Question 1

Which statements about the Lake Victoria cichlid fishes are true? Check all that apply.

Accepted Answer

A)  The adaptive radiation of the estimated 300 species of cichlid fish was very rapid and took place during the last 200,000 years.
B)  The adaptive radiation of the Lake Victoria cichlids may have resulted from a key evolutionary innovation.
C)  Speciation of the Lake Victoria cichlids was mainly sympatric.
D)  The diversity of the Lake Victoria cichlids continues today because the lake is devoid of predators.
E)  Many of the Lake Victoria cichlids have very specialized adaptations that allow them to occupy diverse habitats within the lake.F) A) and E)
G) All of the above

Question 2

The ________ model assumes that evolution occurs in spurts,between which there are long periods of stasis with little evolutionary change.

Accepted Answer

punctuated...

Question 3

Studies of snapping shrimp on either side of the Isthmus of Panama have shown that each Caribbean shrimp species is more closely related to a Pacific shrimp species than it is to any other Caribbean shrimp species.The most likely explanation for this result is

Accepted Answer

A)  snapping shrimp in the Caribbean and the Pacific were never part of the same population.
B)  snapping shrimp species in each ocean diverged prior to the formation of the Isthmus of Panama.
C)  snapping shrimp species in each ocean diverged after the formation of the Isthmus of Panama.
D)  creation of the Panama Canal allowed interbreeding between populations of shrimp.E) B) and C)
F) All of the above

Question 4

The model that assumes that evolution proceeds with slow successive change in a given evolutionary line is referred to as

Accepted Answer

A)  successive descent model.
B)  punctuated equilibrium.
C)  gradualism.
D)  the allopatric model.
E)  the sympatric model.F) B) and C)
G) A) and D)

Question 5

The most common mechanism for sympatric speciation in plants is

Accepted Answer

A)  polyploidy.
B)  geographic isolation.
C)  spontaneous mutation.
D)  punctuated equilibrium.
E)  disruptive selection.F) B) and D)
G) B) and C) A

Question 6

The sunflower species Helianthus anomalus is thought to have been formed by hybridization between the sunflower species H.petiolaris and H.annuus because it contains a set of chromosomes from both parental species.H.anomalus is most likely an example of instantaneous speciation through

Accepted Answer

A)  allopolyploidy.
B)  autopolyploidy.
C)  parthenogenesis.
D)  hybrid sterility.E) B) and D)
F) B) and C)

Question 7

Which is an example of temporal isolation?

Accepted Answer

A)  one plant species blooms in June-July and a second plant species blooms in August-September.
B)  one plant species is pollinated by bees and a second plant species is pollinated by moths.
C)  two plant species live on the same mountainside,but one lives on rocky outcrops and the other in open meadows.
D)  two plant species have incompatible gametes.E) None of the above
F) All of the above

Question 8

Adaptive radiation is best described as the

Accepted Answer

A)  existence of groups of closely related species recently evolved from a common ancestor.
B)  existence of groups of distantly related species recently evolved from a common ancestor.
C)  existence of groups of closely related species recently evolved from different ancestors through hybridization.
D)  existence of individuals of closely related species that originated in different areas within diverse habitats,but that have rejoined as a single species.E) A) and C)
F) All of the above

Question 9

Why do the Galápagos Islands and the Hawaiian Islands have so many endemic species of flies and birds? Check all that apply.

Accepted Answer

A)  There are numerous islands in each archipelago.
B)  There is adequate distance between islands to allow divergence.
C)  The founder effect was common when islands were colonized.
D)  Each bird or fly species has many common ancestors.E) None of the above
F) A) and C)

Question 10

Indicate the scenario(s) that could directly result in sympatric speciation.Check all that apply.

Accepted Answer

A)  Two sunflower species cross to form a healthy hybrid individual with equal copies of chromosomes from each parental species.
B)  A new river channel divides a population of beetles into two populations.
C)  A large fence blocks the intermingling of two populations of a species.
D)  A subset of flies within a larger population colonizes a new host plant.E) A) and B)
F) C) and D)

Question 11

Hybridization regularly occurs between three species of Darwin's finches on Daphne Major,but the finches are still considered different species because

Accepted Answer

A)  they have different fitnesses.
B)  they are reproductively isolated.
C)  they are mechanically isolated.
D)  they occupy different niches.E) B) and D)
F) A) and B) D

Question 12

Evolution acts at the level of the

Accepted Answer

A)  ecosystem.
B)  population.
C)  species.
D)  community.E) A) and B)
F) A) and C)

Question 13

After an initial rapid rise in the number of species on Earth,there was a plateau that experienced very little fluctuation in the number of species.

Accepted Answer

A) True 
 B)False

Question 14

Select the concepts emphasized by Ernst Mayr's biological species concept.Check all that apply.

Accepted Answer

A)  hybridization between different species
B)  production of fertile offspring within the species
C)  populations in zoos
D)  reproductive isolation from other speciesE) A) and C)
F) B) and C)

Question 15

If species are competing for the same resource,one species is likely to go extinct through competitive exclusion,or natural selection will drive the evolution of

Accepted Answer

A)  prezygotic isolating mechanisms.
B)  hybrids.
C)  character displacement.
D)  polyploid individuals.E) C) and D)
F) B) and C)

Question 16

Select all of the following that are postzygotic isolating mechanisms.

Accepted Answer

A)  Hybrids are sterile.
B)  Hybrids develop abnormally.
C)  Hybrids fail to become established in nature.
D)  Hybrids cannot be formed.E) None of the above
F) B) and C)

Question 17

The hundreds of species of Drosophila in Hawaii exhibit different mating rituals.This isolating mechanism is

Accepted Answer

A)  prezygotic and behavioral.
B)  prezygotic and temporal.
C)  prezygotic and geographical.
D)  postzygotic and mechanical.
E)  prezygotic and ecological.F) B) and C)
G) A) and B)

Question 18

Which isolating mechanism is postzygotic?

Accepted Answer

A)  hybrid sterility
B)  behavioral isolation
C)  ecological isolation
D)  mechanical isolation
E)  temporal isolationF) A) and B)
G) A) and E)

Question 19

Many male songbirds have very distinctive songs that are used to attract females.These songs are an example of a ________ isolating mechanism.

Accepted Answer

A)  postzygotic,ecological
B)  prezygotic,behavioral
C)  prezygotic,temporal
D)  postzygotic,mechanical
E)  prezygotic,gamete fusionF) B) and E)
G) None of the above B

Question 20

The ________ definition of species says that a species is a group of organisms that are reproductively isolated from other such groups.

Accepted Answer

The answer of The ________ definition of species says that...

Exam 22: The Origin of Species

Which statements about the Lake Victoria cichlid fishes are true? Check all that apply.

Correct AnswerverifiedShow Answer

The ________ model assumes that evolution occurs in spurts,between which there are long periods of stasis with little evolutionary change.

Correct Answerverifiedpunctuated...View AnswerShow Answer

Studies of snapping shrimp on either side of the Isthmus of Panama have shown that each Caribbean shrimp species is more closely related to a Pacific shrimp species than it is to any other Caribbean shrimp species.The most likely explanation for this result is

Correct AnswerverifiedShow Answer

The model that assumes that evolution proceeds with slow successive change in a given evolutionary line is referred to as

Correct AnswerverifiedShow Answer

The most common mechanism for sympatric speciation in plants is

Correct AnswerverifiedA

The sunflower species Helianthus anomalus is thought to have been formed by hybridization between the sunflower species H.petiolaris and H.annuus because it contains a set of chromosomes from both parental species.H.anomalus is most likely an example of instantaneous speciation through

Correct AnswerverifiedShow Answer

Which is an example of temporal isolation?

Correct AnswerverifiedShow Answer

Adaptive radiation is best described as the

Correct AnswerverifiedShow Answer

Why do the Galápagos Islands and the Hawaiian Islands have so many endemic species of flies and birds? Check all that apply.

Correct AnswerverifiedShow Answer

Indicate the scenario(s) that could directly result in sympatric speciation.Check all that apply.

Correct AnswerverifiedShow Answer

Hybridization regularly occurs between three species of Darwin's finches on Daphne Major,but the finches are still considered different species because

Correct AnswerverifiedD

Evolution acts at the level of the

Correct AnswerverifiedShow Answer

After an initial rapid rise in the number of species on Earth,there was a plateau that experienced very little fluctuation in the number of species.

Correct AnswerverifiedShow Answer

Select the concepts emphasized by Ernst Mayr's biological species concept.Check all that apply.

Correct AnswerverifiedShow Answer

If species are competing for the same resource,one species is likely to go extinct through competitive exclusion,or natural selection will drive the evolution of

Correct AnswerverifiedShow Answer

Select all of the following that are postzygotic isolating mechanisms.

Correct AnswerverifiedShow Answer

The hundreds of species of Drosophila in Hawaii exhibit different mating rituals.This isolating mechanism is

Correct AnswerverifiedShow Answer

Which isolating mechanism is postzygotic?

Correct AnswerverifiedShow Answer

Many male songbirds have very distinctive songs that are used to attract females.These songs are an example of a ________ isolating mechanism.

Correct AnswerverifiedB

The ________ definition of species says that a species is a group of organisms that are reproductively isolated from other such groups.

Correct AnswerverifiedShow Answer

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A

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D

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B

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