What Mad Pursuit BOOKS IN THE ALFRED P. SLOAN FOUNDATION SERIES Disturbing the Universe by Freeman Dyson Advice to a Young Scientist by Peter Medawar The Youngest Science by Lewis Thomas Haphazard Reality by Hendrik B. G. Casimir In Search of Mind by Jerome Bruner A Slot Machine, a Broken Test Tube by S. E. Luria Enigmas of Chance by Mark Kac Rabi: Scientist and Citizen by John Rigden Alvarez: Adventures of a Physicist by Luis W. Alvarez Making Weapons, Talking Peace by Herbert F. York The Statue Within by François Jacob In Praise of Imperfection by Rita Levi-Montalcini Memoirs of an Unregulated Economist by George J. Stigler Astronomer by Chance by Bernard Lovell THIS BOOK IS PUBLISHED AS PART OF AN ALFRED P. SLOAN FOUNDATION PROGRAM What Mad Pursuit A Personal View of Scientific Discovery FRANCIS CRICK Library of Congress Cataloging-in-Publication Data Crick, Francis, 1916– What mad pursuit. (Alfred P. Sloan Foundation series) Includes index. 1. Crick, Francis, 1916– 2. Biologists—England—Biography. 3. Physicists—England—Biography. I. Title. II. Series. QH31.C85A3 1988 574.19’1’0924 [B] 88–47693 ISBN 0–465–09137–7 (cloth) ISBN-10: 0-465-09138-5 ISBN-13: 978-0-465-09138-6 (paper) eBook ISBN: 9780786725847 Published by BasicBooks, A Member of the Perseus Books Group Copyright © 1988 by Francis Crick Printed in the United States of America Designed by Vincent Torre Experience is the name everyone gives to their mistakes. —OSCAR WILDE Preface to the Series THE ALFRED P. SLOAN FOUNDATION has for many years had an interest in encouraging public understanding of science. Science in this century has become a complex endeavor. Scientific statements may reflect many centuries of experimentation and theory, and are likely to be expressed in the language of advanced mathematics or in highly technical terms. As scientific knowledge expands, the goal of general public understanding of science becomes increasingly difficult to reach. Yet an understanding of the scientific enterprise, as distinct from data, concepts, and theories, is certainly within the grasp of us all. It is an enterprise conducted by men and women who are stimulated by hopes and purposes that are universal, rewarded by occasional successes, and distressed by setbacks. Science is an enterprise with its own rules and customs, but an understanding of that enterprise is accessible, for it is quintessentially human. And an understanding of the enterprise inevitably brings with it insights into the nature of its products. The Sloan Foundation expresses great appreciation to the advisory committee. Present members include the chairman, Simon Michael Bessie, Co-Publisher, Cornelia and Michael Bessie Books; Howard Hiatt, Professor, School of Medicine, Harvard University; Eric R. Kandel, University Professor, Columbia University College of Physicians and Surgeons, and Senior Investigator, Howard Hughes Medical Institute; Daniel Kevles, Professor of History, California Institute of Technology; Robert Merton, University Professor Emeritus, Columbia University; Paul Samuelson, Institute Professor of Economics, Massachusetts Institute of Technology; Robert Sinsheimer, Chancellor Emeritus, University of California, Santa Cruz; Steven Weinberg, Professor of Physics, University of Texas at Austin; and Stephen White, former Vice-President of the Alfred P. Sloan Foundation. Previous members of the committee were Daniel McFadden, Professor of Economics, and Philip Morrison, Professor of Physics, both of the Massachusetts Institute of Technology; George Miller, Professor Emeritus of Psychology, Princeton University; Mark Kac (deceased), formerly Professor of Mathematics, University of Southern California; and Frederick E. Terman (deceased), formerly Provost Emeritus, Stanford University. The Sloan Foundation has been represented by Arthur L. Singer, Jr., Stephen White, Eric Wanner, and Sandra Panem. The first publisher of the program, Harper & Row, was represented by Edward L. Burlingame and Sallie Coolidge. This volume is the seventh to be published by Basic Books, represented by Martin Kessler and Richard Liebmann- Smith. The Alfred P. Sloan Foundation Acknowledgments THIS BOOK was started at the suggestion of the Sloan Foundation, for whose generous support I am most grateful. I was approached in 1978 by Stephen White, who persuaded me to sign the initial memorandum of agreement but I was very dilatory about beginning to write. I might have stayed in this state indefinitely but for Sandra Panem, who took over as book program director in 1986. She liked the idea of the book that was forming in my mind, and stimulated by her enthusiastic encouragement I produced a first draft. This was expanded and improved enormously as the result of her detailed comments, together with those of the Sloan Advisory Committee. I have also been helped by the comments of Martin Kessler, Richard Liebmann-Smith, and Paul Golob of Basic Books and by the copy editor, Debra Manette, who has improved my English in many places. I am also grateful to Ron Cape, Pat Church-land, Michael Crick, Odile Crick, V. S. (Rama) Ramachandran, Leslie Orgel, and Jim Watson, all of whom made helpful comments on one or another of the earlier drafts. In writing the rest of the book, I have not made a deliberate attempt to acknowledge those who have been very close associates and have also influenced me strongly. While I shall not try to list here all my many friends and colleagues, there are three whom I must single out for special mention. The text does make clear how much I owe to Jim Watson. It does less than justice to my long and very fruitful association with Sydney Brenner. He was my closest associate for almost twenty years, and during much of that time we had long scientific discussions on almost every working day. His clarity, incisiveness, and fertile enthusiasm made him an ideal colleague. My third debt is to Georg Kreisel, the mathematical logician, whom I always address by his last name in spite of our having known each other for about forty-five years. When I met Kreisel I was a very sloppy thinker. His powerful, rigorous mind gently but steadily made my thinking more incisive and occasionally more precise. Quite a number of my mental mannerisms spring from him. Without these three friends my scientific career would have been very different. My other major debt is to my family. Not only did they encourage me to become a scientist but they helped me financially. My parents made considerable sacrifices to enable me to go away to boarding school, especially during the Depression. My uncle Arthur Crick and his wife not only assisted me financially while I was a graduate student at University College but also gave me the money to buy our first house. My aunt Ethel, in addition to teaching me to read, helped financially when I first went to Cambridge after the war, as did my mother. They both helped also with the education of my son Michael. While I had very little money when I was young, I was secure in the knowledge that, thanks to my relatives, I would have enough to live on. During most of the period covered by the main sections of this book I was employed in Cambridge by the British Medical Research Council. I am especially grateful to them, and in particular to Sir Harold Himsworth (then Secretary of the MRC) for providing such perfect working conditions there for me and my colleagues. I should also record my gratitude to my present employer, The Salk Institute for Biological Studies, and in particular its president, Dr. Frederic de Hoffmann, for allowing me to work in such a delightful and stimulating atmosphere. While writing this book I was mainly occupied in studying the brain. I thank the Kieckhefer Foundation, the System Development Foundation, and the Noble Foundation for their financial support of my efforts. I thank the Editor of Nature for allowing me to quote at length from my article entitled, “The Double Helix: A Personal View,” published on April 26, 1974; the New York Academy of Sciences for permission to quote extensively from an article of mine, “How to Live with a Golden Helix,” which appeared in The Sciences in September 1979; Richard Dawkins and W. W. Norton and Company for permission to use several passages from his book, The Blind Watchmaker, published in 1986; V. S. (Rama) Ramachandran and Cambridge University Press for allowing me to quote a paragraph from his chapter “Interactions Between Motion, Depth, Color, Form and Texture: The Utilitarian Theory of Perception,” soon to appear in Vision, Coding and Efficacy, edited by Colin Blakemore; and Jamie Simon for doing the drawings. Finally, my warmest thanks to my secretary, Betty (“Maria”) Lang, who has coped splendidly with the many successive versions and all the tedious chores associated with producing a manuscript. What Mad Pursuit FRONTISPIECE To show the approximate size of various objects, from molecules to man. Note that each step in the scale is a factor of ten. Introduction THE MAIN PURPOSE of this book is to set out some of my experiences before and during the classical period of molecular biology, which stretched from the discovery of the DNA double helix in 1953 till about 1966 when the genetic code—the dictionary relating the nucleic acid language to the protein language—was finally elucidated. As a preliminary I have put a short prologue that outlines a few details of my upbringing and education, including my early religious education, followed by an account of how I decided (after the Second World War) what branch of science to study, using the “gossip test” to help me. I have also included an epilogue, describing in outline what I have been doing since 1966. There is an important difference between the scientific work described in the main body of the book and that touched on in the epilogue.