Francis Crick

British biologist

• Born: June 8, 1916; Northampton, England
• Died: July 28, 2004; San Diego, California

In 1953, while still a graduate student, British molecular biologist Francis Crick helped discover the double-helix structure of DNA and the process of replication responsible for heredity. For this discovery, he and James Watson, along with biophysicist Maurice Wilkins, were awarded the 1962 Nobel Prize in Physiology or Medicine.

Primary field: Biology

Specialties: Molecular biology; biophysics

Early Life

Francis Harry Compton Crick was born on June 8, 1916, near Northampton, England. His father, Harry Crick, managed the family business, a footwear factory. Crick was a curious child who especially enjoyed science and often conducted experiments at home. He was particularly interested in reading books about science and inventing. After primary school, Crick obtained a scholarship to attend boarding school, where he studied physics, chemistry, and mathematics.

Crick went on to study physics at University College London and graduated with honors in 1937. He then began his PhD work, also at University College, researching the viscosity of water. However, his studies were interrupted by the start of World War II, which forced the university’s physics department to relocate to Wales. Crick remained in England, and in 1940 he began to work in the research laboratory of the British Admiralty. He later transferred to another department, where he worked on the design of magnetic and acoustic mines. Also in 1940, Crick married Ruth Doreen Dodd, with whom he later had a son. The couple divorced after several years, and Crick married Odile Speed, with whom he had two daughters, in 1949.

After the war, Crick continued to work for the Admiralty in scientific intelligence. During this period, he read many contemporary science books, including What Is Life? (1944) by theoretical physicist Erwin Schrödinger. The book inspired Crick to go into molecular biology. Coincidentally, it was this same book that influenced Crick’s later colleague James Watson to change his career path, as well.

Crick discussed his career possibilities with many scientists, including Maurice Wilkins, a biophysicist researching deoxyribonucleic acid (DNA) at King’s College London. He was then offered a position with a team analyzing tissue culture at the Strangeways Research Laboratory at Cambridge University, where he became a PhD student and honorary fellow. In 1949 he moved to the Medical Research Council Unit, located in the Cavendish Laboratory at Cambridge. Along with future Nobel Prize winners Max Perutz and John Kendrew, he studied the structure of three-dimensional proteins, such as hemoglobin and myoglobin, and learned X-ray crystallography.

Life’s Work

In October 1951, James Watson, a young American who had been researching bacteriophage-infected cells at the University of Copenhagen, joined the team at Cavendish Laboratory. Crick and Watson struck up a friendship based on their shared interest in DNA. Crick shared everything he had heard about the King’s College team, which had been making considerable progress in cracking the “genetic code.” Watson mentioned seeing Maurice Wilkins at a symposium in Naples, Italy, earlier that year and raved about his X-ray diffraction photograph, which showed a helical DNA structure.

Despite the fact that neither scientist was assigned to research heredity, they decided to enter the race to determine the structure of the DNA molecule. Their first model had three strands, or spirals, and the bases were positioned incorrectly and lacked the right chemical structures. In the spring of 1952, Watson and Crick saw an X-ray diffraction photograph taken by Rosalind Franklin, a chemist and expert X-ray crystallographer working with Wilkins at King’s College. Her photograph clearly depicted the double-helix structure of DNA. With the assistance of chemists Erwin Chargaff and Jerry Donohue, Watson and Crick determined the proper structure of DNA, putting together their final model by March 7, 1953.

Crick and Watson submitted a paper on their findings, titled “A Structure for Deoxyribose Nucleic Acid,” to the scientific journal Nature. It was published on April 25, 1953, with another article published on May 30, 1953. Watson and Crick had beaten the King’s College team as well as the American chemist Linus Pauling, who had also been close to solving the DNA puzzle. For this accomplishment, Watson and Crick were awarded the 1962 Nobel Prize in Physiology or Medicine. Wilkins also shared the award; Franklin, whose X-ray diffraction photograph was essential to Crick and Watson’s discovery, had died prior to 1962.

In 1954, Crick returned to Cambridge after lecturing in the United States. He completed his dissertation, “X-ray Diffraction: Polypeptides and Proteins,” and received his PhD from Cambridge. In 1955, Watson returned to Cavendish Laboratory for a year, and the two worked together on a theory about the structure of DNA in viruses.

Crick continued to study DNA at Cavendish and in 1956 proposed a theory about amino acid adaptors as a key part of the protein synthesis process in a paper called “On Degenerate Templates and the Adaptor Hypothesis.” The unpublished paper was distributed to members of the RNA Tie Club, a fraternal organization for select molecular biologists started by the physicist George Gamow. Crick’s theory turned out to be correct, and the adaptors were later named “transfer RNA.”

Crick eventually moved into the field of embryology. In the mid-1960s, he lectured in the United States at Harvard University, the University of Rochester, and the Johns Hopkins School of Medicine. In 1976, Crick embarked on a new career in neurobiology at the Salk Institute for Biological Studies in La Jolla, California. Within a year, he was offered an endowed chair and a lifetime appointment. He became president of the institute in 1994.

Deeply interested in understanding consciousness and how the mind processes images, Crick felt molecular biology was the best route to uncovering the secrets of the brain. This was in direct contrast to behaviorism, the predominant theory in psychology at the time. He befriended psychologists at the University of California, San Diego, and was appointed an adjunct professor in the psychology department.

In 1981, Crick published the book Life Itself, which presents his theory of how life on Earth began with just a few microorganisms. Based on his earlier work, which demonstrated that the genetic code is the same for all species, he speculated on the possibility of another, earlier civilization intentionally depositing microorganisms on the Earth from space, beginning the long process of evolution, an idea he called “directed panspermia.” Two years later, he and a colleague, Graeme Mitchison, put forth their hypothesis that an automatic correction mechanism in the brain that helps to manage memory helps rid the body of unwanted memories in the form of dreams. According to this theory, the same mechanism also causes the rapid eye movement (REM) period of sleep.

Crick continued to research and write throughout the 1980s and 1990s, publishing the books What Mad Pursuit (1988) and The Astonishing Hypothesis (1994). He died of colon cancer in San Diego on July 28, 2004.

Impact

Scholars have compared Crick and Watson’s discovery of the double helix with Charles Darwin’s discovery of natural selection and Gregor Mendel’s discovery of the laws of heredity. It is widely regarded as establishing the foundation of molecular biology, since no problem is more fundamental than the mechanism of heredity. The double helix did not disappoint scientists eager to understand this mechanism: In the years after the model was unveiled, it proved surpassingly suitable for explaining on the molecular level how cells replicate. In recognition of his role in the discovery of the structure of DNA, Crick received many honors in addition to the Nobel Prize, including the British Order of Merit, and was inducted into several prestigious scientific organizations.

Bibliography

Crick, Francis. What Mad Pursuit. New York: Basic, 1988. Print. Provides insight into Crick’s career beyond his work with DNA, focusing in particular on the years prior to the discovery as well as his later career.

Olby, Robert. Francis Crick: Hunter of Life’s Secrets. Cold Spring Harbor: Cold Spring Harbor Lab, 2009. Print. Explores Crick’s life and career, from his research concerning DNA to his later work in the field of neuroscience.

Watson, James D. The Double Helix. London: Phoenix, 2011. Print. Chronicles the discovery of the structure of DNA from the perspective of Crick’s colleague James Watson.