Exam 3

Front 1

Also known as Lamarckism; the theory, now discounted, that individuals genetically pass on to their offspring physical and behavioral changes developed during the individuals' own lifetime.

Back 1

inheritance of acquired characteristics

Front 2

the movement of alleles from one population to another

Back 2

Gene flow

Front 3

a breeder selects for the desired characteristics

Back 3

artificial selection

Front 4

environmental conditions determine which individuals in a population produce the most offspring

Back 4

natural selection

Front 5

For natural selection to occur and to result in evolutionary change, three conditions must be met:

Back 5

Variation must exist among individuals in a population
Variation among individuals must result in differences in the number of offspring surviving in the next generation
Variation must be genetically inherited

Front 6

Five agents of evolutionary change

Back 6

mutation, gene flow, nonrandom mating, genetic drift in small populations, and the pressures of natural selection

Front 7

Alleles often affect multiple aspects of a phenotype

Back 7

pleiotropy

Front 8

the phenomenon in which an allele for one gene may have different effects, depending on alleles present at other genes

Back 8

epistasis

Front 9

The study of the properties of genes in populations.

Back 9

population genetics

Front 10

The presence in a population of more than one allele of a gene at a frequency greater than that of newly arising mutations.

Back 10

polymorphism

Front 11

Genetic change in a population of organisms

Back 11

evolution

Front 12

A mathematical description of the fact that allele and genotype frequencies remain constant in a random-mating population in the absence of inbreeding, selection, or other evolutionary forces; usually stated: if the frequency of allele a is p and the frequency of allele b is q, then the genotype frequencies after one generation of random mating will always be p2 + 2pq + q2 = 1.

Back 12

Hardy-Weinberg equilibrium

Front 13

A measure of the occurrence of an allele in a population, expressed as proportion of the entire population, for example, an occurrence of 0.84 (84%).

Back 13

allele frequency

Front 14

A type of nonrandom mating in which phenotypically similar individuals mate more frequently.

Back 14

assortative mating

Front 15

A type of nonrandom mating in which phenotypically different individuals mate more frequently.

Back 15

disassortative mating

Front 16

Random fluctuation in allele frequencies over time by chance.

Back 16

genetic drift

Front 17

The effect by which rare alleles and combinations of alleles may be enhanced in new populations.

Back 17

founder effect

Front 18

A loss of genetic variability that occurs when a population is reduced drastically in size.

Back 18

bottleneck effect

Front 19

The process by which some organisms leave more offspring than competing ones, and their genetic traits tend to appear in greater proportions among members of succeeding generations than the traits of those individuals that leave fewer offspring.

Back 19

selection

Front 20

The genetic contribution of an individual to succeeding generations.

Back 20

fitness

Front 21

A type of selection that depends on how frequently or infrequently a phenotype occurs in a population.

Back 21

frequency-dependent selection

Front 22

The situation in which selection alternately favors one phenotype at one time, and a different phenotype at a another time, for example, during drought conditions versus during wet conditions.

Back 22

oscillating selection

Front 23

The situation in which individuals heterozygous for a trait have a selective advantage over those who are homozygous; an example is sickle cell anemia.

Back 23

heterozygote advantage

Front 24

A form of selection in which selection acts to eliminate rather than favor the intermediate type. 2 phenotypically distinct groups

Back 24

disruptive selection

Front 25

A form of selection in which selection acts to eliminate one extreme from an array of phenotypes.

Back 25

directional selection

Front 26

A form of selection in which selection acts to eliminate both extremes from a range of phenotypes.

Back 26

stabilizing selection

Front 27

structures with different appearances and functions that all derived from the same body part in a common ancestor.

Back 27

homologous structures

Front 28

Phrase used to describe the evolutionary process in which initially light-colored organisms become dark as a result of natural selection.

Back 28

industrial melanism

Front 29

A morphological feature that has no apparent current function and is thought to be an evolutionary relic

Back 29

vestigial structure

Front 30

The study of the geographic distribution of species.

Back 30

biogeography

Front 31

The independent development of similar structures in organisms that are not directly related; often found in organisms living in similar environments.

Back 31

convergent evolution

Front 32

An alternative hypothesis proposes that the distinctions among species are maintained by natural selection.

Back 32

ecological species concept

Front 33

The differentiation of populations within a common geographic area into species.

Back 33

sympatric speciation

Front 34

A geographically defined population or group of populations within a single species that has distinctive characteristics.

Back 34

subspecies

Front 35

The concept that defines species as groups of populations that have the potential to interbreed and that are reproductively isolated from other groups

Back 35

biological species concept (BSC)

Front 36

Any barrier that prevents genetic exchange between species.

Back 36

reproductive isolating mechanism

Front 37

A type of reproductive isolation in which the formation of a zygote is prevented; these mechanisms may range from physical separation in different habitats to gametic in which gametes are incapable of fusing.

Back 37

prezygotic isolating mechanism

Front 38

A type of reproductive isolation in which zygotes are produced but are unable to develop into reproducing adults; these mechanisms may range from inviability of zygotes or embryos to adults that are sterile.

Back 38

postzygotic isolating mechanism

Front 39

Chemical substance released by one organism that influences the behavior or physiological processes of another organism of the same species.

Back 39

pheromone

Front 40

takes place when populations are geographically isolated

Back 40

Allopatric speciation

Front 41

occurs without geographic separation

Back 41

Sympatric speciation

Front 42

In speciation, the process by which partial reproductive isolation between populations is increased by selection against mating between members of the two populations, eventually resulting in complete reproductive isolation.

Back 42

reinforcement

Front 43

Condition in which one or more entire sets of chromosomes is added to the diploid genome.

Back 43

polyploidy

Front 44

A polyploid organism that contains a duplicated genome of the same species; may result from a meiotic error.

Back 44

autopolyploid

Front 45

A polyploid organism that contains the genomes of two or more different species.

Back 45

allopolyploid

Front 46

The evolution of several divergent forms from a primitive and unspecialized ancestor

Back 46

adaptive radiation

Front 47

A newly evolved trait in a species that allows members to use resources or other aspects of the environment that were previously inaccessible.

Back 47

key innovation

Front 48

A process in which natural selection favors individuals in a species that use resources not used by other species. This results in evolutionary change leading to species dissimilar in resource use.

Back 48

character displacement

Front 49

The view that species change very slowly in ways that may be imperceptible from one generation to the next but that accumulate and lead to major changes over thousands or millions of years.

Back 49

gradualism

Front 50

A period of time during which little evolutionary change occurs

Back 50

stasis

Front 51

A hypothesis about the mechanism of evolutionary change proposing that long periods of little or no change are punctuated by periods of rapid evolution.

Back 51

punctuated equilibrium

Front 52

A relatively sudden, sharp decline in the number of species

Back 52

mass extinction

Front 53

similarity among species that is inherited from the most recent common ancestor of an entire group

Back 53

derived

Front 54

similarity that arose prior to the common ancestor of the group

Back 54

ancestral

Front 55

The reconstruction and study of evolutionary relationships.

Back 55

systematics

Front 56

The evolutionary history of an organism, including which species are closely related and in what order related species evolved; often represented in the form of an evolutionary tree.

Back 56

phylogeny

Front 57

A taxonomic technique used for creating hierarchies of organisms that represent true phylogenetic relationship and descent.

Back 57

cladistics

Front 58

In cladistics, character states that are shared by species and that are different from the ancestral character state.

Back 58

shared derived character

Front 59

In cladistics, one of two or more distinguishable forms of a character, such as the presence or absence of teeth in amniote vertebrates.

Back 59

character state

Front 60

In cladistics, to determine whether character states are ancestral or derived.

Back 60

polarize

Front 61

A taxonomic group composed of an ancestor and all its descendents.

Back 61

clade

Front 62

In systematics, a derived character that is shared by clade members.

Back 62

synapomorphy

Front 63

In cladistics, a shared character state that has not been inherited from a common ancestor exhibiting that state; may result from convergent evolution or evolutionary reversal. The wings of birds and of bats, which are convergent structures, are examples.

Back 63

homoplasy

Front 64

Principle stating that scientists should favor the hypothesis that requires the fewest assumptions.

Back 64

principle of parsimony

Front 65

In evolutionary theory, the method in which the rate of evolution of a molecule is constant through time.

Back 65

molecular clock method

Front 66

refers to how we place species and higher groups—genus, family, class, and so forth—into the taxonomic hierarchy

Back 66

classification

Front 67

features are derived from the same ancestral source

Back 67

homologous

Front 68

features aren't derived from the same ancestral source

Back 68

homoplastic

Front 69

In phylogenetic classification, a group that includes the most recent common ancestor of the group and all its descendants.

Back 69

monophyletic

Front 70

In phylogenetic classification, a group that includes the most recent common ancestor of the group, but not all its descendants.

Back 70

paraphyletic

Front 71

In phylogenetic classification, a group that does not include the most recent common ancestor of all members of the group.

Back 71

polyphyletic

Front 72

The concept that defines species on the basis of their phylogenetic relationships.

Back 72

phylogenetic species concept (PSC)

Front 73

Darwin proposed that natural selection occurs in an environment by:
>favoring heritable features that make the organism better suited to survive and reproduce.
>producing a constant number of offspring while in that environment.
>surviving for a fixed amount of time.
>resisting the environment and keeping the environment from changing.
>favoring those individuals with the most favorable acquired characteristics.

Back 73

favoring heritable features that make the organism better suited to survive and reproduce.

Front 74

The genetic contribution of an individual to succeeding generations, compared with that of other individuals in the population, is known as:
>variation.
>microevolution.
>macroevolution.
>fitness.
>adaptive makeup.

Back 74

fitness

Front 75

Features that increase the likelihood of survival and reproduction by an organism in a particular environment are called
>genes.
>fitness.
>mutations.
>adaptations.
>selection.

Back 75

adaptations

Front 76

A locus with more variation than can be explained by mutation is referred to as:
>dominant.
>polynomial.
>polymorphic.
>heterozygous.
>somatic.

Back 76

polymorphic

Front 77

The gene pool includes:
>all of the fitness within a population.
>all of the individuals within a population.
>all of the mutations within a population.
>all of the adaptations within a population.
>all of the alleles of genes within a population.

Back 77

all of the alleles of genes within a population.

Front 78

A restriction in genetic variability caused by a drastic reduction in population size is called a:
>founder effect.
>Hardy-Weinberg effect.
>bottleneck effect.
>polymorphic effect.
>adaptive effect.

Back 78

bottleneck effect.

Front 79

Migration and hybridization between individuals of adjacent populations causes gene ______.
>blending
>flow
>mutation
>dominance

Back 79

flow

Front 80

The phenomenon in which rare alleles become more common in new populations is called:
>founder effect.
>gene flow.
>genetic drift.
>assortative mating.
>mutation.

Back 80

founder effect.

Front 81

In small populations, frequencies of certain alleles may change by chance alone. Such random change in the frequency of alleles is called:
>mutation.
>migration.
>genetic drift.
>nonrandom mating.
>selection.

Back 81

genetic drift.

Front 82

The type of non-random mating that causes the frequencies of particular genotypes to differ greatly from those predicted by the Hardy-Weinberg equilibrium is called:
>mutation.
>assisted mating.
>genetic drift.
>assortative mating.
>selection.

Back 82

assortative mating.

Front 83

When selection acts to eliminate one extreme from an array of phenotypes it is called:
>natural selection.
>stabilizing selection.
>disruptive selection.
>directional selection.
>artificial selection.

Back 83

directional selection.

Front 84

In some instances environmental change causes a situation where one phenotype is favored for a period of time, and then a different phenotype is favored. This oscillating selection causes:
>the maintenance of genetic variation in the population.
>elimination of rarer genotypes because of uneven selection.
>an increase in point mutations.
>high population increase to maintain phenotypic variation.
>extinction of the population.

Back 84

the maintenance of genetic variation in the population.

Front 85

In disruptive selection, over time:
>a population goes extinct.
>the most extreme outliers of a population are eliminated (e.g., the largest beaks and smallest beaks are eliminated).
>the population is strongly selected for in one direction (e.g., larger beak size).
>the population is strongly selected for in two directions (e.g., larger beak size and smaller beak size).
>a population increases its variation (e.g., a wide selection of all beak sizes).

Back 85

the population is strongly selected for in two directions (e.g., larger beak size and smaller beak size).

Front 86

The midrange of an array of phenotypes is favored.
>directional selection
>stabilizing selection
>disruptive selection
>guppies with pike cichlids and killifish
>guppies with killifish

Back 86

stabilizing selection

Front 87

In negative frequency-dependent selection, such as in the study done on the water boatman insect, the incidence of predation leads to an:
>elimination of a rare genotype.
>even distribution of genotype frequencies.
>increase in a rare genotype.
>increase in variation within the population.
>increase in a rare genotype and an increase in variation within the population.

Back 87

increase in a rare genotype.

Front 88

According to Darwin, the different species of finches of the Galapagos Islands were a group of ______ related species evolving from ______ species.
>closely; several
>distantly; one
>closely; one
>distantly; several

Back 88

closely; one

Front 89

Darwin's finches have adapted to feed in different ways in response to:
>the available food supply.
>the available nest building material supplies.
>the availability of potential mating partners.
>the presence of ectoparasites on their feathers.
>the need to improve their feather preening abilities.

Back 89

the available food supply.

Front 90

According to Tutt, why did dark peppered moths (Biston betularia) become more common in industrialized regions?
>They were less visible to predators
>They were more tolerant of toxic pollutants
>Soot from factories settled on the moths making them darker
>They were less likely to be detected by prey

Back 90

They were less visible to predators

Front 91

What is the likely cause of the change in frequency of melanic moths in Michigan and at Caldy Common in England?
>Air pollution has decreased in both regions
>Air pollution has increased in both regions
>Predatory birds have decreased in both regions
>Predatory birds have increased in both regions

Back 91

Air pollution has decreased in both regions

Front 92

Which of the following is NOT true about artificial selection?
>Artificial selection shows that evolutionary change can occur over a short time
>Artificial selection shows that natural selection is capable of producing major evolutionary change
>Artificial selection occurs when humans selectively breed individuals of a species with desirable traits
>Artificial selection results in only minor changes within a species

Back 92

Artificial selection results in only minor changes within a species

Front 93

The shape of the beaks of Darwin's finches and industrial melanism are often cited as examples of the process of _______________ leading to evolutionary change.
>artificial selection
>coevolution
>intelligent design
>founder effect
>natural selection

Back 93

natural selection

Front 94

Natural selection has favored the dark form of the peppered moth in areas subject to severe air pollution, perhaps because on darkened trees moth-eating birds see them less easily. As pollution abated, the light forms were favored because:
>they were less visible after the lichens returned.
>of migration from more polluted areas.
of mutation.
>they were preyed on more.
>of a bottleneck effect.

Back 94

they were less visible after the lichens returned.

Front 95

In comparing artificial and natural selection, which of the following statements is true?
>Artificial selection is slower than natural selection.
>Artificial selection is reversible; natural selection is not.
>Artificial selection can produce maladaptive structures, natural selection cannot.
>Artificial selection cannot produce changes as large as changes produced by natural selection.
>In artificial selection, the magnitude of the selection pressure can be varied; in natural selection, it cannot.

Back 95

Artificial selection can produce maladaptive structures, natural selection cannot.

Front 96

Which of the following best describes a scientific theory?
>an educated guess about natural phenomena based on observations
>an explanation that fits current evidence and has withstood rigorous testing
>a generalization about a group of observations that is applicable under a given set of conditions
>an explanation for many observations that has not yet been tested

Back 96

an explanation that fits current evidence and has withstood rigorous testing

Front 97

Today, the fossil record:
>can be dated only with one layer in relation to older layers below and younger layers above, no actual dates can be estimated.
>can be dated reasonably well only with uranium-238.
>can be dated reasonably well using a variety of radioactive isotopes with known half-lives.
>can be dated precisely, to within a single year, using radioactive isotopes.
>can be dated precisely, to within a single year, using DNA hybridization.

Back 97

can be dated reasonably well using a variety of radioactive isotopes with known half-lives.

Front 98

Which one of the following features of Archaeopteryx clearly demonstrates that it was on the evolutionary line leading from dinosaurs to birds?
>egg-laying ability
>teeth
>feathers
>bony tail
>claws on forelimbs

Back 98

feathers

Front 99

In the case of the toothed whales, the fossil record
>shows they evolved from fish.
>shows they evolved from swimming dinosaurs.
>shows they evolved from a land mammal with hooves.
>has fragmentary evidence that cannot be explained.
>has no evidence about how they evolved.

Back 99

shows they evolved from a land mammal with hooves.

Front 100

Which of the following features of ancient horses is not an adaptation for living on open grasslands?
>multiple toes
>complex patterns of ridges on molar and premolars
>lengthening of limbs
>increase in body size
>high-speed locomotion

Back 100

multiple toes

Front 101

Structures that are derived from the same body part in a common ancestor but may have different appearances and functions are called
>analogous structures.
>homologous structures.
>vestigial structures.
>embryonic structures.
>homozygous structures.

Back 101

homologous structures.

Front 102

Many organisms possess structures that have no apparent function, but they resemble structures of presumed ancestors. This is the study of:
>the fossil record.
>the molecular record.
>homology.
>development.
>vestigial structures.

Back 102

vestigial structures.

Front 103

During growth in the mother's uterus, human embryos and fetuses exhibit characteristics of other vertebrates, suggesting that humans are related to the other forms. This represents which of the following lines of evolutionary evidence?
>fossil record
>homology
>convergent evolution
>biogeography
>development

Back 103

development

Front 104

The evolution of similar forms in different lineages when exposed to the same selective pressures is:
>called divergence.
>called convergence.
>referred to as successive homologies.
>referred to as descent.
>also known as natural selection.

Back 104

called convergence.

Front 105

Evolution is said to violate the second law of thermodynamics. Which of the following statements best describes why this is not true?
>Evolution does not always produce more complex forms; sometimes less complex forms arise.
>Because evolution is a random process, it does not require an input of energy.
>Earth is not a closed system; it constantly receives an input of energy from the sun.
>Living organisms are not subject to the second law.
>The disorder generated by extinction balances the order created by evolution.

Back 105

Earth is not a closed system; it constantly receives an input of energy from the sun.

Front 106

The type of speciation that results in the formation of separate species as a result of geographic isolation is called ____________ speciation.
>gradual
>sympatric
>allopatric
>sexual
>adaptive

Back 106

allopatric

Front 107

The model proposed by Eldredge and Gould for the formation of species, that says evolution occurs in spurts, is called the ___________ model.
>gradualism
>punctuated equilibrium
>adaptation
>natural selection
common descent

Back 107

punctuated equilibrium

Front 108

Which of the following statements describe the assumptions of the gradualism model?
>Evolution occurs in spurts, between which there are long periods in where there is little evolutionary change.
>Evolution proceeds incrementally, with incremental change in a given evolutionary line.
>There is variability in the rates of evolution.
>Speciation is essential to evolution.
>Periods of stasis occur.

Back 108

Evolution proceeds incrementally, with incremental change in a given evolutionary line.

Front 109

If populations within the same area split into species, the process is known as
>sympatric speciation.
>allopatric speciation.
>racial speciation.
>ecotypical speciation.
>reproductive speciation.

Back 109

sympatric speciation.

Front 110

Adaptive radiation is likely to produce several to many:
>key innovations.
>species clusters.
>sterile hybrids.
>reproductive isolating mechanisms
>races.

Back 110

species clusters.

Front 111

Very rapid speciation occurred when cichlid fishes were isolated in Lake Victoria. Widespread extinction was dramatically seen when:
>artificial selection stopped.
>predatory fish were added.
>hybridization stopped.
>fishing was prohibited.
>insect larvae stocks were depleted.

Back 111

predatory fish were added.

Front 112

Species formation among alpine buttercups in New Zealand was promoted by:
>mechanical isolation.
>gametic isolation.
>periodic isolation by glaciation.
>temporal isolation.
>geographical isolation.

Back 112

periodic isolation by glaciation.

Front 113

The production of new species through hybridization is especially important in
>finches.
>fruit flies.
>humans.
>plants.
>mules.

Back 113

plants.

Front 114

The production of new species through hybridization is sometimes made easier in plants by:
>adaptation.
>meiosis.
>parthenogenesis.
>hybrid sterility.
>polyploidy.

Back 114

polyploidy

Front 115

Which of the following would BEST characterize the pattern of speciation on Earth?
>Decreasing since the Cambrian period caused by five mass extinctions
>Increasing after the Cambrian period to a maximum 200 million years ago with a steady decline since that time
>Increasing after the Cambrian period interspersed with sharp declines in species
>Increasing steadily to the Cambrian period and decreasing after the Ordovician mass extinction

Back 115

Increasing after the Cambrian period interspersed with sharp declines in species

Front 116

According to the phylogeny depicted in the figure, which of the following is most closely related to humans?
>Gibbon
>Orangutan
>Gorilla
>Chimpanzee

Back 116

Chimpanzee

Front 117

Characteristics between the branch points of a cladogram that are shared by all organisms above the branch point and are not present in any below it are called:
>homologous characters.
>homoplastic characters.
>ancestral characters.
>derived characters.
>novel characters.

Back 117

derived characters.

Front 118

Characteristics that have arisen in organisms as a result of common evolutionary descent are said to be ______________ characteristics.
>homologous
>homoplastic
>adaptive
>derived
>ancestral

Back 118

ancestral

Front 119

A phylogenetically based taxonomy is important not only in creating a logical way to name organisms, but also in learning about ________ of organisms using information in related species.
>physiology
>behavior
>development
>physiology, behavior, and development

Back 119

physiology, behavior, and development

Front 120

Character states shared by the ancestor or outgroup of a clade are called:
>derived traits.
>homoplasies.
>synapomorphies.
>plesiomorphies.
>symplesiomorphies.

Back 120

symplesiomorphies.

Front 121

Birds, snakes, lizards, turtles, and crocodiles are all thought to share a common ancestor and several homologous traits. Assuming that this is true, these groups of animals would best represent
>a polyphyletic group.
>a monophyletic group.
>homoplastic convergence.
>several clades.
>a species cluster.

Back 121

a monophyletic group.

Front 122

A group is considered paraphyletic if:
>all members of the group share a common ancestor.
>not all descendants of the common ancestor are included.
>the common ancestor of the group is not included in the group.
>the group does not contain the most recent common ancestor.
>it is the most parsimonious grouping.

Back 122

not all descendants of the common ancestor are included.

Front 123

A group is considered polyphyletic if:
>all members of the group share a common ancestor.
>not all descendants of the common ancestor are included.
>all members share homoplastic traits.
>the group does not contain the most recent common ancestor.
>it is the most parsimonious grouping.

Back 123

the group does not contain the most recent common ancestor.

Front 124

Which one of the following statements about molecular clocks is false?
>All molecular clocks tick at the same rate.
>Molecular clocks can be calibrated using fossil evidence.
>The rate of a molecular clock for a given DNA character might vary depending on how constrained the character is by natural selection.
>Ultimately, all molecular clocks depend on the rate of DNA mutation and DNA repair mechanisms.

Back 124

All molecular clocks tick at the same rate.

Front 125

Homoplasies can result from:
>convergent evolution.
>evolutionary reversals.
>both convergent evolution and evolutionary reversals.
>divergent evolution.
>adaptive radiations.

Back 125

both convergent evolution and evolutionary reversals.

Front 126

Parental care in dinosaurs, crocodiles, and birds is an example of:
>homoplasy caused by convergence.
>homoplasy caused by common descent.
>homoplasy caused by evolutionary reversal.
>homology caused by convergence.
>homology caused by common descent.

Back 126

homology caused by common descent.

Front 127

The evolution of saber teeth in a number of groups of extinct carnivorous mammals is an example of:
>homoplasy caused by convergence.
>homoplasy caused by common descent.
>homoplasy caused by evolutionary reversal.
>homology caused by convergence.
>homology caused by common descent.

Back 127

homoplasy caused by convergence.

Front 128

Which one of the following statements about the evolution of complex characters, such as powered flight, is false?
>Phylogenetic analysis using cladistics can help reveal the sequence leading to the evolution of a complex character.
>Usually a single mutation in a key gene controlling development leads to the simultaneous appearance of the complex character.
>Often the initial stage in the evolution of a complex character was an adaptation to some unrelated selection pressure.
>All of the intermediate stages in the evolution of a complex character contributed to the fitness of the species.
>Long periods of time are required for the evolution of complex characters.

Back 128

Usually a single mutation in a key gene controlling development leads to the simultaneous appearance of the complex character.

Front 129

Which one of the following statements about the evolution of HIV is false?
>All strains of HIV are included within clades of SIV strains.
>Each strain of HIV is more closely related to a strain of SIV than to other HIV strains.
>Humans acquired different subtypes of HIV from different primate hosts.
>AIDS appeared first in Africa, probably prior to 1940.
>Because of the low mutation rate of the HIV virus, it is possible to use phylogenetics to determine the source of infection for specific individuals.

Back 129

Because of the low mutation rate of the HIV virus, it is possible to use phylogenetics to determine the source of infection for specific individuals.

Front 130

refers to an inherited trait reverting back to an earlier form over the course of many generations.

Back 130

Evolutionary reversal

Front 131

Genotypes are said to be in ___________ equilibrium if there is random mating and no other forces tend to alter the proportions of alleles from one generation to the next.
A. steady state
B. homeostatic
C. Hardy-Weinberg
D. Medelian

Back 131

C. Hardy-Weinberg

Front 132

Features that increase the likelihood of survival and reproduction by an organism in a particular environment are called
A. genes.
B. fitness.
C. mutations.
D. adaptations.

Back 132

D. adaptations.

Front 133

A restriction in genetic variability caused by a drastic reduction in population size is called a
A. Hardy-Weinberg effect.
B. bottleneck effect.
C. polymorphic effect.
D. adaptive effect.

Back 133

B. bottleneck effect.

Front 134

The frequency of a particular allele within a population can be changed, over time, by
A. large population size.
B. selection.
C. inheritance of acquired characteristics.
D. random mating.

Back 134

B. selection.

Front 135

For a gene with two alternative alleles, a (frequency p) and a (frequency q), the term in the algebraic form of the Hardy-Weinberg equilibrium for the heterozygote genotype frequency is
A. p2.
B. q2.
C. 2pq.
D. (p+q)2.

Back 135

C. 2pq.

Front 136

. When selection acts to eliminate one extreme from an array of phenotypes it is called
A. natural selection.
B. stabilizing selection.
C. disruptive selection.
D. directional selection.

Back 136

D. directional selection.

Front 137

In small populations, frequencies of certain alleles may change by chance alone. Such random change in the frequency of alleles is called
A. mutation.
B. migration.
C. genetic drift.
D. nonrandom mating

Back 137

C. genetic drift.

Front 138

In order for natural selection to occur within a population, certain conditions must be met. One such condition is
A. phenotypic differences resulting from environmental conditions.
B. frequent mutations that are inherited.
C. low rates of immigration.
D. phenotypic variations that are genetic.

Back 138

D. phenotypic variations that are genetic.

Front 139

The total of all the alleles of all the genes in a population can be thought of as
A. an allele mixture.
B. a gene pool.
C. a genetic melting pot.
D. variant genes.

Back 139

B. a gene pool.

Front 140

In a large population of randomly reproducing rabbits, a recessive allele r comprises 80% of the alleles for a gene, while a dominant allele R comprises the remaining 20%. What percentage of the rabbits would you expect to have the recessive phenotype?
A. 4%
B. 32%
C. 64%
D. 80%

Back 140

C. 64%

Front 141

Which one of the following features of Archaeopteryx clearly demonstrates that it was on the evolutionary line leading from dinosaurs to birds?
A. egg-laying ability
B. teeth
C. feathers
D. bony tail

Back 141

C. feathers

Front 142

Industrial melanism involving the peppered moths (Biston sp.) is cited as an example of natural selection that has been observed in the last one hundred years. Recall that the peppered moth exhibits two distinct morphological types with dark and light colored wings. Which of the following statements about changes in these two types of moths as a result of industrial melanism is true?
A. The dark forms are selected against in nonpolluted forests.
B. The dark forms are distasteful to birds and are thus safe in polluted forests.
C. The light forms are selected against in nonpolluted forests.
D. Birds prey more on the dark forms in polluted forests

Back 142

A. The dark forms are selected against in nonpolluted forests.

Front 143

In comparing artificial and natural selection, which of the following statements is true?
A. Artificial selection is slower than natural selection.
B. Artificial selection is reversible; natural selection is not.
C. Artificial selection can produce maladaptive structures, natural selection cannot.
D. Artificial selection cannot produce changes as large as changes produced by natural selection

Back 143

C. Artificial selection can produce maladaptive structures, natural selection cannot.

Front 144

Today, the fossil record
A. can be dated only with one layer in relation to older layers below and younger layers above, no actual dates can be estimated.
B. can be dated reasonably well only with uranium-238.
C. can be dated reasonably well using a variety of radioactive isotopes with known half-lives.
D. can be dated precisely, to within a single year, using radioactive isotopes.

Back 144

C. can be dated reasonably well using a variety of radioactive isotopes with known half-lives.

Front 145

Which of the following features of ancient horses is not an adaptation for living on open grasslands?
A. multiple toes
B. complex patterns of ridges on molar and premolars
C. lengthening of limbs
D. increase in body size

Back 145

A. multiple toes

Front 146

The type of speciation that geographically isolates populations and results in the divergence of distinct species is called ____________ speciation.
A. gradual
B. sympatric
C. allopatric
D. sexual

Back 146

C. allopatric

Front 147

You see a sign on a door that reads "Homologous Structures Inside." You go in and find
A. structures of animals that appear to have evolved from different parts of their bodies.
B. structures of animals that have difference appearances and functions but seem to have evolved from the same body part in a common ancestor.
C. structures of animals that have the same appearances and functions but obviously no common ancestor.
D. structures of animals that have different appearances and functions but different ancestors.

Back 147

B. structures of animals that have difference appearances and functions but seem to have evolved from the same body part in a common ancestor.

Front 148

Which of the following would be an example of a vestigial structure?
A. The common body form of sharks and dolphins
B. The structure of an invertebrates eye when compared to a vertebrate eye
C. The common pattern of bones in the forelimbs of mammals
D. The non-functional remains of the pelvic girdle found in modern whales

Back 148

D. The non-functional remains of the pelvic girdle found in modern whales

Front 149

The observation that different geographical areas sometimes exhibit plant and animal communities of similar appearance, even though the individual plants and animals are not closely related, is called
A. homology.
B. convergent evolution.
C. divergent evolution.
D. adaptation.

Back 149

B. convergent evolution.

Front 150

A biologist seeing a sign describing evolution as "just a theory" would think that
A. evolution is a theory that is supported with a tremendous amount of evidence.
B. evolution is just a collection of facts without a central theme and this is not a theory.
C. evolution is what Darwin proposed to account for all the changes he observed in the finches so it is a hypothesis, not a theory.
D. evolution occurred in the past, but it is not occurring in the present, so it cannot be a theory.

Back 150

A. evolution is a theory that is supported with a tremendous amount of evidence.

Front 151

A type of isolating mechanism that leads to reproductive isolation after a hybrid zygote has formed is called _____________ isolating mechanism.
A. hybridization
B. postzygotic
C. prezygotic
D. adaptive

Back 151

B. postzygotic

Front 152

A biological species is defined as
A. a group of organisms that look very similar
B. an actual or potentially interbreeding natural population which is reproductively isolated from other such groups
C. a group of organisms with the identical genotype
D. a population of organisms, natural or artificial, that is geographically isolated from other populations

Back 152

B. an actual or potentially interbreeding natural population which is reproductively isolated from other such groups

Front 153

Which of the following statements describe the assumptions of the gradualism model?
A. Evolution occurs in spurts, between which there are long periods in where there is little evolutionary change.
B. Evolution proceeds incrementally, with incremental change in a given evolutionary line.
C. There is variability in the rates of evolution.
D. Periods of stasis occur.

Back 153

B. Evolution proceeds incrementally, with incremental change in a given evolutionary line.

Front 154

All of the following are examples of prezygotic isolating mechanisms except
A. ecological isolation.
B. temporal isolation.
C. mechanical incompatibility.
D. hybrid sterility.

Back 154

D. hybrid sterility.

Front 155

Very rapid speciation occurred when cichlid fishes were isolated in Lake Victoria. Widespread extinction was dramatically seen when
A. artificial selection stopped.
B. predatory fish were added.
C. hybridization stopped.
D. insect larvae stocks were depleted.

Back 155

B. predatory fish were added.

Front 156

The production of new species through hybridization is sometimes made easier in plants by
A. adaptation.
B. meiosis.
C. parthenogenesis.
D. polyploidy.

Back 156

D. polyploidy.

Front 157

Which one of the following statements about mass extinctions is false?
A. The five major mass extinctions were all followed by a rebound in species diversity.
B. By definition, in mass extinctions all major groups are affected equally.
C. Major changes in the direction of evolution have often occurred after mass extinctions.
D. The five major mass extinctions were caused mainly by geological events and, perhaps, collision with asteroids.

Back 157

B. By definition, in mass extinctions all major groups are affected equally.

Front 158

Derived character states shared by clade members are called
A. ancestral traits.
B. homoplasies.
C. synapomorphies.
D. symplesiomorphies

Back 158

C. synapomorphies.

Front 159

A group is considered paraphyletic if
A. all members of the group share a common ancestor.
B. not all descendants of the common ancestor are included.
C. the common ancestor of the group is not included in the group.
D. the group does not contain the most recent common ancestor.

Back 159

B. not all descendants of the common ancestor are included.

Front 160

Parental care in dinosaurs, crocodiles, and birds is an example of
A. homoplasy caused by convergence.
B. homoplasy caused by common descent.
C. homology caused by convergence.
D. homology caused by common descent.

Back 160

D. homology caused by common descent.