Chapter 10: Evolution and Natural Selection

Question 1

Which of the following best describes the difference between artificial and natural selection?

1. Charles Darwin understood natural selection but was unaware of artificial selection in his time.
2. Natural selection’s effectiveness is limited by physiological and developmental constraints; artificial selection’s effectiveness is free of these constraints.
3. Natural selection acts without the input of humans; artificial selection requires human input.
4. Artificial selection has produced many of the most delicious food items for humans; natural selection has not.
5. Natural selection works on all species; artificial selection only works on lab-reared species.

Answer 1

Natural selection acts without the input of humans; artificial selection requires human input

Question 2

The origin of all genetic variation is:

1. mutation.
2. respiration.
3. glycolosis.
4. digestion.
5. mitosis.

Answer 2

mutation

Question 3

Which of the following types of organisms have rapidly evolved resistance to the chemicals humans use to control them?

1. bacteria
2. head lice
3. insects
4. all the above

Answer 3

all of the above

Question 4

Which of the following would be most effective in lowering the number of deaths due to bacterial infections?

1. If doctors began to prescribe antibiotics for viral infections.
2. If we stopped the use of new antibiotics and continued using the ones that were effective in the 1940s.
3. If we stopped using antibiotics altogether and allowed our natural immune systems to fight off disease.
4. If everyone who was prescribed antibiotics for a bacterial infection took the entire course of their treatment.

Answer 4

If everyone who was prescribed antibiotics for a bacterial infection took the entire course of their treatment

Question 5

Which of the following best explains why genetic bottlenecks and founder effects are evolutionarily important?

a. In both cases, strong selective pressures lead to fast directional selection.
b. Both result in stabilizing selection due to strong selective pressures.
c. Both result in small populations that are influenced more by genetic drift.
d. Both result in increased fitness.
e. Both a) and d) are correct.

Answer 5

Both result in small populations that are influenced more by genetic drift

Question 6

Evolution occurs:

1. by altering physical traits but not behavioral traits.
2. only when the environment is changing.
3. primarily via natural selection, genetic drift, migration, or mutation.
4. entirely because of directional selection.
5. only through natural selection.

Answer 6

primarily via natural selection, genetic drift, migration, or mutation

Question 7

A storm washed 5 female and 5 male tiger beetles from the mainland to a small island that had no previous population of tiger beetles. In tiger beetles, having six spots (A) is dominant to having four spots (a). All 10 beetles had six spots, but 1 male and 1 female were heterozygous for the four-spot trait. If 6 of the beetles died randomly without reproducing, the ratio of the genotypes could be quite different in subsequent generations. This change in allele frequencies would be an example of:

1. genetic drift.
2. convergent evolution.
3. natural selection leading to perfect organisms.
4. mutation.
5. stabilizing selection.

Answer 7

genetic drift

Question 8

From an evolutionary perspective, behavior can be viewed best as:

a. not subject to the normal evolutionary process because it involves a neurological system.
b. a trait that can satisfy the three conditions required for evolution by natural selection.
c. something that is too complex to arise through natural selection.
d. Both b) and c) are correct.
e. All of the above are correct.

Answer 8

a trait that can satisfy the three conditions required for evolution by natural selection

Question 9

Why is the presence of vestigial structures strong evidence that organisms share a common ancestor?

1. They are evidence of common ancestry with organisms in which these structures are functional.
2. They illustrate the fact that convergences in homologous characteristics can be found in organisms in completely different taxonomic groups.
3. They show that unrelated species can evolve similar structures in response to different environmental pressures.
4. They are found in greater numbers among species that are more distantly related to each other.

Answer 9

They are evidence of common ancestry with organisms in which these structures are functional

Question 10

Until the middle of the 19th century, all peppered moths (Biston betularia) observed around Manchester, England, were light in color. In 1845, a single black peppered moth was reported. As Manchester became more industrialized and dark soot began to cover the bark of the trees, the frequency of black moths increased greatly. The change in proportion of light and dark forms resulted from:

1. directional selection.
2. increased mutation.
3. genetic drift.
4. stabilizing selection.
5. disruptive selection.

Answer 10

directional selection

Question 11

The appropriate group in which to measure genetic variation is in the:

1. species
2. population.
3. community.
4. ecosystem.
5. individual.

Answer 11

population

Question 12

Many mosquito populations today are resistant to pesticides that were historically effective killing mosquitos. This pesticide resistance arose in these populations because:

1. individual mosquitoes built up immunity to the pesticides after exposure.
2. the pesticides caused mutations in the DNA of mosquitoes that conferred resistance phenotypes, and were passed on to subsequent generations.
3. populations had to develop tolerance in order to survive.
4. some individuals were resistant to the pesticides before they were used, and those mosquitoes were more likely to survive and reproduce.
5. these populations were outside the range of the original pesticide application.

Answer 12

some individuals were resistant to the pesticides before they were used, and those mosquitoes were more likely to survive and reproduce

Question 13

You are studying a population of American robins, Turdus migratorius, in which approximately 2% of all individuals carry a recessive allele for leucistic (unusually white) coloration. The population suddenly expands when an influx of robins arrives during spring migration, and the frequency of the leucistic allele drops to only 1.5%. Has evolution occurred in the robin population in your study area?

1. No, because no mutation occurred.
2. No, because natural selection did not occur.
3. Yes, because the leucistic trait was not adaptive, and it decreased in frequency.
4. Yes, because allele frequencies in the population have changed over time.
5. No, because the change in allele frequency occurred in just one generation.

Answer 13

Yes, because allele frequencies in the population have changed over time

Question 14

Human birth weight is a classic example of the result of:

1. stabilizing selection.
2. disruptive selection.
3. genotype by environment interaction.
4. genetic drift.
5. directional selection.

Answer 14

stabilizing selection

Question 15

A breeder of thoroughbreds selects only the fastest horses for breeding stock. This is an example of artificial ____________ selection.

1. directional
2. sexual
3. stabilizing
4. frequency-dependent
5. disruptive

Answer 15

directional

Question 16

Genetic drift has the greatest effects for populations:

1. that are very small.
2. that are undergoing stabilizing selection.
3. that are in Hardy-Weinberg equilibrium.
4. that are undergoing directional selection.
5. with a high degree of gene exchange with other populations.

Answer 16

that are very small

Question 17

______________ selection favors organisms that have character values at both extremes of the phenotypic distribution.

1. Disruptive.
2. Intermittent
3. Intense
4. Stabilizing
5. Directional

Answer 17

disruptive

Question 18

Anatomical homology in vertebrate forelimbs is considered to be evidence for evolution because:

1. differences among vertebrate forelimbs suggest that they evolved independently.
2. similarities among vertebrate forelimbs suggest that they evolved from a common ancestor.
3. the anatomy of the vertebrate forelimb is not currently under natural selection.
4. similarities among vertebrate forelimbs suggest that they have evolved convergently.
5. such homologies do not exist in other areas of the vertebrate skeleton.

Answer 18

similarities among vertebrate forelimbs suggest that they evolved from a common ancestor

Question 19

Why is genetic variation among individuals in a population necessary for natural selection to occur?

1. Without genetic variation all individuals would appear the same and selection would not be able to tell the difference to select some over the others.
2. Genetic variation is the cause of mutation, which provides the raw material for natural selection.
3. Genetic variation is necessary for acquired traits to be passed on to offspring. If this didn’t happen, then natural selection would be almost impossible.
4. Genetic variation insures that more offspring will be produced than will survive.

Answer 19

Without genetic variation all individuals would appear the same and selection would not be able to tell the difference to select some over the others