CRICK, FRANCIS HARRY COMPTON

(b. Weston Favell, Northampton, United Kingdom, 8 June 1916;

d. La Jolla, California, 28 July 2004), molecular biology, the genetic code, the neuroscience of consciousness.

Crick was one of the central figures, one might say the central figure, in the molecular revolution that swept through biology in the latter half of the twentieth century. Having with James Watson discovered the structure of deoxyribonucleic acid (DNA), Crick went on to play a central role in the elucidation of the genetic code and the mechanism of protein synthesis. These achievements won him a share in the Nobel Prize in Physiology or Medicine in 1962. Much sought after as a lecturer, he became the “molecular evangelist,” seeking to convert biochemists and biologists to the new science. He traveled extensively, broadcast on radio, and frequently wrote for Scientific American. His later years were spent in California, where he plunged into the complex world of neuroscience. Crick was vivacious, party-loving, gregarious, hospitable, and a gentleman. But he could react in a forthright manner to pomposity, pretentiousness, and stupidity. Those who knew him well did not find him arrogant or immodest.

Crick was the firstborn of Harry Crick, boot and shoe manufacturer, and Annie Elizabeth Wilkins, the elder daughter of F. W. Wilkins, a gentlemen’s outfitter. Educated to the age of fourteen at Northampton Grammar School for Boys, he then entered Mill Hill School as a scholar and boarder. By the age of sixteen he had passed the Higher Certificate exams, gaining a distinction in physics, but stayed on a further two years. Failing to win a scholarship at either Cambridge or Oxford, he was accepted into the physics course at University College London. There he graduated with a second-class degree and began research on the viscosity of water. When World War II broke out in 1939, his physics department was evacuated to Wales, but he stayed behind.

Naval Research . Crick was among the six thousand scientists selected to support the armed forces as civilian scientists, and in 1940, he began work at the Admiralty Research Laboratory on the outskirts of London. In the winter of 1942, he was one of a five-man team of physicists and mathematicians sent to Havant, close to Portsmouth. There this team set to work to revitalize the Royal Navy’s mine design program. Put in charge of the design of mine-firing mechanisms, Crick displayed imagination and skillful planning in challenging the enemy’s use of mines as offensive weapons. Crick’s performance in this work won him the respect of his seniors. Although at war’s end Crick returned to London as a civil servant in the Admiralty, he felt dissatisfied with military research and decided to make a change.

Casting around for suggestions, he reflected on the principal subject matter of his scientific chats with colleagues. Instead of being physics it was biology: How do chromosomes perform their amazing “dance” in cell division? What is it that distinguishes a crystalline virus capable of reproduction from other organic crystals incapable of reproduction? What can neurophysiology reveal about the mystery of consciousness? Behind these concerns lay his ambition to show that “detailed scientific knowledge” that has already made many religious beliefs untenable, can banish the mystery of life and of consciousness too. While these mysteries “remain unexplained,” he judged, “they can serve as an easy refuge for religious superstition.” Removing these “unfortunate vestiges of earlier beliefs” would enable us to “find our true place in the universe.” “Obviously,” he confessed, “a disbelief in religious dogma was a very deep part of my nature” (Crick, 1988, p. 11).

A New Career: Crystallography . Cricks ambition was to learn the art of x-ray crystallography in order to study the structure of proteins, for in them surely lay the secret of life itself. The Medical Research Council (MRC) agreed to support him, however, only if he would first immerse himself in biology. That meant studying the whole cell, not just extracted material. After he spent two years at the Strangeways Laboratory fulfilling this requirement, his wish to study the structure of proteins was granted, and in 1949, he moved to the MRC Unit for the Study of the Molecular Structure of Biological Systems in Cambridge Universitys Cavendish Laboratory. There his first achievement was to administer a frontal attack on the methods of interpretation of x-ray data being used by his bosses, Sir Lawrence Bragg and Max Perutz, in their brave attempt to find the structure of hemoglobin. Teaching himself, Crick had mastered the application of Fourier theory to the data of x-ray diffraction patterns. Now he possessed an unrivaled insight into the strengths and limitations of these

techniques and a remarkable ability to visualize molecular structures and their symmetry relations in space. This was manifested in his success simultaneously with William Cochran in deriving the main features of the x-ray diffraction pattern that a helical molecule should yield. Next he introduced the idea of supercoiling of helices to account for anomalous diffraction data from the αkeratin of wool that had proved so difficult to accommodate in helical models.

Armed with this knowledge, Crick realized that conventional approaches to the structural interpretation of diffraction patterns have limited value when dealing with DNA fibers, for these consist of long chain molecules packed in a regular order only in the fiber direction. Therefore they lack the three-dimensional lattice of a single crystal. That said, there are strict limitations on the different conformations that long chain molecules can take because they are oriented and packed tightly together in the fiber direction. So it is possible to guess a plausible structure, predict its diffraction pattern and check this against the diffraction data without carrying out the traditional, lengthy calculations, and without knowing the phases of the reflections. Linus Pauling’s success with his alpha helix in 1951 was the classic example of this “stochastic method,” as Pauling called it.

The Structure of DNA . In the fall of 1951, Crick was diverted somewhat from his protein research by the arrival of a young American, James D. Watson. Now Crick had found a collaborator, who like him recognized DNA as the chief if not the sole hereditary material, and after two attempts at building a model by the stochastic method, they arrived at the essentially correct structure in the spring of 1953. Their first attempt in 1951 had proved a fiasco and had caused the ire of Professor Bragg. Not until Pauling was about to publish his own structure for DNA had Bragg in February 1953 permitted Watson and Crick to make a second attempt. Now they opted for a two-chain cylindrical molecule, the helical chains on the outside of the cylinder held together by hydrogen bonds between the bases on the inside. This pairing of bases was specific, always adenine paired with thymine and guanine with cytosine, thus accounting for the strange 1:1 ratios between these pairs of bases described by the biochemist Erwin Chargaff.

The Watson-Crick structure was a proposal, based upon—and therefore supported by—the data of Rosalind Franklin, Raymond Gosling, and Maurice Wilkins published alongside it. Definitive proof of the structure, however, took almost another quarter of a century, owing to the difficulty of synthesizing small stretches of DNA in the form of single crystals.

Watson and Crick’s first communication was exceedingly brief and went over the heads of most biologists, unfamiliar as they were with x-ray crystallography. The second paper, written largely by Crick, brought their proposal down to earth because it explained the relevance of their unusual two-stranded model to biologists. There they explained’

the precise sequence of the bases [on one chain] is the code which carries the genetical information. If the actual order of the bases on one of the pair of chains were given, one could write down the exact order of the bases on the other one, because of the specific pairing. Thus one chain is, as it were, the complement of the other, and it is this feature which suggests how the deoxyribonucleic acid molecule might duplicate itself. . . . The hypothesis we are suggesting is that the template is the pattern of bases formed by one chain … and that the gene contains a complementary pair of such templates. (Watson and Crick, 1953b, p. 966, 967)’

But could DNA carry the enormous variety of genetic determinants involved? Providing the pairing rules were followed, any conceivable sequence was possible on one chain, the other carrying the complementary sequence. Here was speculation on a grand scale.

Despite all the excitement about DNA—the steady stream of visitors coming to see the model, among them Pauling from California and Gerald Pomerat from the Rockefeller Foundation—the impact of Watson and Cricks proposal within the Cavendish laboratory was mixed. Members of the university’s Subdepartment of Crystallography—quite distinct from the Medical Research Council Unit—were unimpressed. But Bragg became very excited. He had been looking forward to Crick’s departure from the lab once his doctoral thesis was completed. Now he began to appreciate Crick’s potential. But Crick was scheduled to spend the next academic year at the Protein Institute in Brooklyn, New York, to help the team there studying the structure of the protein ribonuclease. Then he had the option to work with Linus Pauling at the California Institute of Technology.

Fortunately Crick was able to complete his doctoral dissertation and defend it before leaving for Brooklyn. It was formally awarded to him in absentia in 1954. Meanwhile his future was uncertain. Not until the spring of that year did he receive a new seven-year contract from the Medical Research Council and decide to return to Cambridge.

Crick stayed with the MRC Unit in Cambridge when in 1957 it was moved out of the Cavendish into the hut close by then, in 1962, to the new Laboratory of Molecular Biology two miles from the center of Cambridge. Meanwhile his friends’ nomination of him for a fellowship at King’s College Cambridge in 1956 failed, as did his application for the chair of genetics at Cambridge University as Ronald Fisher’s successor in 1957. The fellowship he accepted at the projected Churchill College in 1960 turned sour when the decision was taken to build a college chapel. Crick resigned over the issue in 1961, but was persuaded to accept an honorary fellowship subsequently. He was a member of Gonville and Caius College, subsequently was given dining rights, and made an honorary fellow in 1976.

The Genetic Code and Protein Synthesis . Given that the gene’s specificity or “information” is encoded in a base sequence of DNA, how is that translated into the immediate gene product: a polypeptide chain composed of a specific sequence of amino acids? Stimulated by the physicist George Gamow, Crick joined in the effort to use cryptography to solve the problem, but all the schemes considered suffered from limitations on the variety of possible amino acid sequences. Nature’;s proteins showed no such limitations.

Cogitating on the coding problem, Crick began to ponder the relation between the nucleic acids and the proteins, and to make this the subject of his lecture, “On Protein Synthesis,” delivered to the Society for Experimental Biology in 1957. Here he laid out the framework that was to constitute the core principles of what became the classical period of molecular biology. First came the Sequence Hypothesis stating that “the specificity of a piece of nucleic acid is expressed solely by the sequence of its bases, and that this sequence is a (simple) code for the amino acid sequence of a particular protein” (1958, p. 152). Second came the Central Dogma: “the transfer of information from nucleic acid to nucleic acid, or from nucleic acid to protein may be possible, but transfer from protein to protein, or from protein to nucleic acid is impossible. Information means here the precise determination of sequence …” (p. 153).

Given these restrictions on information transfer, how can a match be achieved between a triplet of bases and the amino acid for which the triplet is the cipher? Crick had already discussed this problem earlier and had suggested the existence of “adaptor molecules,” small molecules with hydrogen-bonding sites attached to the appropriate amino acid by special enzymes. His prediction was fulfilled by the discovery of transfer RNA (tRNA).

This framework served its purpose admirably at the time. The extraordinarily complex picture that has since emerged has understandably introduced qualifications. But the discovery in 1970 of a type of RNA that can transfer sequence information back to DNA (reverse transcriptase) did not flout Crick’s definition of the Central Dogma. The great surprise came eight years later. This was the discovery that whole chunks of the RNA transcribed from the gene are often excised before translation of the message into protein begins. Crick commented on these discoveries, accepting that the early ideas were too simple. In this sense he admitted that some of his critics were proved right.

When Sydney Brenner joined the MRC Unit in 1957, their remarkable collaboration began. Also attracted to the unit as visitors that year were the world experts on the genetics of bacterial viruses (bacteriophages or “phages”) Seymour Benzer and George Streisinger. They attempted to discover the code by establishing the base sequence in a gene and the corresponding amino acid sequence in its protein product. But Crick and Brenner continued their own study of the genetics of phage mutations.

In February 1961, Crick began a series of experiments based on an idea he had about the manner in which a mutation can be “suppressed” by a further mutation. The results led him to support Brenner’s suggestion that such “suppressions” are due not to substitution of a different base in a sequence of bases on the DNA molecule, but to addition or deletion of a base. After conducting extensive experiments for some five months, Crick attended a meeting in the Alps. There he mentioned this idea, and the hypothesis “that the code is read in short groups, starting from one end of the gene. The exact starting point is supposed to determine which group is read” (Crick, 1961a, p. 188).

Back in Cambridge Crick carried out further experiments to clinch the case for the “short groups” being composed of three bases or a multiple thereof. In their classic paper summarizing this work, the Cambridge group claimed that the genetic code “is of the following general type”: three bases (or a multiple of three) codes for one amino acid. It is not an overlapping code, “probably ‘degenerate’; that is, in general, one particular amino-acid can be coded by one of several triplets of bases,” and “the sequence of the bases is read from a fixed starting point.… There are no special ‘commas’ to show how to select the right triplets” (Crick et al., 1961, 1227).

Meanwhile he had listened in Moscow to Marshall Nirenberg describe the stunning result of his work with Johann Matthaei on the synthesis of the polypeptide polyphenylalanine (polyPhe), using as template the synthetic RNA polyuridylic acid. PolyU, they concluded, codes for polyPhe. The Cambridge group had revealed the general nature of the code, and Nirenberg and Matthaei had identified the specific cipher for one of the twenty amino acids.

This discovery of the code was the last time Crick worked at the bench. After exploring embryological development with Peter Lawrence, he turned to the mysteries of the chromosome, excited by the discussions ongoing over the enormous amount of nongenetic DNA therein. Here was a chance to provide a model the structure of which might suggest why there is so much repetitive DNA in chromatin and how gene expression is regulated. Unfortunately his structure was proved to be entirely wrong, but it served as the stimulus to attract Roger Kornberg and Aaron Klug to the subject. Kornberg turned the field upside-down by situating the histone on the inside of the chromosome in the form of beads (nucleosomes) and around these beads the DNA is wound. Crick went on to collaborate with Klug on a model that could achieve the ten-thousand-fold compacting suffered by human chromosomes during nuclear division.

From 1959 he had helped Jacob Bronowski and Jonas Salk formulate the plans for the projected Salk Institute in La Jolla, California, and was a nonresident fellow to the institute from 1962 until 1974. The academic year 1976–1977 he spent on sabbatical there. In 1977, he accepted the position of Kieckhefer Distinguished Professor at the Salk, holding it for the rest of his life. Although he avoided whenever possible undertaking administrative work and sitting on committees, he was a powerful influence in deciding policy both in Cambridge and in La Jolla. He refused honorary degrees, the CBE, and a knighthood, but in 1991, he accepted the very exclusive Order of Merit from Queen Elizabeth II. However, he has frequently been referred to erroneously as Sir Francis and even as Lord Crick.

The Brain and Consciousness . For many years Crick had been following developments in neurophysiology from a distance. It was the move to California that helped him to extricate himself from old agendas and turn to new ones. His long-term goal was to tackle “the problem of consciousness,” concentrating on visual perception in primates. He had “rather little expectation of producing any radically new theoretical ideas at such an advanced age,” but he thought he “might interact fruitfully with younger scientists.” At this time in his life, he felt he “had a right to do things” for his own amusement, so long as he “could make an occasional useful contribution” (What Mad Pursuit, p. 152).

He approached the subject without prejudice, ready to consider mathematical-computational and physiological approaches. Having Tomaso Poggio, David Marr, and Graeme Mitchison visit and work with him at the Salk Institute, he immersed himself in the computational approach. But he became skeptical of some of the mathematical modeling of visual processing. His strongest criticisms were directed at those cognitive psychologists who showed no concern for the lack of biological realism in their schemes. Repeatedly he stressed how inappropriate was the analogy drawn between the standard digital computer and the brain. And when he joined the group in the Psychology Department of the University of California at San Diego studying parallel distributed processing—as distinct from the serial processing of standard computers—he repeatedly stressed the need to consider whether their schemes were applicable to the manner in which the brain is wired.

An example of a computational approach that led to an interesting hypothesis was Crick and Mitchison’s paper on the function of dreaming. They found that computer simulations of neural nets when subjected to heavy use become overloaded and unable to continue functioning normally. Cutting off any input, and permitting the nets to cycle over and over, mysteriously restored normal function. Might this not happen in the brain also? Is that what happens when people dream, sensory input being cut off, and rapid eye movements (REM sleep) occurring? Accordingly they suggested that the function of REM sleep is to “unlearn” unwanted “modes of excitation.” They called it “reverse learning.”’

Crick laid most emphasis upon physiological and anatomical approaches to the brain, for these involved opening the “black box.” He had been delighted at the way David Hubel and Torsten Wiesel used the technique of single-cell recording to reveal the “functional anatomy” in the visual centers of the brain. Looking ahead, he urged that greater effort be put into developing new techniques for unraveling the brain’s immensely intricate anatomy.

For the last fourteen years of his life, Crick collaborated with Christoff Koch, professor of cognitive and behavioral biology at Caltech, on the subject of consciousness. Putting aside the difficult problem of explaining how neural events can yield the subjective states of consciousness known as qualia, they looked for the neural correlates of consciousness (NCC). What particular neural activity is present during conscious activity, but absent from activity that is not conscious? Their ambition was to achieve a “framework” that would do for consciousness what the DNA double helix did for molecular biology.

This framework, they claimed, was the first “coherent scheme for the NCC.” Underlying it was the idea of competing coalitions of neurons, some at the back of the brain, others at the front. The mechanisms of attention “bias the competition among these nascent coalitions.” Crick had the conviction that most of what people assume is conscious activity is in fact zombie-like activity. People have the sense of consciously coming to decisions, but they are really the product of unconscious computation. What they are conscious of is only the end result of that computation. As for the function of consciousness, Crick and Koch suggested it serves “to produce the best current interpretation” of the sensory data. Like an “executive summary” it overcomes the problem of data overload thus making possible a swift response.

Crick as Author . From the earliest of his scientific papers, Crick showed good organization and clarity of expression. Not surprisingly, he was the one asked to write the first draft of so many of the jointly authored papers. In writing for general audiences, he knew how to explain the science at their level without being condescending. He started several book projects, but traveling so frequently to meetings and being on the international lecture circuit he was rarely sufficiently settled to carry them through. His first book Of Molecules and Men contained his John Danz lectures. They were devoted to critiquing vitalism by marshaling the successes of molecular biology. The lectures ended with a denunciation of religious education, denial of the existence of an immortal soul, and a prevision of “a time when vitalism will not seriously be considered by educated men” (p. 99).

Very different in tone was Life Itself: Its Origin and Nature. This was distilled from his many discussions with Leslie Orgel, his colleague at the Salk Institute, and enlarges on an idea they had in 1973 and called “directed panspermia.” They suggested that life did not originate on this Earth, but was brought to it in the form of microorganisms carried in an unmanned spaceship from a “higher civilization” elsewhere. This would account for the fact that the genetic code on this Earth is universal, barring a few trivial variants. It assumes that the primitive environment of the Earth was too hostile for the emergence of life here. As an exercise in imagination it was intended to provoke the reader. Crick doubted whether it was likely to be true.

Asked by the Sloan Foundation to write about his life, Crick decided to use his experiences “to teach some general lessons about how research is done, and what mistakes to avoid.” Hence, the book begins with a quotation from Oscar Wilde: “Experience is the name everyone gives to their mistakes.” The book’s title he took from his first public talk on the structure of the proteins: What Mad Pursuit. Crick described the experience early in his career at Cambridge of witnessing Bragg’s failure to discover the alpha helix that made such a deep impression on him. The most striking error he identified was that of assuming that the nucleoprotein particles in the cytoplasm, later called ribosomes, contain the genetic message. Here, fortunately, aided by their colleague Francois Jacob from the Pasteur Institute, Crick and Brenner were among the first to realize there must be a separate RNA messenger (mRNA).

His last book, The Astonishing Hypothesis, was the product of his long-felt need to reconstitute the moral and legal framework of society on a scientific basis. Hence the need to understand human nature, but to achieve this, he claimed, requires a scientific understanding of the nature of consciousness. Only then can people hope to understand humanity’s place in nature. Continuing with outmoded concepts will only lead, he foresaw, to a world so overpopulated as to spell disaster. After explaining with consummate skill many of the complex features of the brain, he ended with “Dr. Crick’s Sunday Morning Service.” Here he expressed his hope that scientific research will make it possible to argue that “the idea that man has a disembodied soul is as unnecessary as the old idea that there was a Life Force” (p. 261).

Crick died in 2004 after a courageous fight against colon cancer. Following a private family memorial, a public memorial was held at the Salk Institute to honor his remarkable contributions to twentieth-century science. Crick’s marriage to Ruth Doreen Dobbs in 1940 was dissolved seven years later. In 1949, he married Odile Speed. He was survived by his wife, his son Michael from his first marriage, and Gabrielle and Jacqueline from his second, plus six grandchildren.

BIBLIOGRAPHY

For a complete list of Crick’s published papers see: http://www.pitt.edu/rpsdept/people/primary_faculty.html#Olby.For manuscript sources see: The Wellcome Library for the History and Understanding of Medicine. Online catalogue of Western Manuscripts and Modern Papers. Reference PP/CRI/A to M. A copy of these papers is at the Mandeville Special Collections Library 0175-S, University of California at San Diego, MSS 600. The Crick Family Papers are only available at UCSD, MSS 660.

WORKS BY CRICK

With W. Cochran. “Evidence for the Pauling-Corey _-Helix in Synthetic Polypeptides.” Nature169 (1952): 234–235.

“Is αKeratin a Coiled Coil?” Nature170 (1952): 882–883.

With W. Cochran and V. Vand. “The Structure of Synthetic Polypeptides: I. The Transform of Atoms on a Helix.” Acta Crystallographica 5 (1952): 581–586.

With James D. Watson. “The Molecular Structure of Nucleic Acids: A Structure for Deoxyribonucleic Acid.” Nature171 (1953a): 737–738.

With James D. Watson. “Genetical Implications of the Structure of Deoxyribonucleic Acid.” Nature171 (1953b): 964–967.

With James D. Watson. “The Complementary Structure of Deoxyribonucleic Acid.” Proceedings of the Royal Society, Series B, 223 (1954): 80–96.

“The Structure of the Synthetic αPolypeptides.” Science Progress 42 (1954): 205–219.

“The Structure of the Hereditary Material.” Scientific American 191 (1954): 54–61.

With B. S. Magdoff and V. Luzzati. “The Three-Dimensional Patterson Function of Ribonuclease II.” Acta Crystallographica 9 (1956): 156–162.

With James D. Watson. “The Structure of Small Viruses.”Nature 177 (1956): 473–476.

“On Degenerate Templates and the Adaptor Hypothesis: A Note for the RNA Tie Club.” Unpublished paper distributed to members of the RNA Tie Club, 1956. Crick Papers, Wellcome Library. Online catalogue of Western Manuscripts and Modern Papers. Reference PP/CRI/H/1/38.

With J. C. Griffith and L. E. Orgel. “Codes without Commas.” Proceedings of the National Academy of Sciences of the United States of America43 (1957): 416–421.

“On Protein Synthesis.” In “The Biological Replication of Macromolecules.” Symposia of the Society of Experimental Biology12 (1958): 138–163.

With Leslie Barnett, S. Brenner, and R. J. Watts-Tobin. “General Nature of the Genetic Code for Proteins.” Nature 192 (1961): 1227–1232.

“The Genetic Code.” Scientific American207 (1962): 66–74.

“Discussion.” Deoxyribonucleic Acid. Structure, Synthesis and Function, Proceedings of the 11th Annual Reunion of the Société de Chimie Physique, June 1961, p. 188.

Of Molecules and Men. Seattle: University of Washington Press,1966.

“Central Dogma of Molecular Biology.” Nature227 (1970):561–563.

“General Model for the Chromosomes of Higher Organisms.” Nature234 (1971): 25–27.

With P. A. Lawrence. “Compartments and Polyclones in Insect Development.” Science189 (1975): 340–347.

“Split Genes and RNA Splicing.” Science204 (1979): 264–271.

“Thinking about the Brain.” Scientific American241, no. 3(1970): 219–232.

Life Itself: Its Origin and Nature. New York: Simon and Schuster,1981.

With G. Mitchison. “The Function of Dream Sleep.” Nature304 (1983): 111–114.

What Mad Pursuit: A Personal View of Scientific Discovery. New York: Basic Books, 1988.

With C. Koch. “The Problem of Consciousness.” Scientific American267 (1992): 152–159.

The Astonishing Hypothesis: The Scientific Search for the Soul. New York: Simon and Schuster, 1994.

With C. Koch. “A Framework for Consciousness.” Nature Neuroscience6 (2003): 119–126.

OTHER SOURCES

Ashe Lincoln, F. Secret Naval Investigator. London: William Kimber, 1961.

Blackmore, Susan. Conversations on Consciousness. Oxford:Oxford University Press, 2006.

Brenner, Sydney. My Life in Science. London: BioMed Central, 2001.

Chadarevian, Soraya de. Designs for Life: Molecular Biology after World War II. Cambridge, U.K.: Cambridge University Press, 2002.

Cowie, Captain J. S. Mines, Minelayers, and Minelaying. London:Oxford University Press, 1949.

Judson, Horace F. The Eighth Day of Creation: Makers of the Revolution in Biology. Expanded edition. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory, 1996.

Olby, Robert. “Francis Crick, DNA, and the Central Dogma.” Daedalus 99 (1970): 938–987. Reprinted with a postscript and comments from Dr. Crick and his aunt, Mrs. Arnold Dickens. In The Twentieth-Century Sciences: Studies in the Biographies of Ideas, edited by Gerald Holton. New York: Norton, 1972.

Ridley, Matthew. Francis Crick: Discoverer of the Genetic Code.London: Harper Collins, 2006.

Watson, James D. The Double Helix: A Personal Account of the Discovery of the Structure of DNA. Norton Critical Edition. New York: Norton, 1980.

Robert C. Olby

Crick, Francis Harry Compton (1916–2004) British molecular biologist, who in 1951 teamed up with James Watson at Cambridge University to try to find the structure of DNA. This they achieved in 1953, using the X-ray diffraction data of Rosalind Franklin (1920–58) and Maurice Wilkins (1916– ). Crick went on to investigate codons and the role of transfer RNA. Crick, Watson, and Wilkins shared a Nobel Prize in 1962.

Crick, Francis H. C. (1916–2004) The British geneticist who, with J. D.Watson and M. Wilkins, won the 1962 Nobel Prize for Physiology or Medicine for their modelling of the DNA molecule. Crick and Watson worked at the Cavendish Laboratory, Cambridge, and in 1977 Crick moved to the Salk Institute, California.

Crick, Francis H. C. (1916–2004) The British geneticist who, with J. D. Watson and M. Wilkins, won the 1962 Nobel Prize for Physiology or Medicine for their modelling of the DNA molecule. Crick and Watson worked at the Cavendish Laboratory, Cambridge; in 1977 Crick moved to the Salk Institute, California.

Crick, Francis Harry Compton (1916–2004) English biophysicist. In the 1950s, with James Watson and Maurice Wilkins, Crick established the double-helix molecular structure of deoxyribonucleic acid (DNA). The three were jointly awarded the Nobel Prize in physiology or medicine in 1962.