An Appetite for Wonder Page 23

  I should point out that neither in my lectures of the 1960s nor in The Selfish Gene did I see as very novel the idea of the gene as the fundamental unit of natural selection. I thought of it – and clearly said so – as implicit in the orthodox neo-Darwinian theory of evolution: that is to say, the theory first clearly formalized in the 1930s by Fisher, Haldane, Wright and the other founding fathers of the so-called Modern Synthesis such as Ernst Mayr, Theodosius Dobzhansky, George Gaylord Simpson and Julian Huxley. It was only after The Selfish Gene was published that both critics and admirers came to see the idea as revolutionary. That was not how I thought of it at the time.

  Having said that, however, I should add that not all the founding fathers of the Modern Synthesis were clear about this important implication of the theory that they collectively put together. To the end of his centenarian life, the authoritative German-American taxonomist Ernst Mayr expressed hostility to the idea of gene selectionism, in terms that suggested to me that he misunderstood it. And Julian Huxley, the founding father who actually coined the phrase ‘Modern Synthesis’, was an out-and-out group selectionist, without clearly realizing it. The first time I met the great Peter Medawar, he startled my student self with a deliciously sacrilegious remark, delivered with his characteristically patrician, yet impish style. ‘The trouble with Julian is that he really doesn’t understand evolution.’ Fancy saying that – of a Huxley! I could hardly believe my ears and, as you see, I have never forgotten it. I later heard another Nobel Prize-winner, the French molecular biologist Jacques Monod, say something a bit similar, though not about Huxley: ‘The trouble with natural selection is that everybody thinks he understands it.’

  I mentioned that I began The Selfish Gene when power cuts interrupted my cricket research. I had completed only the first chapter of the book when I happened to meet an editor from the publishers Allen & Unwin. He was paying a routine visit to the Department of Zoology in search of possible books, and I told him about my embryonic project. He sat down and read that first chapter on the spot, liked it and encouraged me to continue. But then – unfortunately from one narrow point of view, fortunately from others – the industrial unrest came to an end and the lights came back on. I shoved my chapter in a drawer and forgot about it as I resumed my research on crickets.

  From time to time during the next two years I contemplated returning to the book. The impetus was especially strong when I read and lectured about new publications that were beginning to appear in the early 1970s and proved beautifully compatible with the thesis of my gestating book. Most notable among these were papers by the young American biologist Robert Trivers, and others by the veteran British professor John Maynard Smith. Both these authors made use of the intuitive shortcut I mentioned (the philosopher Daniel Dennett would now call it an intuition pump):59 the shortcut of imagining that an individual organism behaves ‘as if’ consciously calculating the best policy for preserving and propagating its genes.

  Trivers treated a parent animal as if it were a rational agent calculating what economists call the ‘opportunity cost’ of an action. A parent has to pay the costs of rearing each offspring. Among these costs might be food, including time and effort spent gathering it, time spent protecting the child from predators, and the risks incurred by the parent in doing so. Trivers wrapped them all up in one metric which he called Parental Investment or PI. Trivers’ key insight was that that PI must be an opportunity cost: the investment in any one child is measured as lost opportunities to invest in other children. Trivers used the notion to develop a penetrating theory of ‘parent–offspring conflict’. The decision on the best time to wean a child, for example, is subject to a ‘disagreement’ between the child and its mother, both behaving as rational economists whose ‘utility function’ is the long-term survival of their own genes. The mother ‘wants’ to terminate suckling earlier than the child does, because she places greater ‘value’ than he does on her future offspring, who will benefit from early weaning of the present child. The present child also ‘values’ his future siblings, but only half as highly as his mother does because of the way Hamilton’s Rule pans out. Therefore there is a period of ‘weaning conflict’, an uneasy phase of transition between the early time when both parties ‘agree’ that suckling should continue and the later time when both parties ‘agree’ that it should end. During this phase, when the mother ‘wants’ weaning but the child doesn’t, observers of animal behaviour should see the symptoms of a subtle battle between mother and child. In passing I should add that, long after The Selfish Gene was published, the Australian biologist David Haig cleverly showed how many of the ailments of pregnancy can be explained in terms of the same Triversian conflict going on inside the womb – not about weaning in this case, obviously, but about other aspects of the allocation of necessarily scarce resources.

  Parent–offspring conflict was obviously a subject tailor-made for my book, and Trivers’ brilliant paper on the subject was one of the spurs that encouraged me to take my first chapter out of the drawer where it had languished since the end of the power strike. It became the inspiration for chapter 7 of The Selfish Gene, ‘Battle of the generations’. Chapter 8, ‘Battle of the sexes’, also made use of Trivers’ ideas, this time showing how males and females might compute their opportunity costs differently. When might a male, for example, desert his mate, leaving her ‘holding the baby’ and ‘in a cruel bind’ while he seeks a new one? Trivers also influenced chapter 10, ‘You scratch my back, I’ll ride on yours’. His paper in this case was an earlier one, on reciprocal altruism, which showed that kin selection is not the only evolutionary pressure towards altruism. Reciprocation – the repaying of favours – can also be very important, and it works across species, not just within them as kin selection does. So Trivers’ name was added to those of Hamilton and Williams among the four authors who had greatest influence on The Selfish Gene. I also asked him to write the foreword – which he graciously did, although at that point we had never met.

  The fourth was John Maynard Smith, who later became a beloved mentor. As a boy I had met the book that he would refer to as ‘my little Penguin’, and I was much taken by the smiling author photograph: shock of nutty professor hair askew like the pipe in his mouth, thick round glasses in need of a clean – the sort of man I was immediately drawn to. I also liked the biographical note, which explained that he had been an engineer designing aircraft, but gave it up and went back to university to study biology because he noticed that ‘aircraft were noisy and old fashioned’. Many years later, a new edition of that book, The Theory of Evolution, was published by Cambridge University Press and I was honoured to be invited to write the foreword.60 I included the following tribute to this genial hero:

  Readers of ‘campus novels’ know that a conference is where you can catch academics at their worst. The conference bar, in particular, is the academy in microcosm. Professors huddle together in exclusive, conspiratorial corners, talking not about science or scholarship but about ‘tenure-track hiring’ (their word for jobs) and ‘funding’ (their word for money). If they do talk shop, too often it will be to make an impression rather than to enlighten. John Maynard Smith is a splendid, triumphant, lovable exception. He values creative ideas above money, plain language above jargon. He is always the centre of a lively, laughing crowd of students and young research workers of both sexes. Never mind the lectures or the ‘workshops’; be blowed to the motor coach excursions to local beauty spots; forget your fancy visual aids and radio microphones; the only thing that really matters at a conference is that John Maynard Smith must be in residence and there must be a spacious, convivial bar. If he can’t manage the dates you have in mind, you must just reschedule the conference. He doesn’t have to give a formal talk (although he is a riveting speaker) and he doesn’t have to chair a formal session (although he is a wise, sympathetic and witty chairman). He has only to turn up and your conference will succeed. He will charm and amuse the young research workers, listen to t
heir stories, inspire them, rekindle enthusiasms that might be flagging, and send them back to their laboratories or their muddy fields, enlivened and invigorated, eager to try out the new ideas he has generously shared with them.

  My relationship with John didn’t get off to an outstandingly good start, however. I first met him in 1966 when, as Dean of Biological Sciences, he interviewed me for a job at the University of Sussex. I was already pretty much committed to going to Berkeley. However, there was a job going at Sussex and Richard Andrew, their resident expert on our shared subject of animal behaviour, pressed me with flattering urgency to apply. I told Richard about my near-commitment to go to Berkeley, but he said there was no harm in doing the Sussex interview anyway, so I thought: What the hell, why not? I’m afraid my ‘what the hell’ attitude didn’t endear me to Maynard Smith in the interview. I said I wouldn’t lecture about animal taxonomy. He said it was part of the job. I rather arrogantly said: Well, I’ve got a job offer at Berkeley and I’m not quite sure why I am doing this interview anyway. He was nice about it when he and Dr Andrew took me to lunch, but, as I said, it was not a good start to what was later to prove a delightful friendship.

  In the early 1970s, Maynard Smith began the long series of papers in which, together with colleagues such as Geoffrey Parker and the late George Price, he deployed a version of the mathematical theory of games to solve a number of problems in evolution. These ideas were immensely congenial to the idea of the selfish gene, and Maynard Smith’s papers constituted the other major stimulus that led me to dust off my old chapter 1 and write the whole book.

  Maynard Smith’s particular contribution was the notion of the evolutionarily stable strategy or ESS. ‘Strategy’ in this sense can be construed as ‘preprogrammed rule’. Maynard Smith set up mathematical models in which preprogrammed rules with names like (for the particular case of animal combat) Hawk, Dove, Retaliator, Bully, are let loose in an imagined (or simulated) world to interact with each other. Once again, it is important to understand that the animals implementing the rules are not assumed to be consciously aware of what they are doing, or why. Each preprogrammed rule has a frequency in the population (like genes in a gene pool, although the link with DNA doesn’t have to be made explicit in the models). The frequencies change in accordance with ‘payoffs’. In the social and economic sciences where game theory originated, payoffs can be thought of as equivalent to money. In evolutionary game theory, payoffs have the special meaning of reproductive success: high payoffs for a strategy lead to increased representation in the population.

  The key point is that a successful strategy is not necessarily one that wins its particular contests against other strategies. A successful strategy is one that numerically dominates the population. And since a numerically dominant strategy is by definition likely to encounter copies of itself, it will stay numerically dominant only if it flourishes in the presence of copies of itself. This is the meaning of ‘evolutionarily stable’ in Maynard Smith’s ‘ESS’. We expect to see ESSs in nature, because if a strategy is evolutionarily unstable, it will tend to disappear from the population as rival strategies outbreed it.

  I won’t expound evolutionary game theory any further here because I did that in The Selfish Gene, and the same applies to Trivers’ ideas on parental investment. Here it is sufficient to say that the publications of Trivers and Maynard Smith in the early 1970s rekindled my interest in the ideas of Hamilton that had inspired me in the 1960s, and moved me to return to the book whose first chapter had slumbered in a drawer since the end of the power strikes. Maynard Smith’s game-theoretic ideas dominated the chapter on aggression, and inspired my treatment of many topics in later chapters.

  So, finally, in 1975, having finished my ‘hierarchical organization’ paper, I took the sabbatical leave to which I was entitled, stayed at home every morning, and devoted myself to my typewriter and The Selfish Gene. Indeed, so devoted was I to the task that I didn’t attend the crucial meeting at which New College was electing a new Warden. A colleague slipped out of the meeting and telephoned urgently to tell me the vote was extremely close and to beg me to come quickly. I now think that, although my sabbatical leave entitled me to do so, my absenting myself from such a crucial vote was an act of self-indulgent irresponsibility. The meeting would have taken only a few hours of my time, and the repercussions of my lost vote potentially might have been felt for many years. Fortunately, the man for whom I would have voted got in anyway (and became an excellent Warden), so I don’t have to endure a burden of guilt for changing the course of college history. Actually, his rival would have been very good too, and college meetings would certainly have been amusing as he was justly reputed to be the wittiest man in Oxford.

  I wrote The Selfish Gene in a frenzy of creative energy. I’d completed three or four chapters when I spoke to my friend Desmond Morris about publication. A legendarily successful author himself, Desmond arranged a meeting with Tom Maschler, doyen of London publishers. I met Mr Maschler in his high-ceilinged, book-lined room at Jonathan Cape in London. He’d read my chapters and liked them, but urged me to change the title. ‘Selfish’, he explained to me, is a ‘down word’. Why not The Immortal Gene? With hindsight, he was very probably right. I can’t now remember why I didn’t follow his advice. I think I should have done.

  I didn’t, in any case, pursue him as a publisher because matters were rather forcefully taken out of my hands. At lunch one day in New College Roger (now Sir Roger) Elliott, Oxford’s Professor of Theoretical Physics, said he had heard I was writing a book, and asked me about it. I told him a little of what I was trying to do, and he seemed interested. As it happened, he was a member of the Board of Delegates of Oxford University Press, and he passed the word to Michael Rodgers, the appropriate editor at that ancient publishing house. Michael wrote and asked to see my chapters. I sent them to him.

  And then the whirlwind hit – beginning with his characteristically loud voice, over the telephone: ‘I’ve read your chapters. Haven’t been able to sleep since. I MUST HAVE THAT BOOK!’ Well, some people might resist that kind of persuasion, but not me. Michael was clearly my kind of publisher. I signed the contract and set to work with redoubled urgency to complete the book.

  I now find it quite hard to comprehend how we all used to tolerate the burden of writing in the age before computer word processors. Pretty much every sentence I write is revised, fiddled with, re-ordered, crossed out and reworked. I reread my work obsessively, subjecting the text to a kind of Darwinian sieving which, I hope and believe, improves it with every pass. Even as I type a sentence for the first time, at least half the words are deleted and changed before the sentence ends. I have always worked like this. But while a computer is naturally congenial to this way of working, and the text itself remains clean with every revision, on a typewriter the result was a mess. Scissors and sticky tape were tools of the trade as important as the typewriter itself. The growing typescript of The Selfish Gene was covered with xxxxxxx deletions, handwritten insertions, words ringed and moved with arrows to other places, strips of paper inelegantly taped to the margin or the bottom of the page. One would think it a necessary part of composition that one should be able to read one’s text fluently. This would seem to be impossible when working on paper. Yet, mysteriously, writing style does not seem to have shown any general improvement since the introduction of computer word processors. Why not?

  The Selfish Gene went through two fair copies typed up by Pat Searle, the motherly secretary of the Animal Behaviour Research Group. Each one went to Michael Rodgers and came back with his helpful, handwritten annotations. In particular, he excised some purple passages that my romantically youthful enthusiasm had pushed way over the top. In Peter Medawar’s metaphor of the writer as organist, ‘a scientist’s fingers, unlike a historian’s, must never stray toward the diapason’. The end of chapter 2 of The Selfish Gene is about as purple as science prose should get, and I blush to recall (and am glad I haven’t preserved) the parag
raph that followed it. Here’s the paragraph of paler purple that survived Michael’s moderating pen. It’s the end of the chapter on the origin of life and the spontaneous arising in the primeval soup of ‘replicators’, which later moved into the world of ‘vehicles’ – living organisms.

  Was there to be any end to the gradual improvement in the techniques and artifices used by the replicators to ensure their own continuation in the world? There would be plenty of time for improvement. What weird engines of self-preservation would the millennia bring forth? Four thousand million years on, what was to be the fate of the ancient replicators? They did not die out, for they are past masters of the survival arts. But do not look for them floating loose in the sea; they gave up that cavalier freedom long ago. Now they swarm in huge colonies, safe inside gigantic lumbering robots, sealed off from the outside world, communicating with it by tortuous indirect routes, manipulating it by remote control. They are in you and in me; they created us, body and mind; and their preservation is the ultimate rationale for our existence. They have come a long way, those replicators. Now they go by the name of genes, and we are their survival machines.