At the Water's Edge. John Lister-Kaye
in search of the final secret? The journey is difficult, immense and at times impossible, yet that will not deter some of us from attempting it. We cannot know all that has happened in the past, or the reason for all of these events, any more than we can with surety discern what lies ahead. We have joined the caravan, you might say, at a certain point; we will travel as far as we can, but we cannot in one lifetime see all that we would like to see or learn all that we hunger to know.
Had I possessed the wit and the courage, aged thirteen, to press the point, I fear that I would have been disappointed. There were no answers in his biology department (despite having it endlessly banged into us that bios logos meant the ‘reasoning of life’), nor were they in his long shelves of books gathering dust beneath the lab windows; not even, I suspect, inside that wise old head. The answers I sought were then and are to this day back in my jam jar – dreams and sunbeams mingling.
Back in 1953 (only six years before I discovered the joys of photosynthesis) Stanley Miller hit lucky. The young Stan, of whom I have a photograph in front of me on my desk, is dutifully dressed in a collar and tie and an immaculate white lab coat. He looks serious, with trim ’50s short back and sides and horn-rimmed glasses. He seems to be posing: holding up a flask at the University of Chicago, where he conducted his groundbreaking experiment. He looks a little nervous, which is hardly surprising since at the raw age of twenty-three he had just been catapulted into the global forefront of organic science. Nervous or not, he is every inch the chemistry student. I get the impression he’s never been shopping in his life, that he has an over-protective mother, folds his pyjamas every morning and persistently ducked out of games at school.
He is standing in front of a grid of retorts from which hangs a tangle of apparatus: a flask and a pressure vessel, pipes, valves, U-tubes and cables. This is the young man who set the science world a-buzzing with what the world’s press headlined as ‘Finally ringing the death knell on Creationism’ – a final blow added to the still-haemorrhaging wound of iconoclasm inflicted by Darwin and the Evolutionists back in the 1860s. Miller had, they proclaimed, handed science the unequivocal proof for the origin of life on Earth. The question was inevitable. At a seminar presenting his results to rows of famous faces in the internationally acclaimed and predominantly sceptical audience of scientists, he was asked if he thought this was how life started. Miller’s professor, Harold Urey, leapt to his student’s defence. ‘If God didn’t do it this way, then he surely missed a trick!’
What the young graduate student had actually done was nothing of the sort – he hadn’t proved a thing. But he had managed to simulate in his flasks and vessels the primitive conditions that probably existed on Earth about 3,000 million years ago, roughly when life might first have emerged.
The Earth is about 5,000 million years old; for the first 2,000 million it was too hot and all the oxygen was tied up in rust – bonded into oxides with other elements such as iron and silicon, which form much of the Earth’s crust. The atmosphere consisted principally of four gases: methane, ammonia, hydrogen and water vapour from volcanic eruptions. Then along comes the irreversible influence of the sun.
Somehow, somewhere, all those billions of years ago, in some anonymous mist of eye-stinging, nauseous vapour swirling through the Earth’s electrically crackling atmosphere, lightning, together with ultraviolet and gamma radiation from the sun, bombarded those four gases until they metamorphosed, brewing themselves into a stew of amino acids. Bang! (or perhaps it was Fizz! – the first building blocks of proteins had arrived on our planet.
Stanley L. Miller rigged up his pipes, tubes and electrodes with the water flask, pressure vessels and a cooling jacket, sealing the vital ingredients within a bell jar. He sucked out the air, creating a sterile vacuum. Then he pumped in the mix of gases and boiled up the water in the flask so that steam circulated throughout. Once he was satisfied that they were all in place in the sparking chamber he gave it a kick of home-made lightning.
He ran it for a week. The solution in the flask turned yellow-brown and an oily tar formed on the walls of the sparking vessel. As the water cooled he found that fifteen different amino acids had condensed out in the U-tube. This was laboratory-induced prebiotic synthesis.
The experiment was opened to peer review with publication in Science – one of the leading journals of the scientific world – on May 15th 1953. It was an experiment, no more than that – a shot in the almost-dark of inspired guesswork. It had not proved how life did start, but it did demonstrate how life could have started. Later, Melvin Calvin did much the same thing using gamma radiation, shunting Miller’s work a quantum leap further forward. As well as a mix of amino acids, Calvin’s experiment produced simple sugars, and some of the purines needed for nucleic acids. Nineteen fifty-three was an extraordinarily productive year in the world of organic chemistry. Only a few months later Watson and Crick would publish their double-helix model of DNA.
If, in fact, these primitive organic molecules were synthesised in the atmosphere, it is likely they were washed down to Earth by rains, which in time accumulated in oceans and lakes – life’s natal soup. By some unfathomable twist of chemistry these tiny molecules – now blue-green algae or bacteria-like organisms – discovered how to replicate each other (asexual reproduction) and nourish themselves by grazing on the others around them. Some stole a march – did better than the rest. Competition was born. It was probably competition that forced some of them to abandon chemosynthesis (munching other molecules for energy), and turn to sunlight – photosynthesis – instead. That was the really smart move. Now we had single-cell organisms pumping out free atmospheric oxygen – so far absent from our story – and the beginnings of a balanced ecosystem. One lot of primitive organisms was capable of synthesising organic food from inorganic materials and providing the oxygen for the rest, which hungrily consumed it and emitted carbon dioxide for the first lot to feed on – the very beginning of the cycle of interdependence of all living things, of which we are an essential part.
So there you have it – the progenitors of the plant kingdom busy feeding the progenitors of the animal kingdom. Let Darwin have his say and before you can mutter ‘deoxyribonucleic acid’ you have asexual and sexual reproduction operating side by side, both primed with variant mutations (thanks to radiation from the sun) and all replicating and out-competing themselves as fast as they can. Suddenly there are sharks and whales in oceans brimming with plankton, iguanas clambering over rocks, mountains wrapping themselves in jungle, kiwis not bothering to fly, dung beetles rolling globes of their own, albatrosses circumnavigating the oceans of the world and Red Indians chasing buffalo over cliffs. Here we all are, from the amoeba to Einstein, munching each other in glorious sunlight for all we are worth. God, meanwhile, whoever he may be and wherever he lives and moves and has his being, and whether he engineered the whole thing or not, has somehow been left in the shade.
The grass I am lying on is heading in two directions at once. The pallid stalks of winter are going to ground. The forces of decay are already breaking them down, microbes are jostling for their sugars, bacteria are ravenously ingesting, saprophytic mould and slime fungi are pitching in with the slow, mechanical infiltration of their fibres. In a few weeks the old mat will be gone, no longer distinguishable as grass, just a mushy, khaki mulch rapidly decomposing its way to becoming soil, loaded with humic microbes, providing nutrients for its own roots. The new shoots of photosynthesis are heading up, worshipping the sun, dizzy with light and carbon dioxide.
A shadow crosses my closed eyes. For the briefest flicker something has passed between me and the sun. I am instantly awake. I know I’m no longer alone. My eyes ease open, feeling the drag of my irises urgently and involuntarily stopping down. Squinting, I glance to the right and left. The sky above me is enamelled with brilliance, but the chaffinches are no longer singing. Even the busy wren has stilled her trill. Slowly I pull up onto one elbow.
Twenty yards to my left a line of electricity distribution poles crosses a field. My eye is drawn to the apex of the nearest pole. There, shining in newly burnished copper, is a kestrel. He is small, smaller than a pigeon and neat with it in a dressy way, but he