Evolution’s Witness: How Eyes Evolved

323 Pages·2012·14.325 MB·English

by  Ivan R. Schwab, Richard R. Dubielzig, Charles Schobert

Evolution’s Witness
Odontodactylus scyallurus
Mantis Shrimp
Image © James Brandt, MD
Evolution’s
Witness
How Eyes Evolved
Ivan R. Schwab
University of California, Davis
Histology by Richard Dubielzig, DVM, and Charles Schobert, DVM
Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW)
1
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Library of Congress Cataloging-in-Publication Data
Schwab, Ivan R.
Evolution’s witness : how eyes evolved / Ivan R. Schwab ; histology by
Richard Dubielzig, Charles Schobert.
p. cm.
Includes bibliographical references and index.
ISBN 978-0-19-536974-8 (hardback)
1. Eye—Evolution. 2. Adaptation (Biology). 3. Anatomy, Comparative.
4. Evolution (Biology) I. Title.
[DNLM: 1. Eye—anatomy & histology. 2. Adaptation, Biological.
3. Anatomy, Comparative. 4. Biological Evolution. 5. Vision,
Ocular--physiology. WW 101]
QP475.S374 2012
612.8’4—dc23 2011016413
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1 3 5 7 9 8 6 4 2
Printed in China
on acid-free paper
To all my students, who have taught me much
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CONTENTS
Foreword by Russell Fernald, PhD xi 3. Eukaryotes Organize and Metazoans Arise
Acknowledgments xiii Neoproterozoic Era 1000–543 million years ago,
Introduction xv Cryogenian Period 850–650 million years ago,
Ediacaran Period 650–543 million years ago 17
Multicellular Animals 17
Prologue: Molecular Genesis: Sensory Input 21
Hadean Eon 4600–3750 million years ago 3 Th e Eye and the Brain 21
1. Th e Age of First Cellular Life Metazoans and Th eir Eyes 24
Archean Eon 3750–2500 million years ago 5 4. Early Animals Prepare the Ground
Prokaryotes 5 Ediacaran Period 650–543 million years ago 25
Early Cells—Protobionts 5 A Major Genetic Step 27
First Life 5 Urbilateria 27
First Witness 6 Another Major Genetic Step 28
Th e Road to Cellular Success 8 Wormy Beginnings 28
Retinal (or Retinaldehyde, a form of Genetic Development of Eyes 29
Vitamin A) 8 Annelids 31
Photolyases and Cryptochromes 9 Mollusks Take the Stage 36
Sunlight and Blue Light 9 Kimberella quadrata and
Beginning to Organize 10 Acanthochiton communis 36
Genetic Machinery—Th e Toolkit 10 Small Shelly Fauna 37
Prokaryotic Gifts 10 5. Vision’s Big Bang Blazes the Trail
Further Organization 11 Early Paleozoic Era, Cambrian Explosion 543–490
2. Th e Age of Complex Cellular Life million years ago 38
Proterozoic Eon 2500–543 million years ago, Th e Burgess Shale 38
Cryogenian Period 850–650 million years ago, Invertebrates in Ascendancy 38
Ediacaran Period 650–543 million years ago 12 Th e First Eye 39
Inception of Eukaryotes 12 Trilobites 39
Nucleated Kleptomaniacs 12 More Invertebrates and Th eir Eyes Appear 43
Bridging the Gap to Metazoa 15 Specifi c Examples 43
vii
6. Th e Age of Arthropods Arthropods Come Ashore 109
A Major Phylum Begins: Paleozoic Era, Cambrian Th e Superposition Eye 109
Period 543–490 million years ago 50 Th e Apposition Eye 110
Compound Eye Development 50 12. Stealth, Speed, and Predation
Apposition Eye 51 Paleozoic Era, Devonian Period 415–362 million
Superposition Eye 56 years ago 114
Th e Crabs 61 Arachnida 114
7. Vertebrates Gain a Foothold 13. Th e Age of Tetrapods and Terrestrials
Paleozoic Era, Cambrian Vertebrate Animalia Comes Ashore . . . Paleozoic Era,
Period 543–490 million years ago 63 Late Devonian Period 385–362 million years ago 119
Phylum Chordata 63 Vertebrate Quest for Land 119
First True Vertebrate 65 Early Tetrapodian Eyes 121
Conodonts 65 Th e Challenge of a Terrestrial Environment 124
Building a Vertebrate Eye 66 Eyelids and the Lacrimal System 125
Tapetum 68 Extraocular Muscles 125
Why Color Vision? 69 Tear Glands 126
8. Shelly Fauna Rule the Seas Cornea and Lens 126
Paleozoic Era, Ordovician Retina and Vision 127
Period 490–445 million years ago 70 Neurologic Changes 128
Mollusca 70 Consolidation of the Assumption of Land 130
Bivalvia 70 14. Terrestrial Life Flourishes
Gastropoda 75 Paleozoic Era, Carboniferous Period
9. Th e Piscine Eye Develops 362–299 million years ago, Permian
Paleozoic Era, Silurian Period 299–251 million years ago 131
Period 445–415 million years ago 77 Vertebrates 131
Vertebrate Expansion 77 Synapsids and Th eir Eyes 131
Placoderms 77 Diapsids and Th eir Eyes 132
Elasmobranchs 81 Invertebrates of the Permian 133
10. Th e Piscine Eye Matures Permian Extinction 136
Paleozoic Era, Early Devonian 15. Reptiles Push the Ocular Envelope
Period 415–398 million years ago 85 Th e Age of Reptiles: Mesozoic Era,
Bony Fish Appear 85 Triassic Period 251–208 million
Anatomy of Piscine Eye 85 years ago 138
Th e Outer Coats of the Eye 85 Synapsids 138
Th e Lens 87 Sauropsids 138
Neurology and Optics 97 Anapsids 138
Habitat Expansion 100 Diapsids 139
Piscine Camoufl age 107 Th e Adnexa of the Reptilian Eye 139
11. Insects Arise to Fly Reptilian Eye 142
Paleozoic Era, Early Devonian Lepidosaurs 149
Period 415–398 million years ago 109 Archosaurs 151
viii Contents
16. March of the Archosaurs Nictitans 186
Mesozoic Era, Triassic Period 251–208 million Cornea 189
years ago, Jurassic Period 208–145 million Iris and Pupil 189
years ago 152 Accommodation 189
Archosaurs 152 Uvea: Choroid, Ciliary Body, and Iris 189
Th e Order Testudines Retina 190
(Turtles, Terrapins, and Tortoises) 152 Visual Processing 190
Crocodilians 156 Oil Droplets 192
Archosaurian Sisters 158 Macular Design 192
Ichthyosaurs 158 Single Fovea 193
17. Dinosaurs and Th eir Companions Infula 193
Mesozoic Era, Triassic Period 251–208 million Convexiclivate Fovea—Single Deep
years ago, Jurassic Period 208–145 million Fovea 194
years ago 161 Bifoveate Birds 194
Pterosaurs 161 Pecten 197
Dinosaurs 162 Neurologic Evolution 199
Sauropods 162 21. Pollinators Coevolve
Th eropods 162 Mesozoic Era, Cretaceous Period 145–65 million
18. Cephalopods Change Direction years ago; Cenozoic Era, Tertiary Period 65–2 million
Mesozoic Era, Jurassic years ago 202
Period 208–145 million years ago 164 Th e Earth in Bloom 202
Coleoids 164 A Bounty for Insects 202
Cephalopod Lens 164 Social Hymenoptera: Wasp, Bees,
Extraocular Muscles 164 Ants, and Sawfl ies 207
Coleoid Expansion 164 True Flies and a New Eye 211
19. Snakes Arise from the Ground Diptera 211
Mesozoic Era, Cretaceous Brachyceran Flies 212
Period 145–65 million years ago 172 22. Mammalia Diversifi es
Fossorial Lizards 172 Mesozoic Era, Cretaceous Period 145–65 million years
Recreating an Eye 172 ago; Cenozoic Era, Early to Mid-Tertiary Period
20. Th e Age of Birds—Th e Eye Taken to Great Heights 65–56 million years ago 216
Mesozoic Era, Cretaceous Period Mammals Th rive 216
145–65 million years ago; Cenozoic Era, Th e Descent of Color Vision 218
Tertiary Period 65–2 million years ago 176 Marsupials 221
Birds Arise 176 23. Th e Age of Mammals
Globe Morphology 177 Mesozoic Era, Late Cretaceous Period 100–65 million
Globose Globe 178 years ago; Cenozoic Era, Tertiary Period 65–1.8
Flattened Globe 178 million years ago, Quaternary
Tubular Eye 180 Period 1.8 million years ago 224
Orbital Size and Contents 184 Mammals Extend Th eir Dominance 224
Visual Fields 184 Placental Mammals 224
Eyelids 185 Primate Tuning of Color Vision 226
Contents ix