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Campbell Essential Biology, 6e (Simon/Dickey/Hogan/Reece)
Chapter 17 The Evolution of Animals
Chapter 17 Learning Outcomes
17 Biology and Society: The Discovery of the Hobbit People
17.1. Describe the fossil discoveries on the Indonesian island of Flores and relate the findings
to modern humans.
17.1 The Origins of Animal Diversity
17.2. Define what it means to be an animal, including structure and function of a body cavity,
and describe common aspects of animal development.
17.3. Summarize the likely causes and significance of the Cambrian explosion.
17.4. Within the context of animal phylogeny, compare the presence of true tissues and the
type of body symmetry found in each of the nine major animal phyla.
17.2 Major Invertebrate Phyla
17.5. Compare the body structure, lifestyles, and feeding strategies of the nine major animal
phyla, distinguishing between distinct subgroups of these phyla.
17.3 Vertebrate Evolution and Diversity
17.6. Describe four defining characteristics of the phylum Chordata and compare body
structure, lifestyles, and feeding strategies of four subgroups of Chordata.
17.7. Compare aquatic and terrestrial adaptations of amphibians, adaptations of reptiles to life
on land, and adaptations for flight found in birds.
17.8. Describe the characteristics common to all mammals, distinguishing between
monotremes, marsupials, and eutherian mammals.
17.4 The Human Ancestry
17.9. Compare the three main groups of primates, including adaptations for arboreal living.
17.10. Explain the misconceptions that (a) chimpanzees are our ancestors, (b) human evolution
is a ladder, and (c) human traits evolved together.
17.11. Compare the traits of the major hominin species and the relationships between them.
17.12. Describe the evolution and impact of our species as we spread across the world.
Global Learning Outcomes
1. Demonstrate an understanding of the principles of scientific inquiry.
2. Demonstrate the ability to think critically and employ critical-thinking skills.
3. Read and interpret models, graphs, and data.
4. Demonstrate the quantitative skills needed to succeed in biology.
5. Demonstrate an understanding of the impact of science on society.
6. Evaluate the credibility of scientific information from various sources.
7. Demonstrate the ability to make connections between concepts across biology.
8. Communicate effectively in writing.
9. Apply the scientific method to interpret information and draw conclusions.
17.1 Multiple Choice Questions
1) J. R. R. Tolkien is a famous author who wrote, among others, several books about the
adventures of a community of a humanoid (meaning resembling a human) race. The individuals
of this race are described by Tolkien as being “…between 2 and 4 feet (0.61-1.22 m) tall, the
average height being 3 feet 6 inches (1.07 m) … a fairly human figure.” This general description
characterizes the humanoids mostly closely resembling ________.
A) Homo sapiens
B) Homo floresiensis
C) mandrills
D) lemurs
2) Which of these is a defining characteristic of animals that distinguishes them from other
eukaryotes?
A) Animals are multicellular.
B) Animals ingest food.
C) Animals are heterotrophs.
D) Animals use photosynthesis.
3) The common ancestor of all animals is likely to have been a ________.
A) colonial, flagellated protist
B) colonial, ciliated protist
C) colonial, flagellated bacterium
D) sponge
4) Which of these exhibits radial symmetry?
A) butterfly
B) spoon
C) snowflake
D) shoe box
5) Humans are chordates. Which animal group is most closely related to chordates?
A) molluscs
B) echinoderms
C) annelids
D) arthropods
6) How do sponges differ from all other animals?
A) Sponges exhibit radial symmetry.
B) Sponges are autotrophs.
C) Sponges lack a true body cavity.
D) Sponges lack true tissues.
7) What name is given to the food-trapping cells of sponges?
A) cnidocytes
B) amoebocytes
C) skeletal fibers
D) choanocytes
8) The mobile stage of the cnidarian life cycle is the ________ stage.
A) bilateral
B) polyp
C) tadpole
D) medusa
9) ________ are characterized by stinging cells used for defense and for capturing prey.
A) Annelids
B) Sponges
C) Cnidarians
D) Roundworms
10) A(n) ________ is an example of a mollusc that does not have a shell.
A) octopus
B) snail
C) spider
D) oyster
11) Which animals have a cylindrical body that is tapered at both ends?
A) platyhelminthes
B) cnidarians
C) annelids
D) roundworms
12) There are more species of ________ than of any other type of animal.
A) nematodes
B) molluscs
C) arthropods
D) chordates
13) A characteristic of arthropods that has allowed for their great success is the presence of
________.
A) bilateral symmetry
B) an endoskeleton
C) a brain
D) specialized segments
14) The arthropod skeleton is composed of ________.
A) cellulose
B) peptidoglycan
C) chitin
D) glycogen
15) Nearly all ________ are aquatic.
A) crustaceans
B) arachnids
C) flatworms
D) roundworms
16) ________ are the most diverse group of arthropods.
A) Insects
B) Millipedes
C) Arachnids
D) Crustaceans
17) What characteristic is unique to echinoderms?
A) a lack of segmentation
B) a water vascular system
C) radial symmetry
D) larvae with bilateral symmetry
18) You are given the task of confirming the categorization of a newly discovered animal that
has been tagged as a species of annelid. What evidence would convince you that it is indeed an
annelid and not a roundworm or flatworm?
A) an incomplete digestive tract
B) a highly branched gastrovascular cavity
C) parasitic feeding habits
D) body segmentation
19) You encounter an insect with small eyes, long sensory antennae, and a long mouthpart
shaped like a sword. What can you conclude about the environment in which it lives?
A) The environment is dark and has many plants.
B) The environment is wet and has many other insects.
C) The environment is hot and has many primates.
D) The environment is cool and has many reptiles.
20) You discover an organism that has scaly skin and is aquatic but returns to the land to
reproduce. What else would you expect to find in this organism?
A) asexual reproduction
B) amniotic egg
C) a water vascular system
D) radial symmetry
21) Unique features of vertebrates include the presence of a(n) ________.
A) endoskeleton
B) notochord
C) skull and a backbone
D) pharyngeal slit
22) Which of the following is a characteristic of all chordates?
A) They all have vertebral columns.
B) They all exhibit radial symmetry.
C) They all have a notochord sometime during their life cycle.
D) They all have an exoskeleton sometime during their life cycle.
23) A(n) ________ is an example of a chordate that is not a vertebrate.
A) lancelet
B) echinoderm
C) bird
D) fish
24) Among vertebrates, the unique feature of lampreys and hagfish is the ________.
A) presence of a cartilaginous skeleton
B) absence of a backbone
C) absence of jaws
D) absence of a postanal tail
25) Rays are a type of ________.
A) tunicate
B) cartilaginous fish
C) jawless fish
D) bony fish
26) Swim bladders ________.
A) contain the gills
B) are required for fish to exchange gases with the surrounding water
C) are present in both bony and cartilaginous fishes
D) help bony fish maintain buoyancy
27) Which group of fishes includes a lineage that migrated out of fresh water and adapted to life
on land?
A) ray-finned fishes
B) jawless fishes
C) lobe-finned fishes
D) cartilaginous fishes
28) What does the term “tetrapod” mean?
A) egg-laying
B) living on land
C) living a double life
D) having four feet
29) A feature that freed reptiles from dependence on water for reproduction is ________.
A) parental care of eggs
B) ectothermy
C) metamorphosis
D) the amniotic egg
30) A characteristic that is shared by snakes and birds is ________.
A) being ectothermic
B) the presence of only a single ovary in females
C) the amniotic egg
D) being endothermic
31) Almost every element of bird anatomy is modified for what?
A) laying eggs
B) eating seeds
C) enhancement of flight
D) singing unique songs
32) A feature unique to mammals includes ________.
A) the presence of hair
B) extended parental care of the young
C) being endotherms
D) having no egg-laying members
33) ________ are the mammalian group that lays eggs.
A) Eutherians
B) Tunicates
C) Monotremes
D) Marsupials
34) All chordates have ________.
A) a dorsal, hollow nerve cord and a notochord
B) a postanal tail and a single opening for the mouth and anus
C) a cranium and vertebrae
D) pharyngeal slits and a cranium
35) The lancelet is a(n) ________.
A) annelid
B) flatworm
C) chordate
D) tunicate
36) The platypus is a ________.
A) bird
B) marsupial
C) eutherian
D) monotreme
37) While on an archaeology expedition, you unearth a skeleton with the following
characteristics: four long, slender finger bones and a smaller opposable thumb bone, long arm
bones, fingernails, and eye sockets close together on a skull. What type of organism do you
suspect you may have found?
A) an anthropoid
B) a tarsier
C) a crustacean
D) a marsupial
38) At a natural history museum, you see a skeleton with the following characteristics: four long,
slender finger bones and a smaller opposable thumb bone, and larger feet with long toes. In what
type of environment would you expect this organism to have lived?
A) one that lacks vegetation
B) one that is very cold
C) one that is very dry
D) one that is heavily forested
39) How do New World monkeys differ from Old World monkeys?
A) New World monkeys have a prehensile tail.
B) New World monkeys have enhanced depth perception.
C) Old World monkeys are arboreal.
D) Old World monkeys have claws.