CHAPTER 22—SPECIATION
MULTIPLE CHOICE
1. What mechanism seemed to separate the “birds of paradise” in New Guinea?
a.
chromosomal differences
b.
different mating rituals
c.
geographic isolation
d.
interference from humans
e.
mechanical differences between species
2. The habitats of “birds of paradise” in New Guinea are on mountains separated by
a.
areas of unsuitable land.
b.
fierce predators.
c.
man-made borders.
d.
the ocean.
e.
rivers and lakes.
3. Ernst Mayr, the scientist from the New Guinea study on “birds of paradise“, knew that the natives
understood speciation because they
a.
have a museum with many catalogued specimens.
b.
have individual names for many of the species.
c.
have many biologists in New Guinea that studied the speciation.
d.
helped to achieve the speciation.
e.
teach speciation theories in school.
4. An example of the morphological species concept would be achieved by
a.
doing a genetic analysis on the two organisms.
b.
looking at the appearance of two organisms.
c.
mating the two organisms to see if viable offspring result.
d.
observing the mating rituals of the two organisms.
e.
tracing the common ancestry of the two organisms.
5. The morphological approach to speciation is prone to misinterpretation. Which of the following is not
an example?
a.
male birds with strikingly different plumage than females
b.
a chihuahua and a great dane that do not look alike
c.
snails that resemble each other, but cannot mate
d.
snails of quite varied appearance that can all interbreed
e.
snails of quite similar appearance that are shown to be different species via reproductive
isolation
6. The biological species concept relies primarily on the ability of individuals within the species to
a.
adapt to the environment.
b.
have greater longevity.
c.
intermingle with other species.
d.
live in a variety of habitats.
e.
produce fertile offspring when mating with one another.
7. According to the biological species concept, members of the same species look alike primarily because
they
a.
live in the same environment
b.
experience gene flow, which mixes their genetic material
c.
have a common ancestor
d.
have stopped evolving
e.
are adapted to the same life style
8. The phylogenetic species concept looks at both the
a.
environmental adaptations and morphology.
b.
genetic data and environmental adaptations.
c.
morphology and environmental adaptations.
d.
morphology and genetic data.
e.
species response to adverse conditions and genetic data.
9. The concept for examining speciation by reconstructing the evolutionary tree is the
a.
biological species concept.
b.
examination of ring species.
c.
examination of clinal variation.
d.
morphological species concept.
e.
phylogenetic species concept.
10. A ring species is one where
a.
a clinal variation occurs.
b.
all of the various populations can successfully mate in nature.
c.
an area’s climate interferes with speciation.
d.
none of the various populations can successfully mate in nature.
e.
only intermediary populations can mate successfully.
11. Birds living in a cold environment tend to have
a.
long legs and larger bodies.
b.
long legs and smaller bodies.
c.
short legs and larger bodies.
d.
short legs and smaller bodies.
e.
the leg length and body size of birds does not relate to the environment.
12. In the biological species concept, it is specified that two organisms are of the same species if they
breed and
a.
are unsuccessful in producing offspring.
b.
produce any offspring.
c.
produce fertile offspring under laboratory conditions only.
d.
produce fertile offspring under normal circumstances.
e.
produce infertile offspring.
13. When geographic variation occurs among the members of a species, individuals
a.
may be mistaken for separate species.
b.
cannot mate successfully.
c.
cannot produce offspring with intermediate characteristics.
d.
may be absent in most locations.
e.
may be from different subpopulations
14. Gene flow between organisms of ring species occurs
a.
between any of the organisms if they are placed in the same environment.
b.
freely.
c.
never.
d.
only between intermediary populations.
e.
only under laboratory conditions.
15. In a clinal variation, the organisms may
a.
look identical.
b.
not have a normal lifespan.
c.
never be able to mate successfully.
d.
vary in appearance due to adaptations to different environments.
e.
vary in appearance due to human interference.
16. A smooth pattern of variation along a geographical gradient is referred to as a ____.
a.
ring species
b.
hybrid zone
c.
morphological species
d.
cline
e.
cluster of subspecies
17. When two organisms do not mate due to the fact that they mate at different times of the year, it is
known as ____.
a.
behavioral isolation
b.
ecological isolation
c.
gametic isolation
d.
mechanical isolation
e.
temporal isolation
18. An example of mechanical isolation would be
a.
flowers that bloom months apart.
b.
two organisms that are pollinated by different insects.
c.
two organisms that have different habitats.
d.
two organisms that have incompatible gametes.
e.
two organisms that have different mating rituals.
19. Which of the following combinations represent prezygotic mechanisms of isolation?
a.
hybrid breakdown and temporal isolation
b.
hybrid breakdown and gametic isolation
c.
hybrid sterility and temporal isolation
d.
mechanical and temporal isolation
e.
mechanical and hybrid breakdown
20. Postzygotic isolating mechanisms occur when the offspring
a.
survive to reproductive age.
b.
have vigorous health.
c.
inherit the same numbers of chromosomes from each parent.
d.
inherit different sets of instructions for development from each parent.
e.
have hybrid viability.
21. If the F2 generation illustrates a lack of fitness, this is an example of
a.
behavioral isolation.
b.
gametic isolation.
c.
hybrid breakdown.
d.
crossing over.
e.
hybrid sterility.
22. A mule is an example of
a.
hybrid breakdown.
b.
hybrid inviability.
c.
hybrid sterility.
d.
mechanical isolation.
e.
temporal isolation.
23. If an organism with 64 chromosomes mates with a closely related organism with 62 chromosomes, the
most likely result will be
a.
many unhealthy offspring due to hybrid breakdown.
b.
many unhealthy offspring due to hybrid inviability.
c.
no offspring due to hybrid sterility.
d.
sterile offspring due to hybrid inviability.
e.
sterile offspring due to hybrid sterility.
24. If two species of lizards do not mate because their mating rituals differ greatly, this is known as
a.
behavioral isolation.
b.
ecological isolation.
c.
gametic isolation.
d.
mechanical isolation.
e.
temporal isolation.
25. If one plant has a very small tubular type of flower and cannot be pollinated by a large honeybee, it
may develop which type of prezygotic isolation?
a.
behavioral isolation
b.
ecological isolation
c.
gametic isolation
d.
mechanical isolation
e.
temporal isolation
26. Some Drosophila reject the sperm of another species, which is known as
a.
gametic isolation.
b.
hybrid breakdown.
c.
hybrid inviability.
d.
mechanical isolation.
e.
temporal isolation.
27. Crocuses that bloom in the early spring and marigolds that bloom in the summer would definitely
experience which type of isolation?
a.
behavior
b.
ecological
c.
gametic
d.
temporal
e.
should not exhibit any type of isolation
28. Two species of flowering plants live together and flower at the same time. They do not hybridize
because they each have a unique pollinating insect. This is an example of a
a.
genetic bottleneck.
b.
sympatric speciation.
c.
hybrid zone.
d.
postzygotic barrier.
e.
prezygotic barrier.
29. The fact that eggs have the ability to recognize surface proteins on sperm of their own species
illustrates
a.
behavioral isolation.
b.
gametic isolation.
c.
hybrid breakdown.
d.
hybrid inviability.
e.
hybrid sterility.
30. What conclusions can be drawn from the studies on bent grass in a copper-polluted field and the
neighboring population in a non-polluted field?
a.
Flowers in the polluted field will not survive.
b.
The one population now requires copper to survive.
c.
They have different flowering schedules, so isolation may be developing.
d.
They have different types of gametes, so isolation has taken place.
e.
They show no differences.
31. If a flood separated a large population into two populations, this would be an example of which
process?
a.
allopatric speciation
b.
development of a host race
c.
parapatric speciation
d.
polyploidy
e.
sympatric speciation
32. What is the definition of a species cluster?
a.
a group of closely related species with a common ancestor
b.
a group of species that developed host races
c.
a group of species that exhibit polyploidy
d.
a group of totally unrelated species living in a common habitat
e.
when allopatric and parapatric speciation occur together
33. Polyploidy refers to ____ and occurs most often in ____.
a.
an individual getting one or more additional sets of chromosomes; plants
b.
an individual getting one or more additional sets of chromosomes; animals
c.
an individual lacking one or more sets of chromosomes; plants
d.
an individual lacking one or more sets of chromosomes; animals
e.
an individual lacking one or more sets of chromosomes and receiving additional sets of
other chromosomes; animals
34. What is a hybrid zone?
a.
an area where no hybrids exist
b.
an area where two populations may breed and produce inviable, fertile offspring
c.
an area where two populations may breed and produce inviable, infertile offspring
d.
an area where two populations may breed and produce viable, fertile offspring
e.
an area where two populations may breed and produce viable, infertile offspring
35. A sterile hybrid plant can form a fertile new species if its chromosomes are doubled. This is referred
to as
a.
allopatric speciation
b.
cladogenesis
c.
a hybrid zone
d.
anagenesis
e.
sympatric speciation
36. During allopatric speciation, the first event is usually
a.
geographic separation of two populations.
b.
a hybridization event.
c.
competitive exclusion.
d.
disruptive selection.
e.
a prezygotic reproductive barrier.
37. Abrupt genetic changes that quickly lead to the reproductive isolation of a group of individuals is
likely to lead to
a.
sympatric speciation.
b.
allopatric speciation.
c.
extinction.
d.
mutation.
e.
anagenesis.
38. If a hybrid organism has a shorter lifespan, which situation may result?
a.
allopatric speciation
b.
hybrid zones
c.
parapatric speciation
d.
species clusters
e.
sympatric speciation
39. A host race develops when an organism’s
a.
genes for the host plant choice change.
b.
genes for mating preferences change.
c.
geographical barriers exist.
d.
genes for the host plant choice change and genes for mating preferences change.
e.
genes for mating preferences change and geographical barriers exist.
40. Two host races of apple maggots have appeared within the past 100 years. This suggests that they may
be undergoing
a.
parapatric speciation.
b.
allopatric speciation.
c.
sympatric speciation.
d.
genetic drift.
e.
development of a hybrid zone.
41. Hawaiian fruit flies provide an example of which of the following?
a.
founder effects
b.
genetic drift
c.
adaptive radiation
d.
founder effects and genetic drift
e.
founder effects, genetic drift and adaptive radiation
42. If ____ mutation(s) occur(s) in snails, the direction of coiling may reverse, which ____ mating.
a.
1; encourages
b.
1; prohibits
c.
2; encourages
d.
2; prohibits
e.
3; encourages
43. The definition of allopolyploidy is
a.
a genetic divergence that results in nonviable offspring.
b.
a decrease in chromosome number due to hybridization of different species.
c.
a decrease in chromosome number within a single species.
d.
an increase in chromosome number due to hybridization of different species.
e.
an increase in chromosome number within a single species.
44. When a gamete receives the same number of chromosomes as a somatic cell,
a.
a reduced gamete is formed and allopolyploidy is present.
b.
a reduced gamete is formed and autopolyploidy is present.
c.
an unreduced gamete is formed and allopolyploidy is present.
d.
an unreduced gamete is formed and autopolyploidy is present.
e.
an unreduced gamete is formed and allopolyploidy and autopolyploidy are present.
45. A triploid organism is
a.
not viable.
b.
usually sterile because of improper chromosome segregation.
c.
usually sterile because of proper chromosome segregation.
d.
usually fertile because of improper chromosome segregation.
e.
usually fertile because of proper chromosome segregation.
46. Hybridization and polyploidy led to the evolution of
a.
mallard ducks.
b.
common bread wheat.
c.
apple maggots.
d.
bent grass.
e.
the great apes.
47. Polyploidy is a common mechanism of sympatric speciation in
a.
mammals in general.
b.
birds in general.
c.
rodents.
d.
plants.
e.
waterfowl.
48. An allopolyploid is
a.
a polyploid that arose from a hybrid individual.
b.
a species that arose parapatrically.
c.
an allopatrically arising species.
d.
a polyploid arising from a single diploid individual.
e.
any sympatrically arising species.
49. Polyploid individuals that arise from chromosome duplications within a single species are called
a.
allopolyploids.
b.
tetraploids.
c.
triploids.
d.
autopolyploids.
e.
sympatric polyploids.
50. From the studies on chromosome similarities, it looks as though humans are most closely related to
a.
apes.
b.
apes and gorillas.
c.
chimpanzees.
d.
gorillas.
e.
lemurs.
51. In the research on monkey-flower speciation, researchers found that mutations in as few as ____ genes
could result in speciation.
a.
2
b.
4
c.
8
d.
16
e.
25
52. If speciation occurs with the production of two or more species in a small area, ____ is (are) probably
responsible.
a.
both sympatric and parapatric speciation
b.
either sympatric or parapatric speciation
c.
neither sympatric or parapatric speciation
d.
only sympatric speciation
e.
only parapatric speciation
53. What avenues of research would probably not help determine if asexual organisms form species?
a.
determine if a cluster of bacteria constitutes a species
b.
explore various niches in which different populations reside
c.
look into previously undiscovered types of bacteria
d.
genomic research
e.
hybridizing polyploid plants
54. The morphological species concept would relate more to
a.
prezygotic isolation.
b.
postzygotic isolation.
c.
both prezygotic and postzygotic isolation
d.
neither prezygotic nor postzygotic isolation
e.
it would depend on the species used for the study
55. Some of the work with Hawaiian fruit flies illustrated the presence of a
a.
prezygotic isolating mechanism, which involved behavioral isolation.
b.
prezygotic isolating mechanism, which involved gametic isolation.
c.
prezygotic isolating mechanism, which involved temporal isolation.
d.
postzygotic isolating mechanism, which involved behavioral isolation.
e.
postzygotic isolating mechanism, which involved gametic isolation.
Select the Exception
56. All of the following are common polyploidy crops EXCEPT:
a.
broccoli
b.
coffee
c.
cotton
d.
potatoes
e.
wheat
57. Which of the following is NOT an example of a prezygotic isolating mechanism?
a.
An iris blooms at a different time of the year than a daffodil.
b.
A peacock puts on a different mating display than a sparrow.
c.
A snail with a shell coiling in one direction cannot mate with a snail whose shell curls the
other way.
d.
A zebroid is sterile.
e.
One type of roundworm would reject the sperm from another species of roundworm.
58. Which of the following categories of organisms is NOT known to produce viable polyploids?
a.
amphibians
b.
fish
c.
mammals
d.
fish
e.
reptiles
457
MATCHING
Match the appropriate definitions to the scientific terms:
a.
Allopolyploidy
b.
Allopatric speciation
c.
Autopolyploidy
d.
Behavioral isolation
e.
Biological species concept
f.
Hybrid breakdown
g.
Mechanical isolation
h.
Morphological species concept
i.
Parapatric speciation
j.
Polyploidy
k.
Subspecies
l.
Sympatric speciation
m.
Temporal isolation
59. reproductive isolation due to mating at different times of the year
60. determining different species by observing appearance
61. the second generation of the mating shows poor fitness
62. determining different species by checking to see if fertile offspring are produced
63. a “race“
64. closely related species form polyploidy offspring by hybridization
65. an error in mitosis or meiosis forms polyploidy offspring
66. an individual has extra copies of the haploid complement of chromosomes
67. reproductive isolation between subgroups of a single population
68. speciation occurs between adjacent populations
69. a physical barrier divides a population into separate areas, and speciation results
70. speciation occurs due to different mating rituals
71. there is a physical reason why the two organisms cannot mate, and speciation occurs
458
459
Labeling
Assign the following terms appropriately to the accompanying table by labeling with the appropriate
letter:
72. Behavioral isolation
73. Ecological isolation
74. Gametic isolation
75. Hybrid breakdown
76. Hybrid inviability
77. Hybrid sterility
78. Mechanical isolation
79. Temporal isolation
SHORT ANSWER
80. Based on the morphological species concept, why would you assume that there are many different
species of rat snakes?
81. How do animals show clinal variation?
82. Why is reproductive isolation central to the biological species concept?
83. Define a species cluster and provide examples.
84. How did researchers establish the connection between chimpanzees and humans?
OTHER
85. Place the following steps of allopatric speciation in their correct order:
A.
A flood causes a physical barrier down the middle of a population.
B.
A population covers a large area.
C.
The two separate populations evolve differently and form new species.
D.
When the water recedes, the two new species do not mate.
1.
first event
2.
second event
3.
third event
4.
fourth event
ANS:
1.
B
2.
A
3.
C
4.
D
MODIFIED TRUE/FALSE
If the statement is true, answer “T”. If the statement is false, answer “F” and make it correct by
changing the underlined word(s) and writing the correct word(s) in the answer blank(s).
86. Today evolutionary biologists view speciation as an event.
87. The biological species concept cannot be used to distinguish between species that are extant.
88. Individuals from different subspecies usually interbreed where their geographic distributions meet.
89. Unreduced gametes are those that contain additional chromosome numbers.
90. Polyploid plants are often unhealthy as compared to other plants.
91. The apple maggot was used as an example of allopatric speciation.
92. If two organisms cannot mate due to physical differences, it is known as temporal isolation.
93. Reinforcement enhances prezygotic isolation that had begun to develop while the populations were
sympatric.
94. Sympatric speciation often occurs in animals through polyploidy.
95. An example of a prezygotic isolating mechanism is behavioral isolation.
ESSAY
96. How is it that prezygotic isolating mechanisms can often be bypassed in human controlled breeding
experiments?
97. Do you feel that viruses show speciation, and do you consider viruses like the smallpox virus to be an
“endangered species”?