The Tangled Field

By Nathaniel Comfort

Often times when reading a biography of a well-known scientist or contributor to the field of science or technology, the author is full of praise for the subject, or else, damning with new or unknown evidence intended to “set the record straight”. In the case of The Tangled Field, by Nathaniel Comfort, the author chose to write about Barbara McClintock, famous geneticist and Nobel laureate; but in writing her biography, his main focus was to separate the real McClintock from the woman who gained international fame as a misunderstood, mostly ignored scientist. This demythologizing narrative investigates what led to the Barbara McClintock falsehood of underappreciated and marginalized female scientist, and attempts to shed light on the actual events, attitudes, and atmosphere that surrounded her during the span of her lifetime.

The book begins with the McClintock myth, the story of a brilliant young geneticist who, in the 1920s and 30s, made some remarkable contributions concerning the chromosomes of maize, or Indian corn. As the only female member of the maize geneticist group at Cornell University, she could not find a job when every other man did. When she did finally get a job at the University of Missouri in 1936, she quit after five years because her boss told her she had no hope of ever receiving tenure and would be fired soon anyway. This led her to Cold Spring Harbor, Long Island, New York, at the small private research lab funded by the Carnegie Institute of Washington, D.C. Working alone, without any assistant or even a graduate student, McClintock made a remarkable discovery that would revolutionize genetics; only it wouldn’t be appreciated for another thirty years. McClintock discovered that genes were not in fixed positions along the chromosomes, like the popular pearls-on-a-necklace theory hypothesized. Rather, she found that genes near the end of the chromosome could jump spontaneously to a new site toward the center. She called this transposition, and the “jumping genes” were coined transposable elements. When she reported her breakthrough in 1951, at the annual Cold Spring Harbor Symposium, no one believed her and a few scientists were outright hostile. Five years later she tried again and received a similar reaction, causing her to stop publishing altogether and pursue her experiments in isolation for decades. In the 1970s, molecular genetics became the latest trend and McClintock’s work was “rediscovered” when transposable elements were discovered in bacteria and other organisms. Like Mendel, she finally received the recognition she deserved and in 1983, she even won the Nobel Prize in Physiology or Medicine.

The Barbara McClintock of this story is a myth, yet Comfort is quick to point out that myths are not entirely false; they contain both fact and fiction. For the remainder of the book, Comfort attempts to uncover the McClintock myth, put it back into historical context and reinterpret the life of a brilliant, yet flawed geneticist. One of the main contributors to this myth was McClintock herself. When she told her story to Evelyn Fox Keller in 1978 and 1979, Keller wrote a biography, A Feeling for the Organism, which portrayed a woman struggling for acceptance in a male-dominated field, who had to endure professional setbacks, financial hardship and humiliation. This biography was based on McClintock’s own words, and was not disputed by any of the interviews with her colleagues, including George Beadle, Marcus Rhoades, or Harriet Creighton, McClintock’s lifelong friends, Helen Crouse, a student of McClintock’s from Missouri, or Evelyn Witkin, a Cold Spring Harbor colleague. Keller, who was trained in bacterial and viral genetics, as well as physics, painted a view of the history of modern science as the expression of masculine intellectual style. She argued that McClintock was the alternative to this style: holistic, intuitive, interactive, and emotional. This was what McClintock meant when she spoke of having a “feeling for the organism.”

Comfort debunks the McClintock myth in seven steps. First he shows that McClintock was not ignored, ostracized or humiliated. Within two years of finishing graduate school, McClintock had published six articles. She had identified the correct haploid number for maize, developed new techniques, distinguished the chromosomes from one another and assigned most of the linkage groups to a chromosome. In 1944, she was elected the first woman president of the Genetics Society of America. That same year, she was also named to the prestigious National Academy of Sciences, which had admitted only two other women in its eighty-one year history. She was an immensely respected scientist, even at a young age, and received numerous awards over the years.

Secondly, Comfort discusses transposition, McClintock’s most famous discovery. Contrary to the myth though, transposition was neither ignored nor disbelieved. After McClintock discovered transposable elements in maize, it was confirmed independently by many other researchers and by the mid-1950s was accepted as true for corn.

Third, when McClintock discovered mobile genetic elements, she called them controlling elements, not transposable elements and the main focus of her research for the next four decades was the genetic control of development. She viewed transposition as merely a small part of a much bigger picture, and did not make it the center of her work.

Fourth, McClintock was not the epitome of a holistic, intuitive scientific style. She was extremely well educated, had an enormous amount of experience in the lab and field and her style was highly rational and organized. Her seeming ability to solve problems faster than anyone else was simply the result of hours and hours of thinking about the problem, sometimes going without food or sleep so that she could stay in the lab and work on it.

Fifth, Comfort points out that Cold Spring Harbor was not some isolated, backwoods lab, it was a highly respected research institution, and perhaps the only place where McClintock could have been productive. She hated teaching and did not want to be stuck at a university where she would be forced to divide her time between her research, and mentoring students who were not as intelligent as she was. The Carnegie Institute gave her the freedom to conduct her own research, on her own schedule, without the restraints of a professorship.

Sixth, the “rediscovery” of McClintock’s work was not merely a forehead-slapping recognition that she had been right all along. It was a complicated process by which her theory of genetic control of development was finally rejected and transposition, which was never the crux of her research, was found to be incredibly significant. Basically, McClintock’s central idea was cut out and transposition was recast as her major contribution.

Finally, Comfort asserts that McClintock knew that this shift had occurred and for her the Nobel Prize was a bittersweet ending to her lifelong theory. By the 1970s, recombinant DNA technology and protein and gene sequencing were solving some of the major mysteries of the gene, and the new molecular explanations showed that no controller was needed to explain gene actions. Comfort implies that McClintock’s first few nominations for the Nobel were not successful because they made mention of gene control. The final nomination simply described transposition and the influence on gene action, but omitted all mention of controlling elements, which by then had been totally discredited. Comfort does point out though, that many eventual winners of the Nobel Prize are nominated dozens of times, sometimes spanning multiple decades, and many of the most nominated never win. The fact that McClintock was only nominated four times further distinguishes her as an exceptional scientist. During a press conference after the announcement of the award, McClintock was asked why she thought it took so long for her to win the award. Her response was that nobody had the experience she had, but that she didn’t mind the fact that the award came so long after her discovery. When giving a brief description of her work, she stated,

…. the whole point of my going on with it was the regulation part, not so much the transposition, but the regulation, because at that time we had no DNA to work on and we had no regulation about genes. We weren’t concerned with gene regulation, so I put the emphasis on these and called them controlling elements.

Even after winning the Nobel, McClintock told friends that she was disappointed that the recognition had missed her central point. According to her friend and colleague James Shapiro, she was never very interested in transposition. She was interested in regulation.

Publicity following her Nobel often compared McClintock to Mendel, but Comfort goes to great lengths to show that in reality they had little in common. Chronologically, Mendel’s work was rediscovered thirty-four years after publication of his paper on hybridization in peas. McClintock won the Nobel Prize thirty-three years after publication of her paper on transposable elements. Socially, however, Mendel was genuinely ignored and misunderstood. Moreover, had he survived long enough to win the Nobel, it would have been for his most important work, the discovery of the hereditary laws of segregation and independent assortment. McClintock on the other hand, was clearly understood by her peers but insisted on focusing her research on controlling elements, which gained her hardly any support among the scientific community. Even the colleagues that she was closest to found it hard to believe because she did not support it with evidence, she merely hinged her argument on pattern and analogy because she was so certain that she was right, and that science just had to catch up with her. As Comfort states:

She never did demonstrate that that controlling elements transposed in a coordinated way during the development of the plant. She showed (a) that the elements transposed and (b) that they affected gene action. It was known (d) that genes must somehow be turned on and off during development. McClintock never demonstrated the implied (c), that her system affected that coordinated turning-on-and-off.

Despite the fact that McClintock’s lifelong theory of controlling elements was proven wrong, she still made a remarkable impact on the field of genetics. Moreover, her contributions have had significance in other fields, as transposable elements are found to explain how cells produce antibodies to fight bacterial and viral threats, how bacteria strike back by acquiring immunities to human defenses, and how certain cancer cells grow. The implications are still being found and will continue to play a major role in modern genetics.

The Tangled Field is an exceptionally well-written and methodically researched account of the life of Barbara McClintock. Comfort, who is Deputy Director of the Center for History of Recent Science at George Washington University used McClintock’s own research notes and correspondence among fellow scientists, as well as dozens of interviews with McClintock herself, as well as her peers, students, and friends to construct an accurate and complete narrative of her life’s work. The bulk of the book is spent painstakingly reconstructing McClintock’s experiments, right down to describing the crosses of different strains of corn she used. Although it is difficult to follow at times, and contains numerous technical descriptions the average reader may have trouble grasping, it is a valuable resource for anyone with an interest in the history of ideas about genes, and biological regulation. It also provides interesting insight into the way different scientists from different fields work and collaborate with one another, and sometimes impede each others research. Personality clashes, friendships, and gender roles all play a part in the research and lives of the scientists mentioned throughout the book. McClintock’s friends and advocates, as well as her rivals and skeptics all come alive in this book, with personalities and struggles all their own.

Comfort’s biography of McClintock is a valuable contribution to the history of science. It reveals another side to an often times misinterpreted scientist, and replaces the “McClintock myth” with a new story. It is an important reminder of the narrow-mindedness and bias sometimes found in science. Comfort claims at the beginning of the book that in talks and lectures he has given, some have interpreted The Tangled Field as an attack on women scientists, a denial of the discrimination against women in science, or a defense of masculine science. The book does none of these things however. After finishing the book, McClintock manages to preserve her emblem of feminine scientific thinking, and remains one of the most brilliant and influential geneticists of the 20 th century. At the same time, the reality of her work is easily separated from the myths that grew around her. The Tangled Field appears to be the most accurate, unbiased biography of McClintock to date, and is an enjoyable read for anyone interested in learning more about this fascinating and intriguing scientist.