chapter 8 practice test

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.

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

Which of the following best describes the difference between artificial and natural selection? a. Natural selection's effectiveness is limited by physiological and developmental constraints; artificial selection's effectiveness is free of these constraints. b. Natural selection works on all species; artificial selection only works on lab-reared species. c. Natural selection acts without the input of humans; artificial selection requires human input. d. Artificial selection has produced many of the most delicious food items for humans; natural selection has not. e. Charles Darwin understood natural selection but was unaware of artificial selection in his time.

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

Which of the following is a statement that describes the concept of convergent evolution? a. Similar traits evolve at the same time in different organisms. b. Closely related organisms adapt to a wide range of different traits. c. Organisms that are not directly related develop similar traits. d. Closely related organisms develop similar traits. e. Different organisms merge to become one species.

c. Organisms that are not directly related develop similar traits.

A population is: a. a group of individuals of the same species that lives in the same general location and has the potential to interbreed. b. a group of individuals of related species that lives in the same general location and has the potential to interbreed. c. a group of individuals of the same species that has the potential to interbreed. d. a group of species that shares the same habitat. e. a group of individuals of the same species that lives in the same general location and has the same genotypes.

c. a group of individuals of the same species that has the potential to interbreed.

. In Australia, most of the typical mammalian roles are filled by marsupial mammals. There is a marsupial "wolf," and there are several species of marsupial "mice," marsupial "squirrels," and marsupial "anteaters." This example shows the importance of the study of ___________ in understanding evolution. a. missing links b. genetic variance c. biogeography d. molecular biology e. the fossil record

c. biogeography

The average time to death from starvation in a fruit fly is about 20 hours. Selecting for increased starvation resistance in fruit flies: a. has no effect because it is not a trait that influences fruit fly fitness. b. has little effect because constant mutation reduces starvation resistance, counteracting any benefits from selection. c. can produce populations in which the average time to death from starvation is more than 160 hours. d. has no effect because it is too complex a physiological process, dependent upon the effects of too many genes. e. can produce populations in which the average time to death from starvation is 10 hours.

c. can produce populations in which the average time to death from starvation is more than 160 hours.

The longer two species have been evolving on their own, the greater the number of _______ that accumulate between them. a. DNA bases b. genetic differences c. genetic similarities d. homologous structures e. convergences

c. genetic similarities

Evolution occurs: a. by altering physical traits but not behavioral traits. b. almost entirely because of directional selection. c. only via natural selection, genetic drift, migration, or mutation. d. only through natural selection. e. only when the environment is changing

c. only via natural selection, genetic drift, migration, or mutation.

The appropriate unit for defining and measuring genetic variation is the: a. liter. b. kilowatt. c. population. d. gram. e. meter.

c. population

Most mutations are: a. responsible for gene flow. b. found in the cytoplasm. c. random with respect to the environmental needs of the organism in which the mutation takes place. d. accounted for by the Hardy-Weinberg equilibrium. e. beneficial or neutral to the organism in which the mutation takes place.

c. random with respect to the environmental needs of the organism in which the mutation takes place.

"Survival of the fittest" may be a misleading phrase to describe the process of evolution by natural selection because: a. fitness has little to do with natural selection. b. it is impossible to determine the fittest individuals in nature. c. survival matters less to natural selection than reproductive success does. d. natural variation in a population is generally too great to be influenced by differential survival. e. reproductive success on its own does not necessarily guarantee evolution.

c. survival matters less to natural selection than reproductive success does.

_________ selection favors organisms with phenotypes that are at one extreme relative to the average phenotype. a. Stabilizing b. Disruptive c. Intermittent d. Directional e. Intense

d. Directional

The importance of exponential growth to the theory of evolution by natural selection is best explained by which of the following? a. Exponential growth provides for large numbers of individuals for selection to act upon. b. Exponential growth allows for large amounts of variation. c. Exponential growth is the only stable form of population growth. d. In situations of exponential growth, it is often true that not all that are born will live to reproduce. e. Exponential growth always results in maximum fitness.

d. In situations of exponential growth, it is often true that not all that are born will live to reproduce.

Artificial selection is likely to produce population-level changes most quickly in organisms with: a. a long life span. b. a large body size. c. a large genome. d. a short generation time. e. a small litter size.

d. a short generation time.

A breeder of thoroughbreds selects only the fastest horses for breeding stock. This is an example of artificial ____________ selection. a. disruptive b. sexual c. frequency-dependent d. directional e. stabilizing

d. directional

A population's environment sometimes changes too quickly for natural selection to adapt the individuals in the population to the environment. In these situations: a. the rate of somatic mutations increases. b. disruptive selection will occur. c. the individuals' instincts can no longer be trusted to elicit behavior that maximizes reproductive success. d. extinction occurs during the following generation. e. evolution ceases to operate in the population.

d. extinction occurs during the following generation.

All of the following are types of natural selection EXCEPT: a. disruptive selection. b. artificial selection. c. directional selection. d. furniture selection. e. stabilizing selection.

d. furniture selection.

Natural selection results from interactions between: a. species and their populations. b. individual organisms and their genes. c. genes and ecosystems. d. individual organisms and their environment. e. species and their environment.

d. individual organisms and their environment

To demonstrate evolution by natural selection, all of the following conditions must be satisfied EXCEPT: a. heritability of a trait. b. variation for a trait. c. differential reproductive success. d. low environmental variation. e. All of the above are necessary for evolution by natural selection.

d. low environmental variation.

Radioactive isotopes emit high-energy particles that can damage DNA. These substances are considered: a. free radicals. b. DNAses. c. operons. d. mutation-causing agents e. eleutherodactylans.

d. mutation-causing agents

In a particular population, over the course of several dozen generations, an adenine was replaced by a guanine at a particular non-coding locus in the DNA base sequence. The evolutionary mechanism responsible for this change was: a. disruptive selection. b. migration. c. genetic drift. d. mutation. e. directional selection

d. mutation.

Human birth weight is a classic example of the result of: a. genotype by environment interaction. b. directional selection. c. genetic drift. d. stabilizing selection. e. disruptive selection.

d. stabilizing selection.

Exceptionally large babies increase a mother's mortality risk when giving birth and exceptionally small babies tend to die at birth or shortly afterward. For these reasons, birth weight in human babies is generally: a. subject to Caesarean selection. b. a strong predictor of adult weight. c. not a heritable trait. d. subject to stabilizing selection. e. subject to disruptive selection.

d. subject to stabilizing selection.

Which of the following is the best measure of an organism's fitness? a. how long it lives b. its size, compared to other members of the same species c. the amount of care it receives from its parents d. the number of fertile offspring it produces e. the number of mutations it acquires in its lifetime

d. the number of fertile offspring it produces

All of the following statements are true about mutations EXCEPT: a. Most mutations are harmful or neutral to the organism in which they occur. b. A mutation is any change in an organism's DNA. c. The origin of genetic variation is mutation. d. Mutations are almost always random with respect to the needs of the organism. e. The mutation rate can be affected by genetic drift.

e. The mutation rate can be affected by genetic drift.

Convergent evolution can occur only when two species: a. are separated by a barrier such as a new river. b. have a recent common ancestor. c. live in the same geographic area. d. are both inedible to predators. e. evolve under similar selective forces.

e. evolve under similar selective forces.

The migration of reproductive individuals among populations results in a movement of alleles called: a. directional selection. b. recombination. c. disruptive selection. d. hybridization. e. gene flow

e. gene flow

8. The origin of all genetic variation is: a. glycolosis. b. digestion. c. respiration. d. mitosis. e. mutation.

e. mutation

Which of the following phrases describes a type of natural selection in which the mean characteristics of a population are preserved? a. disruptive selection b. directional selection c. artificial selection d. phenotypic selection e. stabilizing selection

e. stabilizing selection

Anatomical homology in vertebrate forelimbs is considered to be evidence for evolution because: a. similarities among vertebrate forelimbs suggest that they evolved from a common ancestor. b. such homologies do not exist in other areas of the vertebrate skeleton. c. the anatomy of the vertebrate forelimb is not currently under natural selection. d. similarities among vertebrate forelimbs suggest that they have evolved convergently. e. differences among vertebrate forelimbs suggest that they evolved independently.

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

Genetic drift has the greatest effects for populations: a. that are very small. b. that are undergoing stabilizing selection. c. that are in Hardy-Weinberg equilibrium. d. with a high degree of gene exchange with other populations. e. that are undergoing directional selection.

a. that are very small.

The fact that fish, penguins, and dolphins all have the same basic shape is BEST explained by which of the following? a. Parallel evolution is common among aquatic mammals. b. Fish, penguins, and dolphins all faced the same physical constraints during their evolution and converged upon the same body plan. c. Divergent evolution and adaptive radiation into new niches often result in convergent evolution. d. The similarities are probably due to random chance. e. The basic shapes of fish, penguins, and dolphins are vestigial structures.

b. Fish, penguins, and dolphins all faced the same physical constraints during their evolution and converged upon the same body plan.

The rise of antibiotic-resistant bacteria demonstrates which of the following? a. It takes decades or longer for organisms to evolve by natural selection. b. Humans have provided the selection pressure which results in more harmful strains of bacteria. c. Resistance alleles in the bacterial populations in the human body are in Hardy-Weinberg equilibrium. d. Bacteria can mutate in order to be immune to antibiotics. e. Bacteria are becoming resistant to antibiotics much more slowly than humans can invent new antibiotics.

b. Humans have provided the selection pressure which results in more harmful strains of bacteria.

What fossil evidence suggests that Tiktaalik represents a transitional phase between fish and land animals? a. Tiktaalik could move about on land for days before it needed to return to water. b. Tiktaalik had forelimbs with hand- and finger-like bones that could flex and support weight. c. The "fish" scales on Tiktaalik are nearly identical to those found on modern-day reptiles. d. The tail of Tiktaalik is much reduced and more amphibian-like than fish-like. e. There is evidence that Tiktaalik was a "fish" but also had lungs.

b. Tiktaalik had forelimbs with hand- and finger-like bones that could flex and support weight

Evolution is defined as: a. a change in the frequency of a physical trait in a population over time. b. a change in the frequency of alleles in a population over time. c. survival of the fittest. d. a change in a physical trait of an individual during its lifetime. e. a progressive "ladder" of changes from most primitive organisms to most advanced organisms.

b. a change in the frequency of alleles in a population over time.

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.

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

In humans, random mating is most likely to occur for which of the following characteristics? a. language b. artificial selection c. personality d. physical appearance e. intelligence

b. artificial selection

The contribution of a genotype or phenotype to the genetic composition of subsequent generations relative to other genotypes or phenotypes best describes which of the following concepts? a. migration b. fitness c. the founder effect d. evolution e. natural selection

b. fitness

Species living in close proximity but in different habitats tend to resemble one another more than species living far apart in very similar habitats. This observation supports the idea that: a. related species can recognize each other as relatives. b. new species arise in different habitats from those established nearby c. similar species prefer to live near each other. d. species that live near each other interbreed. e. All of the above support the observation.

b. new species arise in different habitats from those established nearby

Natural selection can only act on traits: a. that are acquired in an individual's lifetime. b. that are heritable. c. that reduce mortality. d. that confer a reproductive advantage. e. that are adaptive.

b. that are heritable

When a sudden change in the environment, such as a flood or a fire, reduces the size of a population, the survivors' collective gene pool becomes only a limited representation of what was present before the disaster. This phenomenon is called: a. the culling effect. b. the bottleneck effect. c. the founder effect. d. the Hardy-Weinberg equilibrium. e. the genetic load.

b. the bottleneck effect.

A mutation is: a. always recessive. b. usually heritable. c. always dominant. d. usually lethal. e. never adaptive.

b. usually heritable

. _________ selection favors organisms that have character values at both extremes of the phenotypic distribution. a. Disruptive b. Stabilizing c. Directional d. Intermittent e. Intense

a. Disruptive

Select from the choices below the statement that best describes the effect of the migration of individuals into a population. a. Migration of individuals into a population generally increases the genetic variability within a population. b. Migration of individuals into a population generally decreases the genetic variability within a population. c. Migration of individuals into a population generally causes that population to diverge to the extent that it becomes a new species. d. Migration of individuals into a population generally causes no change in the genetic variability within a population because it is a case of artificial selection. e. Only choices a) and c) are correct.

a. Migration of individuals into a population generally increases the genetic variability within a population

Which of the following is an IMPORTANT difference between natural selection and genetic drift? a. Natural selection involves differential reproductive success in the struggle for existence in an environment, while genetic drift does not. b. Natural selection relies on underlying genetic variation as its source, while genetic drift does not. c. Natural selection is more likely to occur in small populations than is genetic drift. d. Natural selection is random, while genetic drift is not. e. Natural selection involves changes in allele frequencies in a population, while genetic drift does not.

a. Natural selection involves differential reproductive success in the struggle for existence in an environment, while genetic drift does not.

Adaptations shaped by natural selection: a. are magnified and enhanced through the complementary force of genetic drift. b. may be out of date, having been shaped in the past, which may have been different from the present. c. are unlikely to be present in humans living in industrial societies. d. are continuously modified so that they are always fitted to the environment in which an organism lives. e. represent perfect solutions to the problems posed by nature.

a. are magnified and enhanced through the complementary force of genetic drift.

Under the right conditions, which type of selection is most likely to lead to the formation of new species? a. disruptive b. directional c. stabilizing d. frequency-dependent e. sexual

a. disruptive