The Glamour of the Molecule: Discovery of the Double Helix

Maggi Rohde, 10 December 1994
Citations available upon request

There's one lecture that I've heard repeated at least five times since I enrolled at Michigan State. It seems to pop up in every molecular biology class I take. And it always starts the same way: "The structure of DNA was discovered by James D. Watson and Sir Francis Crick in 1953..."

This semester it came up in two different classes, a lecture and a laboratory. I never thought much of it, or even thought to question its validity or truth. After all, they did win the Nobel Prize for their molecular model. And their names were always kind of halfheartedly stuck in between some interesting structural facts about DNA, facts that would almost certainly appear on the test, while specific information about the work of two geneticists would just as certainly not. It fell into the cracks, seldom written in my notes, and was lost from short-term memory a few weeks after I heard it. Nevertheless, if you asked me two months ago who discovered the structure of DNA, I would have said, "Watson and Crick," and left it at that, confident I was correct.

But while reading Sandra Harding's book Whose Science? Whose Knowledge?, I came across a new name, one I'd never heard before: Rosalind Franklin. Harding said she had played an important role in the discovery of the structure of DNA, and that she hadn't recieved the credit she deserved. At first I was skeptical. Why hadn't my professors mentioned her name in class before if she was so important? I guessed that none of them had even heard of her before. But in this I was incorrect. Everyone seemed to know who she was -- they just had never said anything about her. Like so many other women in history, she had been ignored, rendered invisible. And much of this invisibility stems from the efforts of the very people who took credit for the award: Watson and Crick, particularly James Watson.

Before one can begin to see what a crucial role Rosalind actually did play in the "race for the double helix," it is necessary to know the history, as well as some of the science, surrounding the discovery. In 1952, Jim Watson was a young American biologist just finishing his postdoctoral research in Copenhagen. He had an interest in working with DNA, which was then a little-researched molecule. Only a few people believed, as Watson did, that DNA was the source of the genetic material. He eventually got a grant to learn X-ray crystallography in Sir Lawrence Bragg's lab at Cambridge. There he met Francis Crick, who at that time was working on his PhD, studying the structure of myoglobin. They became fast friends and found that they had a similar interest in DNA.

One of the most brilliant and highly-regarded scientists in the world at that time was Linus Pauling. Pauling had just published a fantastically important paper about the alpha-helix, a common component of protein structure. Much of his evidence for the shape of this structure came from X-ray crystallography. In this procedure, X-rays are shot at a well-isolated sample of the compound in question, with a piece of film placed behind the compound. The way in which the X-rays diffract off the substance and hit the film make a picture. Scientists can derive incredibly precise measurements from these pictures, as precise as an angstrom, or 1 x 10 to the 10th meter. X-ray diffraction crystallography is a difficult science which takes many years to master.

Rosalind Franklin was an expert crystallographer. She worked at a neighboring lab, King's College in London, with another molecular biologist, Maurice Wilkins. Franklin was already using X-ray diffraction to examine DNA, and had discovered two forms, which she called the A and the B forms. The A form was a drier (fewer water molecules were involved), more irregular form, but she had been getting clearer and better diffraction pictures of the A form, and had thus concentrated her work in that direction.

Maurice Wilkins was convinced that the B form might yield more interesting results, but Rosalind kept working on the A form and would not share her data or X-ray photos with Wilkins. This annoyed him to no end. Apparently, Wilkins had hired Franklin with the idea that she would be his assistant, even though she was the superior scientist. As a consequence, Maurice and Rosalind did not get along at all.

James Watson, a friend of Maurice's, also did not much like Rosalind. They teasingly called her "Rosy" behind her back and believed that her stubbornness was hindering Wilkins' work. "The thought could not be avoided," said Watson in his book, The Double Helix, "that the best home for a feminist was in another person's lab." He thought she dressed too plainly and "might have been quite stunning had she taken even a mild interest in clothes." Her "belligerent moods" supposedly distracted Wilkins from his work and made it impossible for him to "maintain a dominant position that would allow him to think unhindered about DNA... Clearly, Rosy had to go or be put in her place."

Watson's autobiographical book, The Double Helix, is full of similar sexist commentary about Franklin, her "unladylike" behavior and manner of dress, and his efforts to drive her away from her post at King's College. Francis Crick also wrote a book about his work on DNA, called What Mad Pursuit, after his colleague's volume became a best-seller. Curiously, he never once mentioned that Rosalind had a bad temper, or that she was anything other than a superb crystallographer, although he did say that he and his wife often had her as a guest for dinner.

While Rosalind was unquestionably an excellent and thorough scientist, Watson shows little evidence of such qualities. He was certainly brilliant, having achieved his B.S. and PhD by the time he was twenty-three. But he didn't want to work particularly hard. He had hoped that "the gene might be solved without my learning any chemistry," which he found very dull.

He went to see a talk that Rosalind gave about her work so far with DNA and failed to take notes on her presentation. When he later reported what he'd heard to Francis Crick, they concocted a completely incorrect model based on a ghastly mistake about how many water molecules per unit cell there were. It partially destroyed Watson's credibility with his boss, Sir Lawrence Bragg. (9) But it seems to me that Watson's most spectacularly unscientific stunt was how he came to find out about the B form of DNA. He was talking with Wilkins in his lab after an argument with Rosalind, and Wilkins confessed that he'd been secretly making copies of her X-ray photographs. He showed a picture of the B form to Watson, which was apparently the first time Watson had ever heard about this other form:

"The instant I saw the picture my mouth fell open and my pulse began to race. The pattern was unbelievably simpler than those obtained previously ("A" form). Moreover, the black cross... could arise only from a helical structure."
He later drew from memory a picture of what he had seen in the stolen photo. This data was the basis for most of Watson and Crick's postulations about their model for the structure of DNA. "Jim... just wanted the answer," Crick states in his book, "and whether he got it by sound methods or flashy ones did not bother him one bit. All he wanted was to get it as quickly as possible."

Even if we leave all thoughts of method and moral judgement aside, it is clear that Watson and Crick both knew what they were stealing from Rosalind, and that they could not have created their model without her data. Yet they did not credit her work in their first paper, published in Nature in 1953. They did, however, credit Wilkins. He, along with Watson and Crick, won the Nobel prize in 1962. Rosalind, too, knew that her work had been used. But she didn't make any complaint. In fact, Watson says that "her fierce annoyance with me collapsed.... With obvious pleasure Rosy showed Francis her data.... Her past uncompromising statements on this matter thus reflected first-rate science, not the outpourings of a misguided feminist."

Watson expresses the belief that Rosalind's "transformation" was due to her recognition that she was working with capable scientists, not "slackers who wanted to avoid the hard work necessitated by an honest scientific career." He also says that he then realized how difficult her situation had been because her "first-rate crystallographic ability was not given formal attention." Whether or not Rosalind thought this about Watson and Crick is immaterial. What is clear is that Watson never did give Rosalind the credit she was due. He and Crick, along with Maurice Wilkins, accepted the Nobel Prize with no acnowledgement whatsoever that Rosalind Franklin had done much of the essential work, and recieved no reward. She was unfortunately unable to stand up for herself, because she died from cancer in 1956, three years after the DNA structure was revealed. However, since then, several scientists have attempted to set the record straight.

In 1968, Aaron Klug published a paper in Nature concerning the extent of Rosalind's work on DNA. He mentioned that her private analysis of the B form had included helical aspects, as well as other important features, such as the fact that the phosphate backbone was on the outside of the helix. Klug's paper was largely ignored. Later, in 1974, he published another paper, again in Nature, saying that Rosalind had been even closer to the solution of DNA's structure than anyone had realized. He had found a draft manuscript of her paper, written before Watson and Crick's had been published, which included descriptions of a double-helical structure, including precise measurements of the dimensions of the helix. This second paper by Klug was buried on page 787, preceding an article about how more molecular biologists are born under the astrological sign Aries. I have never seen a more classic example of the way in which the media fails to correct mistakes they have reported.

Crick brings up a point in his book about the nature of science: "The path [to the double helix] was, scientifically speaking, fairly commonplace. What was important was not the way it was discovered but the object discovered -- the structure of DNA itself.... It is the molecule that has the glamour, not the scientists." That is to say, the stealing and bickering and all that occurred is common among scientists and between labs, which is true. But I believe this situation is not as entirely commonplace as Crick would like us to think. Rosalind Franklin was a woman, and she was quite blatantly harrassed for no other reason than she was a woman. And like so many other women, she has been rendered historically invisible.

It is impossible to say whether Rosalind would have made the necessary deductive leaps which would have led her to the correct structure for DNA. She probably would have figured it out sooner or later. But one thing it seems every source I've read has overlooked is how alone Rosalind was in her work. She had one assistant -- R.G. Gosling, a graduate student working on her thesis -- and other than that, she had very little input. Rosalind came up with the vast majority of her ideas on her own. Watson and Crick, on the other hand, had multiple resources, not the least of which were their own (male) colleagues. The faculty lounge was reserved for men only, and in there they discussed their work and toyed with ideas. One incredibly crucial piece of information which led Watson to his final work on the structure was given to him by a friend, Jerry Donohue. Jerry was an organic chemist, one of the only chemists in the world at the time who was an expert in tautomeric chemistry. Without Jerry's corrections, Watson would never have been able to discover the correct conformation of the purine and pyridine bases which make up the genetic code of DNA. Rosalind had no such help.

I conducted interviews with both of my genetics professors who mentioned Watson and Crick this semester: Dr. Wendy Champness, who taught the lecture class, and Dr. Larry Snyder, who directed the lab. Dr. Champness knew a lot of detailed information about the situation, partially because she is in the process of writing her own genetics textbook. She seemed to think that modern texts were likely to mention Rosalind and her work. But of the dozen or so texts I looked through, the only two that mentioned her name were Dr. Champness' book (we used an unpublished, rough-draft copy for her class) and a text written by -- who else -- Dr. James D. Watson. The rest mentioned nothing more than Watson and Crick. Dr. Champness added that it's hard to include much historical perspective in a textbook or a class because there's too much factual data about genetics itself to cover. "It's the kind of situation that's really hard to deal with in a textbook," she said, "because the interpretations are interpretations. I mean, you can't come right out and say, 'Well, and Watson is a jerk.'"

Dr. Snyder agreed with Dr. Champness. "I would never say it was discovered by Watson and Crick," he said. "It went back a long way before then. There were a lot of people involved.... It was Watson and Crick who came up with the model, but it was a long time in coming. They were just there at the right time."

When I asked Dr. Snyder if he thought that the history of an event like this in science was important, he was pensive. "It's best not to teach it as history," he said at last. "To teach science without dragging people through the whole system is the point, I think. Because science is not a collection of facts, after all; science is a process."

I disagree with Dr. Snyder on this point. Science is indeed a process, but the so-called "history" of science is part of the process. It shapes the way we learn and the way we view the system in which we learn it. Even though both of my professors expressed the feeling that Watson and Crick were not the most important ones involved in the discovery of the structure of DNA, they each mentioned Watson and Crick's names in their classes. Rosalind Franklin's name was never brought up.

Apologies have been made, but irrevocable damage was done in 1953 when Watson and Crick failed to include Rosalind's name in their paper. The consequences of that damage continues today, in textbooks, undergraduate lectures, laboratories -- and every time we fail to say: "The structure of DNA was discovered in 1953 due to the research of James Watson, Sir Francis Crick and Rosalind Franklin."

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