Читать книгу The New Elizabethans: Sixty Portraits of our Age - James Naughtie, James Naughtie - Страница 21

Even allowing for the tolerance of some pubs in Cambridge, where you might not be surprised if on a chill Monday evening someone threw open the door and shouted the news that Shakespeare’s plays had been written by a mysterious woman whose identity was now going to be revealed for the first time (before subsiding into exhausted silence), a few people must surely have turned their heads on 28 February 1953, when two scientists tumbled into the Eagle in Bene’t Street and announced that they had ‘discovered the secret of life’ and had the proof in their lab.

They were Crick and Watson, Francis and Jim, and the scene is worth remembering because hindsight often lends work like theirs a formal aura as if everything happened in an orderly fashion, properly, in sequence, as if planned. They had worked for years on what we would later come to know as genetic biology, but the circumstances of their great discovery were quite chaotic, and controversial too. Moreover, it was little noticed at the time that they had given a shape to the building blocks of life, and suggested how they might fit together. Not many people, after all, knew about deoxyribonucleic acid. We all know it now as DNA.

Their first scientific paper on the subject was published in the journal Nature in April 1953 – Crick was the principal author – and, looking back from an age where the science of genetics has become a rolling public debate, and often the stuff of headlines, it’s startling to note that it caused no public excitement at all. The only newspaper to pick it up was the News Chronicle, long defunct; there was no broadcast news of it, and the university paper Varsity could hardly claim that its short report was going to shake the world. Yet it was a story that would: a step into the unknown, the invention of a new branch of science, the first serious claim to understand the working of our genes. By whatever name it is known, it was a revolution.

In that first paper Crick wrote the following sentence, which is one of the masterpieces of understatement of our time, with a whiff of self-satisfaction that was characteristic: ‘It has not escaped our notice that the specific pairing that we have postulated immediately suggests a possible copying mechanism for the genetic material.’ In other words, how genetic messages are passed on and how we perpetuate ourselves. Not perhaps who we are, but a clue about how we come still to be here.

The ‘specific pairing’ was revealed by the model Crick and Watson had built in Cambridge University’s Cavendish Laboratory: the double helix that would become the emblem of their discovery, and a Rosetta stone for modern science. At the top of the structure, two threads are intertwined and then, below, they flow outwards like two locks of hair freed from a perfectly pleated pigtail. As it was once described: ‘The two strands of the double helix separate, and a daughter strand is laid down alongside each with a constitution determined by the base sequence of its parent strand.’ They had established how messages might be carried by DNA, the memory system in our genes, and Crick postulated that there were molecular tags that could interpret the make-up of a gene – as if reading a codeword – and then deliver the right amino acid to the right living cell: the machine inside us all, that shapes everything we do.

Nine years later this was the discovery that brought Crick and Watson (with Maurice Wilkins) the Nobel Prize for Medicine, although that simple fact conceals a story of rivalry that sits uncomfortably and sometimes painfully alongside the fact of their success.

In the two years or so before the first paper on DNA, and the construction of the double helix, there was quite a race going on among those who were using X-ray crystallography to try to peer into the inner workings of our biology. Crick was at the centre of it all, and even before the younger zoologist James Watson arrived from the United States in 1951 he was cooperating with a scientist at King’s College London called Maurice Wilkins, whose experiments were making progress. Fortunately, but awkwardly, Wilkins had a colleague at King’s without whom the story of DNA can’t be told. She was Rosalind Franklin.

It was her work that gave Crick and Watson a leg-up. On one visit to London to see some of her experiments, Watson realized that she might have provided the key. Back in Cambridge he and Crick worked on a model. They invited their rivals from King’s to come and see it, describing it as ‘a clever thing’. Rosalind Franklin took one look at it and realized that they had taken her results, applied them to their own, but made a serious mistake. They had built a ‘triple helix’, and she told them where they had gone wrong.

The background was like the setting of a C.P. Snow novel about skulduggery in the senior common room of the kind that he was just settling down to write. At King’s, Wilkins did not get on with Franklin at all. And to complicate matters, the head of the Cavendish Laboratory, William Bragg, was sensitive to the feelings of the King’s scientists, who didn’t want their work to be copied. He is said to have suggested to Crick and Watson that they stop working on DNA altogether. Wilkins confessed his despair at the whole business to Crick in a letter, and the atmosphere is well summed up in Crick’s reply, which came to light only a couple of years ago. He wrote to Wilkins: ‘… so cheer up and take it from us that even if we kicked you in the pants it was between friends. We hope our burglary will at least produce a united front in your group.’ The word ‘burglary’ was presumably meant as a mild joke.

In Cambridge they seemed happy, in London miserable. Wilkins wrote to Crick about Franklin, who was about to leave King’s, and used a poisonous tone: ‘Let’s have some talks afterwards when the air is a little clearer. I hope the smell of witchcraft will soon be getting out of our eyes.’

Crick and Watson carried on. The triple helix was transformed into the double helix, their own mistake corrected, and gradually – after a second article in Nature later in the year – the significance of the discovery began to be appreciated in a wider circle. And the names of Crick and Watson were bolted onto the double helix as if they were part of its origin, though many others had had a part in putting it together. Rosalind Franklin died of cancer in 1958, aged only 38.

Francis Crick was born in Northampton, son of a shoe factory owner, and studied physics in London. In the Second World War he worked on weapons in the Admiralty, designing mines. Afterwards he decided he was more interested in biology. That abrupt change of direction was quite typical of a man who had a reputation for the unexpected gesture and a tendency towards utter certainty. When Watson wrote an account of their discovery in 1968, he produced an opening sentence about his friend and colleague that summed up their over-the-top and maybe brash style, separately and together. ‘I have never seen Francis Crick in a modest mood,’ said Watson. Neither saw any reason to be diplomatic, even about each other.

It was not that their friendship was falling apart – it lasted until Crick’s death in 2004; Watson still survives him – but that they were a pair of swashbuckling scientists, whose meticulous work often seemed to take second place to their love of the instinctive thrust, the imaginative spring. The year after the double helix was built, Watson wrote to Crick: ‘The important thing is to ignore data, which complicates life.’

The style was formidable. After Crick became celebrated he had a postcard printed for his secretary for use as a reply to enquirers. It was headed ‘Dr F.H.C. Crick thanks you for your letter but regrets that he is unable to accept your kind invitation to: …’ There followed a list of requests of the kind he was used to receiving: send an autograph, be interviewed, speak after dinner, deliver a lecture, read a manuscript, even ‘cure your disease’. His secretary had instructions to tick the appropriate category and send the postcard. It repelled all boarders.

So Crick was a character, irascible on subjects like religion, which, like most philosophy, he abhorred. (He resigned from Churchill, a new Cambridge college, when he discovered they were building a chapel.) And those close to Rosalind Franklin, particularly, long held a grudge at what they believed was a betrayal of her originality and the contribution she’d made to genetic research.

But it would be quite wrong to picture Crick as a scientist who happened to break the mould very early – he was 36 when the double helix paper was published – and spent the rest of his life being famous for it. The truth is that much of his pioneering work was done after that first discovery. He never left the territory he had staked out, and long after he was one of the three men who got the Nobel Prize in 1962 he was breaking new ground.

The initial proposition had been that there was some kind of linear genetic message that could be passed on. They had discovered how genes could copy themselves and human life could replicate. We had a glimpse of how the essentials of human life were managed. But then what? It was a beginning, not an end. Crick set about working on the question of how genes coped with the instructions they’d been sent, and it was thirteen years after the first Nature paper before he felt able to declare that he might have an answer.

The occasion was the annual meeting of molecular biologists at Cold Spring Harbor in the United States, where he was now working. They were scientists whose field of study had more or less been created by Crick and Watson and whose successors, a generation later, would find themselves in maybe the most exciting, ever-changing field of science, mapping the genome, inspiring medical research with possibilities, opening up territory for doctors as well as scientists that not long ago had been an impenetrable misty landscape with no signposts.

Crick began that 1966 speech with the words: ‘This is an historic occasion. There have been many meetings about the genetic code during the past ten or twelve years but this is the first important one to be held since the code became known.’ A typically emphatic description. He went on to announce that he could now present to the world the genetic code in its entirety. It was this map that would become a guide for everyone working in molecular biology, and in medical laboratories everywhere the step-by-step unravelling of the genetic puzzle changed everything. Crick himself led the way, and it will be his name that is attached to the institute that will open in 2015 in London to bring together some of the world’s finest minds in biomedicine.

It is worth remembering Watson’s reminder to Crick about data complicating life: go for the big idea. When they marched into the Eagle in Cambridge in 1953 convinced they had ‘got it’ they weren’t talking about a vast tome that they’d been writing in secret. Their article in Nature was only fourteen paragraphs long, and attached to it was a single diagram: the skeletal and beautiful picture of the double helix itself; the strange, sparse outline of the most intimate thing in the world.