Genome The Autobiography of a Species in 23 Chapters

349 Pages·2000·1.42 MB·English

by  Matt Ridley

The author is grateful to the following publishers for permission to
reprint brief extracts: Harvard University Press for four extracts from
Nancy Wexler's article in The Code of Codes, edited by D. Kevles and
R. Hood (pp. 62-9); Aurum Press for an extract from The Gene
Hunters by William Cookson (p. 78); Macmillan Press for extracts from
Philosophical Essays by A. J. Ayer (p. 338) and What Remains to Be
Discovered by J. Maddox (p. 194); W. H. Freeman for extracts from
The Narrow Roads of Gene Land by W. D. Hamilton (p. 131); Oxford
University Press for extracts from The Selfish Gene by Richard Dawkins
(p. 122) and Fatal Protein by Rosalind Ridley and Harry Baker (p. 285);
Weidenfeld and Nicolson for an extract from One Renegade Cell by
Robert Weinberg (p. 237). The author has made every effort to obtain
permission for all other extracts from published work reprinted in this
book.
This book was originally published in Great Britain in 1999 by Fourth
Estate Limited.
GENOME. Copyright © 1999 by Matt Ridley. All rights reserved. Printed
in the United States of America. No part of this book may be used or
reproduced in any manner whatsoever without written permission
except in the case of brief quotations embodied in critical articles and
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FIRST U.S. EDITION
Library of Congress Cataloging-in-Publication Data
Ridley, Matt
Genome: the autobiography of a species in 23 chapters/Matt Ridley.
p. cm.
Includes bibliographical references and index.
ISBN 0-06-019497-9
1. Human genome Popular works. 2. Human genetics Popular
works. I. Title.
QH431.R475 2000
599.93'5—dc21 99-40933
00 01 02 03 04 RRD 10 9 8 7 6 5 4 3 2 1
C O N T E N TS
Acknowledgements l
Preface 3
1 Life 11
2 Species 23
3 History 38
4 Fate 54
5 Environment 65
6 Intelligence 76
7 Instinct 91
X and Y Conflict 107
8 Self-interest 122
9 Disease 136
10 Stress 147
11 Personality 161
12 Self-Assembly 173
13 Pre-History 185
14 Immortality 195
15 Sex 206
16 Memory 219
17 Death 231
18 Cures 243
19 Prevention 258
20 Politics 271
21 Eugenics 286
22 Free Will 301
Bibliography and Notes 314
Index 337
ALSO BY MATT RIDLEY
The Red Queen: Sex and the Evolution of Human Nature
The Origins of Virtue:
Human Instincts and the Evolution of Cooperation
A C K N O W L E D G E M E N TS
In writing this book, I have disturbed, interrupted, interrogated,
emailed and corresponded with a great variety of people, yet I have
never once met anything but patience and politeness. I cannot thank
everybody by name, but I would like to record my great debts of
gratitude to the following: Bill Amos, Rosalind Arden, Christopher
Badcock, Rosa Beddington, David Bendey, Ray Blanchard, Sam
Brittan, John Burn, Francis Crick, Gerhard Cristofori, Paul Davies,
Barry Dickson, Richard Durbin, Jim Edwardson, Myrna Gopnik,
Anthony Gottlieb, Dean Hamer, Nick Hastie, Brett Holland, Tony
Ingram, Mary James, Harmke Kamminga, Terence Kealey, Arnold
Levine, Colin Merritt, Geoffrey Miller, Graeme Mitchison, Anders
Moller, Oliver Morton, Kim Nasmyth, Sasha Norris, Mark Pagel,
Rose Paterson, David Penny, Marion Petrie, Steven Pinker, Robert
Plomin, Anthony Poole, Christine Rees, Janet Rossant, Mark Ridley,
Robert Sapolsky, Tom Shakespeare, Ancino Silva, Lee Silver, Tom
Strachan, John Sulston, Tim Tully, Thomas Vogt, Jim Watson, Eric
Wieschaus and Ian Wilmut.
Special thanks to all my colleagues at the International Centre for
Life, where we have been trying to bring the genome to life. Without
the day-to-day interest and support from them in matters biological
2 G E N O ME
and genetic, I doubt I could have written this book. They are Alastair
Balls, John Burn, Linda Conlon, Ian Fells, Irene Nyguist, Neil Sulli
van, Elspeth Wills and many others.
Parts of two chapters first appeared in newspaper columns and
magazine articles. I am grateful to Charles Moore of the Daily Tele
graph and David Goodhart of Prospect for publishing them.
My agent, Felicity Bryan, has been enthusiasm personified
throughout. Three editors had more faith in this book when it was
just a proposal than (I now admit) I did: Christopher Potter, Marion
Manneker and Maarten Carbo.
But to one person I give deeper and more heartfelt gratitude than
to all the rest put together: my wife, Anya Hurlbert.
P R E F A CE
The human genome — the complete set of human genes - comes
packaged in twenty-three separate pairs of chromosomes. Of these,
twenty-two pairs are numbered in approximate order of size, from
the largest (number 1) to the smallest (number 22), while the remain
ing pair consists of the sex chromosomes: two large X chromosomes
in women, one X and one small Y in men. In size, the X comes
between chromosomes 7 and 8, whereas the Y is the smallest.
The number 23 is of no significance. Many species, including our
closest relatives among the apes, have more chromosomes, and
many have fewer. Nor do genes of similar function and type neces
sarily cluster on the same chromosome. So a few years ago, leaning
over a lap-top computer talking to David Haig, an evolutionary
biologist, I was slightly startled to hear him say that chromosome
19 was his favourite chromosome. It has all sorts of mischievous
genes on it, he explained. I had never thought of chromosomes
as having personalities before. They are, after all, merely arbitrary
collections of genes. But Haig's chance remark planted an idea in
my head and I could not get it out. Why not try to tell the unfolding
story of the human genome, now being discovered in detail for the
first time, chromosome by chromosome, by picking a gene from
4 GENOME
each chromosome to fit the story as it is told? Primo Levi did
something similar with the periodic table of the elements in his
autobiographical short stories. He related each chapter of his life to
an element, one that he had had some contact with during the
period he was describing.
I began to think about the human genome as a sort of autobiog
raphy in its own right — a record, written in 'genetish', of all the
vicissitudes and inventions that had characterised the history of our
species and its ancestors since the very dawn of life. There are
genes that have not changed much since the very first single-celled
creatures populated the primeval ooze. There are genes that were
developed when our ancestors were worm-like. There are genes that
must have first appeared when our ancestors were fish. There are
genes that exist in their present form only because of recent epi
demics of disease. And there are genes that can be used to write
the history of human migrations in the last few thousand years.
From four billion years ago to just a few hundred years ago, the
genome has been a sort of autobiography for our species, recording
the important events as they occurred.
I wrote down a list of the twenty-three chromosomes and next
to each I began to list themes of human nature. Gradually and
painstakingly I began to find genes that were emblematic of my
story. There were frequent frustrations when I could not find a
suitable gene, or when I found the ideal gene and it was on the
wrong chromosome. There was the puzzle of what to do with the
X and Y chromosomes, which I have placed after chromosome 7,
as befits the X chromosome's size. You now know why the last
chapter of a book that boasts in its subtitle that it has twenty-three
chapters is called Chapter 22.
It is, at first glance, a most misleading thing that I have done. I
may seem to be implying that chromosome 1 came first, which it
did not. I may seem to imply that chromosome 11 is exclusively
concerned with human personality, which it is not. There are prob
ably 60,000—80,000 genes in the human genome and I could not
tell you about all of them, partly because fewer than 8,000 have
PREFACE 5
been found (though the number is growing by several hundred a
month) and partly because the great majority of them are tedious
biochemical middle managers.
But what I can give you is a coherent glimpse of the whole: a
whistle-stop tour of some of the more interesting sites in the genome
and what they tell us about ourselves. For we, this lucky generation,
will be the first to read the book that is the genome. Being able to
read the genome will tell us more about our origins, our evolution,
our nature and our minds than all the efforts of science to date. It
will revolutionise anthropology, psychology, medicine, palaeontology
and virtually every other science. This is not to claim that everything
is in the genes, or that genes matter more than other factors. Clearly,
they do not. But they matter, that is for sure.
This is not a book about the Human Genome Project — about
mapping and sequencing techniques - but a book about what that
project has found. Some time in the year 2000, we shall probably
have a rough first draft of the complete human genome. In just a
few short years we will have moved from knowing almost nothing
about our genes to knowing everything. I genuinely believe that we
are living through the greatest intellectual moment in history. Bar
none. Some may protest that the human being is more than his
genes. I do not deny it. There is much, much more to each of us
than a genetic code. But until now human genes were an almost
complete mystery. We will be the first generation to penetrate that
mystery. We stand on the brink of great new answers but, even
more, of great new questions. This is what I have tried to convey
in this book.
PRIMER
The second part of this preface is intended as a brief primer, a sort
of narrative glossary, on the subject of genes and how they work.
I hope that readers will glance through it at the outset and return
to it at intervals if they come across technical terms that are not
explained. Modern genetics is a formidable thicket of jargon. I have