Question 1

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) C) and D)
F) A) and D)

Question 2

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) A) and B)
F) B) and D)

Question 3

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) None of the above
F) All of the above

Question 4

Once species have formed, they keep their identity by

Accepted Answer

A)  developmental differences.
B)  genetic blocks.
C)  isolating mechanisms.
D)  somatic mutations.E) A) and B)
F) None of the above

Question 5

The type of speciation that results in the formation of separate species as a result of geographic isolation is called ____________ speciation.

Accepted Answer

A)  gradual
B)  sympatric
C)  allopatric
D)  sexualE) B) and C)
F) C) and D)

Question 6

In 1938, scientists found a population of coelacanths in the Indian Ocean.This fish species is considered a "living fossil" and appears not to have changed morphologically for 80 million years.This discovery supports the ___________ model of evolution.

Accepted Answer

A)  gradualism
B)  punctuated equilibrium
C)  adaptation
D)  natural selectionE) A) and D)
F) A) and C)

Question 7

In the southeastern U.S., two species of wild lettuce (Lactuca)  do not usually form hybrids, because they bloom at different seasons.The means of isolation appears to be

Accepted Answer

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

Question 8

Lake Victoria is famous for its variety of cichlid fishes.In fact, they offer the most diverse assembly of vertebrates presently known to science.One trait that scientists have focused on as one possible reason for their adaptability is

Accepted Answer

A)  a second set of scales that lie beneath the top outermost scales.
B)  a second set of jaws in their throats.
C)  gill arches that are not covered by an operculum, which prevents hiding places for gill parasites.
D)  digestive tracts that are able to process most substrates, which has eliminated the need for feeding specialization.E) B) and C)
F) A) and B)

Question 9

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) A) and B)
F) A) and C)

Question 10

NASA Scientists send a small population of dogs to a new planet in order to test if it will be hospitable for human colonization.Through a random lottery, only Great Dane and St.Bernard dog breeds are sent, and the resulting population consists of tall, longhaired dogs.After 100 years these dogs return to Earth and are no longer able to mate with Earth dogs.This scenario is an example of

Accepted Answer

A)  allopatric speciation through genetic drift.
B)  allopatric speciation through natural selection.
C)  sympatric speciation through genetic drift.
D)  sympatric speciation through natural selection.E) A) and C)
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) A) and B)
F) B) and C)

Question 12

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) B) and C)
F) A) and D)

Question 13

When species are kept separate by preventing the formation of hybrid zygotes, the mechanism that keeps the species separate is known as a _____________ isolating mechanism.

Accepted Answer

A)  hybridization
B)  postzygotic
C)  prezygotic
D)  adaptiveE) B) and D)
F) A) and B)

Question 14

Imagine two species of birds with similar beak sizes and diets.Where the two species are allopatric, we would expect that their beak sizes

Accepted Answer

A)  should be more different than when sympatric.
B)  should be more similar than when sympatric.
C)  should be larger than when sympatric.
D)  should be smaller than when sympatric.E) All of the above
F) C) and D)

Question 15

Which isolating mechanism is postzygotic?

Accepted Answer

A)  hybrid sterility
B)  behavioral isolation
C)  ecological isolation
D)  mechanical isolationE) A) and C)
F) A) and D)

Question 16

If populations within the same area split into species, the process is known as

Accepted Answer

A)  sympatric speciation.
B)  allopatric speciation.
C)  racial speciation.
D)  ecotypical speciation.E) None of the above
F) B) and D)

Question 17

Scientists found that different beak shapes correlate with different mating songs in Darwin's finches.Which hypothesis does this support?

Accepted Answer

A)  Darwin's finches are not different species according to the Biological Species Concept.
B)  Adaptation to different food sources led to behavioral isolation in Darwin's finches.
C)  Mating songs are primarily determined by the acoustics of different beaks.
D)  Adaptation to different food sources likely occurred after reproductive isolation in Darwin's finches.E) A) and B)
F) A) and C)

Question 18

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 chromsomes 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) A) and D)
F) A) and C)

Question 19

A type of isolating mechanism that leads to reproductive isolation after a hybrid zygote has formed is called a _____________ isolating mechanism.

Accepted Answer

A)  hybridization
B)  postzygotic
C)  prezygotic
D)  adaptiveE) A) and B)
F) A) and C)

Question 20

Which statement is true about speciation on island archipelagos?

Accepted Answer

A)  Speciation is slow because it depends on emigration from the mainland.
B)  Most speciation occurs allopatrically.
C)  Ecological competition may cause new species to go extinct slowing speciation.
D)  Speciation by polyploidy is most common.E) All of the above
F) A) and C)

Exam 22: The Origin of Species

Which is an example of temporal isolation?

Correct Answer
verified

In the southeastern U.S., two species of wild lettuce (Lactuca) do not usually form hybrids, because they bloom at different seasons.The means of isolation appears to be

Correct Answer
verified

Imagine two species of birds with similar beak sizes and diets.Where the two species are allopatric, we would expect that their beak sizes

Correct Answer
verified

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

Correct Answer
verified

If populations within the same area split into species, the process is known as

Correct Answer
verified

Which statement is true about speciation on island archipelagos?

Correct Answer
verified

Once species have formed, they keep their identity by

Correct Answer
verified

Which isolating mechanism is postzygotic?

Correct Answer
verified

A type of isolating mechanism that leads to reproductive isolation after a hybrid zygote has formed is called a _____________ isolating mechanism.

Correct Answer
verified

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

Correct Answer
verified

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 chromsomes from both parental species.H.anomalus is most likely an example of instantaneous speciation through

Correct Answer
verified

In 1938, scientists found a population of coelacanths in the Indian Ocean.This fish species is considered a "living fossil" and appears not to have changed morphologically for 80 million years.This discovery supports the ___________ model of evolution.

Correct Answer
verified

Lake Victoria is famous for its variety of cichlid fishes.In fact, they offer the most diverse assembly of vertebrates presently known to science.One trait that scientists have focused on as one possible reason for their adaptability is

Correct Answer
verified

When species are kept separate by preventing the formation of hybrid zygotes, the mechanism that keeps the species separate is known as a _____________ isolating mechanism.

Correct Answer
verified

The type of speciation that results in the formation of separate species as a result of geographic isolation is called ____________ speciation.

Correct Answer
verified

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 Answer
verified

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

Correct Answer
verified

Scientists found that different beak shapes correlate with different mating songs in Darwin's finches.Which hypothesis does this support?

Correct Answer
verified

Correct Answer
verified

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 Answer
verified

Exam 22: The Origin of Species

Which is an example of temporal isolation?

Correct AnswerverifiedShow Answer

In the southeastern U.S., two species of wild lettuce (Lactuca) do not usually form hybrids, because they bloom at different seasons.The means of isolation appears to be

Correct AnswerverifiedShow Answer

Imagine two species of birds with similar beak sizes and diets.Where the two species are allopatric, we would expect that their beak sizes

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

If populations within the same area split into species, the process is known as

Correct AnswerverifiedShow Answer

Which statement is true about speciation on island archipelagos?

Correct AnswerverifiedShow Answer

Once species have formed, they keep their identity by

Correct AnswerverifiedShow Answer

Which isolating mechanism is postzygotic?

Correct AnswerverifiedShow Answer

A type of isolating mechanism that leads to reproductive isolation after a hybrid zygote has formed is called a _____________ isolating mechanism.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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 chromsomes from both parental species.H.anomalus is most likely an example of instantaneous speciation through

Correct AnswerverifiedShow Answer

In 1938, scientists found a population of coelacanths in the Indian Ocean.This fish species is considered a "living fossil" and appears not to have changed morphologically for 80 million years.This discovery supports the ___________ model of evolution.

Correct AnswerverifiedShow Answer

Lake Victoria is famous for its variety of cichlid fishes.In fact, they offer the most diverse assembly of vertebrates presently known to science.One trait that scientists have focused on as one possible reason for their adaptability is

Correct AnswerverifiedShow Answer

When species are kept separate by preventing the formation of hybrid zygotes, the mechanism that keeps the species separate is known as a _____________ isolating mechanism.

Correct AnswerverifiedShow Answer

The type of speciation that results in the formation of separate species as a result of geographic isolation is called ____________ speciation.

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

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

Correct AnswerverifiedShow Answer

Scientists found that different beak shapes correlate with different mating songs in Darwin's finches.Which hypothesis does this support?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow 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

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