Francis Crick

• 1. Introduction

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  On his death bed, Francis Crick was editing a manuscript. "He was editing a manuscript on his death bed, a scientist until the bitter end," said his colleague Christof Koch. Crick died of colon cancer on the morning of the 28th of July 2004, at a hospital in La Jolla, California. He was 88. His ashes were scattered into the Pacific Ocean.

  Born on the 8th of June 1916, Crick became one of the people who deciphered the helical structure of the DNA molecule. He shared that work with James Watson, Rosalind Franklin, and Maurice Wilkins. He coined the phrase "central dogma" to describe how genetic information flows in one direction only.

  But the man who explained the molecule of heredity began as a physicist measuring the viscosity of water. He called it "the dullest problem imaginable." He spent the war designing mines to sink German minesweepers. And the discovery that made him famous rested in part on data taken from a colleague without her knowledge. How does a bored physicist become the theorist of life itself? Why did he abandon the field he transformed to chase the mystery of human consciousness? And what controversy still trails the most celebrated discovery of twentieth-century biology?

• 2. A Naturalist's Grandson

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  Walter Drawbridge Crick, an amateur naturalist, corresponded with Charles Darwin and had two gastropods named after him. He was Francis Crick's grandfather, and he wrote a survey of local foraminifera, single-celled protists with shells. The family ran a boot and shoe factory in Weston Favell, then a small village near Northampton.

  Francis was attracted to science from an early age, drawn to what he could learn from books. His uncle Walter kept a shed at the bottom of a little garden on Abington Avenue. There he taught the boy to blow glass, to do chemical experiments, and to make photographic prints.

  By about age 12, Crick told his parents he no longer wished to go to church. He preferred a scientific search for answers to religious belief. That preference would harden over a lifetime into open hostility toward Christianity.

  At 14, on a scholarship, Crick went to Mill Hill School in London, where he studied mathematics, physics, and chemistry with his best friend John Shilston. On the school's Foundation Day, Friday the 7th of July 1933, he shared the Walter Knox Prize for Chemistry. He credited his later success to the teaching he received there.

• 3. The Reluctant Physicist

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  A bomb fell through the roof of a University College London laboratory during the Battle of Britain and destroyed Crick's experimental apparatus. He had been measuring the viscosity of water at high temperatures, under the physicist Edward Neville da Costa Andrade. The war deflected him from a possible career in physics. During his second year as a PhD student he had won the Carey Foster Research Prize, which he considered a great honour.

  Crick earned a Bachelor of Science from the University of London in 1937, after studying at University College London. The war interrupted his doctorate before it could begin in earnest.

  During World War II, Crick worked for the Admiralty Research Laboratory. He designed magnetic and acoustic mines and was instrumental in creating a new mine effective against German minesweepers. The laboratory produced many notable scientists, among them Harrie Massey and Nevill Mott.

  In 1947, aged 31, Crick began studying biology. He joined what he called an important migration of physical scientists into biological research, made possible by figures such as Sir John Randall, who had helped win the war with inventions including radar. Crick described the shift as "almost as if one had to be born again."

• 4. The Race For The Helix

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  Sir Lawrence Bragg had won the Nobel Prize in 1915 at the age of 25. He directed the Cavendish Laboratory at Cambridge, which Crick joined after working at the Strangeways Research Laboratory under Honor Bridget Fell. Bragg wanted to beat the American chemist Linus Pauling to the structure of DNA. Pauling had already pipped the Cavendish to the alpha helix structure of proteins.

  Late in 1951, Crick started working with James Watson. Crick was a 35-year-old graduate student, delayed by his war work. Watson was only 23 but already held a PhD. They talked endlessly about DNA and whether they could guess a good molecular model of its structure.

  A leading piece of evidence came from X-ray diffraction images taken by Rosalind Franklin and her graduate student Raymond Gosling at King's College London. The most famous of these was "Photo 51." Crick did not see Franklin's B form image until after the double helix model was published. Of the four DNA researchers, only Franklin held a degree in chemistry.

  The Chargaff ratios proved another key. The amount of guanine equals cytosine, and adenine equals thymine. Watson, playing with cardboard cut-out models of the bases, realised that A pairs with T and C pairs with G, and that each pair is the same length. The hydrogen bonds at the core offered a way to "unzip" the strands for replication. Crick said that without Watson, he would not have found the structure by himself.

• 5. The Stolen Data

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  On the 6th of March 1953, two of Rosalind Franklin's manuscripts on form A DNA reached the journal Acta Crystallographica in Copenhagen, one day before Watson and Crick completed their model. Franklin did not know that Photo 51 and other information had been shared with the two men. In her drafts she argued for a double helical backbone and discovered that form A DNA had antiparallel backbones.

  Watson and Crick drew on three sources for Franklin's unpublished data. The first was a 1951 seminar that Watson attended, where she presented the A and B forms and placed the phosphates on the outside. The second was discussions with Maurice Wilkins, who worked in the same laboratory. The third was a research progress report, prepared for a Medical Research Council committee, that Crick's thesis advisor Max Perutz handed to him in February 1953.

  It remains a matter of debate whether they should have had access to her results without her knowledge or consent. Perutz later published the report, arguing it contained nothing Franklin had not said in her 1951 talk. Brenda Maddox suggests Franklin should have had her name on the original Watson and Crick paper.

  Franklin's colleague Aaron Klug believed she was "two steps away" from the double helix. After analysing her lab notebook, Klug concluded she surely would have had it. When she left King's College, Director Sir John Randall insisted all DNA work belonged to King's and ordered her not to even think about it. She went on to do superb work on the tobacco mosaic virus at J. D. Bernal's lab at Birkbeck College.

• 6. Why You Are You

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  "My Dear Michael, Jim Watson and I have probably made a most important discovery." So Crick began a seven-page handwritten letter to his son at boarding school on the 19th of March 1953. The discovery itself was made on the 28th of February 1953. The letter sold at auction at Christie's New York in April 2013 for $6,059,750, the largest amount ever paid for a letter at auction.

  The first Watson and Crick paper appeared in Nature on the 25th of April 1953. Bragg announced the discovery at a Solvay conference in Belgium on the 8th of April, an announcement the British press ignored. Wider news came after a talk at Guy's Hospital Medical School on the 14th of May, which produced an article headlined "Why You Are You. Nearer Secret of Life."

  In April 1953, Sydney Brenner, Jack Dunitz, Dorothy Hodgkin, Leslie Orgel, and Beryl Oughton were among the first to see the model. Working at Oxford's Chemistry Department, they travelled together in two cars once Hodgkin announced they were off to Cambridge. Brenner was especially impressed and later worked with Crick at the Laboratory of Molecular Biology.

  Crick was often described as very talkative. He spoke rapidly and loudly, with an infectious, reverberating laugh. A Salk Institute colleague called him "a brainstorming intellectual powerhouse with a mischievous smile," adding, "In a room full of smart scientists, Francis continually re-earned his position as the heavyweight champ."

• 7. The Central Dogma

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  DNA to RNA to protein: this one-way flow of genetic information is what Crick named the "central dogma." Some critics thought the word "dogma" implied a rule beyond question. Crick said he only meant a compelling idea without much solid evidence to support it.

  George Gamow had formed the RNA Tie Club, a group interested in RNA as the intermediary between DNA and protein synthesis. In 1956, Crick wrote an informal paper for the group on the genetic coding problem. He proposed small "adaptor molecules" that would hydrogen bond to short nucleic acid sequences and link to specific amino acids. Those adaptors were eventually shown to be tRNAs.

  On the 15th of April 1960, during a conversation with Francois Jacob, Crick and Brenner realised that messenger RNA was not the same as ribosomal RNA. That summer Brenner, Jacob, and Matthew Meselson ran the first experiment to prove messenger RNA exists. Crick had speculated that a triplet of nucleotides could code for an amino acid, with 64 possible triplets covering only 20 amino acids, a code he called "degenerate."

  Proof of the degenerate triplet code came largely from Marshall Nirenberg, who used synthetic RNA as templates for protein synthesis. Nirenberg first announced his results to a small audience in Moscow at a 1961 conference. Crick's reaction was to invite him to deliver the talk to a larger audience.

• 8. From Molecules To Mind

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  In 1958 the University of Cambridge turned down Crick for the Professorship of Genetics. The electors could not reach consensus, so Vice-Chancellor Lord Adrian first offered the post to a compromise candidate, Guido Pontecorvo, who refused. It was then offered to Crick, who also refused. Watson later called the rejection "one of the most uninspiring acts of the University of Cambridge over this past century."

  In 1976, Crick took a sabbatical at the Salk Institute for Biological Studies in La Jolla. He had been a nonresident fellow there since 1960. "I felt at home in Southern California," he wrote. He left Cambridge for good after 30 years, having refused the Mastership of Gonville and Caius. He had to teach himself neuroanatomy and disengage slowly from molecular biology as discoveries kept coming.

  By the 1980s, Crick devoted his full attention to consciousness. In 1983, with Mitchison, he proposed that REM sleep and dreaming serve to remove certain modes of interaction in the cortex, a process they called "reverse learning." From 1990 to 2005 he collaborated with Christof Koch on a series of articles, focusing on how the brain generates visual awareness within a few hundred milliseconds.

  Crick was not knighted. He refused a CBE in 1963, though he was often called "Sir Francis Crick" and even "Lord Crick" in error. He resigned an honorary fellowship at Churchill College when the College Council accepted a donation to build a chapel. Outside Northampton stands a sculpture, Discovery, by Lucy Glendinning, honouring a man one local chairman called "the greatest Northamptonian of all time."