Table Of ContentLIFE’S ENGINES
Science Essentials
Books in the Science Essentials series bring cutting-e dge science to a general audience.
The series provides the foundation for a better understanding of the scientific and
technical advances changing our world. In each volume, a prominent scientist—
chosen by an advisory board of National Academy of Sciences members—conveys
in clear prose the fundamental knowledge underlying a rapidly evolving field of
scientific endeavor.
The Great Brain Debate: Nature or Nurture,
by John Dowling
Memory: The Key to Consciousness,
by Richard F. Thompson and Stephen Madigan
The Faces of Terrorism: Social and Psychological Dimensions,
by Neil J. Smelser
The Mystery of the Missing Antimatter,
by Helen R. Quinn and Yossi Nir
The Long Thaw: How Humans Are Changing the Next 100,000
Years of Earth’s Climate,
by David Archer
The Medea Hypothesis: Is Life on Earth Ultimately Self- Destructive?
by Peter Ward
How to Find a Habitable Planet,
by James Kasting
The Little Book of String Theory,
by Steven S. Gubser
Enhancing Evolution: The Ethical Case for Making Better People,
by John Harris
Nature’s Compass: The Mystery of Animal Navigation,
by James L. Gould and Carol Grant Gould
Heart of Darkness: Unraveling the Mysteries of the Invisible Universe,
by Jeremiah P. Ostriker and Simon Mitton
Oxygen: A Four Billion Year History,
by Donald C. Canfield
The Cosmic Cocktail: Three Parts Dark Matter,
by Katherine Freese
Life’s Engines: How Microbes Made Earth Habitable,
by Paul G. Falkowski
L I F E ’ S E N G I N E S
How Microbes Made Earth Habitable
Paul G. Falkowski
Princeton University Press
Princeton and Oxford
Copyright © 2015 by Princeton University Press
Published by Princeton University Press, 41 William Street, Princeton,
New Jersey 08540
In the United Kingdom: Princeton University Press, 6 Oxford Street, Woodstock,
Oxfordshire OX20 1TW
press.princeton.edu
Jacket Art: Green plant © Pasko Maksim/Shutterstock, E. coli bacteria © Mirumur/
Shutterstock, world © Ase/Shutterstock.
All Rights Reserved
Library of Congress Cataloging- in- Publication Data
Falkowski, Paul G., author.
Life’s engines: how microbes made Earth habitable / Paul G. Falkowski.
pages cm. - - (Science essentials)
Includes bibliographical references and index.
ISBN 978-0-691-15537-1 (hardcover: acid- free paper) - - ISBN 0-691-15537-2
(hardcover: acid- free paper) 1. Microorganisms- - Evolution. 2. Bacteria- - Evolution.
3. Microbial genetics. 4. Life (Biology) I. Title.
QR13.F35 2015
579- - dc23
2014036615
British Library Cataloging- in- Publication Data is available
This book has been composed in Goudy Old Style
Printed on acid- free paper. ∞
Printed in the United States of America
1 3 5 7 9 10 8 6 4 2
To my parents, Ed and Helen, my wife and friend,
Sari Ruskin, and our daughters, Sasha and Mirit
Contents
Acknowledgments ix
Prologue 1
CHAPTER 1 The Missing Microbes 9
CHAPTER 2 Meet the Microbes 23
CHAPTER 3 The World before Time 40
CHAPTER 4 Life’s Little Engines 47
CHAPTER 5 Supercharging the Engines 68
CHAPTER 6 Protecting the Core Genes 91
CHAPTER 7 Cell Mates 108
CHAPTER 8 Supersizing in Wonderland 124
CHAPTER 9 The Fragile Species 145
CHAPTER 10 The Tinkerers 161
CHAPTER 11 Microbes on Mars and
Butterflies on Venus? 173
Further Readings 187
Index 191
Acknowledgments
I had been thinking about this book for some time and wrote it in fits and
starts over a period of almost two years. The core ideas were developed
as an outgrowth of a course I teach every year at Rutgers, History of the
Earth Systems, but I didn’t want to write another textbook. I wanted to
reach a wider readership and to help elucidate what we know, and per-
haps more important, what we don’t know, about the role of microbes in
making Earth a habitable planet. The lion’s share of the work was done
while I was on sabbatical at the Radcliffe Institute for Advanced Studies
at Harvard University. I am extremely grateful to my hosts at the insti-
tute and my fellow Fellows for reading and commenting on the first few
chapters. I especially thank Ray Jayawardhana (Ray Jay), Tamar Schapiro,
Benny Shilo, and Alessandra Buonanno for helping me in the early days.
I am indebted to my friend and colleague, Andy Knoll, at Harvard, for
encouraging and critiquing my early chapters and for many discussions
while I was in Cambridge, Massachusetts. I thank my late friend, Toshiro
Saino, who invited me to give a series of lectures at Nagoya University
in 2006. Early on, the lectures in Japan helped me focus on structuring
this book. Conversations with many people over the years helped me
shape my ideas about the role of microbes in the origins of life on this
planet. I thank Tom Fenchel and Ed Delong for collaborating with me
on a paper describing the role of microbes in maintaining biogeochemical
cycles; the basis of that paper was critical in helping me develop several
chapters in this book. The late Lynn Margulis was extremely supportive,
and we had many discussions over dinner about symbioses. Joe Kirschvink
and Minik Rosing helped me understand what tales very old rocks can
tell. Many people were extremely helpful in reading chapters and giving
constructive comments; I am especially grateful to Sam Elworthy while
