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Faces of Science: François Jacob

The Secret Life of Scientists and EngineersThe Secret Life of Scientists and Engineers

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Mariana Cook’s book , “Faces of Science,” portrays 77 scientists who have made many of the most important discoveries of our time. Each photograph is accompanied by a personal essay written by the scientists. The portraits in this online series are accompanied by excerpts from those essays. For more information, please visit Mariana Cook’s website: .

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François Jacob - Photos and Text ©Mariana Cook “Faces of Science”

When I came back from World War II, I was heavily wounded. I could not become a surgeon as I had wished. I turned to science. Although I knew very little, I understood that something was going to happen at the interface of bacteria, biochemistry, and genetics. That is why I began to work on the genetics of bacteria and the cellular machinery.

It was the work of a lifetime, involving countless experiments and many failures. And successes. With the publication in the Journal of Molecular Biology of “Genetic Regulatory Mechanisms in the Synthesis of Proteins,” Jacques Monod and I were able to prove the existence of messenger RNA and its function in cells. The work showed for the first time how a gene functions; how it sends a continuous stream of information toward the cytoplasm (the part of a cell surrounding the nucleus), rather like a faucet whose flow can be regulated according to the requirements of the cell as a function of signals from the environment. It proposed a model to explain one of the oldest problems in biology: in organisms made up of millions, even billions of cells, every cell possesses a complete set of genes; how, then, is it that all genes do not function in the same way in all tissues? That the nerve cells do not use the same genes as the muscle cells or the liver cells? In short, this article presented a new view of the genetic landscape.

I have felt that life is a constant race with time. It took me a long while to realize that this drive toward tomorrow has an advantage in at least one domain: in research. Late, very late, I discovered the true nature of science, of how it proceeds, of the men and women who do it. I came to understand that, contrary to what I had believed, the march of science does not consist of inevitable conquests, or advance along the royal road of human reason, or result necessarily and inevitably from conclusive observation dictated by experiment and argumentation. I found in science a mode of playfulness and imagination, of obsessions and fixed ideas. To my surprise, those who achieved the unexpected and invented the possible were not simply men of learning and method. More than anything else, they possessed extraordinary minds, enjoyed the difficult, and often were creatures of amazing vision. Those in the front ranks displayed exotic blends of passion and indifference, of rigor and whimsy, of naiveté and the will to power, in a triumph of individuality.