The Selfless Gene

Living with God and Darwin

CHARLES FOSTER

www.hodder.co.uk

Scripture quotations are from the New Revised Standard Version Bible, copyright © 1989 National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved.

First published in Great Britain in 2009 by Hodder & Stoughton
An Hachette UK company

Copyright © Charles Foster, 2009

The right of Charles Foster to be identified as the Author of the Work has been asserted by him in accordance with the Copyright, Designs and Patents Act 1988.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, without the prior written permission of the publisher, nor be otherwise circulated in any form of binding or cover other than that in which it is published and without a similar condition being imposed on the subsequent purchaser.

A CIP catalogue record for this title is available from the British Library

Epub ISBN: 978 1 848 94951 5
Book ISBN: 978 0 340 96436 1

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A great deal of the universe does not need any explanation. Elephants, for instance. Once molecules have learnt to compete and to create other molecules in their own image, elephants, and things resembling elephants, will in due course be found roaming through the countryside . . . Some of the things resembling elephants will be men . . .

(Peter Atkins, The Creation
[San Francisco: Freeman, 1981], p. 3)

Then the LORD answered Job out of the whirlwind:
‘Who is this that darkens counsel by words without knowledge?
. . . I will question you, and you shall declare to me.
Where were you when I laid the foundations of the earth?
Tell me, if you have understanding.’

(Job 38:1–4)

List of Illustrations

Charles Darwin in 1869

HMS Beagle at Tierra del Fuego

Gregor Mendel, the father of genetics

The Creation Museum, North Kentucky

Richard Dawkins lecturing on his book The God Delusion

Thomas Henry Huxley, ‘Darwin’s Bulldog’

The mammalian and the octopus eye compared

The geological column

A creationist car in Athens, Georgia

Homology in the pentadactyl limb

Haeckel’s embryos

The chemical structure of DNA

Darwin’s finches

Stromatolites in Shark Bay, Australia

The bacterial flagellum

‘Man’s place in nature’ (comparison of human and other primate skeletons)

Primate skulls and typical brain weights

The Creation of Adam: Michelangelo

The Creation of Eve, in Monreale Cathedral, Sicily

Acknowledgements

My debts are many and heavy. None of them can be discharged fully here, and only a few of them can even be mentioned.

I am neither a professional evolutionary biologist nor a professional theologian. I am a professional assessor of evidence, and have relied heavily on the biologists and theologians to tell me what I should be assessing.

Michael Lloyd’s work on the problem of animal suffering fascinated and inspired me long before he became a friend. He read some of this manuscript in draft and made a number of important observations.

Professor Sam Berry and Dr Chris Thouless also read the manuscript, and steered me away from some dangerous biological rocks. Both are splendid, learned field biologists of whom Darwin would have been proud.

Professor Simon Conway Morris’s comments on the draft manuscript were invaluable, and have saved me from some deep embarrassment.

I have found particularly useful the work of Leon Kass on the meaning of the Genesis account, Simon Conway Morris on convergence, Jeff Schloss on the evolution of altruism, and Ian Tattersall on human evolution. My gratitude to them is inadequately reflected in the endnotes.

Although he wouldn’t put it this way, Andrew Powell taught me that the noblest destiny of a biological scientist is to be a naturalist, and that to lose sight of the whole animal in peering at its DNA is a catastrophic error. That was a crucial and repercussive lesson.

James Orr patiently put me right on the Greek.

Wendy Grisham, Katherine Venn and the team at Hodder have been tremendous. There are no more efficient, creative or downright congenial publishers.

As always, my long-suffering wife Mary and the children have been victims of my absence and my brooding. I am very grateful for their forbearance, but very sorry that it was necessary.

Preface

I wrote this book because I was angry and worried.

I was angry at the fundamentalist reductionism of Richard Dawkins and his enemies (yet crucial allies) the creationists. And I was worried that if the only explanation for the complexity, colour and variety of the natural world was the selfishness and struggle intrinsic to Darwinian natural selection, it was as immoral to enjoy a walk in the woods as it would be to watch a snuff movie or a piece of extreme sexual sadism.

Richard Dawkins, seen by the TV-watching and paperback-reading public as representing mainstream science, is on the extreme jack-booted right wing of evolutionary biology. Very few in the trade think that things are as simple as he thinks they are. Real biology bristles with fascinating caveats.

If few in the business agree with Dawkins, almost nobody thinks there is anything at all in any of the creationist contentions. It has been to the mutual benefit of these extreme factions to emphasise the divisions, and that is exactly what they have done. Contention is colourful: it draws congregations; it sells books. People love a fight. It is more fun than measured discourse.

In his 1860 debate with Huxley, Wilberforce tried to parody Darwinism into extinction. He famously failed. Since then, Christianity and Darwinism co-existed pretty happily – although with little real conversation – until the relatively recent rise of creationism, a movement that sprang fully deformed from the loins of Seventh Day Adventism. Between them, the creationists and the militant secularists (who cannot believe their luck, or the dollar value of the publicity handed to them by creationism) have transmuted dangerously the relationship between Christianity and evolution. From the ghetto of creationism and ‘intelligent design’, a small, rich and politically influential constituency of Christians bellow at the evolutionists in the language of the King James Version. The evolutionists dismiss the creationists as benighted and medieval, and have tarred the rest of Christendom with the same brush. ‘Why’, they say, ‘should we begin to take Christianity seriously? Its proponents are wholly incapable of handling evidence.’ Creationism has inoculated a whole generation against Christianity.

The overwhelming consensus of modern biology is that some form of evolution by natural selection is the main agent of change in the biological world. Not a single paper espousing creationism or intelligent design has ever been published in a peer-reviewed scientific journal. The creationists say that this is because of scientific Stalinism, and indeed biologists whisper things in private that they would not dream of uttering in public. Careers are quickly destroyed by apparent infidelity to the Darwinian orthodoxy. But this is not the reason for the absence of proper creationist publications. There are no proper creationist publications because there is no proper evidence for any of the creationist assertions.

The currently fashionable fig-leaf to cover the scientific nakedness of creationism is ‘intelligent design’ (ID). It is an idea that paints a strange picture of God – a God who delegates most of the biological craftsmanship to natural selection, but then wanders around the world looking for things that natural selection could have missed or might have done better. He has been strangely selective in what he chooses to put right. Why choose the bacterial flagellum, but not the recurrent laryngeal nerve or the plaice’s head?

Quite apart from the sheer oddness of the idea, ID invites some impossible inferences. Although there is a continuing and exciting debate about the mechanisms used by Darwinism, there is no doubt that Darwinism does operate. And it can potentially explain much of the biological world. It does not follow from this that there is a demonstrable absence of ‘design’. But it does follow from this that the contentions of the ‘intelligent design’ theorists are wrong: it cannot be demonstrated that a designer is necessary.

Despite all this, belief in creationism and intelligent design is growing massively. The ideas have about 50 million adherents in the USA, and they have metastasised across the Atlantic. Churches that ten years ago would have laughed at the mention of creationism now have bookshelves groaning with glossy, expensively produced and unrefereed denunciations of all the achievements of modern biology. An August 2006 survey of British university students found that more than a third believed in either creationism or intelligent design.1 And once you’re in the creationist fold, it is hard to get out again. Not only are the creationist/intelligent design movements energetically evangelistic, they also protect jealously the orthodoxy of their members. The members are never exposed to the scientific consensus; it is regarded as demonic nonsense. It is a worrying sign that many hundreds of thousands are apparently convinced by the arguments in Lee Strobel’s book The Case for a Creator, a series of interviews with creationists. One might have thought – no, one might have hoped – that the book would have the confidence to deal squarely with the objection to its basic premises. But no. And the lack of confidence is well justified.

This steadfast refusal to engage with Darwinism is not restricted to dyed-in-the-wool Texan creationists: it permeates academic theology too. ‘To a great extent,’ writes the theologian John Haught, ‘theologians still think and write as though Darwin had never lived. Their attention remains fixed on the human world and its unique concerns. The nuances of biology or, for that matter, of cosmology have not yet deeply affected current thinking about God and God’s relation to the world.’2

There is a growing intellectual apartheid – an impermeable wall between Christianity and science. That is a shame for science, and disastrous for Christianity. The wall is the work of those (the creationists and the Darwinian ultras) who parody both Darwinism and Christianity. It is built from hardened, sclerosed ideas. There is a deadly failure in both of the radically polarised camps to engage with the thrilling complexity of the real world. It is a sort of autism. Creationism and Dawkinsism are both so dreadfully dull. Dull solutions cannot possibly be correct: the problems posed by the world are so immensely colourful.

Things are not as neat or as quantifiable as the Darwinian ultras represent them as being. It is simply not possible to demonstrate either that natural selection has in fact produced everything that we see in the natural world, or that it could have done. There is plenty of room for other complexity-generators. The other candidates need not elbow natural selection out. Indeed, they plainly have not done so. They may process arm in synergistic arm with natural selection through geological time. One of those candidates has a reassuring character.

Whether or not natural selection is the force driving biological change, the problems raised by suffering, waste and predation remain acute. In some ways they are more acute if the creationists are right. If God willed the nervous system of the zebra to react in the way it does when a lion’s teeth closes on it, and designed the lion to kill, the charge against him is more grave than if natural selection is responsible for the form of the biological world.

There are, however, some tentative answers to the charge.

I am surprised and alarmed by what I have found in the book of Genesis. It is stranger and more radical by far than I have ever imagined it could be. I never dreamt that it could suggest the reconciliation between the Bible and the archaeological record that is sketched out in chapter 9. For years I have looked, baffled, at the astonishing fact that for tens of thousands of years a type of man, as anatomically modern as I am, lived in Africa and the Levant, yet lived entirely intuitively, without any of the trappings of symbolic thought. And then, suddenly, behaviourally modern man exploded into the world, and it was immediately a very, very different place. It is all very odd.

I do not deal in any detail with the contentions of Old Earth creationists. There are several reasons for that. First, Young Earth creationists are louder and more media savvy, and more people will have heard of them. Second, while Old Earth creationists will typically believe that the ‘days’ of creation represent much longer periods, and that there were special acts of creation peppered throughout geological time, there are many nuances separating the various Old Earth creationist factions. Discussion of those nuances would have cluttered further an already packed book. None of those nuances shields Old Earth creationism from the withering fire of modern biology. And third, very broadly, with the exception of the evidence about the age of the earth, Old Earth creationism faces the same problems as Young Earth creationism, and is therefore discussed by implication anyway.

This book will have something in it to frustrate and annoy everyone. The biologists will think that I have oversimplified the biology. They are right. The non-biologists will think that the scientific chapters are terribly heavy going: I expect they are right too. Theologians will justifiably moan that I have summarised too brutally some very big and complex ideas. Non-theologians will cross their eyes in bewilderment at some of those ideas, and wonder if they could not have been put more simply.

So, sorry to everyone.

Writing this book has not made me less angry. But I can now go for a walk without feeling dirty.

Charles Foster,
Oxford, September 2008

CHAPTER 1
The Tangled Bank

It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us. These laws, taken in the largest sense, being Growth with Reproduction; Inheritance which is almost implied by reproduction; Variability from the indirect and direct action of the external conditions of life, and from use and disuse; a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction of less-improved forms. Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.

(Charles Darwin, The Origin of Species, chapter 14)

Imagine, as Darwin did, a tangled bank. To magnify its beauty, brutality and complexity, imagine that it is in the tropics.

It is covered in writhing plants. They wrestle and barge each other. Their roots probe the earth, seeking to take water and nutrients from their neighbours. They do not steal, because nothing holds any title that can be violated. Each organism has what it possesses for the moment. Generally things are taken, not given. There are no rights.

The plants trap sunlight in sugar, and that makes them prey. They are crushed and ground between the teeth of herbivores, and their cells are smashed up by enzymes and bacteria in big fermenting tanks. The sunlight therefore flows for a while into the bodies of the herbivores. How long it stays there depends on many things. It depends on the acuity of the herbivore’s eyes; on the efficiency with which sodium and potassium gates open and shut in the membranes of its nose nerves; on the integrity of the wiring linking its ears to its legs; on the strength of the tendons; on how fearful it is; on how fearful its parents were; on whether or not the night wind has caused a branch to fall in the path along which it bolts.

If it is caught, it may die quickly, or it may die very slowly. If it is a mammal, its nervous system will go on screaming in (so far as we know) very much the way that ours does until the thing (whatever it is) that made it a live rather than a dead mammal has fled or been extinguished. Probably, if it is a mammal being eaten by another mammal, the death will be relatively quick, because the continued life of a victim is an inconvenience for a predator. It makes the victim flounder around, which gets in the way of the feed. But on the way to the death there are dislocations, breaks and rips. The eyes roll. Death does not seem to be welcomed.

Sometimes the death is prolonged. In the stream running by the side of the tangled bank, a fish has been caught by a lamprey. Two weeks ago the lamprey attached itself to the side of the fish, like a large leech. Its grinding jaws eroded the fish’s body wall, and the head of the lamprey, and most of its body, is now inside the body cavity, still grinding away, but destroying nothing vital. To kill would be to change desirably fresh fish to carrion. Only the lamprey’s tail now waves in the water. The waving tail attracts a larger predatory fish. Both the lamprey and its victim are swallowed whole. They will be marinated in digestive enzymes and dissolved into the body of the larger fish.

Back on the bank, a vole is eating seeds made partly from the body of a weasel which had thrived five years ago on the vole’s great-great-great-great-great-grandparents. The bank is a graveyard, seething with life. Everything is a cannibal. The whole place is profoundly and vitally septic. Take away the bacteria that coat everything, and the bank would weigh a lot less and would soon be a desert.

The bank is a culture of intimate interdependence. The vole needs the owl that kills it no less than the owl needs the vole. One of the hawk moth species on the bank has acquired transparent wings to pretend to be a bumblebee and, unlike most moths, has changed its schedule to fly alongside the bees during the day.1 Some of the orchids have fashioned cups which fill with nectar to entice insects. When an insect lands, it depresses the landing stage. As the insect crawls towards the cup, the stage springs back up, trapping the insect. The only way out is past hanging baskets of pollen. The insect flies away full of sugar and dusty with sperm.2

There is someone watching all this, and describing it. He is a man. What he makes of it all will depend on what he believes about himself. But whatever he makes of it, he thinks that it is interesting and terrible. And something in him dislikes the idea of being eaten by worms.

If he is a typical creationist, he believes that the species on the tangled bank are broadly as they were when they were created by God six to ten thousand years ago (depending on how he reads the biblical chronologies).3 There has been some speciation since, but only in the direction of degeneration – as the genome sheds information like confetti. Man himself has no familial relationship with any of the creatures of the bank, and the different species on the bank are themselves related only by the fact that they spill, rather than share, one another’s blood. The horrors of the bank are the fault of primordial man, whose arrogant usurping of the divine prerogative corrupted, by an obscure spiritual mechanism, the whole of creation. All species were originally vegetarian,4 and lived in happy co-existence – a proposition that of course assumes that plants are happy being eaten. Before Eve plucked the forbidden fruit there was no death, no pain and no predation. The water creatures, the birds and humans (but not, apparently, the plants or the land animals) were commanded to multiply.5 The strategy for ensuring that there was not catastrophic overpopulation is not clear.

Depending on whether the creationist believes Genesis 1 or Genesis 2, he should believe either that man was spoken into existence after the animals,6 and set over them as ruler; or that man was formed from the dust of the earth, before the creation of the animals, the plants, or even the first rainfall,7 and that the animals were thought of originally as company for him.8 Probably, though, in a way mysterious to most of us, he will believe both.

If the observer is a mainstream evolutionist, he is in many ways more mystical than the creationist. He believes, like Genesis 2, that he was fashioned from dust, but believes that it was stardust. He describes, and, if he is that way inclined, senses an intimate familial communion with all the animals and plants on the bank. His wondering fascination with the biochemistry of the bacteria means that he sees no slight in being called their cousin. His sense of the immense age of the world gives him an exhilarating chronological vertigo when he looks at the bank. He thinks that the universe was formed about 15 billion years ago, and the earth about 4.5 billion years ago. If he thinks that there is a God, his God must be very big and very old.

He thinks that conditions on the earth were for a long time incompatible with life, but probably thinks that life sprang into existence about as soon as it could – about 3.8 billion years ago. Life is not only tenacious and fecund once it exists,9 but also seems to loathe non-existence.

If the evolutionist is honest, he has no idea how life began, and points out that evolution itself does not pretend to have anything to say on the subject.10 He acknowledges that the promise shown by the 1953 Miller-Urey experiment that we all learned about at school (in which amino acids were formed by discharging lightning-simulating voltages through an atmosphere of water, methane, ammonia and hydrogen) has evaporated: most think that the experiment made unsustainable assumptions about the chemistry of the early earth. He thinks that early forms of life were unicellular. The genesis of the cell is again, if he is candid, a complete mystery, although there are some elegant hypotheses. He notes that the general direction of evolution has been towards increased size and increased complexity. Cells initially got together in loose conglomerations. The conglomerations then became organised, centrally directed, and so transmuted into multicellular organisms.

Several forces drove this magnificent white-knuckle ride towards complexity. The evolutionist will not agree with all his fellows about the relative contribution of the various forces, but there will be a fair degree of agreement. He will subscribe, along with almost all of the scientific world, to the neo-Darwinian synthesis.

Charles Darwin in 1869. Photo by J. Cameron.

In The Origin of Species, published in 1859, Darwin set out the idea of evolution (which everyone acknowledged had happened) by natural selection (which was the real novelty). The idea was outrageously simple. Thomas Huxley,11 when he heard of it, is said to have slapped his forehead and said, ‘How stupid of me not to have thought of that.’ Darwin, through his round-the-world trip on the Beagle, his readings of Malthus,12 his afternoon perambulations around the Sandwalk at Downe House, and his obsessive observations of worms, finches, rocks, beetles, men and everything else, had been compelled to the conclusion that since

many more individuals of each species are born than can possibly survive, and as consequently there is a frequently recurring struggle for existence, it follows that any being, if it vary however slightly in any manner profitable to itself, under the complex and sometimes varying conditions of life, will have a better chance of survival and thus be naturally selected. From the strong principle of inheritance, any selected variety will tend to propagate its new and modified form.13

HMS Beagle at Tierra Del Fuego, painted by the onboard artist, Conrad Martens, during the Beagle’s voyage, 1831–36.

Darwin had no idea about the mechanism of ‘the strong principle of inheritance’. It was supplied just seven years after the publication of The Origin of Species by the Austrian Augustinian monk Gregor Mendel and his pea plants. The peas indicated that the units of inheritance were physically discrete. They would later be called ‘genes’, and identified as the sequences of nucleotides on the DNA molecule that determine the amino acid sequences of, and therefore the characteristics of, proteins. Biology starts from the presumption that I am the sum of my proteins, and then gets interesting.

Mendel’s 1866 paper was forgotten during his own lifetime, but was rediscovered and dusted down at the start of the twentieth century. Darwinism, languishing for want of an explanation of heredity, acquired new energy and confidence. The fusion of Darwin’s original thesis with the new science of genetics is what is described as the ‘neo-Darwinian synthesis’.14 The synthesis reformulated Darwin’s thesis by defining selective advantage. A characteristic coded for by gene X was advantageous in evolutionary terms if it increased the incidence of gene X in subsequent generations.

Gregor Mendel, the father of genetics.

The ratios in Mendel’s pea paper allowed some exciting and intimidating mathematics to perfuse evolutionary biology. If you knew the mechanism of inheritance, you could determine the expected incidence of inherited traits. If you then compared this expected incidence with the observed incidence in populations, you were looking at more or less dim reflections of the forces of change themselves. You could begin to make mathematically informed guesses about the power, and possibly the nature, of the forces.

All evolutionists agree that classic natural selection is one of the forces. Genetic change occurs in various ways: mutations (most of which are harmful, but some of which will be beneficial); genetic recombination through the normal process of sexual reproduction; gene duplication (particularly in plants and bacteria); regulator genes, which switch on and off and otherwise determine the function of other genes; the introduction of new genes from other populations, and so on. There is bitter and highly technical disagreement about which of these mechanisms of change is predominant. The disagreements are irrelevant for the purposes of our look at the bank. Everyone agrees that genetic change occurs, and that at least some changes are detected by natural selection, which then gets to work, altering the gene frequency in subsequent generations. The really interesting disputes relate to the sensitivity of natural selection in picking up the change, and its efficacy in turning its detection into a final verdict on the relevant gene. We have noted that Darwin wrote, ‘any being, if it vary however slightly in any manner profitable to itself . . . will have a better chance of survival and thus be naturally selected’. Much of modern evolutionary biology is concerned with how slight a variation can be before it attracts the approving or disapproving attention of natural selection, with the role of contingency, and with the ability of natural selection to fashion new species rather than merely altering existing ones.

It has to be said that natural selection, whether or not it is the sole or principal engine of evolutionary change, is surprisingly sensitive and powerful. A tiny change (for instance in the number of stripes on a snail shell) can result in a dramatic change in the chance of the snail being smashed and eaten by a thrush.

If natural selection is not the only thing producing change, what else might be? Various candidates have been put forward by orthodox science, but when their credentials are examined carefully, they all turn out to be chance, dressed up in various more or less exotic ways. This book will suggest another possibility. But there is nothing necessarily disreputable about chance. Our own anecdotal experience might lead us to prefer its candidacy. Genuine accidents, unavoidable by the most refined nervous system or most beautifully toned muscle, do happen. If you are at the pinnacle of the natural selective tree, your rigorously selected genes will not help you much if you are also at the pinnacle of an erupting volcano which smothers you in boiling lava. If the volcano has not erupted for a few million years, it can hardly be said that you were stupid to live there, and that the lava has sought out and dealt sternly with the genes making you stupid. Natural selection is very good at picking up the pieces; it is often pretty dismal at stopping the destruction in the first place.

The mammals were tiny, unimpressive creatures in the age of the dinosaurs. The extinction of the dinosaurs gave mammals their chance, and natural selection vigorously promoted the mammals. But natural selection did not direct the asteroid that may well have ushered the dinosaurs into the museums.15 If the asteroid had not landed, would mammals ever have had the chance to rule the earth?16, 17

If our bank-gazing evolutionist has been brought up conventionally in biology (and particularly if he has been brought up in the UK), he will tend to look at all the attributes of the bank-dwellers through an adaptationist lens. He will assume that everything about the hawk moth is precisely the way it is because natural selection has decreed it that way. He will credit natural selection with a superb eye for detail and the sculpting hand of a Michelangelo. He will credit little to chance, and nothing to God. God is a hypothesis of which he has no need, and indeed he will happily quote Laplace’s dictum when given any opportunity.18 Chance produces the entirely random mutations which give natural selection something to get to work on, but natural selection is so assiduous at sifting the phenotypic nuances thrown up by mutation that it refuses to delegate to chance any of the sifting.

But if he has read a bit (and particularly if he has studied in the US), he might have embarrassing doubts about this monolithic adaptationism. Perhaps his capacity to harbour such heresies is a function as much of his psychology as his academic upbringing. He might think that nothing in the world, let alone in biology, is likely to be quite so straightforward. He might be prepared to rejoice in the tangles of the bank, and to think that they might not be comfortably accommodated within the strait-jacket of a single thought. He might be excited rather than outraged to hear Stephen Jay Gould asking, ‘What is wrong with messy richness, so long as we can construct an equally rich texture of satisfying explanation?’19

The ‘satisfying explanation’, though, remains an essentially Darwinian one. Natural selection might not hone as finely as Darwin and Dawkins like to think; instead of a stately, gradual march towards complexity there may be genuine stasis in the fossil record, followed by massive, innovative jumps; there may be plenty of characteristics that confer neither significant advantage nor disadvantage, and therefore flap happily and neutrally through evolutionary history, unrecognised by the supposedly infallible eye of Darwin; if we were to re-run the tape of biological history again, the outcome might look very different; we might sometimes be tennis balls of the stars rather than of our genes. But let’s not try to pretend (as some creationists outrageously do) that Gould was not a thoroughgoing Darwinist. And at first blush it looks as if God might be too. Allowing room for contingency on the bank does not edge natural selection from its central place. And even if contingency were enthroned there, contingency is not, or at least not obviously, another word for God. It is not even clear that a bank ruled by contingency allows more space for God than does straightforward natural selection. Natural selection is powered by selfishness, appetite, waste, pain and death. Chance just could not care less about anything using any of these fuels to power anything. Neither looks much like the kind of God the Christians talk about.

Darwin concluded:

There is a grandeur in this view of life having been originally breathed into a few forms, or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms, most beautiful and most wonderful have been, and are being, evolved.20

No doubt – but it is an icy grandeur, a grandeur that can be appreciated only if you are deaf to screams and inured to gore. It is not the sort of thing you want your children to appreciate. Dusk has fallen on the bank. Bats begin to flicker around the trees, hunting by sonar the moths that hatched that day in the undergrowth. They kill particularly the very young – those on their first wing-stretch. The evolutionist stares into the fire he has made, and starts to get introspective. He sees pictures in the flames. They suggest stories that he has never heard. He conjures ghosts from the shadows, and sees teeth that are not there. His guide has a headache: he gives the guide some paracetamol from the medical kit, and then wonders why. He looks up at the sky, and feels smaller. This is absurd, because he has a PhD from Harvard and knows very well that he is the same size as ever. He has had a good day, and feels thankful. But he does not know whom to thank, or why gratitude is appropriate. He is used to dealing with death – his PhD involved thousands of post-mortems on field mice – but in the dark he begins to think of his mother, who died ten years ago, and he starts to cry. He is embarrassed and turns his face away so that the tears cannot be seen. It does not seem right that she died, although, having had six children, her function as a gene replicator had been amply fulfilled. He remembers her kindness to him long after he had had his own vasectomy and ceased to be a reproductively relevant animal. He remembers too her love of water-colours, of Etruscan frescoes, of the poetry of Gerard Manley Hopkins and, worst of all, the novels of Nabokov, which he hated. These were all useless things.

He remembers how his mother had tenderly taunted his reductionism in a letter, quoting Nabokov the fanatical lepidopterist. Nabokov had said that moth mimicry was ‘carried to a point of mimetic subtlety, exuberance and luxury far in excess of the predator’s power of appreciation’.21 He remembers how he had felt forced to disagree loudly with this quote for the sake of his creed, although he had secretly wondered the same thing himself. And he remembers how he had first become a biologist: how, before he had ever heard of genes, DNA or bell curves, he had collected beetles, writing their names in childish handwriting on labels stolen from school. He had given them individual baby names, too, and had stayed up at night seeing how the reading lamp made their iridescent backs shimmer. It was not the biggest or most impressive that he had liked best. He liked the smallest ones, and the ones with the best names, but most of all he had liked the collection as a whole, as a community, because in that community the individuality of each was seen best. He remembers how they had buried his mother; how the brothers had thrown flowers into the grave, and how, although the sun was bright, the world was black.

Early next morning the evolutionist looks out of his tent onto the bank, sees a snake snatch a fledgling, and knows that whatever nonsense had come into his head in the night, the presumptions in his PhD were right all along.