Unfortunately, Marshall’s analysis doesn’t really allow us to draw any secure conclusion about pigeons. How do we know whether the grammar he proposed is ‘correct’? In the case of human syntax, any native speaker of the language can immediately tell you if it is correct. Marshall had no such checking mechanism. As with much of the research that I did during this period, my goal state was not so much to find something permanently true about particular animals as to find novel and exciting ways in which animal behaviour might be studied in the future.
The Madingley paper56 represented a kind of closure for me, a climax to the first part of my scientific career, beginning in my early twenties and ending in my early thirties. At this point, I took off in an entirely new direction, never to return to those youthful mathematical pastures. That new direction, which was to define the rest of my career, and approximately the second half of my life, opened up with the publication of my first book, The Selfish Gene.
THE IMMORTAL GENE
IN 1973, strike action by the National Union of Mineworkers led to a crisis in which the Conservative government of Edward Heath imposed a so-called ‘three-day week’ in Britain. In order to conserve fuel stocks, electricity for non-essential purposes was rationed. We were limited to three days per week, and there were frequent power cuts. My cricket research depended on electricity but writing didn’t – in those days I wrote with a portable typewriter on, of all outlandish surfaces, sheets of flat white stuff called paper. So I decided to call a temporary halt to my cricket research and begin work on my first book. This was the genesis of The Selfish Gene.
Selfishness and altruism and the whole idea of a ‘social contract’ were much in the air at the time. Those of us on the political left tried to balance our sympathy for the miners on the one hand with hostility to what some saw as their strong-arm tactics, holding society at large to ransom, on the other. Did evolutionary theory have anything to contribute to this important dilemma? The previous decade had seen a string of popular science books and television documentaries, gallantly attempting to apply Darwinian theory to questions of altruism and selfishness, collective versus individual welfare, but actually getting the theory flat-out wrong. The error was always a version of what has been called ‘evolutionary panglossism’.
As reported by my friend and mentor the late John Maynard Smith, his own mentor the formidable J. B. S. Haldane satirically coined three erroneous, or at best unreliable, ‘theorems’. Aunt Jobiska’s Theorem (from Edward Lear) was ‘It’s a fact the whole world knows . . .’ The Bellman’s Theorem (from Lewis Carroll) was ‘What I tell you three times is true.’ And Pangloss’s Theorem (from Voltaire) was ‘All is for the best in this best of all possible worlds.’
Evolutionary panglossians are vaguely aware that natural selection does a pretty effective job of making living things good at their business of living. Albatrosses seem beautifully designed for flying above the waves, penguins for flying beneath them (I happen to be writing this on a ship in Antarctic waters, marvelling through my binoculars at these prodigies of avian virtuosity). But panglossians forget, as it is so easy to forget, that this ‘good at’ applies to individuals, not to species. Good at flying, good at swimming, surviving, reproducing, yes, natural selection will tend to make individual animals good at those things. But there is no reason to expect natural selection to make species good at avoiding extinction, good at balancing their sex ratio, good at limiting their population in the interests of the common weal, good at husbanding their food supply and conserving their environment for the benefit of future generations. That would be panglossism. Group survival may emerge as a consequence of improved individual survival, but that is a fortunate by-product. Group survival is not what natural selection is about.
The panglossian error is tempting because we humans are blessed with foresight and can judge which actions are likely to benefit our species, or our town, or our nation, or the whole world, or any specified entity or interest group, in the future. We can foresee that to overfish the seas would be in the long run counterproductive for all fishermen. We can foresee a happier future if we limit our birth rate so that fewer individuals are born, to enjoy richer lives. We can decide that self-restraint now will pay dividends in the future. But natural selection has no foresight.
To be sure, a panglossian version of natural selection theory had been proposed, which, if only it worked, might achieve something like the ‘all is for the best’ utopia. But unfortunately it doesn’t work. At any rate, it was one of my aims in The Selfish Gene to persuade my readers that it doesn’t work. This was the theory called ‘group selection’. This maddeningly seductive error – the Great Group Selection Fallacy or GGSF – ran all through Konrad Lorenz’s popular 1964 book On Aggression. It also pervaded Robert Ardrey’s best-sellers, The Territorial Imperative and The Social Contract – where I was especially affronted by the mismatch between Ardrey’s erroneous message and the high quality of the English in which he expressed it.57 I aspired to publish a book on the same theme as Ardrey’s Social Contract (itself a sort of biological rewrite of Rousseau’s famous treatise); but mine would be based on rigorous natural selection theory, not the GGSF. My ambition was to undo the damage done by Ardrey and Lorenz – and by many television documentaries of the time, whose promulgation of the error was so ubiquitous that in The Selfish Gene I even dubbed it ‘the BBC Theorem’.
I was all too familiar with panglossism and the GGSF because I met them weekly in undergraduate essays. And indeed I, when an undergraduate myself, had laced many of my essays with the fallacious view that what really matters in natural selection is the survival of the species (my tutors never noticed). When I eventually came to write The Selfish Gene, my dream was that I would change all that. I was daunted by the knowledge that, in order to succeed, my book would need to be as well-written as Ardrey’s and sell as prolifically as Lorenz’s. I jokingly spoke of it as ‘my best-seller’, never really believing that it would become one but giving self-consciously ironic voice to my wilder ambition.
Natural selection is a purely mechanical, automatic process. The world is constantly tending to become full of entities that are good at surviving, denuded of things that are not. Natural selection has no foresight, but brains have, and that is why panglossism is so appealing to us. Brains may agonize about the long-term future and project forward this century’s self-indulgence into next century’s catastrophe. Natural selection cannot do that. Natural selection can’t agonize about anything. Natural selection can only blindly favour short-term gain, because every generation is automatically filled with the offspring of those individuals who did whatever it took, in the short term, to manufacture offspring more effectively than other individuals of their own generation.
And when you look carefully and hard at exactly what is going on as the generations flash by, your gaze is drawn irresistibly to the gene as the level at which natural selection really works. Natural selection automatically favours self-interest among entities that potentially can pass through the generational filter and survive into the distant future. As far as life on this planet is concerned, that means genes. Here’s how I put it in The Selfish Gene, where I introduced the phrase ‘survival machine’ to describe the role of (mortal) individual organisms vis-à-vis their (potentially immortal) genes:
The genes are the immortals . . . [they] have an expectation of life that must be measured not in decades but in thousands and millions of years.
In sexually reproducing species, the individual is too large and too temporary a genetic unit to qualify as a significant unit of natural selection. The group of individuals is an even larger unit. Genetically speaking, individuals and groups are like clouds in the sky or dust-storms in the desert. They are temporary aggregations or federations. They are not stable through evolutionary time. Populations may last a long while, but they are constantly blending with other populations and so losing their identity. They are also subject to evolutionary change from within. A popu
lation is not a discrete enough entity to be a unit of natural selection, not stable and unitary enough to be ‘selected’ in preference to another population.
An individual body seems discrete enough while it lasts, but alas, how long is that? Each individual is unique. You cannot get evolution by selecting between entities when there is only one copy of each entity! Sexual reproduction is not replication. Just as a population is contaminated by other populations, so an individual’s posterity is contaminated by that of his sexual partner. Your children are only half you, your grandchildren only a quarter you. In a few generations the most you can hope for is a large number of descendants, each of whom bears only a tiny portion of you – a few genes – even if a few do bear your surname as well.
Individuals are not stable things, they are fleeting. Chromosomes too are shuffled into oblivion, like hands of cards soon after they are dealt. But the cards themselves survive the shuffling. The cards are the genes. The genes are not destroyed by crossing-over, they merely change partners and march on. Of course they march on. That is their business. They are the replicators and we are their survival machines. When we have served our purpose we are cast aside. But genes are denizens of geological time: genes are forever.
I had already convinced myself of this truth a decade earlier, in almost exactly the same words, when I gave the 1966 undergraduate lectures in Oxford that I have already described. I recalled on page 199 the rhetorical flourishes with which I tried to persuade the undergraduates of the centrality of the immortal gene in the logic of natural selection. Here are my 1966 words, and you can see how similar they are to the equivalent, more rhetorical paragraphs of The Selfish Gene.
Genes are in a sense immortal. They pass through the generations, reshuffling themselves each time they pass from parent to offspring. The body of an animal is but a temporary resting place for the genes; the further survival of the genes depends on the survival of that body at least until it reproduces, and the genes pass into another body . . . the genes build themselves a temporary house, mortal, but efficient for as long as it needs to be . . . To use the terms ‘selfish’ and ‘altruistic’ then, our basic expectation on the basis of the orthodox neo-Darwinian theory of evolution is that Genes will be ‘selfish’.
When I recently found the text of that 1966 lecture (with its encouraging marginal note by Mike Cullen), I was surprised to realize that I had not then read George C. Williams’s book, Adaptation and Natural Selection, published in the same year:58
With Socrates’ death, not only did his phenotype disappear, but also his genotype . . . The loss of Socrates’ genotype is not assuaged by any consideration of how prolifically he may have reproduced. Socrates’ genes may be with us yet, but not his genotype, because meiosis and recombination destroy genotypes as surely as death.
It is only the meiotically dissociated fragments of the genotype that are transmitted in sexual reproduction, and these fragments are further fragmented by meoisis in the next generation. If there is an ultimately indivisible fragment it is, by definition, ‘the gene’ that is treated in the abstract discussions of population genetics.
When I eventually read Williams’s great book (some years later, I regret to say), his Socrates passage immediately resonated with me and I prominently acknowledged Williams’s importance, as well as Hamilton’s, for the theme of The Selfish Gene when I came to write it.
Williams and Hamilton were somewhat similar characters: quiet, withdrawn, self-effacing, deep-thinking. Williams had a dignity and mien which – perhaps enhanced by his high forehead and the cut of his beard – reminded many of Abraham Lincoln. Hamilton had more an air of A. A. Milne’s Eeyore. But when I wrote The Selfish Gene I didn’t know either man, just their published work and how central it was for our understanding of evolution.
Because genes are potentially immortal in the form of accurate copies, the difference between successful genes and unsuccessful genes really matters: it has long-term significance. The world becomes filled with genes that are good at being there, good at surviving through many generations. In practice that means good at cooperating with other genes in the business of building bodies that have what it takes to survive long enough to reproduce – for bodies are the temporary vehicles in which genes reside and which pass them on. Throughout The Selfish Gene I used that phrase ‘survival machine’ as my name for an organism. Organisms are the entities in life that actually do things – move, behave, search, hunt, swim, run, fly, feed their young. And the best way to explain everything that an organism does is to assume that it has been programmed, by the genes that ride inside it, to preserve those genes and pass them on before the organism itself dies.
I also used the word ‘vehicle’ as equivalent to ‘survival machine’. It reminds me of an amusing occasion when a Japanese television crew came to interview me about The Selfish Gene. They all travelled to Oxford from London packed into a black cab, with tripods and floodlights and, as it seemed, arms and legs sticking out of every window. The director informed me, in halting English (the official interpreter couldn’t make me understand him at all and had been sent off in disgrace), that he wanted to film me in the taxi as it drove around Oxford. This puzzled me, and I asked why. ‘Hoh!’ came the puzzled reply: ‘Are you not author of Taxicab Theory of Evolution?’ I afterwards guessed that the Japanese translators of my writings must have rendered ‘vehicle’ as ‘taxicab’.
The interview itself was quite amusing. I rode in the taxi alone except for the cameraman and sound man. In the absence of the official interpreter, there was no interviewer, and I was bidden simply to talk ad lib about The Selfish Gene while we did a scenic tour of Oxford. The taxi driver doubtless had the streets of London intricately mapped in his enlarged hippocampus, but he didn’t know Oxford. It therefore fell to me to guide him, and my otherwise measured discourse on selfish genes was punctuated by frantic shouts of ‘Turn left here!’ or ‘Turn right at the traffic lights and then get in the right-hand lane!’ I hope they managed to find the unfortunate interpreter before returning to London.
In The Selfish Gene, I criticized the panglossian idea that animals have foresight and work out what would be good for the long-term future of their species or group. What is wrong with this is not the idea that animals ‘work out what would be good’. There is in any case no suggestion that the ‘working out’ is conscious. No: what is wrong is the idea of the species or group as the entity whose benefit is maximized. Biologists often legitimately use the language of ‘working out what would be good’ as a shorthand route to sound Darwinian reasoning. The trick is to identify the correct level in the hierarchy of life at which the shorthand metaphor of conscious reasoning is applied. It is quite OK to put yourself in the position of an individual animal and ask: ‘What would I do if I were trying to achieve the goal of propagating my genes?’
The Selfish Gene is filled with imagined soliloquies in which a hypothetical animal ‘reasons’ to itself: ‘Should I do X or Y?’ The meaning of ‘should’ is: ‘Would X or Y be better for my genes?’ This is legitimate, but only because it can be translated into the question: ‘Would a gene for making individuals do X (in this situation) become more frequent in the gene pool?’ The subjective soliloquy is justified by the fact that it can be translated into the language of gene survival.
One might be tempted to interpret ‘Should I do X or Y?’ as meaning ‘Would X or Y be more likely to prolong my own life?’ But if long life is bought at the expense of not reproducing – that is to say, if we pit individual longevity against gene survival – natural selection will not favour it. Reproduction can be a dangerous business. Male pheasants that are gorgeously coloured to attract females also attract predators. A drab, inconspicuous male would probably live longer than a brightly coloured, attractive male. But he’d be more likely to die unmated, and the genes for safety-first drabness are less likely to be passed on. Gene survival is what really matters in natural selection.
The following is a legitimate
shorthand, put into the mouth of a male pheasant: ‘If I grow drab feathers I shall probably live a long time, but I won’t get a mate. If I grow bright feathers I’ll probably die young, but I’ll pass on lots of genes before I die, including the genes for making bright feathers. Therefore I should take the “decision” to grow bright feathers.’ Needless to say, ‘decision’ doesn’t mean what a human would ordinarily mean by it. Conscious thought is not involved. Organism-level shorthand can be confusing, but it works so long as you remember always to keep open the pathway to a translation back into gene language. No pheasant actually takes a ‘decision’ to grow bright feathers or drab. Instead, genes for growing bright feathers or drab have different probabilities of surviving through the generations.
It really can be helpful, when trying to understand from a Darwinian point of view what animals do, to see them as robot machines, ‘thinking’ about what steps to take in order to pass on their genes to future generations. Such steps may involve behaving in certain ways, or growing organs of a particular shape or character. It can also be helpful to think metaphorically of genes as ‘thinking’ about what steps to take in order to pass themselves on to future generations. Such steps will usually involve manipulating individual organisms via the processes of embryonic development.
But it is never even metaphorically legitimate to treat animals as thinking about what steps to take in order to preserve their species, or their group. Differential group or species survival is not what happens in natural selection. What happens is differential gene survival. Therefore, legitimate shorthands are of the form ‘If I were a gene, what would I do to preserve myself?’ Or – and ideally this should be exactly equivalent – ‘If I were an organism, what would I do to preserve my genes?’ But ‘If I were an organism, what would I do to preserve my species?’ is an illegitimate shorthand. So is – this time for a different reason – ‘If I were a species, what would I do to preserve myself?’ The latter metaphor is illegitimate because a species, unlike an individual organism, is not the kind of entity that even metaphorically behaves as an agent, doing things, acting upon decisions. Species don’t have brains and muscles, they are just collections of individual organisms that do. Species and groups are not ‘vehicles’. Individual organisms are.
An Appetite for Wonder Page 22
