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The Discovery of Earth's Earliest Fossils
J. W I L L I A M S C H O P F
Princeton University Press, Princeton, New Jersey
NORTH CENTRAL REGIONAL LIBRARY Headquarters Weaatchee WA
Copyright © 1999 by Princeton University Press Published by Princeton University Press, 41 William Street, Princeton, New Jersey 08540 In the United Kingdom: Princeton University Press, Chichester, West Sussex All Rights Reserved Library
of Congress
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Schopf, J. William, 1 9 4 1 Cradle of life : the discovery of earth's earliest fossils / J. William Schopf. p. cm. Includes bibliographical references, (p. - ) and index. ISBN 0-691-00230-4 (cl: alk. paper) 1. Life—Origin. 2. Evolutionary paleobiology. 3. Paleontology—Precambrian. 4. Micropaleontology. I. Title. QH325.S384 576.8'3—dc21
1999 98-42443
This book has been composed in Times Roman The paper used in this publication meets the minimum requirements of ANSI/NISO Z39.48-1992 (R1997) {Permanence of Paper) http://pup.princeton.edu Printed in the United States of America 1 3 5 7 9
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8 6 4 2
To my teachers, from whom I learned and my students, who teach me still
Contents
Prologue Acknowledgments Chapter 1. Darwin's Dilemma Breakthrough to the Ancient Past The Nature of Geologic Time The "Schoolbook" History of Life Darwin's Dilemma Denouement
Chapter 2. Birth of a New Field of Science The Floodgates Crack Open Famous Figures Enter the Field A Youngster Joins the Fray The Floodgates Open Full Bore
Chapter 3. The Oldest Fossils and What They Mean "Trust but Verify" "Real World Problems" in the Search for Early Life Questions and Answers about the Oldest Records of Life The Oldest Fossils Known
Chapter 4. How Did Life Begin? The Basics of Biology The Universals of Life How Did Monomers of CHON Arise on the Lifeless Earth? Organic Monomers beyond the Earth How Did Monomers Become Linked into Polymers? From Monomers to Polymers toward Life
Chapter 5. Metabolic Memories of the Earliest Cells How Did Cells Begin? The Essentials of Life Life's Earliest Way to Make a Living Air and Light: A New Source of Glucose Why Do We Breathe Oxygen ? The Four-Stage Development of Modern Metabolism
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CONTENTS
Chapter 6. So Far, So Fast, So Early? How Old Is the Modern Ecosystem? When Did Life Begin How Did Evolution Proceed So Far, So Fast, So Early? Paleobiology: Fossils, Geology, and Geochemistry Isotopic Evidence of Ancient Metabolisms Paleobiology: Direct Evidence of Early Evolution
164 ?
Chapter 7. Stromatolites: Earth's First High-Rise Condos Nature Is Not Compartmentalized Stromatolites: Earth's First High-Rise Condos Stromatolites of the Geologic Past What Are Stromatolites Good For?
Chapter 8. Cyanobacteria: Earth's Oldest "Living Fossils"
164 166 168 169 173 181
183 183 184 195 201
209
Modes and Tempos in the Evolution of Life The Status Quo Evolution of Cyanobacteria Evolution's Most Successful Ecologic Generalists
209 215 231
Chapter 9. Cells Like Ours Arise at Last
236
Life Like Us Has Cells Like Ours DNA and Development: Keys to Eukaryotic Success How Old Are the Eukaryotes? Eukaryotes Perfect the Art of Cloning Sex: A New Lifestyle Brings Major Change The Wax and Wane of Precambrian Acritarchs Prelude to the Phanerozoic
236 237 240 243 246 252 259
Chapter 10. Solution to Darwin's Dilemma
264
The Adventure of Science Take-Home Lessons Solution to Darwin's Dilemma
264 269 269 EPILOGUE
EXTRAORDINARY CLAIMS! EXTRAORDINARY EVIDENCE?
Chapter 11. Fossils, Foibles, and Frauds (t
The Goal Is to Get It Right" "Man, a Witness of the Deluge " Beringer's