My Times review of Gareth Williams's new book Unravelling The Double Helix.
Who discovered DNA? James Watson and Francis Crick, right? Wrong. Eighty years before they even approached the topic, in 1868, a young Swiss researcher, Friedrich Miescher, working at the University of Tübingen, discovered DNA as a chemical substance, though not its revealing structure.
Miescher, who was not squeamish, analysed the pus extracted from bandages applied to wounds by a local surgeon. He painstakingly precipitated out a fluffy substance he called “nuclein” that was rich in phosphorus, unlike any protein and found mostly in the nuclei of white blood cells in the pus. However, to those who speculated that nuclein might carry the secret of heredity and life itself, Miescher was dismissive: no, it was just a store of phosphorus. Heredity was surely determined by the much more intricate and varied structures of proteins.
Gareth Williams, the former dean of medicine at Bristol University, has woven a truly superb narrative from short biographies of all the scientists who contributed to, and in some cases just missed out on, the epochal discovery that the secret of life is a digital linear code written on DNA. We now know the answer to Miescher’s objection: DNA looks boring and repetitive as a book looks boring and repetitive: it’s just a pile of bases, as a book is just a pile of pages. But what’s spelt out on the pages in linear digital code can be far from boring, as this book proves.
Miescher’s mistake — that genes are made of protein — dogged the topic for decades. As late as the 1940s, in New York, the Canadian Oswald Avery and two associates struggled to persuade the world that genes were made of DNA, despite his penetratingly clever and careful experiments with pneumonia-causing bacteria that showed conclusively that it was a piece of DNA that heritably transformed the character of the bacterium from harmless to virulent.
Avery, like Miescher, was an unworldly workaholic unprepared to fight for his heresy against the protein orthodoxy that dominated scientific opinion. By contrast, his own colleague at the Rockefeller Institute Alfred Mirsky showed a positively unhinged obsession with criticising poor Avery and defending proteins to the bitter end.
There are terrible near-misses in all of science, people who could have been as famous as Newton if they had taken one more step. The tale of DNA is rich in them. John Masson Gulland, a Scottish biochemist, spotted in 1947 that hydrogen bonds almost certainly held DNA strands weakly together (the key to how reproduction works at the molecular level) and was even asked at the end of a talk by one of his students if DNA might have a helical structure. He ignored the point in his answer. Shortly after, Gulland gave up the subject in a fury at not being made professor of biochemistry at Edinburgh and was killed in a train crash a few months later.
A young Norwegian, Sven Furberg, while working in London in 1949, came tantalisingly close to unravelling the structure of DNA, having had the key insight that the planes of the bases and sugars were at right angles to each other. He even built a model, but his supervisor, the flamboyant, philandering communist JD Bernal, was otherwise preoccupied. Bernal was attending a peace conference in Moscow at the time, where Pravda said he got “stormy and prolonged applause” for praising Comrade Stalin as the “great protector of peace and science”. Bernal even visited Trofim Lysenko, whose persecution of geneticists had recently led to the death of the great Russian geneticist Nikolai Vavilov in prison for biochemical thought crimes. Bernal praised Lysenko, a mystical and murderous quack, as “a scientist of the Darwin-Rutherford type”.
Meanwhile, in Leeds, where the wool industry had financed early work on the molecular structure of fibres, Bill Astbury was honing the technique that would lead to the answer, x-ray crystallography. His student Elwyn Beighton took a series of superb photographs in 1951 that revealed in all its glory that the structure of DNA was a double helix — if only he knew how to interpret them. But Beighton and Astbury did not know, and Astbury lost interest in DNA, so the pictures went into a filing cabinet and were forgotten.
A year later, in 1952, Raymond Gosling took an x-ray photograph at King’s College, London, which showed almost exactly the same pattern as Beighton’s. This became one of the most famous icons in all science, “photograph 51”, about which a play has been written. But Gosling’s supervisor, Rosalind Franklin, put it to one side for several months, before writing up her work when preparing to leave for Bernal’s laboratory. She handed the DNA project, plus Gosling and the photograph, to her colleague Maurice Wilkins, who had started the DNA work at King’s. Wilkins showed the picture to Watson, who realised its significance and described it to Crick, who knew better than anybody how to interpret it, and the rest is history.
Many of these stories of scientific also-rans and near-misses are well known. Others are not. Despite being Crick’s biographer, I did not know the story of Beighton’s photographs, nor had heard of Gulland. By choosing to fill in the gaps in conventional accounts, Williams has done a good job of telling the whole story of science’s greatest discovery. He has done it with fluency and a real feel for narrative.
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