Wilkins, Maurice Hugh Frederick
WILKINS, MAURICE HUGH FREDERICK
Originally trained as a physicist, Wilkins was one of the participants in the Manhattan Project who moved into the nascent field of molecular biology in the immediate post–World War II era. Working at King’s College, London, he used x-ray diffraction of the DNA molecule in order to discern its structure. His preparations were used by Rosalind Franklin to take x-ray photographs of DNA in crystalline form. Those photographs helped James Watson and Francis Crick to elucidate the double-helical structure of DNA. Wilkins shared the 1962 Nobel Prize in Physiology or Medicine with Watson and Crick and was active in the British Society for Social Responsibility in Science. He is perhaps best known in the history of science for his conflict with Franklin, which was scientifically and personally damaging to both.
Early Life. Maurice Hugh Frederick Wilkins was born in New Zealand to Irish parents. His father Edgar was a physician who had a strong interest in public health and the family moved to London in 1922 so that he could pursue a diploma of public health. When he finished, the family moved to Birmingham, where Edgar was a school doctor. In his autobiography, Maurice Wilkins recalled how as a boy he developed a love of science and sense of pride in British achievements in technology by reading the Modern Boy magazine. His childhood hobby of building models of flying machines matured into the study of astronomy and physics at Cambridge University.
Physics Career. Wilkins thrived intellectually and socially at Cambridge. He became active in several student organizations, including the Cambridge Scientists’ Anti-War Group and the Natural Sciences Club. His talk for the club was a presentation on J. D. Bernal’s work on x-ray crystallography. Wilkins’s first mentor in physics at Cambridge was Marcus Oliphant, and after graduating in 1938, he followed his professor back to Birmingham to study thermoluminescence under John T. Randall. Luminescence allowed Wilkins to combine his interests in crystalline structure and x-ray diffraction. After World War II began, nearly the entire Department of Physics was involved in defense research on radar. Wilkins completed the requirements for his PhD in 1940, and soon joined Oliphant’s atomic bomb research team and investigated how to evaporate uranium metal.
In 1944, the Birmingham Bomb Lab relocated to Berkeley, California, to join forces with the Manhattan Project. When the war ended, Wilkins was not interested in continuing nuclear research. Randall was starting a new
project exploring the links between physics and biology and offered Wilkins a spot in his laboratory. After reading Erwin Schrödinger’s What Is Life?, he was inspired to join Randall and investigate Schrödinger’s proposal that the gene was an aperiodic crystal. After spending a year at St Andrews in Scotland, Randall’s biophysics group moved to King’s College, London, with funding from the Medical Research Council early in 1947.
Biophysics to the Double Helix of DNA. Wilkins cast about for an appropriate research subject within the complex structure of the cell. While he was searching, he met a physics graduate student named Francis Crick, who was interested in interdisciplinary approaches to biology. Although Randall did not offer Crick a position in the biophysics unit, Wilkins and Crick socialized often.
By 1950, Wilkins had settled on macromolecules as a way to combine his physics skills and biology interests. The question of macromolecular structure was tantalizing, and evidence was accumulating from biochemistry, genetics, and x-ray crystallography. In 1944, Oswald Avery had shown that genes were made of DNA, and his work was slowly disseminated through the genetics community. In the mid-1940s, a team of researchers in Leeds had determined that DNA fibers repeated their structure every 3.4 angstroms (Å) along their backbone. Wilkins began to collect specimens of nucleic acids, proteins, and viruses to x-ray and examine using ultraviolet microscopes, and soon narrowed his focus to DNA.
In a stroke of luck, he attended a seminar on 12 May 1950 by the Austrian researcher Rudolf Signer, who distributed samples of his high-quality calf thymus DNA. While preparing the samples for x-raying, Wilkins noticed that when he touched a glass rod to the moist DNA gel, he was able to draw out a thin filament of the molecule. As he recalled in his Nobel lecture, “the perfection and uniformity of the fibres suggested that the molecules in them were regularly arranged” and would be “excellent objects to study by X-ray diffraction analysis” (p. 756). Wilkins applied this technique to extracted DNA as well as to DNA in cells, but the Signer DNA gave the clearest pictures. Along with a graduate student, Raymond Gosling, Wilkins obtained clear diffraction patterns of wet DNA and noted that when the fibers were stretched and then constricted, they made patterns that appeared to be crystals. If DNA were a crystal, then it would be possible to analyze the x-ray images and draw conclusions about its structure. The correct model would have to account for the biochemical, genetic, and physical data on DNA, but the images could provide a direct method for determining its molecular structure.
Earlier that spring, Randall had endorsed the application of a talented x-ray crystallographer named Rosalind Franklin for a fellowship to join the biophysics unit at King's. Franklin was scheduled to begin her fellowship in January 1951, and in November 1950, Randall sent her a letter describing her future research project on “certain biological fibres in which we are interested.” It was a small group, Randall noted, and so “as far as the experimental X-ray effort is concerned there will be at the moment only yourself and Gosling” (cited in Maddox, 2002, p. 114, and Olby, 1994, p. 346). Apparently, he intended for Franklin and Gosling to study extracted DNA while Wilkins focused on cellular samples. Nevertheless, it is unclear why he excluded Wilkins from the description of DNA research at King's, and Wilkins was unaware of this letter.
The ensuing misunderstandings and acrimony led Franklin’s biographer Brenda Maddox to call this letter “the biggest mistake” of Randall’s life (p. 116). When Franklin first arrived at King's, she and Wilkins had cordial interactions, and even had meals together at the laboratory. They soon clashed over scientific questions, and by the summer of 1951, their working relationship had degenerated and they had little direct communication. Franklin was committed to a fine analysis of the x-ray diffraction patterns and was not interested in Wilkins’s more free-flowing approach. They rarely shared data, and Wilkins often disparaged her to Crick and Watson. In his frustration, Wilkins referred to Franklin as “Rosy,” or “the dark lady.” To the chagrin of many who knew her, James Watson used the same disrespectful nickname in The Double Helix (1980).
In May 1951, Wilkins traveled to Naples, Italy, to report on his research to a meeting on “Submicroscopical Structure of Protoplasm.” His images of a crystalline DNA pattern caught the attention of James Watson, who was in his first year of his European postdoctoral research. Wilkins’s presentation was part of the reason Watson decided to move to Cambridge to study the structure of nucleic acids under Lawrence Bragg. Wilkins went to the United States that summer to attend the Gordon Conference and meet Erwin Chargaff, the Columbia biochemist whose research on DNA had established the 1:1 ratio of its base pairs, adenine to thymine and guanine to cytosine.
Stimulated by his encounter with Chargaff, Wilkins returned to London only to discover that Franklin was not interested in biochemical data. She had recently noticed that DNA actually formed two patterns, labeled A and B, depending on how wet the samples were. The B, or “wet,” form yielded a clear crystalline pattern, but Franklin was focusing on doing a Patterson analysis of the more complicated A form. Although Randall told Wilkins to concentrate on the B form, he was soon inspired by Linus Pauling’s publication on the protein α-helix to search in his experimental data for evidence that DNA was also helical. He spent the rest of that year taking more x-ray photographs of different living samples of DNA, and trying to reconcile the diffraction and biochemical data. Wilkins contacted Signer in Vienna to try to get more samples of his high-quality DNA, since he had given all of his to Franklin, but Signer had none left.
Despite his lack of progress, Wilkins was heartened when he, Franklin, and several other colleagues were invited to Cambridge in late November 1951 to see a three-chain model of the DNA molecule that Watson and Crick had built. One look from Franklin was all it took to tell them that their model did not fit the diffraction data or rules of chemistry. When Bragg and Randall heard about the incorrect model, they agreed that Watson and Crick should leave the DNA problem to the team at King's.
However, Wilkins and Franklin made little noticeable progress on DNA in 1952. In May, Franklin took a clear photograph of the B form, which she labeled 51, but put it aside because she was intently focused on a mathematical analysis of the A form. Wilkins spent most of the summer at a scientific conference in Brazil, and he brought back more cellular specimens to analyze as he perfected his x-ray equipment.
January 1953 brought renewed energy to the DNA project at King's. Wilkins saw Franklin’s clear Photograph 51 from May 1952, and understood that it showed a helical structure. He also began thinking seriously about the implications of Chargaff’s base-pair ratios. Franklin had decided to leave King’s and DNA research in favor of virus research at Birkbeck College, but as she was finishing up her research, she began to consider the possibility that the B form was evidence of a two-chain helix. However, because the relationship between them was so hostile, they did not consult each other on how to combine these ideas with the experimental evidence.
The King’s College researchers were unaware that Watson and Crick had once again begun working on DNA after hearing that Pauling was interested in its structure. When Wilkins showed Watson a copy of Photograph 51 in early February 1953, he had no idea that it would be the catalyst for Watson’s building of a correct model. Soon thereafter, Watson and Crick invited Wilkins to Cambridge to show him Pauling’s incorrect structure and to ask if they could once again tackle the DNA problem. He agreed, not knowing how close they were to a complete model. When they finished it in early March, Wilkins was the first person outside of Cambridge to see the double helix. After an afternoon of difficult conversation about how much the King’s work had helped Watson and Crick, he agreed that Wilkins and his colleagues would publish their data jointly with Watson and Crick’s announcement in Nature. Gosling and Franklin added a short note describing the helical evidence in the B photographs, and the three papers appeared on 25 April 1953.
Life after the Double Helix. The validity and importance of the double helix was quickly accepted by the scientific community, and its discoverers were given numerous awards. Wilkins was elected to the Royal Society in 1959, and he shared the 1960 Albert Lasker Award with Watson and Crick. Two years later, they were awarded the Nobel Prize in Physiology or Medicine for “discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material.” (Nobel citation). In 1962, Wilkins was also honored as a Companion of the British Empire. Wilkins married Patricia Chidgey in 1958; they had four children.
Horace Freeland Judson describes Wilkins as “one who came early to X-ray studies of DNA and stayed late” (1979, p. 25). Wilkins spent many years using x-ray techniques to confirm and expand the double helix model of DNA and RNA, and officially stopped his DNA research in 1967. With colleagues at King’s College, he then turned to neurobiology and used diffraction techniques to examine cellular structures such as nucleohistone, lipids, photoreceptors, and different types of membranes.
Wilkins was dogged by historical accounts of his relationship with Franklin. He was outraged by the manuscript of Watson’s The Double Helix in part because of the portrayal of his relationship with Franklin. Wilkins was cast as a villain in Anne Sayre’s 1975 biography of Franklin, intended to be a balance to the story told in The Double Helix. He deeply resented Judson’s implication that he deliberately took Photograph 51 out of Franklin’s drawer to show Watson and defended himself on several occasions. Maddox’s 2002 biography of Franklin places part of the blame for her unhappiness at King’s on Randall, but provides evidence from Franklin’s letters that Wilkins’s behavior was a large factor in her decision to move to Birkbeck. In 2003, Wilkins published The Third Man of the Double Helix as an attempt to clarify his interactions with Franklin. In his account, he and Franklin both behaved in ways that prevented them from collaborating on DNA, and he regretted that their personal clash had a role in their losing the race to the double helix.
Science and Society. Since his student days at Cambridge, Wilkins was interested in the social implications of science and technology. Starting in the 1960s, he was involved with various antinuclear groups, including Pugwash, Food and Disarmament International, and the Campaign for Nuclear Disarmament. Wilkins was particularly proud of his role as president of the British Society for Social Responsibility in Science (BSSRS) from 1969 to 1991. In 1970, with support from the Salk Institute in San Diego, BSSRS organized a three-day public meeting to discuss “the social impact of modern biology.” Wilkins served as the chair of the discussions, and offered introductory and closing remarks to the eight hundred attendees. In an atmosphere of intense antiscience sentiment, Wilkins argued for the value of scientific research to modern society and noted that scientists had an obligation to ensure that the public had a thorough understanding of the content and applications of their work.
In 1984, Wilkins expounded on the same theme in an address on “The Nobility of the Scientific Enterprise,” delivered at the thirty-fourth meeting of medical Nobel laureates. Unabashedly optimistic, he praised scientists for their love of nature and dedication to knowledge, and urged them to consider the advancement of science as a way to further human ideals. Science and technology had done harm to the world in the twentieth century, but with a moral approach, scientists could simultaneously “save the world from war and restore dignity and nobility to science” (1985, p. 90).
Wilkins retired from teaching at King’s College in 1981, having spent virtually his entire career there, as professor of molecular biology from 1963 to 1970, professor of biophysics from 1970 to 1981, and director of the MRC Cell Biophysics Unit from 1974 to 1980. In March 2000, King’s named a major new building for Franklin and Wilkins. He continued to attend seminars on scientific and social issues until shortly before his death on 5 October 2004.
A complete list of Wilkins’s scientific publications is available through the Web of Science database. Archival collections with correspondence from Wilkins include the Francis Crick Papers, the Wellcome Library for the History and Understanding of Medicine; the James D. Watson Papers, the Cold Spring Harbor Laboratory; and the Linus and Ava Helen Pauling Papers, Oregon State University.
WORKS BY WILKINS
With Raymond Gosling and William E. Seeds. “Physical Studies of Nucleic Acid: An Extensible Molecule.” Nature 167 (1951): 759–760.
“Engineering, Biophysics and Physics at King’s College, London.” Nature 170 (1952): 261–263.
With Alec R. Stokes and Herbert R. Wilson. “Molecular Structure of Deoxypentose Nucleic Acids.” Nature 171 (1953): 738–740.
With William E. Seeds, Alec R. Stokes, and Herbert R. Wilson. “Helical Structure of Crystalline Deoxypentose Nucleic Acid.” Nature 172 (1953): 759–762.
“Physical Studies of the Molecular Structure of Deoxyribose Nucleic Acid and Nucleoprotein.” In Genetic Mechanisms: Structure and Function. Cold Spring Harbor Symposia on Quantitative Biology 21. Cold Spring Harbor, NY: Biological Laboratory, 1956.
“Structure of DNA and Nucleoprotein.” Transactions of the Faraday Society 53 (1957): 249.
“The Molecular Structure of Nucleic Acids.” In Nobel Lectures, Physiology or Medicine, 1942–1962. Amsterdam: Elsevier Publishing Company, 1964. Also available from http://nobelprize.org/.
With J. F. Pardon and B. M. Richards. “Super-Helical Model for Nucleohistone.” Nature 215 (1967): 509.
With Max Perutz and James D. Watson. “DNA Helix.” Science 164 (1969): 1537–1539.
“Introduction” and “Possible Ways to Rebuild Science.” In The Social Impact of Modern Biology, edited by Watson Fuller. London: Routledge and Kegan Paul, 1971.
“The Nobility of the Scientific Enterprise.” Interdisciplinary Science Reviews 10 (1985): 86–90.
“John Turton Randall, 23 March 1905–16 June 1984.” Biographical Memoirs of the Fellows of the Royal Society 33 (1987): 491–535.
“DNA at King’s College, London.” In DNA: The Double Helix. Perspective and Prospective at Forty Years, edited by Donald A. Chambers. Annals of the New York Academy of Sciences 758 (1995): 200–204.
The Third Man of the Double Helix: The Autobiography of Maurice Wilkins. Oxford: Oxford University Press, 2003.
Crick, Francis. What Mad Pursuit? A Personal View of Scientific Discovery. New York: Basic Books, 1988.
De Chadarevian, Soraya. Designs for Life: Molecular Biology after World War II. Cambridge, U.K.: Cambridge University Press, 2002.
Franklin, Rosalind E., and R. G. Gosling. “Molecular Configuration in Sodium Thymonucleate” Nature 171 (1953): 740–741.
Gratzer, Walter. “Obituary: Maurice Wilkins (1916–2004).” Nature 431 (2004): 922.
Judson, Horace Freeland. The Eighth Day of Creation: Makers of the Revolution in Biology. New York: Simon and Schuster, 1979.
Maddox, Brenda. Rosalind Franklin: The Dark Lady of DNA. New York: HarperCollins, 2002.
Morange, Michel. A History of Molecular Biology. Cambridge, MA: Harvard University Press, 1998.
“Nobel Prize in Physiology or Medicine, 1962.” Nobel Prize. Available from http://www.nobelprize.org/nobelprizes/medicine. Includes the Nobel citation and text of Nobel speeches.
Olby, Robert. The Path to the Double Helix: The Discovery of DNA. Seattle: University of Washington Press, 1974. 2nd ed. 1994.
Sayre, Anne. Rosalind Franklin and DNA. New York: Norton, 1975.
Stent, Gunther S. “That Was the Molecular Biology That Was.” Science 160 (26 April 1968): 390–395.
Watson, J. D. and F. H. C. Crick. “A Structure for Deoxyribose Nucleic Acid.” Nature 171 (1953): 737–738.
Watson, James D. The Double Helix: A Personal Account of the Discovery of the Structure of DNA. Norton Critical Edition, edited by Gunther Stent. New York: W. W. Norton Company, 1980.
Wilkins, Maurice Hugh Frederick (1916- )
Wilkins, Maurice Hugh Frederick (1916- )
New Zealand English biophysicist
Maurice Hugh Frederick Wilkins is best known for his work regarding the discovery of the structure of deoxyribonucleic acid (DNA ). Along with American molecular biologist James D. Watson (1924– ) and English molecular biologist Francis Crick (1916– ), Wilkins received the 1962 Nobel Prize in physiology or medicine for his contributions to the discovery of the molecular mechanisms underlying the transmission of genetic information. Specifically, Wilkins' contribution involved discerning the structure of DNA through the use of x–ray diffraction techniques.
Wilkins was born in Pongaroa, New Zealand to Irish immigrants Edgar Henry, a physician, and Eveline Constance Jane (Whittaker) Wilkins. Euperior education began at an early age for Wilkins, who began attending King Edward's School in Birmingham, England, at age six. He later received his B.A. in physics from Cambridge University in 1938. After graduation, he joined the Ministry of Home Security and Aircraft Production and was assigned to conduct graduate research on radar at the University of Birmingham. Wilkins' research centered on improving the accuracy of radar screens.
Soon after earning his Ph.D. in 1940, Wilkins, still with the Ministry of Home Security, was relocated to a new team of British scientists researching the application of uranium isotopes to atomic bombs. A short time later Wilkins became part of another team sent to the United States to work on the Manhattan Project—the military effort to develop the atomic bomb—with other scientists at the University of California at Berkeley. He spent two years there researching the separation of uranium isotopes.
Wilkins' interest in the intersection of physics and biology emerged soon after his arrival to the United States. He was significantly influenced by a book by Erwin Schrödinger, a fellow physicist, entitled What is Life? The Physical Aspects of the Living Cell. The book centers on the possibility that the science of quantum physics could lead to the understanding of the essence of life itself, including the process of biological growth. In addition to Schrödinger's book, the undeniable and undesirable ramifications of his work on the atomic bomb also played a role in Wilkins' declining interest in the field of nuclear physics and emerging interest in biology.
After the war, the opportunity arose for Wilkins to begin a career in biophysics. In 1945, Wilkins'former graduate school professor, Scottish physicist John T. Randall, invited him to become a physics lecturer at St. Andrews University, Scotland, in that school's new biophysics research unit. Later, in 1946, Wilkins and Randall moved on to a new research pursuit combining the sciences of physics, chemistry, and biology to the study of living cells. Together they established the Medical Research Council Biophysics Unit at King's College in London. Wilkins was, for a time, informally the second in command. He officially became deputy director of the unit in 1955 and was promoted to director in 1970, a position he held until 1972.
It was at this biophysics unit, in 1946, that Wilkins soon concentrated his research on DNA, shortly after scientists at the Rockefeller Institute (now Rockefeller University) in New York announced that DNA is the constituent of genes. Realizing the enormous importance of the DNA molecule, Wilkins became excited about uncovering its precise structure. He was prepared to attack this project by a number of different methods. However, he fortuitously discovered that the particular makeup of DNA, specifically the uniformity of its fibers, made it an excellent specimen for x–ray diffraction studies. x–ray diffraction is an extremely useful method for photographing atom arrangements in molecules. The regularly–spaced atoms of the molecule actually diffract the x rays, creating a picture from which the sizing and spacing of the atoms within the molecule can be deduced. This was the tool used by Wilkins to help unravel the structure of DNA.
Physical chemist Rosalind Franklin joined Wilkins in 1951. Franklin, who had been conducting research in Paris, was adept in x–ray diffraction. Together they were able to retrieve some very high quality DNA patterns. One initial and important outcome of their research was that phosphate groups were located outside of the structure, which overturned Linus Pauling's theory that they were on the inside. In another important finding, Wilkins thought the photographs suggested a helical structure, although Franklin hesitated to draw that conclusion. Subsequently, Wilkins passed on to Watson one of the best x–ray pictures Franklin had taken of DNA. These DNA images provided clues to Watson and Crick, who used the pictures to solve the last piece of the DNA structure puzzle.
Consequently, in 1953, Watson and Crick were able to reconstruct the famous double–helix structure of DNA. Their model shows that DNA is composed of two strands of alternating units of sugar and phosphate on the outside, with pairs of bases—including the molecular compounds adenine, thymine, guanine, and cytosine—inside, bonded by hydrogen. It is important to note that while Wilkins' contribution to the discernment DNA's structure is undeniable, controversy surrounds how Watson and Crick obtained Franklin's photographs and the fact that Franklin was not recognized for this scientific breakthrough, particularly in terms of the Nobel Prize. Because the Nobel Prize is not awarded posthumously, Franklin, who died of cancer in 1958, did not receive the same recognition as did Watson, Crick, and Wilkins.
The knowledge of the DNA structure, which has been described as resembling a spiral staircase, has provided the impetus for advanced research in the field of genetics. For example, scientists can now determine predispositions for certain diseases based on the presence of certain genes. Also, the exciting but sometimes controversial area of genetic engineering has developed.
Wilkins, Watson, and Crick were awarded the 1962 Nobel Prize for physiology or medicine for their work which uncovered the structure of hereditary material DNA. After winning the Nobel Prize, Wilkins focused next on elucidating the structure of ribonucleic acids (RNA)—a compound like DNA associated with the control of cellular chemical activities—and, later, nerve cell membranes. In 1962, Wilkins was able to show that RNA also had a helical structure somewhat similar to that of DNA. Besides his directorship appointments at the Medical Research Council's Biophysics Unit, Wilkins was also appointed director of the Council's Neurobiology Unit, a post he held from 1974 to 1980. Additionally, he was a professor at King's College, teaching molecular biology from 1963 to 1970, and then biophysics as the department head from 1970 to 1982. In 1981, he was named professor emeritus at King's College. Utilizing some of his professional expertise for social causes, Wilkins has maintained membership in the British Society for Social Responsibility in Science (of which he is president), the Russell Committee against Chemical Weapons, and Food and Disarmament International.
Wilkins is an honorary member of the American Society of Biological Chemists and the American Academy of Arts and Sciences. He was also honored with the 1960 Albert Lasker Award of the American Public Health Association (given jointly to Wilkins, Watson, and Crick), and was named Fellow of the Royal Society of King's College in 1959.
See also DNA (Deoxyribonucleic acid); DNA chips and micro arrays; Gene; Genetic mapping; Molecular biology and molecular genetics
Maurice Hugh Frederick Wilkins
Maurice Hugh Frederick Wilkins
Although Maurice Wilkins (born 1916) is best known for his role in discovering the "double helix" structure of DNA (deoxyribonucleic acid) molecules—the molecules carrying the genetic information from which all life is formed—he has worked to encourage scientists, lawyers, medical people, and the public to think deeply about the possible cultural, social, and philosophical effects of scientific discoveries.
Maurice Hugh Frederick Wilkins was born on December 15, 1916, in Pongaroa, New Zealand. His parents were Irish, and his father, Edgar Henry Wilkins, was a doctor. When Wilkins was six-yearsold, he moved to England to attend King Edward's School in Birmingham. He also attended St. John's College, Cambridge, earning a degree in physics in 1938. In 1940, he received his Ph.D. in physics at Birmingham University, studying phosphorescence as a research assistant to the physicist John T. Randall.
During World War II he applied his knowledge to such problems as the improvement of cathode-ray screens for radar. He then worked with physicist M.L.E. Oliphant on the separation of uranium isotopes for use in atomic bombs, which led to Wilkins' involvement in the Manhattan Project in Berkeley, California, where the hydrogen bomb was invented. "Partly on account of the bomb," he said in the Saturday Review, "I lost some interest in physics."
His moral crisis eventually led him to the study of biology. He has credited Erwin Schrodinger's book What is Life with sparking his interest in a highly complex molecular structure that could control living processes. His former teachers Randall and Oliphant believed strongly that the field of physics had much to offer biology, and advised him to join a biophysics project begun by Randall at his alma mater, St. John's College, in 1945. In 1946, the project moved to King's College, London, where Wilkins joined the newly formed Medical Research Council Biophysics Research Unit.
While there, he studied the genetic effects of ultrasonics and worked on developing ultraviolet microscopes to study nucleic acids in cells. Although the existence of these acids in cellular nuclei had been acknowledged decades before, recently one of the acids-deoxyribonucleic acid (DNA)-had been recognized as a transmitter of physical characteristics from one generation to the next. Determining the composition of DNA was made more challenging because it varied greatly depending on the type of cell in which it appeared. As Wilkins studied the variations, he realized that any biologist could examine the cells as well as he could. He felt he could contribute better as a physicist by studying DNA in isolation, outside the cell.
Discovering the Double Helix
Using a technique from the field of physics known as the analysis of diachroism patterns, Wilkins placed the DNA specimen under the microscope and then subjected it to two colors of light simultaneously. One color was transmitted directly onto the molecule; the other was reflected. The contrast was intended to reveal the structure of the specimen. However, as Wilkins observed the molecule through the microscope, he observed that each time he lifted the glass rod used to orient the molecule, a small fiber hung from the tip. Wilkins determined that the uniformity of the fibers suggested that the DNA molecules were arranged in a regular pattern. What he could not determine was the pattern.
In what has been called a "moment of truth," Wilkins realized that although the pattern could not be seen in the microscope, the fiber could be studied by X-ray diffraction analysis, in which X-rays are bounced off the object and onto film, leaving a record of the object's shape. With the help of Raymond Gosling and Rosalind Franklin, Wilkins obtained the first evidence of DNA's spiral shape. After studying the patterns from several species of DNA, he could see that in each species the pattern was identical: two long strands coiled around each other in a shape called a double helix.
It was already known that the two strands were made of alternating units of sugar and phosphate, but Wilkins' model did not take into account the other chemicals known to be present in DNA: two large submolecules called adenine and guanine, and two small ones called thymine and cytosine. These four chemicals appeared in DNA in a seemingly random pattern. If the DNA molecule was as regular as Wilkins' model suggested, the irregular presence of these chemicals could not be explained.
The contribution of two biologists, James Watson and Francis Crick, solved the puzzle. They reasoned that the double helix shape of DNA was similar to a spiral staircase, with the chemicals serving as steps on the spiral. When a unit of adenine appeared on one spiral, a unit of thymine appeared on the other; similarly a guanine was linked to a cytosine. Because each step in the staircase consisted of one large and one small unit, all the steps took up the same amount of space. No matter what their arrangement, the regular shape of the double helix would not change.
Nobel Prize Leads to Opportunities and Controversy
As Science magazine reported in 1962, this discovery had far-reaching consequences. Now that the structure of DNA was understood, scientists could understand the process of genetic replication, or the method by which the genes of the parent are passed down to its child. "Until about 1950, biochemists had … tried to imagine mechanisms by which protein molecules could make replicas of themselves…. The double helix of DNA, on the other hand, could be pictured as unwinding into two single chains, each complementary to the other. As unwinding proceeded, each could serve as a template for the replication of another chain, complementary to itself, thereby reproducing both the original chain components of the double helix." With this information, geneticists would be able to make maps of genetic codes, enabling the study of hereditary traits and diseases.
For this achievement, Wilkins, along with Watson and Crick, received the 1962 Nobel Prize in Medicine and Physiology. They had also been recognized in 1960 by the American Public Health Association with the Albert Lasker Award, and Wilkins was made Companion of the British Empire. Wilkins took his position as Nobel Laureate seriously. While he acknowledged that some of the benefits of winning the prize included an "increase in salary and professional status," he told The American Biology Teacher that it is "in Alfred Nobel's spirit to accept some responsibility" for larger social issues, outside of his main field of expertise. "Some Laureates feel it's wrong to speak on other topics," he said, adding that this may be "a weak excuse to get out of responsibility."
In addition to his work on ribonucleic acid (RNA), which was discovered to act as a messenger, carrying the genetic code from the nuclear DNA, Wilkins took the opportunities created by the Nobel Prize to speak on such topics as "Science and the World" and "Science and Religion." He joined the British Society for Social Responsibility in Science and became president of that organization in 1969. In 1973 he joined with over 100 other Nobel Laureates to protest the Soviet Union's restrictions on scientist Andrei Sakharov and author Alexander Solzhenitsyn.
In 1975 he participated in a meeting of the Democratic Socialist Organizing Committee, a group formed by American socialists with the aim of advancing their ideas within the existing Democratic Party. While Wilkins did not profess to be a socialist, he joined in the statement of six other Nobel Laureates, saying that "the exploration of alternatives to the prevailing Western economic systems must be placed on the agenda at once." In their greeting to the Organizing Committee, the Laureates stated, "Though we have different attitudes as to what this will mean, the process of discussion and political mobilization must begin now." Following his interests in famine and nuclear disarmament, he became a member of Food and Disarmament International in 1984.
Wilkins also found himself embroiled in controversy over the story of his discovery of the double helix with Watson and Crick. When Watson attempted to publish his book The Double Helix, both Crick and Wilkins protested several passages. The book took a very personal approach to the story, describing Crick as egocentric and Wilkins as distracted by his assistant Rosalind Franklin. Although some changes were made, they continued to oppose its publication, and Harvard University Press pulled its support for the book and refused to publish it. Critics complained that the press was "less interested in diversity of viewpoint than bland tranquillity," according to The New York Times. In 1987, Wilkins was still critical of his old partners: "They think everything about life and human beings can be explained in terms of atoms and molecules."
Wilkins has remained interested in the implications of his earlier work, especially the possibility of genetic manipulation: "This would be, as people say, playing God. And who would decide what genes you would alter and what the forms of the new genes ought to be?" His concern over the ethical problems raised by genetic research led him to create a course at King's College on the social impact of bioscience.
The American Biology Teacher, March 1989.
Newsweek, October 29, 1962.
New York Times, February 15, 1968; December 2, 1973; January 26, 1975.
Saturday Review, March 2, 1963.
Science, October 26, 1962.
Science Digest, January 1986.
Time, October 26, 1962.
"Maurice Hugh Frederick Wilkins," The Nobel Foundation,http://www.nobel.se/index.html (March 20, 1998)