Study Guide – Ch 36: The Evolution of Vertebrates
1
Section Review: In this section you learned that our best understanding of the evolutionary relationships
between vertebrate groups can be shown as a phylogenetic tree. In divergent evolution, related evolutionary
lines become more dissimilar as they are subjected to different forces of natural selection. Divergent evolution
is also known as adaptive radiation. In convergent evolution, evolutionary lines that are subjected to similar
forces of natural selection become more similar to one another as they evolve.
Ectotherms must obtain the heat they need from their environment. They typically rely primarily on behavior to
regulate their body temperature. Endotherms generate all the heat they need through metabolic activity. They
typically rely on physiological mechanisms to regulate their body temperature. They also use a number of
behaviors to prevent overheating.
Comparing Evolutionary Complexity: Finding the Main Ideas
Complete the chart:
Animal
Vertebrate Group
Three Other examples of Animals
in this Group
Amphibian
Toad, salamander, newt, etc
Mammal
Dog, cat horse, cow, human, etc.
Bird
Robin, gull, parrot, parkeet,
bluejay, etc
Reptile
Snake, lizard, turtle, tuatara, etc.
a.
b.
c.
d.
Study Guide – Ch 36: The Evolution of Vertebrates
Comparing Evolutionary Trends: Building Vocabulary Skills
2
The charge below lists tow general evolutionary trends. In the spaces provided, describe and give examples of
each trend.
Evolutionary Trend
Description
Examples
Ex. Ocelot (placental) and quoll
Adaptive radiation among
(marsupial) are both spooted
Convergent
different groups of organisms
catlike carnivores; flying squirrel
produce species that are similar in
(placental) and squirrel glider
appearance and behavior.
(marsupial) are both gliding
herbivores that live in trees;
groundhog (placental) and
wombat (marsupial) are both
stocky burrowing herbivores;
giant anteater (placental) and
numbat (marsupial) are both
adapted for feeding on ants and
termites.
Ex. Therapsids gave rise to
One species give rise to many
monotremes, placentals and
species that appear different
marsupials; thecodonts gave rise
externally but are similar
to crocodilians and birds; early
Divergent
internally.
jawed fishes gave rise to sharks,
rays and some bony fishes;
Darwin’s finches are all
descended from a single ancestral
species.
Concept Mapping:
Consider the concepts presented in Section 36-1 and how you would organize them into a concept map. Now
look at the concept map for Chapter 36 at the end of this package. Notice that the map has been started for you.
Add the key facts and concepts you fell are important for Section 36-1. When you have finished the chapter,
you will have a completed concept map.
Section 36-2: Form and Function in Vertebrates
Section Review: In this section you learned that as you move through the vertebrate classes from fishes to
mammals, organ systems tend to become increasingly complex. In more primitive vertebrates, the limbs stick
out from the sides of the body. In more advanced vertebrates, the limbs tend to be positioned directly beneath
the body.
The digestive systems of vertebrates are adapted to a number of different foods and methods of feeding.
Some vertebrates use gills for respiration; others use lungs. Lungs increase in efficiency as you move from
amphibians to reptiles to mammals. Birds have the most advanced respiratory system of all vertebrates.
Vertebrates that have a single-loop circulatory system also have a two-chambered heart. Double-loop
circulatory systems are associated with lungs. As vertebrates with lungs evolved, the separation of the two
loops of the circulatory system improved. Frogs and toads have a three-chambered heart. Most reptiles have a
three-chambered heart that has partial partition in the ventricle. Birds, mammals, and crocodiles have a four-
Study Guide – Ch 36: The Evolution of Vertebrates
chambered heart. Most fishes and aquatic amphibians excrete nitrogenous wastes in the form of ammonia.
Mammals and most cartilaginous fishes excrete urea. Birds and reptiles excrete uric acid.
As you move through the vertebrate classes from fishes to mammals, the relative size and complexity of the
cerebrum and cerebellum increase.
Primitive vertebrates tend to have external fertilization; more advanced vertebrates tend to have internal
fertilization. Vertebrates may be oviparous, ovoviviparous, or viviparous.
Identifying Internal Structures: Building Vocabulary Skills
The drawings below represent the digestive systems of different classes of vertebrates. Identify each of the
numbered parts in the spaces provided on the following page.
1. Esophagus
2. Crop
3. Stomach
4. Gizzard
5. Cecum
6. Intestine
7. Liver
8. Gall Bladder
9. Pancreas
10. Cloaca
11. Rectum
Comparing Vertebrate Characteristics
Using the following list of characteristics, fill in the chart below (on the next page).
Hops: has four legs
Has six legs; walks; flies
Lays soft-shelled eggs on land
Walks and runs on four legs
Insects, worms, berries, seeds
Small mollusks, worms, small crabs
Deserts; forests
Produces live young
Wooded or bushy areas
Crawls on belly
Pollen and nectar
Queen lays thousands of eggs
Lays eggs in water
Lizards, insects, small snakes,
Flies; walks on two legs
rodents
Swims using fins
Fields; flower gardens
Lays hard-shelled eggs in a nest
Ponds, marshes, streams
Rats, mice rabbits, squirrels
Trees
Salt water or fresh water
Lays eggs in water
Insects; spiders
3
Study Guide – Ch 36: The Evolution of Vertebrates
Animal
Movement
Hops: has four legs
Reproduction
Lays eggs in water
Food
Insects; spiders
Flies; walks on two
legs
Swims using fins
Lays hard-shelled
eggs in a nest
Lays eggs in water
Has six legs; walks;
flies
Crawls on belly
Queen lays
thousands of eggs
Lays soft-shelled
eggs on land
Insects, worms,
berries, seeds
Small mollusks,
worms, small crabs
Pollen and nectar
Walks and runs on
four legs
Produces live
young
Bullfrog
Blackbird
Flounder
Honeybee
Coral Snake
Red Fox
Lizards, insects,
small snakes,
rodents
Rats, Mice, rabbits,
squirrels
4
Habitat
Ponds, marshes,
streams
Trees
Salt water or fresh
water
Fields; flower
gardens
Deserts; forests
Wooded or bushy
areas
Analyzing Vertebrate Adaptations
Humans and other vertebrate land animals are adapted for living in air. Fishes are adapted for living in water.
Fill in the chart below by comparing the adaptations that enable land vertebrates and fishes to perform various
life processes.
Life Process
Getting Oxygen
Moving
Excretion
Internal Transport
Vertebrate Land Animals
Amphibians use gills, lungs, and
skin; reptiles, birds and mammals
use lungs
Fishes
Use gills; some gulp air into their
swim bladders
Limbs or wings (modified
forelimbs); legless amphibians
and reptiles slither and/or burrow
Nitrogenous wastes typically
converted to more concentrated,
less toxic forms such as urea and
uric acid
Double-loop circulatory system;
heart partially or completely
partitioned into three or four
chambers
Use fins and/or wavelike
movements of the body
Nitrogenous wastes can be
excreted as ammonia because it is
easily diluted and carried away by
the surrounding water.
Single-loop circulatory system;
heart with two chambers
1. Explain why fishes need to be more streamlined than land animals.
Fishes need to be
streamlined in order to move quickly and easily through the water. Land animals moving through air
do not need this adaptation.
2. Fishes are covered with a slimy material that is produced by glands in the skin. Suggest a reason for this
covering.
This slimy covering helps to waterproof the fishes and allows them to escape from
predators more easily.
Study Guide – Ch 36: The Evolution of Vertebrates
5
3. When a puffer fish is approached by a predator, it puffs itself up, causing its spines to stick out from its body.
What land animals uses a similar form of protection?
Porcupines and spiny anteaters also use this form
of protection.
4. The moray eel is a fish that swims by wriggling its body. What land animal moves in a similar way?
Snakes move with a wriggling motion.
Identifying Internal Structures: Building Vocabulary Skills
The drawing below represents the reproductive systems of several classes of vertebrates. Identify each of the
numbered parts.
1. Testis
5. Sperm duct
2. Cloaca
6. Shell gland
3. Ovary
7. Urethra
4. Oviduct
8. Uterus
Concept Mapping:
Consider the concepts presented in Section 36-2 and how you would organize them into a concept map. Now
look at the concept map for Chapter 36 at the end of this package. Notice that the map has been started for you.
Add the key facts and concepts you fell are important for Section 36-2. When you have finished the chapter,
you will have a completed concept map.
Study Guide – Ch 36: The Evolution of Vertebrates
6