Question 1

Explain how disruptive selection could lead to the development of two species from one original founding population.

Accepted Answer

Disruptive selection favors th...

Question 2

Which of the following is most likely to experience genetic drift?

Accepted Answer

A)   A population of endangered birds that includes only five individuals
B)   A species of insect that occurs all across North America
C)   A population of bears that is growing by thousands of individuals each year
D)   A plant species that has spread to many different habitats all around the world
E)   A population of common rodents that includes millions of individuals

Question 3

When one species evolves a new phenotypic feature and another species evolves new adaptations in response, it is called

Accepted Answer

A)   gene flow.
B)   genetic drift.
C)   sexual selection.
D)   stabilizing selection.
E)   coevolution.

Question 4

Evolution by natural selection is

Accepted Answer

A)   a process that occurs as a result of differences in fitness.
B)   a rare event that has never been observed by scientists.
C)   constantly occurring at the same rate in all organisms.
D)   currently occurring but only in scientific laboratories.
E)   a process that has occurred only in the past.

Question 5

The elaborate courtship displays common among animals are the result of

Accepted Answer

A)   sexual selection.
B)   spontaneous mutations.
C)   stabilizing selection.
D)   disruptive selection.
E)   random mating.

Question 6

The extreme loss of genetic diversity that has occurred in cheetah populations due to overhunting is the result of

Accepted Answer

A)   genetic drift.
B)   coevolution.
C)   the founder effect.
D)   natural selection.
E)   a population bottleneck.

Question 7

In an equilibrium population

Accepted Answer

A)   mutation rates do not change.
B)   natural selection occurs.
C)   allele frequencies do not change.
D)   rates of gene flow are constant.
E)   population size cannot change.

Question 8

A new predator is introduced to an area that can feed on any millipedes shorter than 200 millimeters. No millipedes that live in that area are longer than 15 millimeters. What will happen?

Accepted Answer

A)   Directional selection will favor predators that consume the smallest millipedes.
B)   Disruptive selection will favor 15- millimeter- long millipedes.
C)   The millipedes will necessarily mutate to be longer.
D)   All millipedes will be potential prey.
E)   Millipedes will necessarily evolve to avoid the predator.

Question 9

Gene flow

Accepted Answer

A)   prevents migration of individuals into other populations.
B)   negates the influence of evolution on a population.
C)   limits evolutionary fitness.
D)   isolates populations from one another.
E)   can spread certain alleles throughout a species.

Question 10

In central Africa, the frequency of the sickle- cell allele has remained stable over the years because the allele protects against malaria. In the United States, malaria was eradicated by eliminating the mosquito that spreads the disease. The decreasing frequency of the sickle- cell allele in African Americans since malaria was eliminated in the United States is an example of

Accepted Answer

A)   stabilizing selection.
B)   genetic drift.
C)   the founder effect.
D)   directional selection.
E)   disruptive selection.

Question 11

In a very small population of birds, assume 5 out of 20 alleles are the type that codes for blue feathers. What is the allele frequency of the "blue feather allele" in this population?

Accepted Answer

A)   5
B)   0.40
C)   0.20
D)   0.25
E)   0.50

Question 12

Evolutionary adaptations are not always the "best" solution to a problem. Explain how the long necks of giraffes can be both advantageous and disadvantageous.

Accepted Answer

The long neck provides an advantage to m...

Question 13

Habitat loss, natural catastrophes, and/or excessive harvesting of a species often result in

Accepted Answer

A)   artificial selection.
B)   increased gene flow.
C)   population bottlenecks.
D)   increased fitness of individuals.
E)   increased mutation rates.

Question 14

A city was intensively sprayed with the chemical DDT to control houseflies. The number of houseflies was immediately greatly reduced. Each year thereafter, the city was sprayed again, but the flies gradually increased in numbers until 10 years later when they were as abundant as they were before the control program began. Provide an evolutionary explanation of what happened.

Accepted Answer

The few flies that happened to be born w...

Question 15

The type of selection most likely to act on a well- adapted population in a relatively constant environment is

Accepted Answer

A)   artificial.
B)   nonrandom.
C)   directional.
D)   disruptive.
E)   stabilizing.

Question 16

In the context of evolution, equilibrium means

Accepted Answer

A)   equal numbers of all alleles.
B)   no change in population size.
C)   equal numbers of males and females.
D)   no change in allele frequency.
E)   no individuals move into or out of the population.

Question 17

In one butterfly species, the colors of individuals range from white to black, with many shades of gray in between. If the butterflies in a mountain population become more and more similar in color over several generations (e.g., if most butterflies are the same shade of gray) , what kind of evolutionary force is likely acting on the population?

Accepted Answer

A)   Stabilizing selection
B)   Disruptive selection
C)   Artificial selection
D)   Directional selection

Question 18

A population that maintains several different phenotypes of the same trait displays .

Accepted Answer

balanced p...

Question 19

Which of the following occurs due to chance events that change the allele frequencies in small populations?

Accepted Answer

A)   Gene flow
B)   Genetic drift
C)   Sexual selection
D)   Stabilizing selection
E)   Coevolution

Question 20

Multidrug- resistant bacteria

Accepted Answer

A)   are not serious threats to human health.
B)   are becoming less widespread.
C)   have been eradicated worldwide.
D)   are becoming more widespread.
E)   have always been common in the natural environment.

Exam 16: How Populations Evolve

Evolutionary adaptations are not always the "best" solution to a problem. Explain how the long necks of giraffes can be both advantageous and disadvantageous.

Correct Answer
verified
The long neck provides an advantage to m...
View Answer

Which of the following is most likely to experience genetic drift?

Correct Answer
verified

The elaborate courtship displays common among animals are the result of

Correct Answer
verified

When one species evolves a new phenotypic feature and another species evolves new adaptations in response, it is called

Correct Answer
verified

Habitat loss, natural catastrophes, and/or excessive harvesting of a species often result in

Correct Answer
verified

Correct Answer
verified

Evolution by natural selection is

Correct Answer
verified

Gene flow

Correct Answer
verified

In the context of evolution, equilibrium means

Correct Answer
verified

The type of selection most likely to act on a well- adapted population in a relatively constant environment is

Correct Answer
verified

In an equilibrium population

Correct Answer
verified

A new predator is introduced to an area that can feed on any millipedes shorter than 200 millimeters. No millipedes that live in that area are longer than 15 millimeters. What will happen?

Correct Answer
verified

Multidrug- resistant bacteria

Correct Answer
verified

In a very small population of birds, assume 5 out of 20 alleles are the type that codes for blue feathers. What is the allele frequency of the "blue feather allele" in this population?

Correct Answer
verified

Explain how disruptive selection could lead to the development of two species from one original founding population.

Correct Answer
verified
Disruptive selection favors th...
View Answer

A population that maintains several different phenotypes of the same trait displays .

Correct Answer
verified
balanced p...
View Answer

The extreme loss of genetic diversity that has occurred in cheetah populations due to overhunting is the result of

Correct Answer
verified

Correct Answer
verified
The few flies that happened to be born w...
View Answer

Correct Answer
verified

Which of the following occurs due to chance events that change the allele frequencies in small populations?

Correct Answer
verified

Exam 16: How Populations Evolve

Evolutionary adaptations are not always the "best" solution to a problem. Explain how the long necks of giraffes can be both advantageous and disadvantageous.

Correct AnswerverifiedThe long neck provides an advantage to m...View AnswerShow Answer

Which of the following is most likely to experience genetic drift?

Correct AnswerverifiedShow Answer

The elaborate courtship displays common among animals are the result of

Correct AnswerverifiedShow Answer

When one species evolves a new phenotypic feature and another species evolves new adaptations in response, it is called

Correct AnswerverifiedShow Answer

Habitat loss, natural catastrophes, and/or excessive harvesting of a species often result in

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Evolution by natural selection is

Correct AnswerverifiedShow Answer

Gene flow

Correct AnswerverifiedShow Answer

In the context of evolution, equilibrium means

Correct AnswerverifiedShow Answer

The type of selection most likely to act on a well- adapted population in a relatively constant environment is

Correct AnswerverifiedShow Answer

In an equilibrium population

Correct AnswerverifiedShow Answer

A new predator is introduced to an area that can feed on any millipedes shorter than 200 millimeters. No millipedes that live in that area are longer than 15 millimeters. What will happen?

Correct AnswerverifiedShow Answer

Multidrug- resistant bacteria

Correct AnswerverifiedShow Answer

In a very small population of birds, assume 5 out of 20 alleles are the type that codes for blue feathers. What is the allele frequency of the "blue feather allele" in this population?

Correct AnswerverifiedShow Answer

Explain how disruptive selection could lead to the development of two species from one original founding population.

Correct AnswerverifiedDisruptive selection favors th...View AnswerShow Answer

A population that maintains several different phenotypes of the same trait displays .

Correct Answerverifiedbalanced p...View AnswerShow Answer

The extreme loss of genetic diversity that has occurred in cheetah populations due to overhunting is the result of

Correct AnswerverifiedShow Answer

Correct AnswerverifiedThe few flies that happened to be born w...View AnswerShow Answer

Correct AnswerverifiedShow Answer

Which of the following occurs due to chance events that change the allele frequencies in small populations?

Correct AnswerverifiedShow Answer

Correct Answer
verified
The long neck provides an advantage to m...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Disruptive selection favors th...
View Answer

Correct Answer
verified
balanced p...
View Answer

Correct Answer
verified

Correct Answer
verified
The few flies that happened to be born w...
View Answer

Correct Answer
verified

Correct Answer
verified