Body by Darwin: How Evolution Shapes Our Health and Transforms Medicine

261 Pages·2015·0.96 MB·English

by  Jeremy Taylor

BODY BY DARWIN
B O D Y
B Y
D A R W I N
How Evolution Shapes Our Health
and Transforms Medicine
JEREMY TAYLOR
THE UNIVERSITY OF CHICAGO PRESS
Chicago and London
Jeremy Taylor was previously a senior producer and director for
BBC Television, and he has made numerous science flms for the
Discovery Channel and the Learning Channel, among others. He
is also the author of Not a Chimp: The Hunt to Find the Genes That
Make Us Human. He lives in London.
The University of Chicago Press, Chicago 60637
The University of Chicago Press, Ltd., London
© 2015 by Jeremy Taylor
All rights reserved. Published 2015.
Printed in the United States of America
24 23 22 21 20 19 18 17 16 15  1 2 3 4 5
ISBN-1 3: 978-0 -2 26-0 5988-4 (cloth)
ISBN-1 3: 978-0 -2 26-0 5991-4 (e- book)
DOI: 10.7208/chicago/9780226059914.001.0001
Library of Congress Cataloging-in-Publication Data
Taylor, Jeremy, 1946– author.
Body by Darwin: how evolution shapes our health
and transforms medicine / Jeremy Taylor.
pages; cm
Includes bibliographical references.
ISBN 978-0-226-05988-4 (cloth: alk. paper)—
ISBN 978-0-226-05991-4 (e-book) 1. Evolution (Biology) 
2. Human evolution. 3. Evolutionary genetics. I. Title.
qh366.2.t374 2015
576.8—dc23 2015019942
♾ This paper meets the requirements of ANSI/NISO Z39.48-1 992
(Permanence of Paper).
For Linus and Barbara
CONTENTS
Introduction 1
ABSENT FRIENDS
How the Hygiene Hypothesis Explains Allergies
and Autoimmune Diseases 13
A FINE ROMANCE
How Evolutionary Theory Explains Infertility
and Diseases of Pregnancy 49
THE DOWNSIDE OF UPRIGHT
The Relationship between Bipedalism and Orthopedic Illnesses 81
DIY EYE
How Developmental Biology Cures Blindness
and Rebuts Creationism 113
HOPEFUL MONSTERS
Why Cancer Is Almost Impossible to Cure 141
A PROBLEM WITH THE PLUMBING
Why the Evolution of Coronary Arteries Makes
Us Prone to Heart Attacks 175
THREE SCORE YEARS—AND THEN?
How Evolution Is Breathing New Life into Moribund
Dementia Research 207
Acknowledgments 245
Suggestions for Further Reading 247
INTRODUCTION
Why can’t we live forever? Why can’t we make human dis-
ease a thing of the past? Why is it taking such a long time to
cure cancer? These are the sorts of questions that schoolkids
often pose to popular science blogers, student forums, and
the “Ask a Scientist” columns of daily newspapers, but they
are no less interesting for that. Yet human life expectancy is
increasing rapidly in countries worldwide and in some now
exceeds eighty years. A recent study shows that the diference
today in the decrease in human mortality between hunter-
gathers and modern Western-l ifestyle populations is greater
than that between hunter-g atherers and wild chimpanzees.
The bulk of this mortality reduction has occurred in just the
last four generations of the roughly eight thousand genera-
tions of humans that have ever lived. You only have to look at
the incredible advances over the last century in surgery, phar-
macology, public health, immunology, and transplantation to
see what a success story modern medicine has been.
But sweeping statistics like this disguise a perplexing and
worrying amount of disease, the incidence of which is get-
ting worse not better. The pattern of human illness, the sick-
ness landscape, is forever changing. To the deceptively naive
schoolkid questions above, we can easily add: Why do so
many of us sufer from autoimmune diseases such as rheuma-
toid arthritis, multiple sclerosis, type 1 diabetes, and infam-
matory bowel disease? Why are so many people doged by
1