“crackpots” who were right 16: Barbara McClintock

All 15 scientists featured in this series so far have been men and it has been very hard to find a women that fits the criteria for a “crackpot” who was right. Of course there are plenty of cases of women who have found it difficult to gain acceptance as scientists, but here I am looking for something else; scientists whose work was regarded as wrong for many years before it was eventually found to be correct. The lack of women in this situation could be regarded as a good or bad sign for women in science. Is it just a reflection of the general problems that women have had entering into the male dominated domain of science, or is it because when they do succeed their work is more likely to be accepted? Perhaps they have just avoided more controversial subjects, or maybe there is some other factor at play. Whatever the correct explanation, I’m glad at least to be able to document one example to prove that it is possible for women to do science that is so revolutionary that it is at first treated as a crazy idea.

There have been only two women who won a Nobel prize in physics. In chemistry the count is four but in medicine there have been ten female Nobel laureates. Barbara McClintock is one of those ten. By 1940 McClintock had already become recognised as an accomplished geneticist since graduating with a PhD in botany from Cornell University in 1927. Working mostly with Maize she used microscopic analysis to demonstrate many fundamental genetic ideas such the recombination mechanisms by which chromosomes exchange information. Early in her career her advisor Lowell Randolph became very irritated when she solved a problem he had been struggling with for his whole scientific life. McClintock had to depart when Randolph could not tolerate her success. This was not atypical of her relations with her colleagues.  As one of the best in her field it is difficult to account for her failure to find a tenured position for so long, unless it was her gender. Finally  nothing could stop her being elected a member of the national Academy of Sciences in 1944. After several unsettling moves she found a place at the Cold Spring Harbor Laboratory and stayed.

Even then her best work was ahead of her. In the 1940s she discovered the process of transposition in which sequences of DNA can move to different positions within the genome causing mutations. It was for this work that she was made a Nobel Laureate in 1983, but it is a later series of discoveries that led to controversy.

From 1948 she investigated the role of Activators and Dissociators in the DNA sequence. She observed that these elements could control the transposition of genes. This discovery ran against the concept of the genome as a static set of instructions passed from generation to generation. She published her ideas in 1953 and undertook lecture tours to speak of the work, but the reception was one of puzzlement and hostility. It was in that year that the double helix structure of DNA was discovered, changing the way people worked in genetics. Sensing that she risked alienating the scientific mainstream and damaging her career, she stopped publishing such work and moved onto other things.

In 1961 two French geneticists Jacob and Monod discovered the genetic regulation of the lac operon. McClintock subsequently published an article showing that the mechanism was similar to her work on controlling elements.  In 1973 she described the situation,

Over the years I have found that it is difficult if not impossible to bring to consciousness of another person the nature of his tacit assumptions when, by some special experiences, I have been made aware of them. This became painfully evident to me in my attempts during the 1950s to convince geneticists that the action of genes had to be and was controlled. It is now equally painful to recognize the fixity of assumptions that many persons hold on the nature of controlling elements in maize and the manners of their operation. One must await the right time for conceptual change.”

Even now not everyone accepts that hers was a prior discovery of genetic regulation. Some people even prefer to say that the work of Jacob and Monod proved her wrong!

2 Responses to “crackpots” who were right 16: Barbara McClintock

  1. Francisco J Oyarzun says:

    …it has been very hard to find a woman that fits the criteria for a “crackpot” who was right…

    Lynn Margulis!

  2. philipgibbs says:

    I have Lynn on my list of candidates for this series, but from her wikipedia entry it is difficult to make her case fit. She has some well accepted ideas, and some others that are controversial. What I need is something that was once controversial and is now generally accepted.

    Perhaps it is too early to assess her case or perhaps I just need to do more investigating. Was there a particular part of her work that you think I should look into?

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