The Gene: An Intimate History - Siddhartha Mukherjee Page 0,73

To “see” DNA is to immediately perceive its function as a repository of information. The most important molecule in biology needs no name to be understood.

Watson and Crick built their complete model in the first week of March 1953. Watson ran down to the metal shop in the basement of the Cavendish labs to expedite the fabrication of the modeling parts. The hammering, soldering, and polishing took hours, while Crick paced impatiently upstairs. With the shiny metallic parts in hand, they began to build the model, adding part to part, as if building a house of cards. Every piece had to fit—and it had to match the known molecular measurements. Each time Crick frowned as he added another component, Watson’s stomach took a turn—but in the end, the whole thing fit together, like a perfectly solved puzzle. The next day, they came back with a plumb line and a ruler to measure every distance between every component. Every measurement—every angle and width, all the spaces separating the molecules—was nearly perfect.

Maurice Wilkins came to take a look at the model the next morning. He needed but “a minute’s look . . . to like it.” “The model was standing high on a lab table,” Wilkins later recalled. “[It] had a life of its own—rather like looking at a baby that had just been born. . . . The model seemed to speak for itself, saying—‘I don’t care what you think—I know I am right.’ ” He returned to London and confirmed that his most recent crystallographic data, as well as Franklin’s, clearly supported a double helix. “I think you’re a couple of old rogues, but you may well have something,” Wilkins wrote from London on March 18, 1953. “I like the idea.”

Franklin saw the model later that fortnight, and she too was quickly convinced. At first, Watson feared that her “sharp, stubborn mind, caught in her self-made . . . trap” would resist the model. But Franklin needed no further convincing. Her steel-trap mind knew a beautiful solution when it saw one. “The positioning of the backbone on the outside [and] the uniqueness of the A-T and G-C pairs was a fact that she saw no reason to argue about.” The structure, as Watson described it, “was too pretty not to be true.”

On April 25, 1953, Watson and Crick published their paper—“Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid”—in Nature magazine. Accompanying the article was another, by Gosling and Franklin, providing strong crystallographic evidence for the double-helical structure. A third article, from Wilkins, corroborated the evidence further with experimental data from DNA crystals.

In keeping with the grand tradition of counterposing the most significant discoveries in biology with supreme understatement—recall Mendel, Avery, and Griffith—Watson and Crick added a final line to their paper: “It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material.” The most important function of DNA—its capacity to transmit copies of information from cell to cell, and organism to organism—was buried in the structure. Message; movement; information; form; Darwin; Mendel; Morgan: all was writ into that precarious assemblage of molecules.

In 1962, Watson, Crick, and Wilkins won the Nobel Prize for their discovery. Franklin was not included in the prize. She had died in 1958, at the age of thirty-seven, from diffusely metastatic ovarian cancer—an illness ultimately linked to mutations in genes.

In London, where the river Thames arches away from the city near Belgravia, one might begin a walk at Vincent Square, the trapezoid-shaped park that abuts the office of the Royal Horticultural Society. It was here, in 1900, that William Bateson brought news of Mendel’s paper to the scientific world, thereby launching the era of modern genetics. From the square, a brisk stroll northwest, past the southern edge of Buckingham Palace, brings us to the elegant town houses of Rutland Gate, where, in the 1900s, Francis Galton conjured up the theory of eugenics, hoping to manipulate genetic technologies to achieve human perfection.

About three miles due east, across the river, sits the former site of the Pathological Laboratories of the Ministry of Health, where, in the early 1920s, Frederick Griffith discovered the transformation reaction—the transfer of genetic material from one organism to another, the experiment that led to the identification of DNA as the “gene molecule.” Cross the river to the north, and you arrive at the King’s College labs, where Rosalind Franklin and Maurice Wilkins began their work on DNA crystals in the early