4 The Evolution of the Birds The Origin of Birds is Disputed Arboreal Monkeys were not Able to Develop Wings

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1 Contents 1 Introduction To the Reader Two Centuries of Ornithology An Impressive Contribution to Science The Preparation of the Plates Covering Specific Bird Traits The Molecular Determination of a Bird s Pattern A Succession of Molecular Events Leads to the Formation of a Bird Permanence of Characters in Inheritance and Development No Animal is Structurally or Physiologically Static Programmed Cell Death The Origin of Feathers is a Source of Controversy They Evolved in Dinosaurs Before Birds Appeared Fingers Evolved to Play the Piano The Idea of Purpose in Biological Thought The Biological Pattern of Birds is Written on their Feathers Feather Growth and Replacement are Highly Ordered The Regeneration of Feathers Occurs Periodically Being Dependent on Day Length and Hormone Activity Hormones Control the Size, Shape and Colour of Feathers Two Genes are Responsible for Feather Development Proteins and Other Molecules Decide Hierarchical Order in Feather Branching Chemistry and Physics of Colours The Location of Pigments in Feathers is Guided by Proteins and Other Molecules Sources of Figures The Occurrence of Conspicuous Feathers at Different Body Locations and Their Genetic Interdependence Two Long Feathers Emerging from the Tail A Bird Gets its Body Trait Whether it Likes it or Not DNA Follows its Own Atomic Evolution Two Long and Short Feathers Protruding from the Head Two Long Feathers Arising from the Wing Particular Feathers Which Appear in Other Body Regions Indicating a Common Molecular Event Feather Numbers Which are Multiples of Two Occur on Tail and Head The Occurrence of Fixed Numbers in Other Animals Sources of Figures vii

2 viii Contents 4 The Evolution of the Birds The Origin of Birds is Disputed Arboreal Monkeys were not Able to Develop Wings The Long Journey that Led to the Establishment of Chemical Periodicity From Chemical to Biological Periodicity The Periodicity of Flight Molecular Mechanisms that may be Responsible for Periodicity and the Emergence of Coherent Structures Genetic Analysis Discloses that the Same Genes are Involved in the Flight of Insects and Birds The Impossible Became Possible The Direct Production of Flies with Four Wings Wings in Birds may have Appeared Ready-Made and As A Surprise to the Animal Birds with Extra Wings Produced in the Laboratory Evolution was not Kind to the Birds Wings have no Prehensile Fingers, Jaws Lack Teeth and the Penis is Rare Evolution Created Serious Limitations in Birds A Sense of Frustration or of Amputation may have Remained in a Bird s Mind The Constant Replacement of Teeth in Vertebrates Actually there is Method in this Seeming Madness Most Bird Species Lack a Penis But in Flatworms this Organ is Highly Developed Sources of Figures The Bird Genome and the Molecular Determination of Wings, Legs and Beaks What is a Genome The Unity of the Chromosome Remains a Question Mark What was Revealed by Sequencing the Chicken Genome Humans and Birds are Genetically Similar Genome Sequencing of a Wild Bird Discloses That Song Behaviour is Dependent on RNA Expression in the Brain Comparison of Large and Small Chromosomes in Birds How to Obtain a Bird With Extra Wings and Legs Genes Interact With Specific Proteins Producing Normal Wings and Legs Whether Wings or Legs are Formed Depends on the Change in Position of a Protein Great Variation in Beak Morphology The Same Evolutionary Solution Occurred in Distant Islands and also on the Mainland How to Recreate Beak Evolution Proteins Shape the Beaks of Ducks and Finches Sources of Figures The Mental Ability of Birds Takes Many Forms Cognition and the Use of Tools Migration was a Highly Innovative Process that Demanded New Solutions Landmasses have Moved Across the Earth s Surface The Emergence of New Continents, Seas and Deserts Birds are Faced with Challenges The Earth s Magnetic Field is Under Constant Change The Night Sky, with its Stars, Tells the Birds their Latitude The Star Compass

3 Contents ix 6.7 The Physical Basis of the Magnetic Compass and the Evolution of Bird Migration One-Eyed Sleep in Ducks and Brain Activity Active Cooperation Among Birds Leads to Class Distinction To Cope with Water Refraction Birds are Obliged to Make Corrections Song Learning in Birds Depends on the Concentration of a Protein in their Brain and the Action of Hormones The Starling Owned by Mozart Whistled the Theme of his Concerto Sources of Figures How to Redesign the Body Pattern of an Organism A Sophisticated Genetic Technology Opened the Way Early Evidence on Drastic Structural Transformations Feet on the Head The Homeobox Genes Formation of Identical Organs at Different Body Locations Geneticists Transformed Curiosities into Valuable Developmental Keys Eight-Legged and Four-Winged Flies were Produced The Antenna to Leg Transformations Eyes Formed on Wings, Legs and Antennae The Unity of Body Construction Mouse Genes Produce Eyes in Flies The Importance of Eye Genes The Wing of the Fly and the Human Fingers are Controlled by the Same Proteins Feather Development is also Controlled by One of these Proteins Moving from Gene Constructs to Embryonic Development The Avian Molecular Clock The Formation of Stripes Already in the Embryo The Spacing of Feathers is Directed by a Protein Change of Gene Action During Development A Single Gene is Important but not Almighty Since an Antenna can Regenerate into a Leg Sources of Figures The Molecular Geometry What is Geometry? Mathematicians and Physicists Know that there is not One, but Several Geometries Euclidean and Non-Euclidean Geometries Molecular Geometry is Multidimensional Molecular Geometry is Dynamic and Ephemeral Yet it Persists Every Bird is a Lesson in Geometry Emblematic Birds and Crystals do not Lie The Uniqueness of the Avian Eye It Surpasses the Human Eye The Eye A Focus of the Bird s Body The Circularity of the Eye Rings Around the Eye Extend to the Whole Head Horizontal and Vertical Stripes that Cross the Eye are Accompanied by Others which Run Above and Below it The Circularity of the Crest and its Division into Three Distinct Sections Single, Double and Multiple Rings Around the Throat, Breast and Belly Throats, Breasts and Bellies with Stripes Following the Head-Tail Axis The Wing has a More Complex Circularity The Bands and Concentric Semicircles of the Tail Rump, Legs and Beak are also Part of the Body s Geometry... 94

4 x Contents 8.18 Surprisingly the Circularity Extends to the Whole Body in Single Birds The Body Pattern of Birds Condensed in a Geometric Disk The Geometric Disk Like any Figure of Geometry Represents a Simplification of Biological Reality What About the Intermediate Cases? Sources of Figures The Symmetry of Birds Emerges as the Expression of an Uninterrupted Atomic Order The Birds have Spoken The Avian Bilateral Symmetry and its Internal Asymmetry Nothing Essentially New Arose at the Biological Level The Uninterrupted Transfer of Symmetries from Elementary Particles to Humans DNA Knows Nothing about Symmetries and did not Seem to have been Able to Create Novel Ones Mineral Structures, which have no Genes, Produce the Same Ordered Patterns Found in Living Organisms The Final Pattern of a Living Organism Appears to Be Dependent on Atomic Processes Far Removed from the Genetic Code Pure Symmetries are Thought to have only Existed in the Very Beginning of the Universe Sources of Figures Order is Present at Every Level But is not Total The Genetic Code and the Translation Apparatus have Evolved in an Ordered Way The Chromosome Maintains its Original Information by a Series of Efficient Repair Mechanisms The Integrity of RNA is Maintained by the Elimination of Defective Molecules Correction and Repair of Proteins Hierarchical Determination of Molecular Transit in the Cell Nuclear Architecture Regulates Gene Expression Cell Division and Chromosome Movements are Orchestrated by Proteins The Unexpected Regular Arrangement of Chromosomes in the Sperm Previously Despised MicroRNAs and Proteins Coordinate Embryonic Morphogenesis Directed Mutations Advantageous to the Organism are no Longer Disputed Adaptation in Higher Organisms One of the Black Boxes of Genetics Order is Never Total Yet Errors are of Particular Configurations Deviating only Slightly from the Initial Canalization Without Atomic Order Any Molecular Edifice would have Collapsed Sources of Figures A Bird s Plumage is a Stage Curtain Hiding a Molecular Scenario An Overview A Closing Remark The Impact of Novel Technologies on Bird Studies

5 Contents xi 11.3 The Formation of Feathers and the Location of their Pigments are Molecularly Guided The Wing is an Organ that Re-Emerged Periodically in Evolution Similar Genes were Activated at Unexpected Times Extra Wings, Extra Legs and Extra Feathers Appear Ready-Made in Birds and Occur at Different Body Locations The Absence of Teeth in Birds Ought to have a Genetic Basis Teeth, Like Feathers, are Continuously Replaced in Most Vertebrates The Near Absence of Penis in Birds has an Evolutionary History Similar to that of the Wing Beak Morphogenesis and its Final Shape are Decided by Modulating Calcium Signals Bird Behaviour Depends on Genes and these are not Much Different from those of Humans The Eye Appears as a Master Organ Eyes can be Formed on Wings and Wings on Eyes References Author Index Subject Index

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