Evolution of the Eye From Algae and Jellyfish to Humans: How Vision Adapts to Environment

Author: Hudson, Arthur J.
This book offers a contextual analysis of the deviations and similarities in cross species eye structures. It questions the role of evolutionary processes such as random mutations, and genetic control mechanisms.


"Hudson writes about the eye biologically, not clinically, and he leads the reader through the great variations of eye structures found in the many phyla of the animal kingdom, from simple unicells through to the jellyfish and all the way to the exquisite compound eyes of the Arthropods and the simple but complex eyes of the Vertebrates. He has read widely starting with the classical works of Walls and of Duke-Elder, up to present-day Genetics with its enormous influences on many fields. Darwinian ideas of evolution solely affected by random mutations selected for survival have been widely accepted in the scientific world for a long time. Spontaneous mutations have long been exploited by breeders. Barbara McClintock working on maize demonstrated that there are ‘jumping genes’, now called transposons. And there is much else known about many features of genetics including gene-silencing and the diverging features of homozygous twins as they mature. Genes are not fixed in ‘stone’. Dr Hudson dwells very interestingly on ideas of how adaptive evolutionary changes can occur in responses to environmental stressors."
From the Foreword - Prof. Bessie Borwein, Associate Dean Medical Research, University of Western Ontario

"This is a book that will appeal to all students of the visual system from beginners to the most advanced. It is also a book that will be of great value to scientists studying one or another aspect of the eye in living things. Without question, it is the most up-to-date compendium on eye structure available today and researchers wishing to put their work in context with the wonderful world of vision will find its contents invaluable. This is a book that will last and in the years ahead one can expect that it will continue to add value both as a superb reference text and a “must read” for the average person interested in science and the eye."
Prof. Martin J. Hollenberg, Dean Emeritus of Medicine, The University of British Columbia

"[An] exceptionally well-researched and precisely written work by an accomplished academic neurologist... Readers from several related fields will value this unique work as a thorough and comprehensive source of information and insight into this extensive field."
Prof. Warren T. Blume, University of Western Ontario

"The book is valuable, in part because it gives a compact yet detailed survey of the varieties of eye design and also because culminates in the proposal of some thought-provoking hypotheses aimed at tying together the evolutionary history of vision. ... The book ultimately serves as a thoughtful, if cursory, overview of eye evolution, and Hudson deserves credit for filling the rather large gap in book-length treatments of eye evolution." -- Prof. Daniel Graham, Hobart and William Smith Colleges

Table of Contents



Chapter 1: The Beginning of Life on Earth

1. Darwin and Evolution of the Eye
2. Solar Energy as the Source of Life
3. Photosynthesis
4. Rhodopsin

Chapter 2: Eyespots and the Earliest Forms of the Eye
1. Euglena
2. Warnowiidae (Warnowiaceae)
3. Bryozoa

The Visual System of Bryozoa

Evolutionary Changes in Larval Bryozoan Eyespots
4. Concluding Remarks

Chapter 3: Aquatic Invertebrate Eyes
1. Jellyfish

Hydrozoan Jellyfish

Scyphozoa Jellyfish

Cubomedusan Jellyfish
2. Molluscs

Bivalves (Shellfish)

Gastropods (Snails)


Nautilus (Primitive Cephalopod)

Advanced Cephalopods (Octopus, Squid and Cuttlefish)

3. Worms

Platyhelminthes (Flatworms)

Nematoda (Roundworms)

Annelida (Segmented Worms)

Chapter 4: The Eyes of Insects (Hexapoda)
1. General Features of the Compound Eyes
2. The Parts of the Compound Eye
3. Refraction, Reflection and the Rhabdom as a Lightguide



Rhabdom Lightguide

Pigment Cells (Shading Pigments)

Color Filters

Nervous System
4. Simple Eyes

Dorsal Simple Eyes

Lateral Simple Eyes
5. Compound Eyes

Apposition Eyes

Simple Apposition Eye

Afocal Apposition Eye

Neural Superposition Eye

Superposition Eyes

Refracting Superposition

Reflecting Superposition

Parabolic Superposition
6. Possible Evolutionary Change to a Vertebrate Eye

Chapter 5: Crustacean Eyes
1. Nauplius Eye
2. Crustacean Compound Eyes

Chapter 6: The Eyes of Spiders
1. Net-casting Spiders
2. Jumping Spiders (Salticidae)

Side Eyes (AL and PL)

Principal Eyes (AM)

Chapter 7: Vertebrate Eyes
1. Molecular Properties of the Lens

Light Refraction by the Cornea and Lens

Multifocal Optics in Terrestrial Vertebrates
2. Photoreceptor Cells in the Retina
3. Rhodopsin and the Color Vision Opsins
4. Electrical Circuitry of the Retina

On-center and Off-center Organization of the Retina

Rod and Cone Cell Pathways to the Ganglion Cells
5. Protective Pigment Layers of the Retina 6. The Choroid
7. Ocular Design for Animal Needs

Chapter 8: The Eyes of Fish and Other Marine Vertebrates
1. Fish Eyes and the Water Environment

Variations in the Retinal Chromophore
2. Lampreys (Cyclostomes)
3. Sharks and Rays (Elasmobranchs)
4. Bony Fish (Teleostea)

Chapter 9: Eyes of Amphibia, Reptiles and Birds
1. Amphibia

Frogs and Toads (Anurans)

Salamanders (Urodeles)
2. Reptiles

Turtles (Chelonia)

Crocodiles and Alligators (Crocodilians)

Lizards (Lacertilia)

Snakes (Ophidia)
3. Birds

Chapter 10: Mammals
1. Monotreme and Marsupial Eyes


2. Placental Animal Eyes

General Features

The Human Eye
3. Development of the Eye: Larva versus Embryo

The Invertebrate (Insect) Eye

The Vertebrate (Mammalian) Eye

Similarities in Larval and Embryonic Development

Chapter 11: Genetic Control Mechanisms in the Evolution of the Eye
1. Directed or Adaptive Mutations

The Luria-Delbrück Hypothesis

The Cairns Hypothesis

F? Episome Mutagenesis

Opposition to the Directed Mutation Hypothesis
2. Epigenetics and Gene Silencing

Chromatin and DNA Interrelationship

Epigenetics and Its Influence on Memory
3. RNA-Directed Gene Silencing
4. Horizontal Transfer of Transposons

Chapter 12: Conclusions