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.
Further Reading
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)
