for more than a hundred years, the fossil trail from dinosaurs to birds ran cold. No new feathered reptiles were discovered. Palaeontologists muttered about freak mutations, but nothing seemed to make much sense. Then twenty years ago, in the sediments of prehistoric lake beds in Liaoning Province, North Eastern China, local farmers started finding strange fossils.  These were identified as dinosaurs but they all had feathers. In many cases these were just hollow quills with tufts that probably served to insulate them from the cold, but some had flight feathers and wings, which were probably used for display before they evolved for flight. Under normal circumstances, the soft tissues of fossils, including feathers, would decay and be eaten by insects, but the Liaoning lake beds were covered by a layer of volcanic ash, which preserved the structure of fossils in great detail. The fossil beds are so extensive and the specimens so numerous that new discoveries are being made at a rate of one a fortnight.

Palaeontologists now have a complete fossil record of the evolution of birds from Therapod dinosaurs, depicting the development of every change: reduction in size, a light, air-filled skeleton, flight feathers, a beak like structure, the loss of teeth and a unique system of air sacs for breathing. Microscopic examination of the feathers has even revealed melanosomes, little packages of colour, so it is likely that like birds, these small theropods were multicoloured and probably used their plumage for display.

Dinosaurs were the dominant species on Earth for 200 million years between the Triassic and Cretaceous epochs and over that time achieved a remarkable diversity. They were extinguished when a six mile wide asteroid plunged into what is now the Gulf of Mexico, 65 million years ago, but they did not die out completely. The survivors evolved into birds and crocodiles as well as a host of reptiles. But why was it that birds survived while most other groups died out? Was it their small size? After all, it was the shrews, that survived to diversify into mammals. Could they have escaped the destruction of their habitat by flying? Did their covering of feathers allow them to survive the prolonged volcanic winter at would have followed the asteroid impact?

The recent discovery of these spectacular dinosaur fossils in Liaoning overwhelmingly supports the hypothesis that birds are descended from theropod dinosaurs and is probably the best-documented major evolutionary transitions in life history.  As ever, these new discoveries raise lots of new questions, but what an exciting time to be a palaeontologist. The irony is: this exciting discovery comes just as we are on the brink of another species extinction.

 

 

 

Life is a constant process of modification and adaptation,   The basis of our identity is forged early on through the interaction with our parents.  Our whole world is our family, our home.  But then as we grow, become more independent, explore our environment, other people and situations influence us;  extended family, friends, school, holidays, university, marriage, job; they all accrete to our personality to form a distinct, recognisable identity.  But it doesn’t stop there.  We continue to remodel our personality throughout our life.  This usually occurs by a gradual process of evolution, but it sometimes occurs more dramatically by crisis and revolution. 

So what is it that changes us?  The simple answer is experience; the things that happen.  If the environment changes, then we either adapt and grow or we stay put, stuck in the past. Not all events change us, of course; most of what happens can be accommodated within the confines of our experience and serve only to reinforce our view of the world.  But occasionally, we encounter someone or live through some situation that so outside our experience that we are forced to adjust our whole way of thinking to incorporate it.   

Change is an emotional interaction.  Things that are different challenge, excite, shock, frighten and even depress us.  If we engage with them, we may feel envious, guilty, ashamed or angry.  Sometimes we may be able to change the situation, but more often than not, we can’t; the only thing we can change is ourselves.  Working through, coming to terms with, are the processes of change;  the reconstruction of the personality that develops out of emotional crisis.   So if something affects us, makes us think and feel, then we are changed by it.  Change is instigated by emotion.   We fall out with somebody, argue, disengage, fume, but then later, sometimes much later, we pause, start to see it from their point of view, and reconcile our differences.  We are changed by what has happened.    

‘Love changes everything’, wrote Andrew Lloyd Webber.  Such a deep emotional identification with another human being results in coalescence, a  blending of experience that changes both.  Change requires an interaction, an exchange.  We are social beings; other people change us.   Conflict and love; we are changed by sharing of intense emotional experience. 

 But it’s not just direct emotional experience that changes us.  We can be adjusted by culture.  Art, literature, science, technology, religion, politics are all agents of cultural change.   They facilitate change in ourselves by altering the emotional environment.  They can rearrange the way societies perceive their existence and influence the choices they make.  Somebody proves that God no longer exists or that world is finite, and suddenly the restrictions of people’s behaviour are lifted and they change.  The ability to communicate instantly with somebody at the other side of the world, the way we experience war, earthquakes and tsunamis in the comfort of our living room as they are happening, the way we can shop, pay bills, book holidays, conduct our jobs without leaving home; all off this has altered the way we are. 

Governments, yes even Conservative governments, are agents of social change; they change the social environment by legislature and the people have to move into it.  

Architects also change the social environment.  Geoff Cohen said on Radio 4 last week that good architecture must not only be functional, it has to create hope and space for emotional development.   Jaume Plensa (currently at The Yorkshire Sculpture Park) creates  environments for peace and meditation as well as exciting spaces where change can happen.  His sets for opera create such dramatic possibilities.   

Change the environment, change the meaning.   If we move away, get another job, we mix with a whole new social group and we are changed.  If we separate from our partner,  move on, marry someone else, we become a different person.  Relationships change people, probably more than anything else. Parents and teachers create the environment/space in which children can grow, but eventually the child has to separate.  A good teacher or parent equips the child to take advantage of the opportunity. By the same token, psychotherapy can expands perception and creates possibilities for change, but only the individual can change.  You not only need space to change, you need courage to take advantage of the opportunity.  And the good enough parent, teacher or therapist, must facilitate a safe environment for the person to develop with confidence and not seek to overprotect and confine through selfishness and fear.

So why do we help each other?  It defies logic.  According to Dr Samuel Okashi, who was speaking at the Cafe Scientifique last night, if we were the rational, logical creatures we claim to be, then there would always be an advantage not to.  The Prisoner Game, invented by the ‘autistic’ mathematician John Nash (depicted in the film by Russell Crowe),  demonstrated that when you cannot trust your partner what to do, it is always better to defect, because the risk of collaborating when they don’t, could mean you end up with nothing and even if you both defect, you could at least end up with something.  This makes logical sense to prisoners and psychopaths, who cannot trust.  It also makes sense for governments.  Look how difficult it is for states to agree on cutting carbon emissions.  Powerful states with more to lose, defect, because if everybody else cuts emissions they will gain, even though the world will lose.  How could you ever get them to collaborate?

Why should people who are inherently narcissistic and self interested, engage in co-operative altruistic behaviour?   Is it just that we are social animals and as such have an inbuilt need to collaborate?   Such behaviour is built into us from the beginning; it’s instinctive; the baby clings to the mother, the mother’s instinct is to care for her infant.  Families stay together not just because there are distinct advantages for them to do so, but because there is a powerful emotional bond.  People group themselves in tribes.  There’s strength in numbers, but there’s also comfort, creativity and meaning.  In a social unit, the whole is greater than the sum of its parts.  No one person can do everything.  By adopting different roles, they can work as a unit to achieve much more as long as they see advantage in doing so and there is discipline.  And for that you need trust and leadership.  Difficulties arise when you have too many chiefs and not enough Indians.  Our survival as a species is based on collaboration.        

But we don’t collaborate with others just because we discern long term gains from such behaviour or because we avoid long term losses; we avoid being punished.   No, I think it’s deeper than that.  Our lives are built on meaning, the meaning that can only come from social interaction.  Our brains are wired by making emotional connections; neuroscience shows that the more we engage with the people and world around us, the more our brains adapt to cope; the more we grow as individuals.  It’s the way we form our identity.  Defection leads to autism, depression, exclusion and in an evolutionary sense, extinction.  Comparative research among primates indicate that the bigger the social group, the larger the size of the brain.  The implication is that you need big brains to hold in mind the dynamics of so many relationships. 

The key factor is trust.  Relationships, societies are based on trust.  Evolution assumes collaboration, at least for time enough to exchange genes but for social species collaboration must persist for much longer.  Trust is the glue that bonds people into families, friendships and tribes.  We have to know that at the end of the day, those whom we are bonded to by trust, will not abandon, mislead, exploit or betray us.  We need to know we belong.   Without trust we are like prisoners; always suspicious, watching our backs, making sure that others do not steal the advantage leaving us with nothing.  Society disintegrates without trust.  

The Prisoner Game is not the only game. There is another game for social animals and that is what my grandmother quaintly called courtship.  Here the goal is conjunction, the creation of a lasting bond.  In the edgy dance of courtship, each partner attempts to determine the sincerity of the other in all sorts of tests and tasks. ‘if you really loved me, you would do never be late, forget, let me down.’  The object is to build and establish the share mythology of absolute trust that will sustain the sufficiently to rear confident, trusting children while at the same time consolidating their place in the tribe.  In the courtship game, there is only one win.  The philanderer and seductress may achieve a short term gain, but it doesn’t last and both are the losers, gaining only disillusion and loneliness; lust, trust and bust!    

The Prisoner Game is based on false assumptions.  It assumes that human beings are purely logical, rational animals, who have no time for trust and only see personal advantage in relationships.  It is rather similar to the corporate game in which representatives employ the skills of seduction, charm and persuasion, to gain an advantageous deal.   Trust often doesn’t come into it; the best either partner can hope for is mutual advantage, bound by a written agreement, where law replaces trust.   But in the corporate world too, aren’t the best agreements forged during a round of golf or over a drink or meal?  The enjoyment of the game, the companionship, alcohol and food are ways executives still use to break down suspicion and promote trust, but increasingly such individuals are ‘protected’ by their PR companies.  As societies have expanded, so they have developed ever more efficient systems to protect themselves from ‘messy’ emotions.   You need more than the promise of good intentions if you are going to strike the best deal. 

Are so called civilised human beings becoming more selfish and more suspicious?  Do we trust less?   And are we paying the price for this?  Isn’t loneliness the major public health risk of our time?  Hasn’t the birth rate declined  – and the divorce rate gone up?   Are we breeding a generation of mixed up, disenfranchised kids?  Are we more split, more confrontational, more keen on our individual rights than building something together?  Is it better to be right than be together?  Is this the essence of our decline as a society?  Can we do anything about it?

The driver game, in which drivers choose whether to drive on the left or the right,  only works if the players can rely on each other to make the same choice.  A partnership must be mutual, in marriage, friendship or even corporate relationships.  If one partner does everything, if one partner is ambivalent, deceives, plays away, betrays, it doesn’t work.  But collaboration requires energy (though not as much as suspicion) and as long as their basic needs are met,  human beings are lazy. 

So is this the way the world ends – not with a bang, but a whimper?

Human beings don’t just adapt to their environment, they create and control it.  Ever since the early hominids developed an opposable thumb that enabled them to grasp and manipulate objects, they could make things happen.   The ability to throw missiles is a metaphor for how we could influence events at a distance, not only in space but also in time.  The use of tools to make shelters, to control external sources of energy allowed us to escape the urgent prerogatives of survival and find time to think.   Within the space of a few generations, humanoids endowed with the magic of manipulation,  could create the future by intention .   

Evolution does not happen by the gradual accretion of advantage,  it is jerked forwards by a change in environment.  That is what is thought to happen with our ancient ancestors.  A change in climate in eastern Africa constricted the forest, concentrating the apes that lived there and creating a niche on the edge, where the tall grassland encroaches, a space where only those apes with upright postures and opposable thumbs could hunt in.  Within the space of few generations,  certain humanoids have developed a specialised way of life; they became upright savannah apes that hunted in packs with spears and missiles.    

One advance creates the space of opportunity for other adaptations to occur. Using tools and  throwing missiles required a big, strategic brain to imagine, plan, predict and create.   Up to a point these abilities could be learnt by the small chimpanzee-like brain of our early ancestors, but those who had bigger and more clever brains were quicker and better at it, would survive at the expense of the others.   No longer did the strongest and fiercest inherit the earth by fear, the ability to create the future at a distance allowed the development of a meritocracy based on intelligence.  All that was required was the ability to project, not just physically, but literally throw one’s mind forward,  to imagine the way things might be, how others might think, to create a world out of our own mind.  Discovery always favours a mind, prepared by imagination and necessity.    And with imagination comes  strategy, planning, forecast, insight, hope, anticipation, and meaning; all the tools needed  to build a civilisation.

Survival on the savannah needed teamwork, the ability to work together as a group.  The maverick and loner would just starve.   Teamwork requires empathy and identification, the ability to project our wishes and desires onto others, to inspire them and create a group identity, based on meaning.  If people share the same meaning, then they will stay together and help each other.  So tribes stayed together and developed into larger communities not just because of a practical need, but because the tribe could preserve  the word, the identity that held them together.  Having an imaginative brain allowed human beings to derive meaning from things to make sense of their environment, to interpret, tell stories, invent Gods.

We begin to see the enormous advance the upright posture and opposable thumb, how these features allowed humans to project their minds into an infinity of intellectual space, rich in possibility.   

Godlike, we have produced a world in our own image and become adapted to that world.  We have determined our own evolution;  narcissism on an universal  scale.   No longer the tough stone age survivors, fighting to stay alive, dependant on the exigencies of the external environment, constantly on the move to where it is warmer and there is food,  we have tamed the wilderness and created a society, in which we can produce all we need, shelter, energy, food, water, entertainment. 

But in order to do this, we have had to forge ever more complex collaborations.  We have outgrown the narrow self centred confines of the tribe to develop much larger societies with different values, different priorities.   The ever increasing size of our communities from tribes to villages, to towns, cities, countries and finally a global community linked electronically, not only required a major logistic exercise in providing basic human utilities to everybody, but also created the need for civilisation, laws, morals and manners to keep such large in control.  Only those whose behaviour is compatible with the customs of society, will be allowed the freedom to live and breed in that society. Those who are more assertive and aggressive have been weeded out, killed, locked up, exiled. 

So we have we inbred domestication and passivity by our civilisation and laws.  We have selected out dangerous characteristics such as aggression,  ruthlessness,  physical strength and activity, and bred in other characteristics like laziness, passivity, dependency and overeating.  We have tamed ourselves.  And since aggression and physical strength are male prerogatives,  the new man has become more feminine. Civilisation means that men no longer seize their women by force, the power of selection is in the arms of the women, who arguably have a greater grasp of human nature.  And women are more likely to seek out sensitive, caring men to breed with.  They in turn will rear more sensitive children.     

All of this has created a different strain of human being, passive, a civilised, comfort seeking, intelligent and inventive creature.  Experiments conducted in Novobirsk, Eastern Siberia has shown that selective breeding over 50 generations has succeeded in domesticating Silver Foxes.  They become tame like dogs. The strange thing is that in breeding out aggression, other characteristics change too, like the colour of their coats and the shape of their heads, their ears and their tails.  In fact, they become like puppies.  Selective breeding for domesticity favours juvenile characteristics.

Has the same thing happened in human societies?  Has sexual selection succeeded in breeding out aggressive characteristics?   Are we all just big babies?   Have we bred domesticity in ourselves and in doing so become passive, lazy, needy and child-like?   And like the domesticated foxes,  have these social characteristics of being tamed, altered our appearance and the diseases we are predisposed to?    Has it, for example, caused us to become fatty and less hairy.  Has the combination of neediness and passivity predisposed to a plethora of diseases of civilisation; obesity, diabetes, heart attacks as well illnesses related to depression, such as Fibromyalgia and Irritable Bowel Syndrome?

Obesity and depression are the two most common illnesses of western society, affecting more than half the population.  Obesity is a disease of passive overconsumption and insufficient exercise.   We are consuming more than we need and we no longer need to work to get it.  There is an abundance of high energy food in infinite variety in our supermarkets.  Most of it is ready prepared and cooked and just requires reheating.  And without the basic requirements to hunt and fight, there is little need to exercise.  We travel to work in our cars and trains, we get our entertainment from the television, we do not even need to go out to work; we can work from our homes.  We don’t even need to get out of bed. 

In fact, we can exist without ever having to meet other people.  With personal computers, many people have their office at home.  No wonder we become quite isolated and depressed.    

If we remove the need to hunt, to build our own houses, to fight and compete, then we remove personal initiative.   And without human contact and something to strive for, life has little meaning.   We just exist, eating, drinking and sitting in front of the television,  rendered inert by the trappings of our own civilisation. Chronically bored, eating becomes less a necessity, more a displacement activity.  Many obese people are depressed.          

A few years ago,  I walked out from Malleleuca along Tasmania’s South Coast Track, carrying all the food I needed for 9 days on my back.  Meals were rationed; just enough for sustenance and no extra. I walked continuously from dawn to dusk across traversing precipitous mountain ridges interrupted by boggy valleys.  I felt more alive than I had for years and lost over nearly a stone in weight.

It’s our ability to control fire that made us human.  This is the message of Richard Wrangham’s new book, ‘Catching Fire’,  which was published last year.  It’s the latest big idea in evolution, the one that Darwin ignored.    

Wrangham approaches the subject from the perspective of an anthropologist and primatologist; he has worked at Gombe with Jane Goodall.  His hypothesis extrapolates from three sets of observations.  First, when food is cooked, nutrients are more easily digested and assimilated into the body.    Cooking softens meat, loosening connective tissue and allowing enzymes access to muscle proteins and fats.   Cooking also breaches the rigid cell walls of plants, exposing starches and sugars and vegetable fats to digestion.  Cooked meals require less work and less time to eat them.  Less effort needs to be spent in finding food that can be easily digested.  Cooking saves us time; time to think, to plan, to bond and it has to be said, to eat more food. 

By comparison, other mammalian species spend the majority of their time hunting, feeding and digesting their food.  Sheep and cows would never get enough energy to reproduce if they didn’t eat all day.  A male tiger needs to spend nearly all its waking hours hunting.  Only when it has had a big blow out, can the tiger afford to rest up and digest.   

But for humans, it’s different. They had time.  People gathered around their fires in the evening to tell stories, to sing, to drink, to plan the next day’s activities and to make love. It was around the hearth that tribes forged their identity in mythology. Fire became the focus of the social group, the hearth, the forge of civilisation. Cooking expanded the range of foods that could be eaten.  This meant that people didn’t have to hunt and gather particular foods; they could cultivate and herd them in farms.  This allowed people to settle in villages, towns and cities.  

Fire also led to a division of labour. Women were the cooks, the keepers of the fire, the gatherers and of course the mothers, whereas men were the hunters, the farmers and the protectors.    

Not only has fire enabled human beings to evolve socially, Wrangham believes that they have also adapted anatomically and physiology to eating cooked foods.   Our jaws are much weaker than our closest cousins, the chimpanzees; not at all equipped for cracking hard nuts and seeds or for tearing meat.  Our large intestines are nowhere near as commodious and efficient at extracting nutrients from uncooked vegetable matter.  People can live on raw food if they spend time seeking out and preparing foods that are sufficiently soft, but they lose weight and tend to become infertile.  Thus it seems we have evolved into a culinary ape.   Perhaps even our hairlessness was an adaptation to the control of fire.  Did fire allow us to dispense with fur and become the naked ape.        

The important thing about a good hypothesis is not that it’s right but that it makes you think.  Wrangham’s hypothesis certainly makes us think , but it is probably not entirely accurate. 

 We are not the only species with small guts.  Carnivores,  dogs, cats have much smaller guts probably because they don’t need a big fermenter to break down complex plant material.  Perhaps the early homonids were predominantly hunters and scavengers; they ate predominantly meat and were strategically adapted to hunting and trapping animals.  But their poor dentition may indicate that they lived on soft body organs or even on food that was half rotten with some additional fruits and leaves.     

 Cooking is not the only way of softening food, acid in the stomach does it too.  After they have made a kill, lions and tigers need to rest for several hours for acid digestion to occur.  The acid in human stomachs is as strong as that in other carnivores.  The thing is, we can survive without cooking.  We can all eat raw food though we may not have much time for anything else.  Cooking saves time.          

But is there any evidence in the fossil record that links the development of humans with fire?   Humanoids with the characteristic shape that we have now,  Homo habilis and Homo erectus,  appeared about two and half million years ago, but the earliest evidence we have of hominids  controlling fire is 750,000 years ago.     

So was cooking the big breakthrough that allowed human beings to evolve into a more physiologically efficient mammal by relying on an external source of energy?   Did we develop our human shape and physiology because our ancestors had learnt to harness fire?   Or was  cooking an evolutionary accelerant rather than an instigator? 

According to Darwin’s deductions, evolution of species does not tend to occur gradually over millions of years, it is jerked forwards by environmental change;  only certain individuals were sufficiently equipped to survive and breed under the new conditions and they produced more individuals with the same improved adaptations. 

The accepted wisdom is that human evolution was instigated by climate change in sub-Saharan Africa.  Less rainfall led to a dying back of the rainforest and its replacement by savannah.   Certain of our ancestors could survive at the edges of the forest.  They learnt how to trap and kill the grazing animals for food.   Some had a more flexible thumb that could be opposed to the other digits allowing them to grip and manipulate tools.  These better equipped individuals could make and use tools, they could fashion weapons, they could throw things;  they could project into the future.  These adaptations led quickly to others.  Only those with the most efficient weaponry and skill, would survive, the rest would be killed off. 

Genetics provides the potential, the environment brings it out.   The brain develops according to experience, though some brains are more adaptable.  In a rapidly changing environment, only those apes able to adapt, survive.  So, over relatively few generations, a sub culture is selected out.  Seen from this context, fire is another tool, something the advancing ape learnt to control, but it rapidly became indispensible. Hominids adapted to it and indeed could not survive without it.  Fire now does so many other things besides cooking, it drives engines that make things and get us places.  And now we have discovered enormous supplies of fossil fuels, we are totally dependent on the energy it gives us, so much so that few of us would survive without it.  And yet, supplies of fossil fuel are finite.  They will be depleted in 30 years.

David Nash has a real fascination with wood.  He knows his material intimately.  He knows how it weathers, dries out, splits aling the grain.  He understands how it chars and how it becomes waterlogged and rots.  Wood expresses the fundamental elements of life; earth, fire, air and water.  Nash is interested in how wood comes into being, how it occupies a place and how it changes.  It might be a commentary on the human lifespan.   

Some of his creations take years for Nash to complete.  He planted Ash Dome, a ring of ash trees in 1977 and then fletched the joints so that as they grew, they appeared to be dancing in sequence and then bending in on each other to form the shape of a dome.  . 

He launched his wooden boulder in a stream in 1979 and followed its progress, urged on by storms and floods until it reached a bigger river and finally the estuary.  He then plotted its progress with the tide up and down the estuary until it finally disappeared.  Now after three years, it has turned up again in the same estuary. 

In Bretton Park, he has charred a tree trunk and bole by building a palisade of sticks around them and setting them alight with a burner.   The surface of the trunk splits and cracks into shiny charcoal nodules.  He has embedded 28 charred oak steps up the Oxley Bank in 30 tons of Barnsley coal.  They will slowly be worn down by people walking on them and return to the earth.  Nash likes to study how things decay. 

He bought his chapel studio in Blanau Ffestiniog in 1967.   Hunkered down n a wasteland of slate, filled with half completed works, one gets the impression that he is waiting for growth and time to transform them and him.    

Occasionally Nash’s his work is more political.  The charred verticals and cross pieces of ‘An awful falling’ evoke the destruction of The World Trade Centre,  while ‘Husk’ a group of hollowed out, charred, rectangular blocks of oak, resemble a burnt out village in Palestine. 

I love the scale of Nash’s work.   Who would wait 30 years for nature to complete a work?  Who would shape a gigantic piece Californian redwood shaped into a square with a gigantic two man chain saw and install it with off-cuts in an underground gallery in Yorkshire?   Who would arrange three massive tree trunks on the lawn, curious to see the way the wood would split.   But at the other end of the scale is elegant Ubus, two slender limbs of wood, one oak, one beech, leaning into each other to resemble an arch, reminiscent of the whalebone arch in Cley-next-the-sea.

This is my second visit to Nash’s epic retrospective at the Yorkshire Sculpture Park.  Simon gave me his ticket to the opening and I met the artist.  He had the look of an explorer about him, a trained observer, more scientist than artist; clear, perceptive, curious, calculating and full of insight and possibility.  I marvelled again at the confidence and self belief of the artist and guessed that it came from a fascination with the object and not with himself as the artist.

He piercing blue eyes put me in context as they would a block of wood.    

 ‘So you’re Simon’s brother.  Yes, I see.  You’re like him.  Is he still on the boat?’ 

 

David Nash’s exhibition will be at the Yorkshire Sculpture Park until February, changing with time and the seasons.  It’s not far away; I shall evolve with it.   

Our world and everything in it including ourselves has been shaped by water.  Yet how much do we understand it?

Left to itself, water approximates to a sphere, circular currents bounded by surface tension,  but when subjected to gravity, then the circular forces in the water turn the flow into a spiral form (or two spirals in one), bending it from side to side and creating meanders in rivers as silt is taken from the outside off the curve and deposited on the inside of the next bend. The same spiral arrangement also exists where water from different sources come together – the warm waters of the gulf stream spiral around the colder currents, the clear Rio Negro and the muddy Amazonas spiral adjacent to each other for scores of miles after they merge above Manaus.    

Add an external force like dropping a pebble in a bowl and water will adopt a natural frequency of vibration depending on the configuration of the container.  Vibration may also be imposed by wind or obstructions to flow, creating ripples, that can be recorded on sand and rocks.  The gravitational effect of the moon exaggerates natural rhythm of water around the globe.  

Waves in open water are created by the wind on the surface or a rising sea bed close to the shore. Although the wave moves, the water in it just circulates. Rays and other fish swim like a wave through the static circulating water.  The wave ‘breaks’  when wind accelerates the top and causes it to overbalance or when the rising shore line slows down the base.   This creates a horizontal air/water vortex that churns and oxygenates the water. 

In contrast, the standing wave generated by the fall of water in a weir is static and water flows through it.   So the wave is a feature of water, but does not necessarily relate to its flow.  

An obstruction in a river or the flow of a stream of water into a static pool,  creates vertical vortices; paired boundary areas where fluids of different pressures coalesce and mix.  

Multiple sources, sinks and currents combine to create more complex fluid structures that has been compared to a symphony in which different instruments have their own entries and rests and are brought together by an invisible conductor.  Flow must be turbulent for exchange to  occur.  If it is channelled through a straight pipe, or settles at the bottom of a deep pool, it cannot form vortices, transfer of material cannot occur and water stagnates .

Water is a complex, sensitive medium that can respond to the environment to create a multiplicity of forms.  Living creatures start their live as suspensions of cells in water.  They must therefore be  influenced by flow patterns of the medium of suspension and develop out of these patterns   So simple multi cellular organisms living in water often adopt spiral forms.  Snails have a spiral shell.  The muscle fibres of the heart adopt a spiral arrangement with compartments forming at the junction of different flows (oxygenated blood from the lungs and deoxygenated blood from the rest of the body).  Movements of fluid are incredibly sensitive; they respond to minor change.   Nerve cells seem to line up at the boundary zones where the effects of those changes have most effect. 

Now if we imagine that the world and everything in it was initially composed of fluids initially, then we can see how solid forms in nature conform to a vortex configuration.  Vortices are consolidated in rocks when they cool.  Jellyfish are 96% water and resemble complex vortices.  When their mantle contracts, they produce mirror images of themselves in the vortices they leave behind.  And look at other vortex forms, the cochlea of the ear, the semicircular canals, which in the lamprey are still fluid vortices, the turbinate bones of the deer, the intestine of the lungfish is spiral in form, the intestine of the cow circular. Even the embryo starts off as a complex vortex of cells, whirling boundaries where things occur, cells are laid down, nervous connections are created.   We might even envisage organs being created out of paired vortices).     

Water cannot just be understood by its chemical properties.  It is the stuff of life, the circulation that runs through all living things.  Sensitive Chaos; creation of flowing forms in water and air was written by Theodore Schwenk (1910- 1986), anthroposophist, engineer and director of The Institute of Water Research and Flow Science in the Black Forest.  It is a remarkable, thought provoking book that escapes the stagnation of research protocols and methodology and allows the imagination to flow unimpeded; the sort of book that makes us reflect on what might be so.  That, surely, is the  essence of science.    

 

 

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