Thirty kilometers east of Pahiatua and Eketahuna, but still 25 km shy of the Wairarapa coast, lies the tiny hamlet of Pongaroa. While Pongaroa may well be notable for other things, one indisputable claim to fame is that it is the birthplace of Maurice Hugh Frederick Wilkins, the scientist who shared the 1962 Nobel Prize in Medicine or Physiology with James Watson and Francis Crick for the discovery of the structure of deoxyribonucleic acid, or DNA, responsible for the transmission of hereditary characteristics from parents to offspring.(Curiously, another of the three Nobel laureates to have been born in New Zealand, Alan MacDiarmid, who was awarded the prize for chemistry in 2000, also began life in the Wairarapa not far from Pongaroa, in Masterton.)
Wilkins parents, Evilene and Edgar,emigrated to New Zealand from Ireland shortly after Edgar had qualified as a medical practitioner. They arrived in Petone early in 1913, and Edgar set up a practice there. The couple’s first child, Eithne, was born in 1914.
After a time, the family moved to the remote hills of Pongaroa, where Maurice was born on December 15, 1916. In that era, babies were frequently born on the butcher’s block, and Maurice came into the world this way. He was christened in St John’s Church on February 15, 1917. The Wilkins family shifted to Pahiatua in mid-1918, where Edgar developed a passion for preventative medicine in schools. Indeed, later that year he was appointed Director of School Hygiene for the nation, and consequently the family again moved, this time to Kelburn Parade, in Wellington.
Maurice, today aged 87 and the victim of a recent stroke, still remembers Wellington clearly, and fondly recalls family picnics in the surrounding countryside and at the beach. The memory of his first earthquake, and how his mother grabbed his baby sister, Jasmine, as things tumbled from the shelves, remains vivid. Wellington’s wind remains clear in his mind also, and the hazard it posed to light horse-drawn vehicles.
The Wilkins family remained in Wellington until mid-1923, when they returned to Ireland, Edgar and Evilene being motivated by a desire to give their children a better education than was available in Wellington. Edgar had strong and somewhat unorthodox ideas on education, believing young children to be better off learning from their own explorations of the world than turning to “second-hand knowledge from books.”
As a result, neither Maurice nor Eithne received much in the way of formal schooling in New Zealand. A second and perhaps even more significant reason for their departure lay in the clashes that Edgar was having with the authorities over his ideas on improving the health of New Zealand’s schoolchildren. He believed that decent living conditions and good nutrition were the keys to sound health, whereas other doctors seemed concerned only with the treatment of sick children in hospital.
After a short period back in Dublin, Edgar and Evilene decided that better job opportunities existed in England, so the family headed to London, where Edgar took a Diploma of Public Health at King’s College, London—the very place where Maurice was to carry out DNA research some 30 years later. Edgar then wished to practise preventative medicine in the poverty-stricken areas around Birmingham, and the family set up home in that city.
Maurice gained a scholarship to study at King Edward’s School, in Birmingham, and in 1935 went up to Cambridge University to study physics at St John’s College. There he became highly involved in the Cambridge Scientists Anti-War Group (CSAWG), and, like many other students of the era, joined the anti-fascist Communist Party, since his left-leaning tendencies were not satisfied by Labour.At Cambridge, Wilkins was tutored by the Australian Marcus Oliphant, who was Ernest Rutherford’s deputy. Rutherford, New Zealand’s first Nobel laureate, died in 1938 from septicaemia as a result of a fall from a ladder at his home.
Wilkins spent so much time working with the CSAWG that in 1938 he achieved only a lower second-class honours BA degree. In consequence, he was unable to raise support to pursue a PhD at Cambridge. Oliphant had moved to Birmingham and established his own laboratory, so Wilkins contacted him to see what positions might be available there. He obtained a job as a research assistant with John Randall, a physicist studying luminescence phenomena, and began working towards a doctorate.
On the outbreak of war, Wilkins joined the Ministry of Home Security and Aircraft Production, where he completed his PhD and worked at improving the performance of radar screens. Randall, who was Wilkins’ PhD supervisor, had helped design the cavity magnetron, a key to the development of microwave radar, which gave the Allies a much-needed advantage in the early war years.
Surprisingly, in view of his anti-war activities, after Wilkins had finished his PhD he expressed an interest in doing whatever he could to help win the war. He started work on the separation of uranium isotopes with Oliphant, who had become the leader of nuclear-weapons research in the United Kingdom. In February 1944, the group crossed the Atlantic on the Queen Elizabeth and moved to the University of California, Berkeley, to participate in the Manhattan Project. The culmination of this was the devastating explosions of the atom bombs “Fat Man” on Hiroshima and “Little Boy” on Nagasaki.
Involvement in the A-bomb programme was one of three life-changing events for Wilkins at this time. The second was an ill-fated marriage to an American woman that ended in divorce in less than a year, and the third was his reading Erwin Schrödinger’s book What is Life? The Physical Aspects of the Living Cell. Schrödinger’s ideas greatly influenced him, as they did many other physical scientists, and made him decide to move away from straight “somewhat inhuman” physics and to study living systems instead.
After the war Randall invited Wilkins to join him in a new biophysics research unit at St Andrew’s University, in Scotland. But the university proved not very lively, and Wilkins later commented, “the staff Common Room was like a recreation area in a prison, with inmates exchanging stories about lucky escapees who had disappeared into the world outside.” Randall and Wilkins soon moved back to London.
In 1946, Randall gained the physics chair at King’s College, London, after the favoured internal candidate was arrested for passing atomic secrets to the Russians. The courtyard at King’s, in the Strand, had received a direct bomb hit during the war, and the crater was further excavated to provide a site for Randall’s new lab, commonly known as “Randall’s circus.”For several years Wilkins dabbled in various projects, such as imaging DNA in living cells with special microscopes and trying to produce genetic mutations with ultrasound, before becoming involved in investigating the structure of DNA.
In 1950, Rudolph Signer, a European biochemist, had produced pure DNA and made it available to anyone wishing to study it. Wilkins obtained some and was able to produce oriented fibres suitable for X-ray diffraction. Subsequently, he and a colleague, Raymond Gosling, obtained clear X-ray diffraction patterns characteristic of a helical structure. This important discovery set the scene for much of what was to follow.
In 1951, Randall, now head of the Medical Research Council (MRC) Biophysics Research Unit, hired Rosalind Franklin, an expert on the use of X-ray diffraction on coal to create images of crystallised solids, to work on protein solutions. Wilkins suggested she be asked to work on DNA instead, and that, given her field of expertise, she be allowed to supervise Raymond Gosling in his thesis research. Franklin gained the impression that the structure of DNA was to be her problem, whereas Wilkins believed that she had been employed to assist him.
The pair never got on well, and at least some of the fault seems to have lain with Randall, who appeared to be trying to detach Wilkins from the X-ray work so that he could move in on it himself. His desire to gain the coveted Fellowship of the Royal Society was evident to those around him,and he clearly felt that continued progress on DNA would reflect well on him if he had a more direct role in the experimental work. This attempt to manoeuvre Wilkins out of the field in which he had already had a significant impact proved disastrous to personal relations between Franklin and Wilkins, though neither was aware at the time what Randall was up to.
In the spring of 1951, Wilkins went to a conference at the Naples Zoological Station, where he presented his new X-ray data on DNA. James Watson, a young American researcher with an interest in DNA and genetics, was present and realised immediately that X-ray methods had the potential to solve the problem of the structure of DNA. He decided to move to Cambridge to learn how X-ray diffraction patterns were interpreted.
In July 1951, Wilkins was invited to visit Cambridge and give a seminar. He spoke of his belief that DNA was a multi-stranded helical molecule (possibly three-stranded) with a diameter of about 2 nanometres (millionths of a millimetre) and the sugar phosphate backbone on the outside. After his talk he was approached by Rosalind Franklin, who warned him off doing any further X-ray studies. Indeed, she told him to “Go back to your microscopes.” He was shocked and bewildered.
In September, Franklin revealed her discovery that DNA could exist in either of two forms A-form or B-form—dependent on ambient humidity. This was a major step forward. Her data also suggested that the sugar–phosphate backbone indeed lay on the outside of the molecule and, by implication, that the bases were located internally. B-form was the simpler of the two, but Franklin concentrated her efforts on the more crystalline A-form. This was to prove a major misjudgement.
In November, Franklin gave a talk at King’s College, indicating that she preferred to take a classical crystallographic approach to solving the structure of DNA rather than indulge in model building. That same month Watson produced a three-stranded helical model of DNA in which the bases were on the outside and the sugar–phosphate groups on the inside—the opposite of what Wilkins and Franklin had been suggesting.
The King’s group was easily able to show Watson and his English colleague, Francis Crick, that such a structure was incompatible with their data. As a result, Watson and Crick were told by others at Cambridge that they should stop working on DNA and leave the King’s group to it. Such a directive seems quaint by modern standards, but the concept of non-overlapping research and gentlemen’s agreements on dividing up the scientific territory was quite common in those days.
In may 1952, the American chemist Linus Pauling was due to attend a meeting in London but had his passport withdrawn as a consequence of alleged communist sympathies. This was during the infamous McCarthy era. Pauling, the world’s leading theoretical chemist, had postulated the existence of an alpha-helix structure in proteins, a structure he largely developed using model-building principles and stereochemical data. It was expected that he would shortly tackle DNA using a similar approach.
At about the same time, data on the chemical composition of DNA were published, suggesting that the proportions of the bases adenine and thymine, and of guanine and cytosine, were similar. The results were not unequivocal, although, in hindsight, the implications should have been evident to those working in the field.
On July 18 came the bombshell from Franklin that A-form DNA could not possibly be helical, since her careful measurement of X-ray patterns had revealed that they were not axially symmetrical. What she did not reveal, however, was that she had obtained superb X-shaped diffraction patterns from B-form DNA, which provided the most convincing evidence yet that DNA was indeed helical. It is extraordinary that she did not make this observation known.
By December 1952, Pauling was reported to have worked out the structure of DNA. This was devastating news to the Cambridge duo of Crick and Watson. On January 31, 1953, Watson visited Wilkins, who had been given a photograph of B-form DNA by Raymond Gosling to use as he saw fit. Wilkins showed this to Watson, who was overcome with excitement as he saw its significance concerning the likely helical structure of DNA. Wilkins was later to comment ruefully, “I showed it to Jim, and I think if I’d known how much it gave him some sort of kick, I certainly would have thought twice before showing it to him.” Just three days earlier, Rosalind Franklin had admitted, for the first time, that she thought B-form DNA had a helical structure.
In February 1953, Pauling sent his DNA manuscript to his son, Peter, who was working in Cambridge at the time. Pauling’s model was a three-stranded helix with the sugar–phosphate backbone in the centre. To the enormous relief of the English researchers, it contained a major and elementary error. But the Cambridge crew knew Pauling would try again and would surely do better. Urgency was now essential if they were to beat Pauling to the solution.
With the assistance of more data from King’s and elsewhere, Watson and Crick realised that the base adenine could hydrogen-bond to thymine, and guanine to cytosine. This discovery—of what is known as complementary base pairing—was the “eureka event” in the DNA saga. Both base pairings had the same shape and size, thus allowing them to fit easily into the core of a regular helical DNA molecule, like steps in a spiral staircase. The molecule was right-handed and double-stranded. The mystery of life had been unravelled.
Maurice Wilkins and Rosalind Franklin confirmed that their data were consistent with the proposed structure. Three papers appeared in the journal Nature on April 25, 1953, one by Watson and Crick, another by Wilkins, mathematical physicist Alec Stokes and physicist Herbert Wilson, and the third by Franklin and Gosling. In the last of these, Franklin stated for the first time that both A-form and B-form DNA were helical. Interestingly, after her death in 1958, examination of her notebooks showed that she was thinking in terms of a two-stranded helical structure, exactly as proposed by Watson and Crick. She never made these ideas public herself.Maurice Wilkins was offered joint authorship with Watson and Crick of their Nature paper but declined, to his subsequent regret.
Wilkins and his colleagues spent the next 15 years improving the X-ray data and removing any doubt that the double-helix model was correct. This part of the DNA story is often overlooked but was absolutely crucial. In some respects, Wilkins both started the structural studies of DNA and finished them.
Wilkins was appointed director of the MRC Biophysics Research Unit in 1955, and in 1959 was elected a Fellow of the Royal Society. That same year he married Patricia Chidgey, and in due course the couple had two sons and two daughters. In 1960, Wilkins was a co-recipient, with Watson and Crick, of the distinguished Albert Lasker Award for Basic Medical Research, and in 1962 he was made a CBE as well as awarded a one-third share of the Nobel Prize in Medicine and Physiology with the Cambridge pair. The Nobel citation states that the prize was “for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material.” It is said that Wilkins almost turned the prize down, but was persuaded to accept it since it would assist him in his arguments as a campaigner against nuclear weapons. Indeed, much of his time away from work was devoted to CND, the Campaign for Nuclear Disarmament.
Although he was made a professor in 1963 and went on to become director of the MRC Biophysics Research Unit (1970–1972), director of the Neurobiology Unit (1972–1974) and director of the MRC Cell Biophysics Unit (1974–1980), Wilkins had little hands-on involvement in research from the 1970s.As his research activity diminished, so he became something of an elder statesman in science very commendable. On genetic modification—to many as anathema today as nuclear weapons were a generation ago—he remains cautious, commenting he is “not sure that we can control it simply through knowing gene structure.”
In 1980, Wilkins retired to his home purchased with his Nobel Prize winnings—in Blackheath, London, where he devoted himself to gardening and collecting sculptures. His autobiography, entitled The Third Man of the Double Helix, has just been published by Oxford University Press.
Although Wilkins has never returned to New Zealand and doesn’t think of himself as a New Zealander, he has stayed in touch with the land of his birth through such activities as periodic reading in the library of New Zealand House, in London. He has also followed the rise of New Zealand wine—especially that from Wairarapa—with interest and appreciation.The boy from Pongaroa has had an undoubted impact on the scientific history of the world. He is someone that all New Zealanders can justifiably hold in high esteem. After all, he is our second Nobel laureate and the third man of DNA.