Biology of the Vertebrates Study Questions F2010

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Note: These study questions are not comprehensive. They are meant to supplement your lecture notes as you review them, and alert you to the ways in which you should be thinking about the material, and formulate questions to test yourself. Exams will NOT be limited to the material highlighted in these questions, or their formats, so your lecture notes and handouts should be your primary reference.

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Lecture 1 (31 August 2010)

1. What are the reasons for studying a particular group of organisms such as vertebrates?

2. List the basic functions of living organisms. Provide a vertebrate example for each.

3. What is a mechanical constraint? Explain it in terms of one of the three examples (e.g., lizards, Darwin's finches, Hydromantes salamanders) discussed in lecture.

4. Why weren't the ancestors of lizards subject to the same constraint? How have some lizard relatives escaped from this constraint?


Lecture 2 (2 September 2010)

1. Hydromantes salamanders have a high performance, ballistic tongue. What two trade-offs have allowed for this?

2. What is a "monophyletic lineage"? Draw the vertebrate phylogeny and label all major monophyletic groups discussed in lecture.

3. Which major taxonomic group of vertebrates is the most speciose? The least?

4. What vertebrates belong in the monophyletic lineage Lepidosauria? Synapsida? Actinopterygii?

5. What are the five major deuterostome lineages? Provide a representative from each lineage.

6. Briefly discuss the controversy surrounding Xenoturbella. Most recent studies suggest this organism belongs in what taxonomic group?

*Please refer to the Pdficon small.gifPhylogeny Tutorial and Pdficon small.gifTree Quiz for additional help with phylogenetic trees*


Lecture 3 (7 September 2010)

1. Define the term "sister group". What is the sister group of chordates? What is the sister group of vertebrates?

2. Describe "lateral undulation". List three organisms discussed in today's (and past) lectures that use this form of locomotion.

3. What is a "homolog" and give an example.

4. List three key traits (features) found in chordates. Why are Urochordates (sea squirts, tunicates) considered to be chordates when they do not possess any of these features as adults?

5. Describe the feeding behaviors of amphioxus (subphylum Cephalochordata), tunicates (subphylum Urochordata), and hagfishes (subphylum Vertebrata, Myxinoidea). In what group do we see the beginning of a complex digestive system (i.e., midgut cecum)?

6. Describe the reproductive strategies of amphioxus (subphylum Cephalochordata), tunicates (subphylum Urochordata), and hagfishes (subphylum Vertebrata, Myxinoidea). Which of these lineages has the ability of reproduce clonally?

7. Describe the circulatory system of amphioxus (subphylum Cephalochordata), and tunicates (subphylum Urochordata). Which of these groups has a heart?

8. What is direct development? Which of the lineages discussed today consist of direct developers?

9. Why are the "teeth" of hagfish (Myxinoidea) not homologous (i.e., evolutionarily related structures) to the teeth of other vertebrate lineages, like sharks, bony fishes, and mammals? How do hagfishes have the ability to generate significant bite force despite lacking a jaw?

10. What are the two components of hagfish slime? What else do these two components mix with to generate huge amounts of slime?

Lecture 4 (9 September 2010)

1. What is a "synapomorphy"? List the chordate synapomorphies. Which of these are considered to be controversial chordate synapomorphies because similar structures are found in other non-chordate lineages?

2. Provide a brief description of what the probable morphology of the ancestral chordate was. What conclusions can be drawn about its life history and reproductive behavior, given what we know about extant (living) chordate lineages?

3. List three vertebrate synapomorphies. List two hagfish synapomorphies. Both hagfish and lampreys are similar in overall body size and shape (e.g., elongate, and without paired appendages). What are some key morphological/anatomical features that can be used to differentiate between these two organisms?

4. Describe the life history and reproductive behavior of the lamprey (Petromyzontoidea). In what ways does it differ from that of the hagfish (Myxinoidea)?

5. What is a "lateral line system"? In what extant vertebrate lineage do we first see a lateral line system?

6. What key features place the Cambrian fossil Haikouella in the vertebrate lineage? Where would you place it on the vertebrate phylogeny? What are two distinct traits seen in the Cambrian fossil Haikouichthyes (Myllokumingia) that are not seen in Haikouella?

7. What are "conodont fossils"? Why did it take so long to determine what they actually were (i.e., what organism they belonged to)? Where would you place conodont fossils on the vertebrate phylogeny?

Lecture 5 (14 September 2010)

1. What are the three mineralized tissue layers that compose the external skeleton (dermal armor) of jawless armored fishes? What are the hypothesized functions of the external skeleton? List the three major dermal armor derivatives.

2. Describe the mineral composition of each of the three types of fish scales. Provide an example of a type of fish that possesses each of these scale types. What are the advantages of having scales as opposed to body armor?

3. What are the differences between dermal bone, endochondrial bone, and perichondrial bone? What lineage is endochondrial bone a synapomorphy of?

4. In what lineages do we see both paired pectoral and pelvic fins? What is the ancestral function of possessing paired fins? Briefly describe the two theories of fin evolution.

5. The origin of jaws is seen in the ancestor to what lineages? What anatomical feature are jaws modified from? What is the ancestral function of jaws? What is the primary function of jaws in most extant gnathostome (jawed vertebrate) lineages?

6. In what geological period do researchers think placoderms reached their highest diversity? When do chondrichthyians first show up in the fossil record?

7. Name the two major groups within Chondrichthyes (cartilaginous fishes) and give an example of an animal that belongs to each lineage. List some unique features for each group. What are the chondrichthyian synapomorphies?

8. Why would it be advantageous to have a mineralized cartilaginous skeleton? What would be a disadvantage for possessing this type of skeleton?

9. Provide a brief description of reproduction in sharks. How can a female shark control parentage?

Lecture 6 (16 September 2010)

1. What is viviparity? In what vertebrate lineage do we first see viviparous organisms?

2. Elasmobranchs (sharks and rays) have a large diversity of tooth shapes. Describe two different two shapes seen in sharks and rays. What are the functions of each of these different tooth shapes? Briefly describe the jaw movement(s) in sharks.

3. Provide the who (which lineage), why (function), and how of the "Ampullae of Lorenzini"? Why is the Ampullae of Lorenzini thought to be responsible for the unique head shapes in chondichthyians?

4. Why are the largest species of sharks and rays (as well as largest species of mammals) filter feeders? What adaptations allow whale sharks, basking sharks, and manta rays to successfully filter feed on marine microinvertebrates?

5. Name four anatomical/morphological ways rays and skates differ from sharks. Of the elasmobranchs, which lineage (sharks or rays) is more diverse?

6. Provide the who (which lineage), where (what environment), why (ancestral function), and how (physiological function) of the "swim bladder".

Lecture 7 (21 September 2010)

1. List the synapomorphies of Osteichthyes (bony fishes). What two extant lineages belong in Osteichthyes? List the synapomorphies of Actinopterygii (ray-finned fishes).

2. What are the five groups of Actinopterygii? Which of these lineages is the most diverse and the least diverse? What is thought to be one possible explanation for the great diversity of Teleosts despite being evolutionarily "young" (<150 million years old)? List one Teleost synapomorphy.

3. What adaptations have allowed fishes such as the Viperfish, Anglerfish, and Sea Devil to live in the deep ocean? In what ways are Whalefish larvae different from adults and females different from males?

4. What are pharyngeal jaws? What is their function? What is unique about the pharyngeal jaws of the Moray Eel?

5. What is 'sequential hermaphroditism'? Describe 'protogyny' and 'protandry'? Under what circumstances would each most likely evolve? What are typically the limiting factors to the number of reproductive events in males and in females? Why do female Seahorses and Pipefishes compete for males?

Lecture 8 (23 September 2010)

1. What are the key morphological/anatomical characteristics that differentiate coelacanths (Actinistia) from Actinopterygians and other Sarcopterygians? Describe the reproduction of coelacanths. Although there are only two extant species, coelacanths have a very diverse fossil record. When was the first Actinistian fossil found?

Answer the following "who, what, when, where, why, how" questions for each of the following questions:

2. AESTIVATION
What is it?
Who (what lineage) discussed in today's lecture is it seen it?
When (in evolutionary time) is it first seen?
Where (geogaphically, season-wise, and habitat-wise) does it occur?
How does it work?
Why does this lineage aestivate?

3. INTERCRANIAL JOINT
What is it?
Who (what lineage) discussed in today's lecture is it seen it?
When (roughly in evolutionary time) is it first seen?
Where (anatomically) does it occur?
How does it work?
Why (what is the function)?

4. TIKTAALIK
What is it?
When (in evolutionary time)?
Where (geographically, and habitat-wise) was it found?
Why is it considered a transitional fossil between fish and tetrapods. List its fish characteristics and its tetrapod characteristics?

5. What are the synapomorphies for the following lineages? Sarcopterygii, Actinistia, Rhipidistia, Dipnoi, Tetrapoda?

6. Describe how a lungfish can facultatively switch between breathing aquatically and aerially?

7. Why is Ventastega thought to be more closely related to tetrapods than Tiktaalik? What key tetrapod trait is first seen in Acanthostega and Ichthyostega?

Lecture 9 (28 September 2010)

Material about the origin of tetrapods will be included on exam 1; Lissamphibian diversity will be covered on exam 2.

Answer the following "who, what, when, where, why, how" questions for each of the following questions:

1. ACANTHOSTEGA
What is it?
When (in evolutionary time)?
Where (geographically, and habitat-wise) was it found?
Why is it considered a transitional fossil between fish and tetrapods. List its fish characteristics and its tetrapod characteristics?

2. ICHTYOSTEGA
What is it?
When (in evolutionary time)?
Where (geographically, and habitat-wise) was it found?
Why is it considered a transitional fossil between fish and tetrapods. List its fish characteristics and its tetrapod characteristics?

3. ZYGAPOPHYSES
What is it?
When (in evolutionary time do we first observe these)?
Where (anatomically) is it found?
Why (what is its functon)?

4. Where on the vertebrate phylogeny do Tiktaalik, Ventastega, Acanthostega, and Ichthyostega map out? What is the debate surrounding Acanthostega and Ichthyostega? How does this change their placement on the vertebrate phylogeny?

5. List the three Lissamphibian lineages and provide an example of each. What does the Lissamphibia phylogeny look like?

6. What are the adaptations that allow caecilians to successfully live fossorially (underground)? Describe caecilian reproduction. Describe a unique caecilian reproductive/parental behavior that has only recently observed?

7. What morphological characteristics does Eocaecilia share with extant caecilians. What morphological characteristics differ between the two? What is the phylogenetic placement of Eocaecilia?

8. What is the geographic distribution of living caudates? Provide at least one salamander biodiversity hotspot. In what way are caudates (i.e., salamanders and newts) important to ecosystems?

9. How do salamanders communicate with one another? Please describe salamander reproduction (as seen in most lineages). Why is this considered indirect sperm transfer?

EXAM 1 (30 September 2010)



Lecture 10 (5 October 2010)

1. What are three possible explanations for the evolutionary and ecological success of Anura (~5858 species of frogs and toads, global distribution) relative to that of Caudata and Gymnophiona? Provide one example of how a frog has coped with the adverse conditions of a low-productivity (harsh) environment.

2. List the skeletal features of a frog that allows it to be a great jumper. How does the skeleton of Triadobatrachus differ from that of a modern frog? In what ways is it similar? What time period does Triadobatrachus date back to? When in geologic time was the split between anurans and their sister group, the caudates (from Lecture 9)?

3. Why are amphibians (specifically anurans and caudates) so important in the proper functioning of an ecosystem? Briefly comment on the feeding and diet of anurans (i.e., are they specialized feeders?)

4. What are the anatomical, physiological, and ecological changes a tadpole undergoes as it metamorphoses into a frog? Why is this transition considered more drastic in a tadpole, as opposed to a larval salamander?

5. What is the function of frog vocalization? What information does an advertisement call (vocalization) of a male frog convey? In addition to advertisement (or mating) calls, what other types of vocalizations do anurans have?

6. What type of fertilization do most anurans have? How does the male frog help ensure that his sperm fertilizes a female's eggs? What are 'nuptial pads' and how do they aid male frogs in reproduction?

7. What is 'direct development'? Why have many species of frogs (and salamanders) adopted this reproductive strategy? Provide six ways in which anurans provide parental care. Describe the unique reproductive mode of the gastric-brooding frog.

Lecture 11 (7 October 2010)

1. What is Gerobatrachus? When in geological time did it occur? Where does it fit on the amphibian phylogeny? Why (i.e., reasoning behind phylogenetic placement)?

2. What is a synapomorphy of Lissamphibia? What are at least three synapomorphies of Gymnophiona? Anura?

3. What are the two types of skin glands founds in all living amphibians? Please list the functions of each gland type. How have one of these gland types allowed for ~50% of all salamander species, 1 species of frog, and 2 species of caecilians to evolve lunglessness?

4. Please provide several examples of defensive behavior seen in amphibians.

5. List at least five explanations for amphibian declines. What is the primary explanation for loss of amphibian biodiversity? Where are some of the most devastating amphibian declines occurring in the world?

6. What is Bd/chytrid (Batrachochytrium dendrobatidis)? Who does is affect? Where (anatomically, ecologically, geographically) does it occur? How does it work as an infectious organism (i.e., explain complex life cycle)? What is one possible way to prevent or fight off a Bd infection?

7. Describe the plight of the Mountain Yellow-legged Frog from the Sierra Nevada Mountains of California, including two major causes of die-offs. What are some potential actions to remedy this in an attempt to help this endangered amphibian species recover?

Lecture 12 (12 October 2010)

1. What adaptations have amniotes evolved to lessen their dependence on water and become largely terrestrial? Describe the amniotic egg and the function of each of the three membranes. Who produces the shell of an egg? Who produces the amniotic membranes within an egg?

2. What are synapomorphies of each of the following lineages: amniotes, sauropsids, lepidosaurs (lizards, snakes, tuataras), and squamates (lizards, snakes)? Draw the amniote phylogeny.

3. What is tail autonomy? Who is it found in? How does it work? Why (what is the evolutionary/adaptive significance)?

4. What is TSD (temperature-dependent sex determination)? In what lineages discussed in today's lecture is it found in?

5. Compare and contrast the diversity, morphology, reproductive behavior, ecology, and geographical distribution of sphenodons (tuataras) to that of squamates (lizards, snakes).

Lecture 13 (14 October 2010)

1. What are the challenges of living in a desert environment? How do squamates cope with each of these challenges? In what ways are lizards able to thermoregulate? Provide at least two examples of convergent evolution, where two lizard species independently evolved similar adaptations which enabled desert living.

2. List the synapomorphies of snakes. Is the loss of hind limbs and reduction of pelvic girdle a snake synapomorphy? Provide support for your answer.

3. FORKED TONGUE
What is it?
Who (what lineages) do we see it in?
Why (what is its function)?
How does it work?

4. What are three feeding specializations (ways to eat) if you have a small head and a large body? In what ways does a snake skull allow for an increased gape?

5. There has been a reinvasion of snakes into a marine habitat. What are some adaptations that have enabled these snakes to live in the ocean?

Lecture 14 (19 Oct 2010)

1. What are the parts of a turtle shell? What is the shell composed of? In what ways is having a shell beneficial? How is it disadvantageous (not beneficial)?

2. Provide at least 6 turtle synapomorphies. Which of these synapomorphies is seen only in modern lineages of turtles? In what way do modern turtles differ from the 220 million year old fossil Proganochelys? What are the similarities between this fossil and modern turtles?

3. What are the two major lineages of turtles? What is the key morphological/anatomical difference between members of these two lineages?

4. Describe how turtles breathe, given the fact that their ribs are fused to their shell. Why is breathing in turtles more energetically expensive than other tetrapods?

5. How does morphology differ between turtles that are primarily terrestrial and those that spend most of their time in the water? Regardless of what type of habitat they live in, all female turtles must come on land to lay their eggs. Please comment on the reproductive behavior of turtles (e.g., egg laying behavior, presence or absence of parental care).

6. How is the sex of a turtle determined? What approximate temperature would guarantee all female turtle hatchlings and what are the implications of this in the face of global warming?

Lecture 15 (21 October 2010)

1. Describe five synapomorphies of the Archosauria. In what ways have these synapomorphies allowed archosaurs to be highly efficient and successful predators?

2. What is a synapomorphy of the Crurotarsi? Where are crocodilians located relative to dinosaurs on the phylogeny? Which EXTANT group is most closely related to crocodilians? Why aren't these two extant lineages considered sister groups?

3. Describe two crocodilian synapomorphies. What type of predator is a crocodilian? How have these synapomorphies allowed crocodilians to exploit this particular type of predatory strategy? What's unique about the skin of a crocodilian?

4. What are the three major lineages of crocodilians. Discuss a few major morphological and ecological characteristics of each these families.

5. What are some semi-aquatic adaptations of crocodilians? What is their ancestral condition (how do we know this)? Despite their semi-aquatic adaptations, crocodilians move very well on land. What morphological features allow for this?

6. How does the crocodilian heart differ from that of squamates? Briefly describe the shunting mechanism and its functional significance. In addition to the heart, what else enables crocodilians to stay submerged under water for long periods of time.

7. What do crocodilians and turtles have in common regarding their reproductive biology? How do they differ?

Lecture 16 (26 October 2010)

1. What lineage is sister to the Crurotarsi? What group is sister to pterosaurs?

2. If we know both birds and crocodilians build and defend nests, care for hatchlings, and have complex social behavior, what can we infer about the extinct lineages of Archosauria?

3. List the synapomorphies for the following clades: Ornithodira, Pterosauria, Dinosauria, and Ornithischia.

4. Describe some of the morphological characteristics related to flight, and collectively, their ecological implications. What is the first lineage of vertebrates that we see flight as a mode of locomotion? How were they flying (i.e., flapping or gliding)? What are the two main lineages of this group and how do they differ?

5. In what ways were pterosaurs morphologically and ecologically diverse?

6. What extant lineage needs to be included in order for Dinosauria to be considered a monophyletic grouping? What is the ancestral condition of Dinosauria, bipedalism or quadrupedalism?

7. What are the two major groups in Dinosauria? How does the pelvic arrangement differ between these groups? Which of these groups is the one leading to birds, and why are the common names of these groups misleading?

Lecture 17 (28 October 2010)

1. List six Ornithiscian synapomorphies. Give at least four examples of ornithiscian dinosaurs.

2. Comment on the diets of ornithiscians and saurischians. In what ways do you think diet has influenced their anatomy (i.e., think how the rib cage and pelvis orientation differs between these two lineages)?

3. What are the major saurischian synapomorphies? What are the two main groups within Saurischia? Which is the lineage leading to birds?

4. What are three major characteristics of Sauropodomorpha? Provide at least two examples of sauropodomorphs.

5. What is 'homeothermy'? Why would a smaller animal have a harder time staying warm or keeping cool compared to a large animal?

EXAM 2 (2 November 2010)


Lecture 18 (4 November 2010)

1. What fossil evidence provides support that saurischians had parental care in the form of nest building and attendance?

2. List the Theropoda synapomorphies. What are the three main lineages within Theropoda? Name a representative and distinctive characteristic of each group.

3. What is a synapomorphy of maniraptors? In what ways has this synapomorphy contributed to flight in modern birds?

4. What is Archaeopteryx? When was it discovered and what geological period does it date back to? How large was it? Why was the discovery of Archaeopteryx so significant? In what ways is Archaeopteryx similar to both dinosaurs and modern birds? In what ways does it differ from Aves (birds)?

5. Describe 'tridactyl foot' and 'digitigrade walking'? Why is it incorrect to say that the knee of modern birds points (and bends) backwards?

6. List three arguments that have been used to dispute a dinosaurian origin for birds. What types of evidence have been used to dispel these arguments?

7. What are some proposed reasons feathers evolved? What are the two proposed theories for the evolution of flight?

Lecture 19 (9 November 2010)

1. What came first, feathers, flight, or dinosaurs? Describe the evolutionary relationship between feathers and flight in birds.

2. Briefly describe each of the two traditional competing theories for how flight might have evolved in birds (also discussed in Lecture 18). Describe how wing-assisted incline running (WAIR) formulates an alternative hypothesis. What does WAIR specifically demonstrate?

3. Modern birds belong to which group of birds? When did most of the diversification of this lineage take place? When did the modern orders arise? The modern genera? How many described extant bird species are there?

4. Describe how some physical features of “modern birds” differ from some of their early predecessors.

5. Why are birds considered the most successful flying vertebrates? What has allowed for huge variations in beak shape and structure?

6. What are the three main groups of Neornithes? Which one has diversified most recently, and contains the larges number of species?

7. What kinds of “evolutionary commitments” influence avian mating systems? What are the two main types of social/mating systems exhibited by birds? Monogamy in most birds is not strictly “monogamous.” When is monogamy NOT monogamous?

Lecture 20 (11 November 2010)

1. What is the most important factor for dictating avian mating systems? Describe the differences between altricial vs. precocial offspring. How does precocial vs. altricial condition of offspring relate to the type of mating system exhibited by the parents?

2. What influences the form of polygamous mating systems? What factors underlie the differences between male & female interests in reproduction?

3. Why are males more likely to desert a reproductive alliance than females? What makes parental care such an important investment; i.e., what are the potential costs?

4. Briefly describe the polygamy threshold model. Conceptually, what does it represent? Is it better to be polygamous in a higher quality habitat, or monogamous in a lower quality habitat? Explain.

5. What limits clutch size (= number of eggs laid in a given reproductive bout) in birds?

6. Describe the characteristics of the cleidoic shell; i.e., what’s it made of, what functions does it serve, and what are the advantages and disadvantages? Describe some adaptive aspects of egg shape and color variability.

Lecture 21 (16 November 2010)

1. Why do females get to be so choosy about males and nest structures?

2. What’s the difference between a synapomorphy and a trend? Describe five important trends in the Synapsida? Which is the only surviving group of synapsids?

3. Describe four major features mammals have that are evident from the fossil record.

4. Define “anisognathy” and “diphyodonty”, and why they are important in the evolution of mammals. Briefly describe how nasal turbinates work, and how they relate to endothermy.

5. What were early mammals, such as Morganucodon ca. 200 MYA, like?

6. Describe two major mammalian synapomorphies. What are the major advantages of these traits?

7. What are the three major groups of extant mammals? What does the mammalian phylogeny look like?

8. How are monotremes typically distinguished from the other two? Is this a good way of characterizing a group?

9. What are the two major groups within Monotremata? Give examples of species and their major characteristics.


Lecture 22 (November 18, 2010)

1. Describe 5 major characteristics of marsupials. Where do they occur? Where are they most diverse? Give examples of some species and their characteristics.

2. Which major evolutionary feature characterizes Eutheria? How diverse is this group?

3. Eutheria is characterized by prolonged retention of offspring. Describe five main ways in which this is accomplished.

4. From which amniote membrane did the placenta arise? What exactly does the placenta do?

5. Describe some advantages and disadvantages of eutherian reproduction, particularly with regard to prolonged retention of young.

6. List and briefly describe three main groups of eutherians, in terms of their geographic distributions, level of diversity, important morphological, physiological, and/or behavioral attributes, and provide an example or two of each.


Lecture 23 (November 30, 2010)

1. Describe five important trends in the Synapsida? Why is using the term "mammal-like reptiles" to refer to synapsids wrong? Are “pelycosaurs” a type of dinosaur? Why or why not?

2. What is so unique about the jaw/jaw joint/ear in mammals? How do you think it evolved?

3. List six mammalian synapomorphies. In what ways has locomotion affected breathing in mammals (think of the cheetah example).

4. Describe Archonta in terms of their geographic distributions, level of diversity, important morphological, physiological, and/or behavioral attributes, and provide two exampes.

5. List the primate characteristics discussed in class. What are the two major primate lineages? Provide an example of a representative from each lineage. How do you tell monkeys apart from apes. What is the closest living relative to a human?

6. List four differences between the skeleton of Australopithecus afarensis ("Lucy") and Homo sapien. Provide three similarities.

Lecture 24 (December 2, 2010)

1. Who was Lucy? Describe some characteristics of australopithecines (particularly in terms of the feet and pelvis). How do they differ from extant apes and humans, and what are their evolutionary implications? Describe at least six characteristics of Homo neanderthalensis, in comparison to modern humans. How are they related to us?

2. Describe three major trends in primate skull evolution. Which of the following has the largest brain: Homo neanderthalis, Australopithecus afarensis, Chimpanzee, or Homo sapien? Explain the costs to brain enlargement.

3. Describe some characteristics of Carnivora, including diversity, distribution, a key synapomorphy, and examples of representative groups/ species. Why do cats have difficulty chewing?

4. Describe some characteristics of the Ungulata, including diversity, distribution, a key synapomorphy, and examples of representative groups/ species. What is the differences among plantigrade, digitigrade, and unguligrade foot postures, representative mammals possessing each type, and how they affect locomotion.

Lecture 25 (December 7, 2010)

1. List two major extinctions that have occurred at some point during the evolution of life on Earth. What were the consequences of each extinction (i.e., what percentage of species went extinct)? What is the significance of the Chicxulub Crater?

2. What is the single most important threat to vertebrate diversity? What are some other factors that have led to the decline and extinction of vertebrates? Comment on the destruction of wetlands over the past 200+ years. What happened to the passenger pigeon?

Lecture 26 (December 9, 2010)

1. Explain what evidence there is to suggest that humans are accelerating the rate of the current extinction event. What is the background extinction rate from the fossil record, and what is it from historic time?

2. How many species of each birds, mollusks, and plants have gone extinct in the past 400 years? What percentage of freshwater fish has either gone extinct or is endangered of extinction?

3. What is the controversy over climate change about, specifically? What do the skeptics say? How do we know that climate change is actually happening? What are some implications of a 1-3 degree C increase in global temperature?

4. What effect will climate change have on vertebrate habitat? What can animals do in response to these environmental changes?


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