Biology 102 Chapter 4

Front 1

History of Vertebrates

Back 1

1. 540 million years ago first evidence of vertebrates

2. 540-360 million years restricted to the oceans

3. 360 million years: evolution of legs & feet ---> move to land ---> diversification (amphibians, reptiles, birds, mammals)

Front 2

Chordates (Domain Eukarya, Kingdom Animalia, Phylum Chordata)

Back 2

1. deuterostomes with 4 key features (present only during development or present during development & adulthood)

2. evolved from an ancestral deuterostome

3. sister group to chordates are the echinoderms

Front 3

Deuterostome

Back 3

animals with an anus derived from the blastopore

Front 4

Echinoderms

Back 4

1. sea stars, sea urchins, sand dollar, brittle stars, sea cucumber

2. tube feet and water vascular system

3. spines embedded in the dermis

Front 5

Chordate Characteristics

Back 5

1. notochords

2. dorsal, hollow nerve cord

3. pharyngeal slits

4. muscular post-anal tail

Front 6

Notochords

Back 6

longitudinal flexible rod located between the digestive tube & the nerve cord

Front 7

Dorsal, Hollow Nerve Cord

Back 7

develops into the central nervous system (CNS) in some chordates (brain ---> spinal cord)

Front 8

Pharyngeal Slits

Back 8

series of pouches separated by grooves along the pharynx (some gills, some only present during embryonic development, some only present in early development)

Front 9

Muscular Post-Anal Tail

Back 9

tail extending posterior to the anus

Front 10

Chordate Groups

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1. Cephalochordates (lancelets)

2. Urochordates (tunicates)

3. Craniates

Front 11

Cephalochordates (lancelets)

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1. invertebrates

2. marine filter feeders

3. retain all chordate features as adults

Front 12

Urochordates (tunicates)

Back 12

1. invertebrates

2. marine filter feeders

3. loose some chordate features as adults

Front 13

Craniates

Back 13

1. chordates that have a head: skull, brain, eyes, other sensory organs

2. hagfishes

Front 14

Hagfishes

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1. jawless marine craniates

2. not vertebrates

3. cartilaginous skull

4. axial rod of cartilage derived from the notochord

5. "slime eel"

Front 15

Vertebrae Classification

Back 15

1. craniates with a backbone

2. have vertebrae

3. 8/9 classes of vertebrates

Front 16

Vertebrae

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series of bones composing the vertebral column (backbone)

Front 17

Gnathostomes

Back 17

vertebrates with jaws

Front 18

Jaws

Back 18

hinged structures that grip food & slice food

Front 19

Osteichthyans

Back 19

1. bony (ossified) endoskeleton

2. no teeth (birds, many amphibians, turtles)

3. aquatic (ray-finned fishes [ex. striped bass]) & terrestrial (amphibians, reptiles, mammals, birds)

Front 20

Ossified

Back 20

has deposits of calcium phosphate

Front 21

Lobe-fins

Back 21

1. rod-shaped bones extending from the body surrounded by muscle

2. coelacanths (lobe-finned fish)

3. salamanders (lobe-finned tetrapod)

4. ancestors of tetrapods

Front 22

Tetrapods

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1. vertebrates with 4 feet (limbs) & associated appendages

2. much variability (frogs, cows, eagles, amphibians, reptiles, mammals, birds)

Front 23

Amniotes

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1. tetrapods with a terrestrially adopted egg or "amniote egg"

Front 24

Amniote Egg

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1. contains extra embryonic membranes that develop into tissue layers that grow out of embryo

2. functions in gas exchange, waste storage, and nutrient adaptions

2. terrestrial adaptions: shell, other membranes, strategy for survival & fitness for a life on land, do not have to rely on water for egg deposition

Front 25

Vertebrate Classes

Back 25

1. Lampreys

2. Chondrichthyes

3. Ray-finned fishes

4. Coelacanth

5. Lung fishes

6. Amphibia

7. Reptilia

8. Birds

9. Mammalia

Front 26

Lampreys (Petromyzontida)

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1. oldest living lineage of vertebrates

2. parasites of other vertebrates

3. jawless vertebrates

Front 27

Chondrichthyes (Chondrichthyans)

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1. "cartilage fish"

2. skeleton mostly of cartilage

3. ex) sharks, rays, chimeras (ratfish)

Front 28

Ray-Finned Fishes

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1. have fins supported by long, flexible rays (extensions of the endoskeleton)

2. rays support the fin & function as defense

3. most diverse group of fishes

4. diversity is threatened by habitat loss (overfishing)

Front 29

Coelacanth

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1. lobe-finned fish

2. few extant representatives

Front 30

Lung Fishes

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1. lungs or lung derivatives

Front 31

Amphibia (Amphibians) = "amphi": both

Back 31

1. moist skin used for gas exchange

2. lungs often present

3. biphasic life cycle: aquatic and terrestrial

4. reproductive strategy

Front 32

Reproductive Strategy of Amphibians Part 1

Back 32

Front 33

Reproductive Strategy of Amphibians Part 2

Back 33

Front 34

Major Amphibian Group Diversity

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1. frogs and toads

2. salamanders

3. caecilians

Front 35

Reptilia (Reptiles)

Back 35

1. body covered in scales (keratinized)

2. use lungs for gas exchange

3. shelled egg (amniote tetrapod)

4. reptile diversity (turtles, crocodilians, lizards, snakes)

Front 36

Birds (Aves)

Back 36

1. evolved from a small group of carnivorous dinosaurs (theropods)

2. common features (reptiles vs. birds): feathers are modified scales, scaled legs, shelled eggs

3. adaptions for flight: feathers, light skull, no bladder, small gonads, no teeth

Front 37

Bird Diversity

Back 37

1. water fowl

2. wading birds

3. chicken-like birds

4. passerines (warblers, sparrows, finches, vireos)

5. alcids (penguins)

6. gulls

Front 38

Mammalia (Mammals)

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1. amniotes

2. hair

3. mammary glands (produce milk)

Front 39

Primary Mammal Groups

Back 39

1. Monotremes

2. Marsupial

3. Eutherians (placental mammals)

Front 40

Monotremes

Back 40

1. small group of egg laying mammals

2. platypus & echidna

Front 41

Marsupial

Back 41

1. young begin embryonic development attached to a placenta in the uterus but completes development in a maternal pouch

2. opossums, kangaroo, koalas, sugar gliders

Front 42

Eutherians (Placental Mammals)

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1. have young that completes embryonic development attached to a placenta in the uterus

2. 18 orders: Sirenia (Manatee), Carnivora (Wolves), Rodentia (Squirrels), Primata (Chimps), Cetacea (Dolphins)

Front 43

Bioenergetic Strategies

Back 43

1. endothermic strategy: uses metabolic heat to maintain a fairly constant body temp (ex. mammals and birds)

2. endotherms: "inside or within" warm blooded animals

3.ectothermic strategy: rely on external sources of heat for maintaining body temp (ex. reptiles, amphibians, fishes, invertebrates)

4. ectotherms: "external or outside" cold blooded animals

Front 44

Influences on Metabolic Rate

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1. metabolic rate/gram of animal is inversely related to to body size among similar animals (endoderm vs. ectoderm)

2. one hypothesis

3. energy budgets

Front 45

Hypothesis

Back 45

1. for endotherms the smaller the animals, the greater the cost of keeping a stable internal temperature

2. the smaller the animal the greater the surface to volume ratio

3. fast loss of heat in cold weather

4. fast gain of heat in hot weather

Front 46

Energy Budgets

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1. basal metabolic rate

2. activity

3. temperature

4. growth

5. reproduction

Front 47

Internal Regulation

Back 47

1. homeostasis

2. modes of heat exchange

3. balancing heat gain & loss

Front 48

Homeostasis

Back 48

1. an animal's internal steady state

2. a balance between external change & internal controls

Front 49

Modes of Heat Exchange

Back 49

1. thermoregulations: the process by which animals maintain internal temps within a favorable range (thermoregulators)

2. conduction: heat transfer by direct contact

3. convection: indirect transfer of heat through convection currents

4. radiation: electromagnetic spectrum; specifically ultraviolet light

5. evaporation: evaporative cooling (property of water)

Front 50

Balancing Heat Gain & Loss

Back 50

1. behavioral adjustments: panting, bathing, sweating

2. physiological adjustments

3. insulation

4. countercurrent heat exchange

Front 51

Physiological Adjustments

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1. vasoconstriction: decrease in the diameter of blood vessels near the body surface "goosebumps" & warms the body

2. vasodilation: increases in the diameter of blood vessels near the surface to release heat & cool the body

Front 52

Insulation

Back 52

1. hair

2. fat

Front 53

Countercurrent Heat Exchange

Back 53

1. warms blood before it enters the body

2. warms appendages

Front 54

Torpor

Back 54

1. conserves energy during environmental extremes by decreasing metabolic rate

2. environmental extremes

3. hibernation (torpor in winter)

4. estivation

5. daily torpor (during sleep periods)

Front 55

Environmental Extremes

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1. hot weather

2. cold weather

3. drought

4. lack of food

Front 56

Estivation

Back 56

1. torpor in summer or drought

2. ex) siren (large salamander) burrows into mud when wetlands dry (completely aquatic salamander)

3. ex) easter spade foot toad