CHAPTER 34: VERTEBRATE EVOLUTION AND DIVERSITY
INVERTEBRATE CORDATES AND THE ORGIN OF VERTEBRATES
I.
FOUR ANATOMICAL FEATURES CHARACTERIZE THE PHYLUM CHORDATA
A. Notochord–
B. Dorsal, Hollow Nerve Cord
C. Pharyngeal Slits
D. Muscular Postanal Tail
II.
INVERTEBRATE CHORDATES PROVIDE CLUES TO THE ORIGIN OF VERTEBRATES
A. Subphylum Urochordata–
tunicates(sea squirts)– cellulose-like–
B. Subphylum Cephalochordata– lancelets– somites–
C. The Relationship Between Invertebrate Chordates and Vertebrates– paedogenesis–
III.
NEURAL CREST, PRONOUNCED CEPHALIZATION, A VERTEBRAL COLUMN, AND A CLOSED
CIRCULATORY SYSTEM CHARACTERIZE SUBPHYLUM VERTEBRATA
A. Greater Cephalization–
B. Cranium and Vertebral Column Replaced the Notochord as the Main Axis of the Vertebrate
Body– neural crest–
C. Vertebrate Adaptations Support the Greater Metabolic Demands of Increased Size and
Activity; closed circulatory system, improved respiratory system, improved feeding digestion
and absorption
IV.
AN OVERVIEW OF VERTEBRATE DIVERSITY
A. Gnathostomes
B. Tetrapods–
C. Amniotic Egg– amniotes–
V.
VI.
CLASS MYXINI: HAGFISHES ARE THE MOST PRIMITIVE LIVING “VERTEBRATES”
CLASS CEHPALASPIDOMORPHI: LAMPREYS PROVIDE CLUES TO THE EVOLUTION OF THE
VERTEBRAK COLUMN
SOME EXTINCT JAWLESS VERTEBRATES HAD OSSIFIED TEETH AND BONY ARMOR
ostracoderms–
conodonts–
VII.
INTRODUCTION TO THE VERTEBRATES
JAWLESS VERTEBRATES AGNATHANS
FISHES AND AMPHIBIANS
VIII. PLACODERMS WERE ARMORED FISHES WITH JAWS AND PAIRED FINS
IX.
VETEBRATE JAWS EVOLVED FROM SKELETAL SUPPORTS OF THE PHARYNGEAL SLITS
X.
CLASS CHONDRICHTHYES: SHARKS AND RAYS HAVE CARTILAGINOUS SKELETONS
A. Spiral Valve
B. Lateral Line System
C. Oviparous–
D. Ovoviviparous–
E. Viviparous–
cloaca–
XI.
OSTEICHTHYES: THE EXTANT CLASSES OF BONY FISHES ARE THE RAY-FINNED FISHES, THE
LOBE-FINNED FISHES, AND THE LUNGFISHES
A. Operculum–
B. Swim bladder–
Lungs–
C. Ray-Finned Fishes–
D. Lobe-Finned Fishes–
E. Lungfishes–
XII.
TETRAPODS EVOLVED FROM SPECIALIZED FISHES THAT INHABITED SHALLOW WATER
XIII. CLASS AMPHIBIA: SALAMANDERS, FROGS, AND CAECILIANS ARE THE THREE EXTANT
AMPHIBIAN ORDERS
A. General Characteristics
B. Reproduction–
AMNIOTES
XIV. EVOLUTION OF THE AMNIOTIC EGG EXPANDED THE SUCCESS OF VERTEBRATES ON LAND
A. Extraembryonic membranes
1. Amnion–
2. Allantois–
3. Chorion–
4. Yolk sac–
XV. VERTEBRATE SYSTEMATISTS ARE REEVALUATING THE CLASSIFICATION OF AMNIOTES
XVI. A REPTILIAN HERITAGE IS EVIDENT IN ALL AMNIOTES class Reptilia
A. Reptilian Characteristics
1.
2.
3.
4. Ectotherms–
B. The Origin and Evolutionary Radiation of Reptiles
1. Dinosaurs and Pterosaurs– endothermic–
2. The Cretaceous crisis
C. Modern Reptiles
XVII. BIRDS BEGAN AS FEATHERED REPTILES
A. Characteristics of Birds
1.
2.
3.
4.
5.
6.
B. The Origin of Birds– theropods– Archaeopteryx–
C. Modern Birds
XVIII. MAMMALS DIVERSIFIED EXTENSIVELY IN THE WAKE OF THE CRETACEOUS EXTINCTIONS
A. Mammalian Characteristics
Class Mammalia–
1.
2.
3.
4.
5.
6. Placenta–
B. The Evolution of Mammals
therapsids–
C. Monotremes–
D. Marsupials–
E. Eutherian (Placental) Mammals–
PRIMATES AND THE EVOLUTION OF Homo sapiens
XIX. PRIMATE EVOLUTION PROVIDES A CONTEXT FOR UNDERSTANDING HUMAN ORIGINS
A. Some General Primate Characteristics
opposable thumb
B. Modern Primates prosimians–
anthropoids–
XX.
HUMANITY IS ONE VERY YOUNG TWIG ON THE VERTEBRATE TREE Paleoanthropology–
Hominoid–
Hominid–
A. Some Common Misconceptions
B. Early Anthropoids: A Change of Environment
C. Some Major Features of Human Evolution
1. Brain Size2. Jaw Shape–
3. Bipedal Posture–
4. Reduced Size Difference
Between the Sexes
5. Some Key Changes in Family Structure
D. Australopithecines: Early Hominids and the Origin of Bipedal Posture
E. Homo: the Evolution of Larger Brains and the Global dispersion of Humans
1. Homo habilis
2. Homo erectus and Descendants
F. The Origin of Anatomically Modern Humans
1. Multiregional hypothesis
2. “Out of Africa” hypothesis or replacement hypothesis