Maurice Wilkins

British biophysicist

• Born: December 15, 1916; Pongaroa, New Zealand
• Died: October 5, 2004; London, England

Maurice Wilkins’s X-ray diffraction studies were instrumental in determining the double-helical structure of DNA. He came to regard DNA’s simplicity as symbolizing the underlying simplicity of all biological phenomena.

Also known as: Maurice Hugh Frederick Wilkins

Primary fields: Physics; biology

Specialties: Genetics; biophysics

Early Life

Maurice Wilkins was born in Pongaroa, New Zealand, to Edgar Henry and Eveline Constance Jane Whittaker Wilkins, who both came from Dublin, Ireland. At the age of six, Wilkins was brought to England and educated at King Edward’s School in Birmingham. He studied physics at St. John’s College, Cambridge University, where he studied crystallography with John Desmond Bernal. He obtained his BA degree in 1938. Then he attended University of Birmingham, where he became research assistant to John T. Randall in the physics department. Together, they developed the electron-trap theory of phosphorescence and thermoluminescence. Wilkins received his PhD in 1940.

During World War II, Wilkins joined physicists under Mark Oliphant in their work using the mass spectrometer to separate uranium isotopes for the atom bomb. When nuclear research was transferred to the United States, Wilkins followed. He traveled to the University of California, Berkeley, to become part of the Manhattan Project. He continued to use the mass spectrograph to build up quantities of uranium-235 for the American atom bomb. As the war neared its end and the first atom bombs were dropped in Japan, Wilkins’s interest in nuclear physics waned. He read What Is Life? (1944) by physicist Erwin Schrödinger and became eager to apply his understanding of physics to the complexities of living things.

In 1945, Wilkins returned to Great Britain and began a career in biophysics at University of St. Andrews in Scotland, where he again was under the direction of Randall. In 1946, Wilkins and Randall moved to King’s College London.

Life’s Work

By the time Wilkins went to King’s College, scientists at the Rockefeller Institute in New York had proved that genes were made of deoxyribonucleic acid (DNA). Wilkins started doing research on DNA, at first indirectly, by trying to cause mutations in fruit flies with ultrasonic vibrations, and then directly, by developing a special microscope for studying the amount of DNA in cells. Eventually, Wilkins decided to leave the analysis of DNA in intact cells to the biologists; he believed that he could use his specialized skills more effectively to study the DNA molecule in isolation, outside the cell.

One of the techniques physicists had developed by then was the analysis of dichroism patterns. Wilkins placed a specimen of DNA under a microscope and then subjected it to two colors of light simultaneously: One color was transmitted directly and the other was reflected. From the contrast of the colors, some information about the structure of DNA could be inferred.

Wilkins next turned to analysis by X-ray diffraction, a technique that was still in its infancy. X-ray crystallography works by focusing a beam of X-rays on a crystalline structure. The scattered reflected beam is photographed. By rotating the substance under investigation, different diffraction patterns can be observed. The patterns can reveal the positions of the electrons within the substance, their density, and the chemical bonds that attach them to one another.

In 1951, there was considerable controversy in biophysics over the nature of genes. Many biologists believed that they were separate protein molecules within cells; others had come to suspect that the substance DNA, which appears in all living cells, was implicated. To show that DNA contained the genetic information that makes life possible, researchers had to determine not only the molecule’s chemical structure but also how it could replicate itself and transmit genetic information. The DNA molecule, which is large and complex, turned out to be suitable for investigation using X-ray diffraction techniques, and Wilkins’s laboratory began studying it in 1950. Rosalind Franklin, a skilled X-ray crystallographer, joined Wilkins’s team in 1951 and became one of the chief investigators.

Wilkins’s work, which established that DNA has a long crystalline structure, interested Francis Crick and James D. Watson of the Cavendish Laboratory at Cambridge University. However, research was hampered by complex interpersonal relations: Wilkins did not get along well with Franklin, and the two laboratories were both cooperating and competing with each other.

In 1953, Wilkins showed Watson an exceptionally clear photograph made by Franklin. From this picture Watson and Crick were able to hypothesize that the DNA molecule consisted of two identical chemical strands wound around one another helically. The molecule contains more than three billion chemical base pairs that contain genetic information. Crick and Watson published this discovery in April 1953.

Wilkins led much of the investigation and verification that remained to be done. The two laboratories had agreed to joint subsequent publication. After publications in Nature by the two groups in 1953, Wilkins proved that the Watson-Crick model was unique; no other model would give the same X-ray diffraction pattern. The data also allowed Wilkins to readjust and refine the Watson-Crick model. In 1962, Wilkins obtained the first clear X-ray diffraction patterns of ribonucleic acid (RNA), and he showed that it had a helical structure very similar to the Watson-Crick double helix.

Wilkins shared the 1962 Nobel Prize in Physiology or Medicine with Watson and Crick; Franklin had died of ovarian cancer in 1958 and her contribution was less recognized. After his Nobel Prize, Wilkins felt free to broaden his interests and to use his newly acquired prestige for the betterment of human life. Because of the Cuban Missile Crisis of 1962, he became deeply concerned about the dangers posed by biological and chemical weapons. His participation in the Cambridge Scientists’ Anti-War Group helped to focus this interest.

Although his studies on DNA had effectively ended by 1967, his curiosity about basic biological problems continued. For example, he began studies on the structure of nerve membranes. Also, he became the president of the British Society for Social Responsibility in Science.

During the 1980s, Wilkins extended his humanistic efforts by signing a manifesto on poverty and starvation in the developing world, which was connected with his participation in Food and Disarmament International. He also became an important part of the Pugwash movement, which brought together internationally prominent scholars and scientists to discuss ways of reducing the likelihood of war. Though he and his wife avoided public demonstrations, they did undertake nonpolitical work for the Campaign for Nuclear Disarmament during the 1980s and 1990s.

Wilkins’s autobiography, The Third Man of the Double Helix (2003), was largely devoted to his views on the discovery of DNA’s three-dimensional structure and his critique of the earlier accounts of Watson and others. He died on October 5, 2004.

Impact

Despite the complications and human foibles surrounding the discovery of the double helix, the structure itself proved to be a simple and beautiful one. Wilkins was impressed by this simplicity, and he came to regard DNA’s simplicity as symbolizing the underlying simplicity of all biological phenomena. In his later career, he believed that science’s search for simple principles also could be used to resolve social conflicts.

For Wilkins, science represented rationality as well, and in the late twentieth and early twenty-first centuries, he warned of the growth of irrationality. Nonetheless, he recognized that objective thinking could reduce moral sensitivity. According to Wilkins, modern humans live with a dilemma: Science is the only way for human beings to avoid starvation, disease, and premature death, but science can be used to accelerate human annihilation. To reduce these dangers, he felt, science must be carefully interrelated with technology, politics, art, and the rest of society.

Bibliography

Squires, G. L. “The Discovery of the Structure of DNA.” Contemporary Physics 44.4 (2003): 289–305. Print. Describes the careers of Crick, Watson, Wilkins, and Franklin. Traces the events leading up to the discovery of the structure of DNA.

Watson, James, and Andrew Berry. DNA: The Secret of Life. New York: Knopf, 2003. Print. Written fifty years after the discovery of the double helix, this historical study emphasizes the transformative effect that the double helix’s discovery has had on scientific, biotechnological, social, and ethical issues. Also includes Watson’s reflections on the discovery itself, including the role that Wilkins played.

Wilkins, Maurice. The Third Man of the Double Helix: The Autobiography of Maurice Wilkins. New York: Oxford UP, 2003. Print. Written to commemorate the fiftieth anniversary of the discovery of the double helix. Contains Wilkins’s reminiscences of the events and personalities of his early life and career as well as his own perspective on the DNA story and its aftermath. Includes photographs.