Evolution's Witness: How Eyes Evolved

ISBN : 9780195369748

Ivan R. Schwab
328 Pages
224 x 282 mm
Pub date
Jan 2012
Send mail

With predation and carnivory as catalysts, the first known eye appeared in a trilobite during the Cambrian explosion approximately 543 million years ago. This period was a crucible of evolution and teemed with anatomic creativity although the journey to formed vision actually began billions of years before that. The Cambrian period, however, spawned nearly all morphologic forms of the eye, followed by descent over hundreds of millions of years providing an unimaginable variety of eyes with at least ten different designs. Some eyes display spectacular creativity with mirror, scanning or telephoto optics. Some of these ocular designs are merely curiosities, while others offer the finest visual potential packed into a small space, limited only by the laws of diffraction or physiological optics. For example, some spiders developed tiny, well-formed eyes with scanning optics and three visual pigments; scallops have 40-100 eyes circling their mantle, each of which has mirror optics and contains two separate retinae per eye; deep ocean fish have eyes shaped like tubes containing yellow lenses to break camouflage; and some birds have vision five times better than ours; but this is only part of the story. Each animal alive today has an eye that fits is niche perfectly demonstrating the intimacy of the evolutionary process as no other organ could. The evolution of the eye is one of the best examples of Darwinian principles. Although few eyes fossilize in any significant manner, many details of this evolution are known and understood. From initial photoreception 3.75 billion years ago to early spatial recognition in the first cupped eyespot in Euglena to fully formed camera style eyes the size of beach balls in ichthyosaurs, animals have processed light to compete and survive in their respective niches. It is evolution's greatest gift and its greatest triumph. This is the story of the evolution of the eye.


Table of Contents
Foreword: Russell Fernald PhD
Prologue: Molecular Genesis:
Hadean Eon 4600-3750 million years ago
1. The age of first cellular life
Archean Eon 3750-2500 million years ago
Early cells-protobionts
First life
First witness
The road to cellular success
Photolyases and cryptochromes
Sunlight and blue light
Beginning to organize
Genetic machinery-the toolkit
Prokaryotic gifts
Further organization
2. The age of complex cellular life
Proterozoic Eon 2500-543 million years ago
Cryogenian Period 580-650 million years ago
Ediacaran Period 650-543 million years ago
Inception of Eukaryotes
Nucleated Kleptomaniacs
Euglena gracilis
Bridging the Gap to Metozoa
3. Eukaryotes organize and metozoans arise
Neoproterozoic Era 1000-543 millions years ago
Cryogenian Period 850-650 million years ago
Ediacaran Period 650-543 million years ago
Multicellular animals
Sensory Input
The Eye and the Brain
Metazoans and their eyes
4. Early animals prepare the ground
Ediacaran Period 650-543 million years ago
A major genetic step
Another major genetic step
Wormy beginnings
Genetic development of eyes
Mollusks take the stage
Kimberella quadrata
Acanthochiton communis
Small Shelly Fauna
5. Vision's big bang blazes the trail
Early Paleozoic Era, Cambrian Explosion 543-490 million years ago
The Burgess Shale
Invertebrates in ascendancy
The first eye
More invertebrates and their eyes appear
Specific examples
6. The age of Arthropods
A major phylum begins: Paleozoic era, Cambrian Period 534-490 million years ago
Compound Eye Development
Apposition Eye
The Crabs
7. Vertebrates Gain a Foothold
Paleozoic Era, Cambrian Period
543-490 million years ago
Phylum Chordata
First true vertebrates
Building a vertebrate eye
Why Color vision?
8. Shelly fauna rule the sea
Paleozoic Era
490-445 million years ago
9. The piscine eye develops
445-415 million years ago
Vertebrate expansion
Elasmobranchs -
10.The piscine eye matures
Early Devonian Period
415-362 million years ago
Bony fish appear
Anatomy of Piscine eye
The outer coats of the eye
The Lens
Neurology and optics
Habitat expansion
Piscine camouflage
11. Insects arise to fly
Paleozoic Era
Early Devonian
415-398 million years ago
Arthropods come ashore
The Superposition Eye
The apposition eye
12. Stealth, Speed and Predation
Paleozoic Era
415-362 million years ago
13. The age of Tetrapods and Terrestrials
Late Devonian Period
385-362 million years ago,
Vertebrate Animalia comes ashore
Vertebrate quest for land
Early tetrapodian eyes
The challenge of a terrestrial environment
Eyelids and the lacrimal system
Extraocular muscles
Tear Glands
Cornea and lens
Retina and vision
Consolidation of the assumption of land
14.Terrestrial life flourishes
Carboniferous 362-299 million years ago
Permian 299-251 million years ago
Synapsids and their eyes
Diapsids and their eyes
Permian extinction
15. Reptiles push the ocular envelope
The age of reptiles
Mesozoic Era
251-208 million years ago
Adnexa of the reptilian eye
16. March of the Archosaurs
Mesozoic Era
251-208 million years ago
208-145 million years ago
The Order Testudines (turtles, terrapins, and tortoises)
Turtle Eye
Archosaurian sisters
17. Dinosaurs and their companions
Mesozoic Era
251-208 million years ago
208-145 million years ago
18. Cephalopods change direction
Mesozoic Era
208-145 million years ago
Cephalopod lens
Extraocular muscles
Coleoid Expansion
19. Snakes arise from the ground
Cretaceous (145-65million years ago)
Fossorial lizards
Recreating an eye
20. The Age of Birds - The eye is taken to great heights
Mesozoic Era
Cretaceous (145-65 million years ago)
Tertiary Period (65-2million years ago)
Birds arise
Globe morphology
Globose Globe
Flattened Globe
Tubular Eye
Orbital size and contents
Visual fields
Iris and pupil
Uvea: Choroid, ciliary body, iris
Visual Processing
Oil Droplets
Macular design
Area Centralis
Single fovea
Convexiclivate fovea-Single deep fovea
Bifovate retina
White-#ronted Bee Eater
Neurologic evolution
21. Pollinators Co-Evolve
Mesozoic and Cenozoic Eras
Jurassic 208-145 million years ago
Cretaceous 145-64 million years ago
Tertiary 65-2 million years ago
The Earth in bloom
A bounty for insects
Social Hymenoptera
Wasp, Bees, Ants, and Sawflies
True Flies and a new eye
Brachyceran flies
22. Mammalia diversifies
Mesozoic and Cenozoic Eras
Mid to late Jurassic 161 to 145 million years ago)
Cretaceous 145-65 million years ago
Early to mid Tertiary Period 65-56 million years ago)
Mammals thrive
The descent of color vision
23. The Age of Mammals
Mesozoic and Cenozoic Era
Late Cretaceous 100-65 million years ago
Tertiary 65-1.8 million years ago
Quaternary1.8 million years ago to present
Mammals extend their dominance
Placental Mammals
Primate tuning of color vision?
24. Planktonic soup evolves
Cenozoic Era
Tertiary 65 to1.8 million years ago
Quaternary 1.8 million years ago to present
Tiny aquatic Arthropods
Testing the limits of eye size
Transformation of larval eyes
25. Mammals return to the sea
Tertiary 65-1.8 million years ago
Quaternary 1.8 million years ago to present
Aquatic Mammals
26. The visual witness and a conscious brain
Cenozoic Era
Quaternary period 1.8 million years ago-present
The human eye
The direction of the visual witness
A The human eye-a camera style eye
B Extraocular muscles
Medial rectus
Superior oblique
Retractor bulbi
C Retinal Vascularization
Evolution of retinal vascularization
Mammalian forms of retinal vascularization
D Evolution of the cornea and ocular coats
Safeguarding precious contents
E Accommodation
F Crystalline lens
G Photoreceptor cells
H Neurologic evolution in birds
References by Chapter

About the author: 

Ivan R. Schwab M.D. is currently a professor at the University of California, Davis where he has worked as an Ophthalmologist for over twenty years, and was on the faculty at West Virginia University for seven years before coming to UCD. His strong interest in biology and natural history has led him to investigate a diverse range of topics including ocular stem cells, bioengineered tissues for the eye and comparative optics and physiology. He has published extensively in these fields, with three previous books to his credit, and he was the winner of the 2006 IgNobel for Ornithology. He has combined those interests with one in evolution to produce this text on the evolution of the eye.

The price listed on this page is the recommended retail price for Japan. When a discount is applied, the discounted price is indicated as “Discount price”. Prices are subject to change without notice.