Contents:

• Introduction, microevolution, macroevolution, systematics
• Origin and early evolution of the vertebrates
• The first vertebrate radiation -- the jawless fishes
• Origin of jawed fishes and radiation of Chondrichthyes
• Origin and radiation of Osteichthyes
• Comparative biology of fishes:
• basic physiological concepts
• gas exchange, lungs, swim bladders
• circulatory system
• sensory systems
• Origin and early radiations of the tetrapods
• Modern Amphibia
• Origin and early radiations of the amniotes
• Selected  reptiles
• turtles
• archosaurs 
• squamates
• Thermoregulation
• Birds
• Mammals
• Comprehensive material for the final

2. Name the seven "traditional" vertebrate classes and their major subgroups. Include equivalent names as appropriate. For each class, give the approximate number of species. What are gnathostomes, tetrapods, and amniotes? 

3. Define the terms "species", "population" and "gene flow".

4. Describe the process of natural selection, including Darwin's postulates. Illustrate your description with the example of peppered moths in England. Define all relevant terms (e.g., fitness, adaptation, etc.). 

5. Can natural selection create "perfect" organisms? Why or why not? Use examples as appropriate to justify your answer. 

6. What kinds of phenotypic effects can arise from relatively small genetic changes? What are the possible fitness consequences of those changes? 

7. Compare and contrast anagenesis and cladogenesis. 

8. Outline the process of allopatric speciation. What is an adaptive radiation? 

9. Define the terms "systematics", "taxonomy", and "classification." 

10. Compare and contrast evolutionary systematics and cladistics. On what basic points do members of the two "schools" agree? On what do they disagree? Can either be called "correct"? Why or why not? 

1. Who are the chordates? Give the characteristics that "define" the phylum and list the subphyla within the phylum. Who are the vertebrates? What characteristic(s) define(s) this group of chordates? 

2. Describe Garstang's hypothesis for the origin of the vertebrates. Include the proposed selection pressures that would have favored the changes he hypothesizes. 

3. When and where did vertebrates arise? 

4. Describe the current view on the origin of bone (including the fossil evidence). 

1. When (during what geologic time periods) did the first vertebrate radiation take place? What were general conditions like on earth at the time (climate, other kinds of organisms, etc.)? What general niche did the first jawless vertebrates apparently occupy (i.e., what did they eat, etc.)? 

2. Diagram the relationships among the major groups of jawless vertebrates and between the jawless vertebrates and the gnathostomes. To what groups does the name "ostracoderm" apply? Is this a monophyletic group? Defend your answer. Does the current traditional classification system accurately reflect evolutionary relationships within this group? Defend your answer. 

3. Describe the basic characteristics shared by the ostracoderms. Describe the basic characteristics and what we infer about the general ecology of early and late Pteraspida and Cephalaspida. 

4. Is the traditional order Cyclostomata a valid taxon according to cladistic philosophy? Why or why not? 

5. Compare and contrast the general characteristics of lampreys and hagfish, with special attention to the skeletal system, sensory structures, and gills. 

6. Compare and contrast lampreys and hagfish in terms of taxonomic diversity (i.e., approximate number of species and families) and general ecology (habitat, food habits, behavior). 

7. Describe the mucous system of hagfish (what is it, how does it work, what is its function?). 

8. Describe the complex life history (i.e., general stages from hatching to adult, including migrations and metamorphoses) of lampreys. 

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IV. The origin of jawed fishes; the radiation of Chondrichthyes

1. Discuss the timing of the origin of the jawed vertebrates. What were the three clades involved in the major radiations of jawed fishes, when did they live, and what were the evolutionary relationships among them? 

2. What kind(s) of evidence support our current hypotheses for the origins of jaws and pectoral girdles/limbs? 

3. Summarize the current hypothesis for the evolution of jaws from gill arches. Describe the arrangements of bones in the (hyostilic) jaws of Chondrichthyes and Osteichthyes. 

4. Describe the function(s)/benefits of jaws and fins (e.g., what "new" functions did they permit; what advantages did they provide). 

5. How many radiations have the Chondrichthyes undergone to date? Approximately when did each take place? When did modern forms first appear? When did modern genera first appear? 

6. Diagram the evolutionary relationships among the extant Chondrichthyes, with special attention to relationships among the elasmobranchs. 

7. Assume that you are a dedicated cladist. Explain why the older "traditional" classification of elasmobranchii is flawed. Then assume that you are a dedicated traditional systematist. Defend the older classification. 

8. Briefly describe the major characteristics of modern Chondrichthyes. Which of these is/are primitive and which derived for the group? 

9. Review the general features of sharks, skates, and rays as discussed in class and in your text. 

10. Review the main types of fish scales, including the name and types of materials found in each (from the handout). 

1. What is the nearest relative (sister group) to the Osteichthyes? When did this group appear in the fossil record? 

2. When did the first major radiation of Osteichthyes begin? How does this compare to the major radiations of other groups of fishes? 

3. When do early Neopterygii appear in the fossil record? When do the first teleost families appear? 

4. Describe the general characteristics that distinguish extant Osteichthyes from other extant fishes. What general trends have characterized the evolution of Osteichthyes? What kinds of changes in anatomy/physiology have been involved in those trends? 

5. Diagram the evolutionary relationships (1) among the Chondrichthyes, Actinopterygii, Sarcopterygii, and Tetrapoda; (2) among groups within the Sarcopterygii; and (3) among groups within the Actinopterygii. What features distinguish members of the Sarcopterygii from those of the Actinopterygii? 

6. Classify the members of the Osteichthyes using the scheme presented in lecture. Explain what the authors of your text mean when they refer to "plesiomorphic neopterygii" (i.e., to what groups do they refer, and what do they mean by using those terms). 

2. Define the term "homeostasis" and explain its relationship to metabolism. What kinds of factors are regulated as part of homeostasis? 

3. Outline the strategies vertebrates use for thermoregulation. For each, give a brief definition and discuss the relative "costs" and "benefits". Are these strategies mutually exclusive? Defend your answer using specific examples. 

4. Describe the basic physical properties of water and clearly explain their consequences for aquatic vertebrates (e.g., what kinds of "problems" and/or "benefits" do these properties produce?). 

Gas exchange, lungs, and swim bladders
1. What are the primary "problems" with water as a gas exchange medium? What are the general "solutions" to these? 

2. Compare and contrast tidal and unidirectional ventilation of water. What are the advantages of unidirectional ventilation? 

3. Compare and contrast gill structure and ventilation mechanisms among lampreys (adults and juveniles), Chondrichthyes, and Osteichthyes. Clearly relate structure to function. 

4. Describe the mechanics of oxygen uptake across the gills, with special attention to counter current exchange. 

5. Describe the variety of accessory respiratory structures (other than lungs) present in fishes. Describe the conditions under which anoxia might occur (so that such structures might be necessary). 

6. Describe the mechanics of ventilation in lung fishes, with attention to similarities and differences with (1) opercular pumping and (2) the ventilation mechanism we (mammals) use. 

7. Which came first, lungs or swim bladders? 

8. Describe the structure and function of swim bladders. Be sure to address (1) the conditions under which gas must be added/released and (2) the mechanisms used to do so. 

Circulatory systems
1. Describe the general pattern of blood flow through the body of fishes. How, in general, is this different from the circulatory pattern in mammals? 

2. Describe the potential advantages of regional heterothermy and the mechanism(s) used to accomplish it. Be sure to mention why fishes are generally poikilothermic. 

Sensory systems
1. Describe the conditions that might lead to a decrease in light availability in aquatic environments. 

2. Describe the modes of chemoreception common in fishes, including some of the functions of those modes (i.e., what kinds of "senses" do they have, and what are those senses used for?). 

3. Describe the structure and functions of the lateral line system. Include as many specific functions as possible. 

4. Explain why it "makes sense" for natural selection to have favored the evolution of electric sensitivity in aquatic vertebrates. Briefly compare and contrast passive and active electric reception and give specific examples of fishes using each modality. 

1. Describe the abiotic and biotic conditions of terrestrial and aquatic environments through the Devonian. Relate these conditions to the selection pressures that presumably favored the invasion of terrestrial habitats by vertebrates. 

2. Who are the nearest "fish" relatives of tetrapods (to what taxonomic group do they belong)? Describe the current views about the kinds of habitats these relatives inhabited and the characteristics that adapted them to those habitats (while "pre"-adapting them to life on land). 

3. Who were the earliest tetrapods (i.e., to what family do they belong)? What evidence suggests that these animals were at least semi-aquatic? 

4. Describe the major changes in the morphology of the head, vertebral column, limbs and girdles associated with the transition to terrestrial life. Explain how each of these changes enhances function on land. 

5. Describe the early radiation of tetrapods, including (1) the major groups involved; (2) the timing of key events; and (3) the ecological diversity exhibited by the "participants". 

1. Give the scientific names (including synonyms as appropriate), approximate taxonomic diversity, general distribution, and basic characteristics of the three major groups of modern amphibians. 

2. Briefly describe the fossil record for the modern amphibians and explain why the systematic relationships among the three major groups remain unresolved. 

3. For each of the general characteristics we discussed in class (egg, integument, inner ear, urinary bladder, lung, heart/circulatory system, thermoregulation): a) describe the structure, function, etc. of the characteristic as it appears in the modern Amphibia (in the detail covered in class); b) explain whether the characteristic as it appears in the modern Amphibia is underived for tetrapods, derived for tetrapods but ancestral for modern Amphibia, or derived for modern Amphibia; c) relate the structure, function, etc. of the characteristic to life on land in general and to the general ecology of amphibians as appropriate; d) discuss any structural/functional trade-offs and/or constraints imposed by the characteristic on amphibian morphology and/or ecology. 

4. Describe the basic life history pattern common (or at least ancestral) to modern amphibians. Describe paedomorphosis in salamanders, including the variation exhibited among species and among populations within species. Explain the correlation between life history pattern and ecological/environmental conditions (i.e., describe the pattern and offer an evolutionary explanation for it). 

5. Discuss modifications in anuran life history that reduce or eliminate reliance on water for reproduction.  With what conditions are these modifications generally associated? 

1. When did the amniotes first arise and radiate? Describe the important elements of the geology, climate, flora/fauna of the time, and relate those to the early amniote radiations. 

2. What group of organisms are the "intermediates between" anamniotes and amniotes? 

3. Describe the relationships among the major amniote groups, including the major extinct lineages commonly thought of as "dinosaurs." Are ichthyosaurs, plesiosaurs, pelycosaurs, and pterosaurs dinosaurs? Defend your answer. 

4. Give the traditional classification for the major amniote lineages. Give a cladistic defense of the proposition that mammals and birds should be included within the Class Reptilia. Give a traditional defense of the proposition that birds and mammals should constitute separate classes. 

5. Describe the "big picture" trends in early amniote evolution. Relate these to specific changes taking place in the egg, integument, limbs/girdles, head/neck, and respiratory and circulatory systems. Give examples of how these changes are interrelated. 

2. Briefly discuss the patterns of variation in general turtle morphology and relate these to variations in general ecology. 

3. Briefly explain the general structure and function of the heart and lungs in turtles. Describe the "alternative" mechanisms used by some turtles to exchange gases. In what kinds of turtles are these mechanisms found? 

4. Describe the pattern of temperature-dependent sex determination in turtles. Discuss the implications of this and other aspects of turtle reproduction for conservation efforts. 

5. List and briefly describe the major threats to sea turtle populations using information provided by the NMFS (see the Vertebrate Zoology home page on the WWW). 

Archosaurs
1.  When did true crocidilians first appear?  How many species currently survive?  list the families of modern crocodilians and describe the general distribution and habitat(s) of each. 

2.  What are the two groups of true dinosaurs?  Describe the structure and function of the hip in each, and escribe the kinds of novel forms made possible by modifications of the hips.  Give a brief overview of morphological and ecological diversity wihtin each group.  Which group includes the ancestors of birds? 

Squamates
1. When did the Squamata originate? List the three major lineages; for each, give the dates of the oldest fossils and a brief summary of taxonomic diversity. 

2. Defend the view that the term "lizard", as describing organisms distinct from snakes and amphisbaenians, is taxonomically meaningless and should be abandoned. Defend the view that the term "lizard" is useful and should be retained. 

3. Why do snakes exhibit relatively little morphological variation in spite of their ecological diversity? Describe the adaptations of sea snakes to their extreme aquatic habits. 

4. Describe the major hypotheses for the evolution of leglessness in snakes. What kind(s) of evidence support these hypotheses? 

5. How does the possession of a long, slender body potentially constrain body size and activity patterns? How (in general and in detail) do snakes "get around" this constraint? Describe the anatomical modifications that allow snakes to avoid suffocation while swallowing large prey items. 

6. Describe the advantages and disadvantages of constriction as a way of subduing prey. Describe the "Savitzky hypothesis" for the evolution of venom in the Colubroidea, including the relevant evidence that supports it. 

7. Describe the three general classes of snake venoms and the three general mechanisms snakes use to deliver venom, including the general taxonomic distribution of each. 

8. Describe the general body form you would expect to find (and why!) in (1) general terrestrial constrictors; (2) terrestrial snakes adapted for rapid locomotion; (3) highly derived arboreal snakes; and (4) snakes adapted for taking relatively large prey. 

9. Which two lizard families have the largest numbers of species? 

10. Give a brief (but accurate!) overview of lizard diversity, with attention to (1) body size; (2) habitat; (3) food habits; and (4) the presence/absence of leglessness. 

11. Describe the pattern of correlation between foraging mode and characteristics of behavior, predation, physiology, body form, and sociality in lizards. Be sure to explain the mechanisms (i.e., the "why" and "how") responsible for those correlations. 

1. List and describe the routes of energy exchange between organisms and the enviroment. For each route, explain whether the organism gains or loses heat (if both, explain the conditions for each) and describe the factors that regulate the rate of heat exchange. Which routes are particularly important for ectotherms? For endotherms? 

2. Define "active temperature range". List and describe the common behavioral and physiological mechanisms ecotherms use to keep their body temperatures within that range. 

3. Describe the relative costs and benefits of ectothermy in both general and specific terms, with attention to the underlying mechanisms responsible for each. 

4. Explain the consequences of ectothermy for terrestrial ecosystem function. Relate this to conservation of biodiversity. 

5. Describe the general costs and benefits of endothermy. List and describe the four main characteristics of mammalian/avian energetics. Which of these is the primary cause of the high cost of thermoregulation in these animals? 

6. Why do birds/mammals maintain relatively high body temperatures? What is our current explanation for why they maintain such high metabolic rates? 

7. Describe, in general terms, the consequences of their energetics on overall anatomy and physiology in birds and mammals. 

8. Describe and diagram the basic mechanisms of thermoregulation in birds and mammals, with special attention to the patterns of changes in body temperature and metabolic rate across a wide range of ambient temperatures. How would these patterns change with changes in insulation? 

9.  Discuss the current hypotheses for the origin of the energetic patterns in birds and in mammals. 

2. Briefly outline the three major radiations of birds, including when the radiations took place, what general groups were involved,  and the ecological correlates of each.

3. Describe the diversity and distribution of modern birds.

4. Discuss the general structure and functions of feathers.  Describe the differences in structure and function among contour feathers, down feathers, and filoplumes/bristles, being sure to relate differences in structure to differences in function.

5. Describe the adaptations of the musculoskeletal system of birds to flight.  Be sure to be able to identify components of the musculoskeletal system on a diagram such as the one used in class.

6. Discuss the respiratory system of birds.  Explain how and why this system provides more efficient gas exchange than is found in mammals.

7. Briefly outline the major features of the reproduction in birds.

8. Describe the constraints on body size in birds imposed by high metabolic rates and powered flight.  What is/was the largest bird that flies?  What is/was the largest bird?

9. Define aspect ratio and camber and explain how each of these features affects flight.  With what kinds of ecological habits are high and low aspect ratio wings associated?  High and low camber wings?

10. Describe variation in the hind limb and beaks of birds and relate that variation to differences in locomotion and food habits.

11. Briefly outline the sequence of changes that led to flight in birds, and to the improvement in flight seen in modern birds.  During which stages can we legitimately say that changes were associated with adaptations to flight, and during which are adaptations associated with functions other than flight (approximately)? 

12. Compare and contrast the “ground-up” and “trees-down” hypotheses for the origin of flight in birds.

1. To what amniote lineage to mammals belong?  Briefly outline the three major radiations in this group. 

2. Who are the synapsids, pelycosaurs, therapsids, and cynodonts?

3. With what general niche were trends in pre-mammalian evolution throughout the Mesozoic associated?  Describe those trends in general terms (i.e., what were the general results of the changes), then discuss the key changes in detail.

4. Discuss the evolution of the middle ear bones in mammals, including the two hypotheses for “why” it happened the way it did.

5. Who is the earliest “true mammal”, and how old is it?  What basic characteristics do we use to distinguish fossil mammals from their closest non-mammalian relatives?

6. Describe Blacburn’s hypothesis for the evolution of lactation and discuss the major selective benefits of lactation.

7. Briefly outline the three major radiations of “true mammals”.  With which of those radiations is the major diversification in form and function of mammals associated?

8. Describe the evolutionary relationships (and proper terms) among monotremes, marsupials, and placental mammals.  Briefly compare and contrast these groups.

1. Diagram the current hypothesis for the evolutionary relationships among the following groups of extant vertebrates: 

Cephalochordata, Myxinoidea, Petromyzontoidea, Chondrichthyes, Actinopterygii, Actinistia, Dipnoi, Gymnophiona, Anura, Urodela, Testudomorpha, Lepidosauria, Crocodilia, Aves, Mammalia 

2. On the diagram for #1, indicate which group(s) are included within the: "traditional" Agnatha, Gnathostomata, "traditional" Osteichthyes, "traditional" Sarcopterygii, Tetrapoda, Amniota, Diapsida, Synapsida, "traditional" Reptilia, modern Amphibia 

3. For the groups indicated in 1 and 2, state whether each of the following characteristics is primitive (ancestral) for the group, derived ("new") for the group, or not a characteristic of the group: 

pharyngeal slits; dorsal hollow nerve tube; notochord; postanal tail; bilateral symmetry; gill bars composed of a series of elements; jaws; cleidoic egg; bone; anamniote egg; opercular gills; paired fins with internall, medially arranged bones; lung/swim bladder derived from gut; limbs with 1 proximal and 2 distal bones; extra-embryonic membranes; skin modified for gas exchange; neck; robust rib cage; sacral vertebra(e); urinary bladder; epidermal (keratin) scales; buccal pulse lung; aspiration lung; completely subdivided ventricles; feathers; fur; mammary glands; endothermic homeothermy 

4. For each of the seven "traditional" vertebrate classes, give the (1) approximate time of its origin and (2) the approximate number of extant species it includes. Approximately how many species of animals currently exist on earth? 

5. Give one good vertebrate example (with explanation) of each of the following: 
a. a trait originally favored by selection for one "function" is used (and subsequently modified) for a novel function 
b. a new phenotyic trait opens "new" ecological niches; this results in an adaptive radiation 
c. a change in the external environment (biotic or abiotic) opens "new" ecological niches; this results in an adaptive radiation 
d. a change in the timing of development leads to novel phenotypes 
e. cladists and evolutionary ("traditional") systematists disagree on how to name and classify (group) a set of related taxa 
f. selection does not act on single traits in isolation (changes in one trait have effects on other traits) 
g. over time, evolution by natural selection leads to increasingly perfect organisms