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Biological concepts final exam > Bio concepts #3 > Flashcards

Bio concepts #3 Flashcards

1
Q

Charles Darwin is best known for this book

A

On the Origin of Species by Means of Natural Selection

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2
Q

Anaximander argued humans are the offspring of what animal?

A

fish

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3
Q

Jean-Baptiste Lamarck is most notably associated with what theory?

A

Transmutation theory

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4
Q

Characteristics acquired by habits and other behavioral adaptations to changes in the environment could be genetically transmitted to offspring

A

Transmutation theory

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5
Q

The imprints or remains of organisms that lived in the past

A

fossils

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6
Q

document differences between past and present organisms

A

fossils

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7
Q

Reveal that many species have become extinct

A

fossils

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8
Q

Reveals the historical sequence in which organisms have evolved

A

fossil record

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9
Q

Link early extinct species with species living today

A

fossils

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10
Q

What does “descent with modification” mean in Darwin’s theory?

A

all life is connected by common ancestry, and descendants accumulate adaptations to changing environments over time.

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11
Q

How did Darwin’s theory differ from the long-held view of the Earth and species?

A

Darwin’s theory suggested that the Earth is very old and that species change over time through evolution, whereas the long-held belief was that the Earth was young and species were unchanging.

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12
Q

Why is Darwin’s concept of evolution by natural selection considered a theory?

A

it is broader in scope than a hypothesis, generates new hypotheses, and is supported by a large body of evidence.

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13
Q

What discovery in the late 1970s supported the idea that whales evolved from land-dwelling mammals?

A

Paleontologists unearthed transitional fossils and concluded that whales likely arose from a wolf-like carnivore.

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14
Q

What did molecular biologists discover about the relationship between whales and hippopotamuses?

A

Molecular biologists found a close genetic relationship between whales and hippopotamuses and hypothesized that both are descendants of a common cloven-hoofed ancestor.

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15
Q

What did the discovery of Pakicetus and Rodhocetus in 2001 reveal about whale evolution?

A

The fossils of Pakicetus and Rodhocetus showed the distinctive ankle bone of a cloven-hoofed mammal, confirming that whales are closely related to land-dwelling, cloven-hoofed ancestors.

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16
Q

A process of descent with modification

A

evolution

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17
Q

Evolution is described as what type of process?

A

remodeling process

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18
Q

Similarity resulting from common ancestry is known as what?

A

homology

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19
Q

reveal evolutionary relationships

A

structural and molecular homologies

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20
Q

remnants of features that served important functions in the organism’s ancestors

A

vestigial structures

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21
Q

Helps explain why early stages of development in different animal species reveal similarities not visible in adult organisms

A

understanding of homology

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22
Q

How do biologists represent patterns of descent?

A

Biologists use an evolutionary tree (often turned sideways) to show patterns of descent, illustrating how species are related through common ancestry.

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23
Q

What types of homologies can be used to determine the branching sequence of an evolutionary tree?

A

Both anatomical structures (e.g., bones, organs) and molecular structures (e.g., DNA, proteins) can be used to determine the branching sequence of an evolutionary tree.

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24
Q

Darwin’s greatest contribution to biology

A

explanation of how life evolves

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25
Q

How did Darwin use artificial selection to support his theory of natural selection?

A

Darwin reasoned that if artificial selection could produce significant changes in a short time, then natural selection could cause even greater modifications in species over hundreds or thousands of generations.

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26
Q

What does it mean that individuals do not evolve, but populations do?

A

Natural selection acts on individual organisms, but evolution occurs at the population level over time, as the frequency of traits changes across generations.

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27
Q

What types of traits can natural selection act on?

A

Natural selection can only amplify or diminish traits that are heritable—traits that can be passed on to offspring through genetic inheritance.

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28
Q

Is evolution goal-directed?

A

No, evolution is not goal-directed. It does not lead to perfectly adapted organisms

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29
Q

What is an example of natural selection in action related to pesticides?

A

insects with genetic mutations that provide resistance survive and reproduce, leading to more resistant populations over time.

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30
Q

Why is natural selection considered more of an editing process than a creative mechanism?

A

Natural selection edits the gene pool by favoring traits that already exist in a population, rather than creating new traits or perfect organisms. It acts on genetic variation that is already present.

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31
Q

How is natural selection contingent on time and place?

A

Natural selection favors traits that are advantageous in a specific environment at a specific time, meaning the traits that are beneficial can vary depending on environmental conditions.

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32
Q

typically show individual variation

A

organisms

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33
Q

the ultimate source of the genetic variation that serves as raw material for evolution

A

mutations

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34
Q

How is most genetic variation in sexually reproducing organisms generated?

A

Most genetic variation results from the unique combination of alleles that each individual inherits, due to processes like independent assortment, recombination, and random fertilization during sexual reproduction.

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35
Q

What are the three random components of sexual reproduction that generate fresh assortments of alleles every generation?

A

crossing over, independent orientation of homologous chromosomes during meiosis, and random fertilization.

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36
Q

What is crossing over, and how does it contribute to genetic variation?

A

the exchange of genetic material between homologous chromosomes during meiosis, leading to new combinations of alleles.

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37
Q

How does the independent orientation of homologous chromosomes at metaphase I of meiosis contribute to genetic variation?

A

During meiosis, the homologous chromosomes align independently at metaphase I, resulting in a random distribution of maternal and paternal chromosomes to the gametes, increasing genetic diversity.

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38
Q

How does random fertilization contribute to genetic variation?

A

any sperm can fertilize any egg, leading to numerous possible combinations of alleles in the offspring.

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39
Q

a group of individuals of the same species that live in the same area and interbreed

A

population

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40
Q

consists of all copies of every type of allele, at every locus, in all members of the population.

A

gene pool

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41
Q

a change in the frequencies of alleles in a population’s gene pool and evolution occurring on its smallest scale.

A

microevolution

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42
Q

What are the conditions under which allele and genotype frequencies will remain constant, according to the Hardy-Weinberg equilibrium?

A

The conditions are: A large population, Random mating, No mutation, gene flow, or natural selection.

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43
Q

How does a large population contribute to Hardy-Weinberg equilibrium?

A

A large population helps prevent random changes in allele frequencies due to genetic drift, maintaining allele frequencies over generations.

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44
Q

Why is random mating important for Hardy-Weinberg equilibrium?

A

Random mating ensures that alleles combine in a way that does not favor any particular genotype, allowing allele frequencies to remain unchanged.

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45
Q

How do mutation, gene flow, and natural selection affect Hardy-Weinberg equilibrium?

A

These factors disrupt equilibrium by introducing new alleles, changing allele frequencies, or favoring certain genotypes, which causes evolution to occur.

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46
Q

How can the Hardy-Weinberg equation be used to test whether evolution is occurring?

A

The Hardy-Weinberg equation predicts expected allele and genotype frequencies. If observed frequencies differ from the expected ones, it suggests that evolutionary forces are acting on the population.

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47
Q

What does it mean if a population’s allele frequencies match those predicted by the Hardy-Weinberg equation?

A

If the population’s allele frequencies match the predictions, it indicates that no evolution is occurring, and the population is in Hardy-Weinberg equilibrium.

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48
Q

What happens if a population’s allele frequencies do not match those predicted by the Hardy-Weinberg equation?

A

If allele frequencies deviate from the predictions, it suggests that evolutionary processes (e.g., natural selection, mutation, or genetic drift) are influencing the population, causing evolution to occur.

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49
Q

What are the three main causes of evolutionary change?

A

natural selection, genetic drift, and gene flow

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50
Q

How does natural selection contribute to evolutionary change?

A

Natural selection favors individuals with traits that enhance survival and reproduction, causing those traits to become more common in the population over time.

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51
Q

What is genetic drift, and how does it cause evolutionary change?

A

Genetic drift is a random change in allele frequencies due to chance events, and it is more significant in small populations.

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52
Q

How does gene flow lead to evolutionary change?

A

Gene flow occurs when individuals migrate between populations, introducing new alleles and increasing genetic diversity within a population.

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53
Q

What is the bottleneck effect, and how does it impact genetic diversity?

A

The bottleneck effect occurs when a population is drastically reduced in size (due to a catastrophe or other event), leading to a loss of genetic diversity because only a small subset of the original gene pool survives.

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54
Q

How does the founder effect lead to genetic drift?

A

The founder effect occurs when a small group of individuals colonizes a new habitat or island, carrying only a subset of the original population’s genetic variation, leading to reduced genetic diversity in the new population.

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55
Q

How do the bottleneck effect and founder effect contribute to genetic drift?

A

Both effects cause genetic drift by reducing the population size and limiting genetic variation. In the bottleneck effect, this happens due to a population collapse, while in the founder effect, it occurs when a small group establishes a new population.

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56
Q

What is relative fitness?

A

the contribution an individual makes to the gene pool of the next generation, compared to the contributions of other individuals in the population.

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57
Q

How is relative fitness determined?

A

by how many offspring an individual produces and how many of those offspring survive and reproduce, relative to other individuals in the population.

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58
Q

What is stabilizing selection, and how does it affect a population?

A

Stabilizing selection favors intermediate phenotypes, selecting against extreme traits. This reduces variation and maintains the status quo in the population.

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59
Q

What is directional selection, and how does it affect a population?

A

Directional selection shifts the overall makeup of the population by favoring one of the phenotypic extremes over the other, leading to a gradual change in the population’s characteristics.

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60
Q

What is disruptive selection, and when does it occur?

A

Disruptive selection favors individuals at both ends of a phenotypic range over those with intermediate traits. It typically occurs when environmental conditions vary, making extreme traits more advantageous than intermediate ones.

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61
Q

a form of natural selection in which individuals with certain characteristics are more likely than other individuals to obtain mates

A

sexual selection

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62
Q

How can secondary sex characteristics give individuals an advantage in mating?

A

Secondary sex characteristics, such as bright colors, large size, or elaborate displays, can help individuals attract mates, increasing their chances of reproducing and passing on those traits.

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63
Q

What is intrasexual selection, and how does it influence mating?

A

Intrasexual selection occurs when individuals of the same sex compete directly for mates, such as through physical contests or displays, leading to increased reproductive success for the winner.

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64
Q

Why is evolution constrained by existing variation?

A

Evolution can only act on the genetic variation already present in a population. New, advantageous alleles do not arise on demand, and natural selection works with what exists.

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65
Q

How does historical constraints limit evolution?

A

Evolution co-opts existing structures and adapts them to new situations. Organisms are limited by their evolutionary history and cannot create entirely new, unrelated structures from scratch.

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66
Q

Why are adaptations often compromises?

A

Adaptations often serve multiple functions, and optimizing one function may limit the ability to perform others. This makes evolution a process of balancing different needs rather than achieving perfection.

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67
Q

How do chance, natural selection, and the environment interact in evolution?

A

Evolution is shaped by random events (like genetic drift), natural selection, and environmental factors. Because environments change unpredictably, evolution is a dynamic process that can take unexpected paths.

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68
Q

the process by which one species splits into two or more species, accounts for both the unity and diversity of life

A

speciation

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69
Q

What does the biological species concept define a species as?

A

A species is a group of populations whose members can interbreed in nature and produce fertile offspring, but not with members of other species. This concept emphasizes reproductive isolation.

70
Q

What is reproductive isolation in the context of the biological species concept?

A

Reproductive isolation occurs when members of different species are prevented from interbreeding, either by physical barriers or biological differences, maintaining species boundaries.

71
Q

What are some limitations of the biological species concept?

A

The BSC is problematic for: Asexual organisms, Hybridization (when species can interbreed and produce fertile offspring), Fossil species (can’t test interbreeding), Ring species (connected populations with limited or no interbreeding)

72
Q

based on observable physical traits and can be applied to asexual organisms and fossils

A

morphological species concept

73
Q

defines a species by its ecological niche and focuses on unique adaptations to particular roles in a biological communtiy

A

ecological species concept

74
Q

defines a species as the smallest group of individuals that share a common ancestor and thus form one branch of the tree of life

A

phylogenetic species concept

75
Q

serve to isolate the gene pools of species and prevent inbreeding

A

reproductive barriers

76
Q

What is the difference between prezygotic and postzygotic reproductive barriers?

A

Prezygotic barriers prevent fertilization from occurring, while postzygotic barriers affect the viability or fertility of offspring after fertilization.

77
Q

What are some examples of prezygotic barriers?

A

Habitat isolation, Temporal isolation, Behavioral isolation, Mechanical isolation, Gametic isolation

78
Q

What are some examples of postzygotic barriers?

A

Hybrid inviability, Hybrid sterility, Hybrid breakdown

79
Q

How can a geographically separated small population become genetically unique?

A

A small, geographically separated population can become genetically unique due to natural selection, mutation, and genetic drift, which alter its gene pool over time.

80
Q

How does natural selection contribute to genetic uniqueness in a separated population?

A

Natural selection acts on traits that are advantageous in the new environment, leading to changes in allele frequencies that may differ from the original population.

81
Q

How does mutation contribute to genetic uniqueness in a separated population?

A

Mutation introduces new genetic variations in the small population, adding to the differences between the isolated population and the original one.

82
Q

How does genetic drift affect genetic uniqueness in a separated population?

A

Genetic drift causes random changes in allele frequencies in small populations, which can lead to significant genetic differences over time.

83
Q

How can different food sources contribute to the development of reproductive barriers?

A

When populations of a species adapt to different food sources, they may evolve differently in terms of mating preferences and behavior, leading to ecological isolation and reproductive barriers over time.

84
Q

How do different pollinators lead to reproductive isolation?

A

Populations of plants can adapt to different pollinators (e.g., bees vs. hummingbirds), leading to behavioral isolation where populations no longer interbreed due to differences in pollination and mating behaviors.

85
Q

How does flower color influence reproductive isolation in monkey flowers?

A

In monkey flowers, a gene for flower color affects pollinator choice, leading to reproductive isolation between species by attracting different pollinators, which prevents interbreeding.

86
Q

How do predators or environmental pressures contribute to reproductive barriers?

A

Differences in environmental pressures like predators or habitat conditions can lead to geographical isolation and changes in mating behaviors, further promoting reproductive isolation.

87
Q

occurs when a new species arises within the same geographic area as its parent species

A

sympatric speciation

88
Q

duplication of the chromosome number due to errors in cell division

A

polyploidy

89
Q

How can habitat differentiation contribute to sympatric and allopatric speciation?

A

Habitat differentiation can lead to speciation by causing populations to exploit different resources or habitats. This reduces interbreeding, which can eventually lead to sympatric speciation or allopatric speciation

90
Q

How does sexual selection drive speciation?

A

Sexual selection, through mate choice, can cause populations to evolve distinct traits. Over time, this can lead to sympatric speciation when mating preferences cause reproductive isolation within the same geographic area.

91
Q

What is the difference between sympatric and allopatric speciation?

A

Sympatric speciation occurs when new species form within the same geographic area, often due to habitat differentiation or sexual selection. Allopatric speciation occurs when a population is geographically isolated, leading to genetic divergence over time.

92
Q

How does sexual selection contribute to sympatric speciation?

A

Sexual selection can lead to sympatric speciation if different populations within the same area develop distinct mating preferences, causing reproductive isolation and eventually leading to the formation of new species.

93
Q

How does experimental evolution help biologists test speciation?

A

By observing the process of speciation in laboratory populations (e.g., fruit flies or bacteria), scientists can manipulate variables and track how isolation, genetic drift, and natural selection drive species formation.

94
Q

Why are isolated ecosystems (like islands) useful for studying speciation?

A

Isolated ecosystems provide natural laboratories where populations can become genetically isolated, allowing scientists to study how genetic drift, natural selection, and sexual selection lead to the formation of new species.

95
Q

How has sexual selection contributed to the diversification of cichlids in Lake Victoria?

A

driven diversification by favoring traits like coloration and behavior that are selected by females. These preferences have led to speciation through mate choice and sexual dimorphism.

96
Q

What role does coloration play in the speciation of cichlids in Lake Victoria?

A

in mate choice, with females selecting brightly colored males. This has led to the evolution of different color morphs and contributed to reproductive isolation and speciation.

97
Q

What is adaptive radiation, and how does it apply to cichlids in Lake Victoria?

A

Adaptive radiation refers to the rapid diversification of species from a common ancestor. In Lake Victoria, sexual selection and ecological factors have led to the emergence of hundreds of cichlid species in a relatively short time.

98
Q

How does behavioral isolation contribute to speciation in cichlids?

A

Behavioral isolation, such as distinct mating rituals or courtship behaviors, prevents interbreeding between cichlid species, further promoting reproductive isolation and speciation.

99
Q

How is sexual selection a form of sympatric speciation in Lake Victoria?

A

In Lake Victoria, sexual selection based on traits like coloration and behavior has led to sympatric speciation, where new cichlid species form within the same geographic area due to reproductive isolation.

100
Q

the evolution of many diverse species from a common ancestor is known as

A

adaptive radiation

101
Q

How does isolation lead to speciation on islands?

A

reduces gene flow between populations, allowing for genetic divergence and the evolution of distinct species due to different environmental pressures and conditions.

102
Q

What is adaptive radiation, and why does it occur on islands?

A

the rapid diversification of an ancestral species into many species, each adapted to different ecological niches. It occurs on islands due to the availability of various habitats and limited competition.

103
Q

How does recolonization contribute to speciation on islands?

A

Recolonization occurs when populations spread to different parts of an island or chain, leading to further isolation and speciation as populations adapt to different conditions, reinforcing reproductive isolation.

104
Q

What is endemism, and why is it common on islands?

A

refers to species that are found only in a specific geographic location, such as an island. It is common on islands because species evolve independently in isolated environments, becoming specialized to local conditions.

105
Q

Can you give examples of adaptive radiation on islands?

A

Darwin’s finches in the Galápagos, Hawaiian honeycreepers, and cichlids in the African Great Lakes, all of which evolved into multiple species adapted to different ecological niches.

106
Q

Why are islands considered “natural laboratories” for studying evolution?

A

because they often provide geographic isolation, distinct ecological niches, and opportunities for adaptive radiation, allowing scientists to study speciation and the formation of endemic species.

107
Q

How have morphological studies contributed to understanding the speciation of Darwin’s finches?

A

show how traits like beak size and shape evolved to suit different food sources, helping to define distinct species and reinforcing adaptive radiation and speciation in Darwin’s finches.

108
Q

What role does geographic isolation play in the speciation of Darwin’s finches?

A

Geographic isolation between islands in the Galápagos Archipelago reduces gene flow between populations, leading to genetic divergence and the evolution of new species, as seen in Darwin’s finches.

109
Q

How have genetic studies advanced our understanding of Darwin’s finches speciation?

A

Genetic studies have confirmed that Darwin’s finches share a common ancestor and revealed how gene flow and selective pressures have driven their genetic divergence, leading to the formation of distinct species.

110
Q

How does beak morphology correlate with the ecological roles of Darwin’s finches?

A

Beak morphology in Darwin’s finches is adapted to their food sources; large beaks for tough seeds, small beaks for insects, and specialized shapes for cactus flowers, driving their diversification into different species.

111
Q

How have environmental changes influenced the speciation of Darwin’s finches?

A

Environmental changes like climate shifts and food availability (e.g., during droughts) have created selective pressures that favor certain traits in Darwin’s finches, driving speciation through adaptive radiation.

112
Q

What did Peter and Rosemary Grant study in their long-term research on Darwin’s finches?

A

The Grants studied how natural selection influences beak size in Galápagos finches, specifically how environmental factors (like food availability) drive evolutionary changes in real time.

113
Q

How did the 1977 drought impact beak size in Darwin’s finches?

A

led to a scarcity of small seeds, favoring finches with larger beaks that could crack harder seeds, resulting in an increase in average beak size in the population due to natural selection.

114
Q

What did the Grants’ studies reveal about the genetic basis of beak size in Darwin’s finches?

A

The Grants discovered that beak size was heritable, meaning that offspring tended to inherit the beak size of their parents, allowing natural selection to act on this trait over generations.

115
Q

How do environmental changes like drought and rainfall affect evolutionary processes in Darwin’s finches?

A

Environmental changes such as drought and rainfall influence the abundance of different seed types, favoring finches with either larger or smaller beaks depending on the food availability, leading to fluctuations in beak size over time.

116
Q

Why are the Grants’ studies on Darwin’s finches considered a landmark in evolutionary ecology?

A

The Grants’ research is groundbreaking because they observed evolution in real time, documenting how natural selection acts on beak size and other traits in response to immediate environmental pressures.

117
Q

How quickly did the Grants observe evolutionary changes in beak size in their finch population?

A

The Grants observed evolutionary changes in beak size over just a few generations, showing how natural selection can cause rapid evolutionary shifts in response to environmental changes like drought and food availability.

118
Q

What is a hybrid zone?

A

a region where two closely related species come into contact and mate, producing at least some hybrid offspring.

119
Q

What is reinforcement in the context of hybrid zones?

A

Reinforcement occurs when natural selection strengthens reproductive barriers between two species, preventing hybridization and promoting speciation.

120
Q

What does fusion mean in the context of hybrid zones?

A

Fusion is the process by which two species that once diverged and formed a hybrid zone merge back into a single species due to increased gene flow and similar fitness of hybrids.

121
Q

How does a stable hybrid zone differ from other outcomes of hybridization?

A

In a stable hybrid zone, hybrids continue to be produced, but the two species maintain their genetic distinction and do not merge or evolve into separate species over time.

122
Q

What factors determine whether a hybrid zone will result in reinforcement, fusion, or remain stable?

A

the fitness of hybrids, the degree of reproductive isolation between the species, environmental conditions, and the genetic compatibility of the parent populations.

123
Q

How does hybrid fitness influence the outcome of hybridization in contact zones?

A

If hybrids are fit and can reproduce successfully, fusion between species is more likely. If hybrids have low fitness, reinforcement may occur to maintain species separation.

124
Q

What is the key difference between artificial selection and natural selection in terms of the number of generations?

A

Artificial selection occurs over a relatively short number of generations, while natural selection typically requires a much greater number of generations to result in significant changes.

125
Q

Why must some members of a population be genetically resistant to a pesticide for resistance to develop?

A

Some individuals must be genetically resistant so they survive the pesticide and pass on their resistance traits to future generations.

126
Q

What characteristic of Ambulocetus helped it function well on land and in water?

A

Joints of forelimbs (land): allowed movement on land; Powerful tail and large, paddle-like hind feet (water): aided in swimming.

127
Q

What effect did farming and human activities in the 19th and 20th centuries have on the greater prairie chicken population?

A

These populations experienced the bottleneck effect, which reduced their number of alleles.

128
Q

What did Peter and Rosemary Grant’s research on beak size in finches in the Galápagos Islands show?

A

that natural selection is an ongoing, constant process

129
Q

Which outcome from experiments with birds and frogs supports the hypothesis that females prefer male traits linked to “good genes”?

A

The offspring of more attractive males have better health and longer survival than the offspring of less attractive males.

130
Q

What do the similarities in DNA, RNA, and genetic code among all living things provide strong evidence for?

A

They provide strong evidence for descent from a very distant common ancestor.

131
Q

For most plants and animals, what is the mutation rate per generation, and in which type of populations will this rate have the least impact?

A

The mutation rate is about 1/100,000 genes per generation, and it has the least impact in populations with long time spans between generations.

132
Q

What results from an inactive pseudogene that normally encodes for the enzyme GLO?

A

Humans must consume vitamin C in their diet.

133
Q

What is the age range of fossils observed in the sedimentary rock at the Grand Canyon?

A

The fossils are hundreds of millions of years old.

134
Q

What mechanism of microevolution is revealed by rats from one town in Norway hitching rides on different ships, resulting in different fur colors on each ship after ten years?

A

the effects of the founder effect.

135
Q

What causes new alleles to arise, and what does this result in?

A

by mutation, which causes genetic variation.

136
Q

What are the characteristics of a scientific theory?

A

A scientific theory is a widely accepted explanatory idea, broader than a hypothesis, that generates new hypotheses and is supported by a large body of evidence.

137
Q

What is a typical use of the Hardy-Weinberg equation in public health?

A

It is used to estimate the number of people with alleles for specific diseases.

138
Q

What are the consequences for a population of balancing selection and heterozygote advantage?

A

They preserve genetic variation.

139
Q

Why can’t natural selection fashion “perfect” organisms?

A

because adaptations are often compromises, evolution is limited by historical constraints, and change, natural selection, and the environment all interact.

140
Q

What type of selection was operating in Maine when two extremely cold winters led to increased survival of barn swallows with larger bodies?

A

Directional selection.

141
Q

What is the definition of a fossil cast?

A

A fossil cast is an empty mold of a specimen left in sediment that is filled in with dissolved minerals.

142
Q

In evolutionary terms, how is an organism’s relative fitness measured?

A

An organism’s relative fitness is measured by its contribution to the gene pool of the next generation relative to the contribution of other organisms to that gene pool.

143
Q

Among antibiotic-resistant bacteria, which causes the highest number of infections, and which causes the greatest proportion of “urgent” cases according to the CDC?

A

Streptococcus pneumoniae causes the highest number of infections, while Neisseria gonorrhoeae causes the greatest proportion of cases classified as “urgent” by the CDC.

144
Q

Which conditions favor the development of drug resistance in bacteria?

A

Random mutation and nonrandom selection.

145
Q

What is one consequence of increased human mobility compared to 300 years ago?

A

Gene flow is a more important cause of microevolution than in the past.

146
Q

What is the first step in allopatric speciation of a population?

A

Geographic isolation of subpopulations.

147
Q

What does the different mating calls of three frog species living in the same pond illustrate?

A

This illustrates behavioral reproductive isolation, which is a prezygotic barrier to reproduction.

148
Q

Which species concept has been used to identify the largest number of species and is particularly useful for studying speciation in fossils?

A

morphological

149
Q

What might occur over time in a squirrel population after an earthquake causes a large stream to flow down the center of the valley?

A

Two allopatric species of squirrel would evolve.

150
Q

What is it called when one common ancestor gives rise to many diverse species?

A

Adaptive radiation.

151
Q

What is the term for fossils in different layers of rock showing slight differences, with many transitional fossils linking newer species to older ones?

A

Gradual equilibrium.

152
Q

What is the term for fossils that appear suddenly in strata of rock, persist through several layers, then disappear just as suddenly?

A

Punctuated equilibrium.

153
Q

What would you predict will occur as the water of Lake Victoria becomes murkier due to pollution and development, affecting the cichlid fish species?

A

An increasing proportion of hybrids will form.

154
Q

What did the work of Peter and Rosemary Grant in the Galápagos Islands show?

A

evolution of finch beak sizes over a 40-year period.

155
Q

What does the difference in appearance between collared and pied flycatchers in allopatric versus sympatric habitats illustrate?

A

reinforcement of a reproductive barrier.

156
Q

What is one limitation of the biological species concept?

A

Its inability to differentiate species of prokaryotes.

157
Q

What is likely to occur in a hybrid zone?

A

Members of different species have opportunities to meet and mate.

158
Q

What should the farmer write to the rice sellers after discovering that the plants from two different companies produced weak offspring that did not produce seeds?

A

“The rice plants you sent me showed hybrid breakdown. Please refund my money.”

159
Q

How is sympatric speciation best defined?

A

Sympatric speciation is speciation that occurs without geographic separation between populations.

160
Q

What is the chromosome count in the gametes of a tetraploid plant (4n) compared to its parent diploid plant, and with which plants can a tetraploid plant successfully mate?

A

The gametes of a tetraploid plant (4n) contain 2n chromosomes, while the gametes of its parent diploid plant contain n chromosomes. A tetraploid plant can successfully mate with itself or another tetraploid.

161
Q

What would you predict would occur over time if starch- and maltose-preferring fruitflies were allowed to breed only with others of the same food preference?

A

The populations would become more reproductively isolated from one another.

162
Q

The evolution of numerous species, such as Darwin’s finches, on different, isolated islands in the Galápagos is an example of __________.

A

Adaptive radiation

163
Q

Females of different species of firefly respond to different blinking rhythms by the males of their own species. This is an example of a __________ reproductive barrier.

A

behavioral

164
Q

Most hybrid animals are sterile. This illustrates a type of __________.

A

Postzygotic reproductive barrier.

165
Q

Grolar bears result from __________ contact between __________ because of __________.

A

Increased: polar bears and grizzly bears: melting ice.

166
Q

One species of male bowerbirds builds elaborate bowers filled with colorful objects, while another species builds simpler bowers filled with drab-colored objects. This example could be used to demonstrate which of the following?

A

The importance of sexual selection by females in speciation.

167
Q

Which species concept is described by the statement: “Members of the same species occupy the same niche”?

A

Ecological species concept.

168
Q

Which species concept is described by the statement: “Members of the same species have the potential to interbreed in nature and produce fertile offspring”?

A

Biological species concept.

169
Q

Which species concept is described by the statement: “Members of the same species share a common ancestor”?

A

Phylogenetic species concept.

170
Q

What observations did scientists make that led them to conclude that pollinator preference preserves the reproductive barrier between two species of monkeyflowers?

A

Bees visit only pink-colored monkey flowers; hummingbirds visit only red-colored monkey flowers.

Biological concepts final exam (1 decks)

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