The Double Helix
Like many of their colleagues, the physicists Francis Crick and Maurice Wilkins were disgusted by their subject’s contribution to human misery during the Second World War. Turning to biology, they, together with the biologist James Watson and the chemist Rosalind Franklin, deciphered the structure of DNA and in the process generated an enduring myth about who did what and to whom.
In 1944, Halifax-born Oswald Avery identified DNA as the carrier of genetic information. Its chemical composition was by then well known, but it was soon realized that knowing the structure would clarify how the molecule actually works.
Wilkins and his graduate student Raymond Gosling initiated research on DNA at John Randall’s laboratory at King’s College, London. Randall recruited Franklin, well known and highly respected, and in a letter tasked her with also researching DNA. He never discussed this with Wilkins, who was on holiday when Franklin joined the lab and only heard about the letter decades later. He was understandably surprised and frustrated to discover that there was now another scientist working on DNA and, moreover, that Gosling was now Franklin’s PhD student and not his.
The two scientists did not get along. Wilkins was withdrawn, rather depressive and avoided conflict; Franklin was brash and in-your-face.
Watson and Crick (henceforth W&C) were at Cambridge’s Cavendish laboratory and soon became interested in DNA structure because Crick and Wilkins, also friends, frequently discussed the matter.
In November 1951, Watson attended a talk by Franklin about her research. He spoke to Crick about it the next day, but, not well versed in crystallography, did not understand much and forgot a significant amount. Apparently, all he could tell Crick was that Franklin mentioned the possibility of a helical structure.
Inspired by this idea, W&C built a model of a triple helix and invited Franklin over. Big mistake. She shot it down in flames.
By this time, the atmosphere at King’s College was so unpleasant Franklin decided to move to Birbeck College and abandon research on DNA.
W&C on the one hand and Franklin on the other approached their research very differently. She felt that the data should lead to the structure, usually a successful approach, but in this case, it delayed her just long enough to miss the grand prize.
W&C’s angle of attack was “let’s try different structures and see which one fits the crystallographic data.”
Soon, Franklin’s results were summarized in a report to the British Council for Medical Research. It was open to all, and this is important, because it is often not mentioned when W&C are accused of purloining Franklin’s results.
Max Perutz of Cambridge read the report and showed it to W&C. It contained nothing which Franklin had not already said during the lecture Watson attended, but which he misunderstood and/or forgot. Crick, however, immediately realized that the report showed that DNA had two interlocking parts and not three. This realization was strengthened by the (in)famous photo 51, about which more later.
The two built a double helical structure which fit all the crystallographic data and invited Franklin and Wilkins to come over and take a look. The visitors immediately realized that W&C had hit the jackpot.
It was agreed (probably not immediately) that W&C would be the sole authors of a paper in the prestigious scientific journal Nature and that Franklin and Wilkins would, in a separate paper, describe their results on which the structure was based.
I must add that Franklin had, in the meantime, also come to realize that DNA had a helical structure, but W&C crossed the finish line a hairbreadth ahead.
Watson, Crick and Wilkins received the Nobel Prize for medicine and physiology in 1962. Franklin died in 1958, and many have argued that she should have received a posthumous Nobel in chemistry. Posthumous Nobels were possible until 1974, but only two such awards have ever been awarded so the chances of that happening again were slim.
In 1968 James Watson published The Double Helix, his highly personalized and controversial account of the events. It immediately gathered a storm of protests, particularly because W&C were now accused of making use of Franklin’s data without giving her credit.
What actually happened was this: when Franklin decided to leave, Wilkins again became Gosling’s study leader. Randall asked Gosling to share his results with Wilkins, which was only natural. A PhD student cannot work in isolation from his study leader.
While working under Franklin, Gosling took an X-ray photograph of DNA (photo 51) and showed it to Franklin, but she was more interested in another form of DNA. The photograph lay in a drawer for some time before it was shown to Wilkins.
There are two versions of subsequent events: one is that Franklin was unaware that Gosling showed the photograph to Wilkins (although it would have been strange if she did not realize that a PhD student would share results with the study leader); the other is by Gosling himself in a Nature podcast recorded in 2015, shortly before his death, telling how he, at Franklin’s request, handed the photo to Wilkins.
The link to the podcast is at the end, but here are relevant excerpts for those who are unable to access the link:
Gosling: “And the best structure B pattern we ever got is photo 51, which I took and was called 51 because that was the 51st photograph that we’d taken, Rosalind and I, in our efforts to sort out this A and B difference.”
Interviewer: “Somehow, Wilkins got a copy of photo 51.”
Gosling: “I took it down the corridor and gave it to him because it had reached the stage now when Rosalind was going to leave, so she suggested that I go down the corridor and give this beautiful structure B pattern, this photo 51, to Maurice. Maurice couldn’t believe… that I hadn’t stolen it from her desk. He didn’t think that she could ever offer him something as interesting as this. He’d only had it for two or three days when Watson chipped up.”
Matthew Cobb, a noted biologist who has extensively researched the matter, is of the opinion that the importance of photo 51 is somewhat overblown. It is very unlikely, he noted, that a skilled chemist like Franklin would not be able to interpret the photo, while a crystallographic novice like Watson would probably not grasp it after a single glance.
Cobb also writes: “…various lines of evidence — including The Double Helix itself, read carefully — show that it played little, if any, part in Watson and Crick’s inching towards the correct structure between January and March 1953. In fact, it was other data from Franklin and Wilkins that proved crucial, and even then, what really happened was less malicious than is widely assumed.”
There may be uncertainty about just how W&C arrived at their insight, but there can be little doubt that they did not steal Franklin’s data, although this data was very, very useful.
Watson in particular should have given her more credit. Had she been alive in 1962, she should without a doubt have been awarded a richly deserved Nobel prize.
