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Bio 214 > Chapter 20: Microevolution > Flashcards

Chapter 20: Microevolution Flashcards

1
Q

What are continuous traits that can be measured?

A

Quantitative

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2
Q

What are discrete character states or categories called?

A

qualitative

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3
Q

What are the two sources of phenotypic variation?

A
  1. environmental
  2. genetic
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4
Q

What are the two sources of genetic variation?

A
  1. rearrangement of existing alleles
    2.mutations producing new alleles
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5
Q

_______ variation is where there are differences in alleles within a population

A

genetic

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6
Q

________ is the change in allele frequency within a population over time

A

microevolution

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7
Q

_______ _______ is the study of properties of genes in a population

A

population genetics

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8
Q

________ results in a change in the genetic composition of a population

A

evolution

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9
Q

T or F: Natural populations contain substantial genetic variation

A

True

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10
Q

genetic variation is required for ______ to occur

A

evolution

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11
Q

What are five ways to measure genetic variation?

A
  1. lengths of simple sequence repeats (SSRs)
  2. Sequences of individual genes
  3. Karyotypes
  4. whole genome sequencing
  5. single nucleotide polymorphisms
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12
Q

What principle predicts genotype frequencies?

A

Hardy Weinberg principle

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13
Q

With the Hardy Weinberg equilibrium, proportions of genotypes do not change in a population long as:
1.
2.
3.
4.
5.

A
  1. no mutation takes place
  2. no genes are transferred to from other sources
  3. mating is random
  4. The population size is very large
  5. No selection
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14
Q

frequency of first allele is __

A

p

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15
Q

frequency of the second allele is __

A

q

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16
Q

What is the hardy-weinberg principle equation?

A

p^2+2pq+q^2= 1

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17
Q

If all 5 assumptions for Hardy-weinberg equilibrium are true, allele and genotype frequencies do not ______ from one generation to the next

A

change

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18
Q

What makes populations vary from Hardy-Weinberg equilibrium?

A
  1. Natural selection might favor homozygotes over heterozygotes
  2. Individuals may choose to mate with genetically similar individuals
  3. Influx of individuals from other populations
  4. Mutations occurring
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19
Q

What are the five agents of evolutionary change?

A
  1. Mutation
  2. Gene flow
  3. Nonrandom Mating
  4. Genetic Drift
  5. Selection
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20
Q

What agent of evolutionary change:
-rates generally low
-other evolutionary processes usually more important in changing allele frequency
-ultimate source of genetic variation
-makes evolution possible

A

mutation

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21
Q

What agent of evolutionary change:
-movement of alleles from one population to another
-animal physically moves into new population
-drifting of gametes or immature stages of plants or animals into an area
-pollen and seeds can travel long distances

A

gene flow

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22
Q

What agent of evolutionary change:
- assortative mating
-disassortative mating

A

nonrandom mating

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23
Q

What type of mating has:
-phenotypically similar individuals mate
-increases proportion of homozygous individuals

A

assortative mating

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24
Q

What type of mating has:
-phenotypically different individuals mate
-produces excess of heterozygotes

A

disassortative mating

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25
Q

What agent of evolutionary change:
- in small populations, allele frequency may change by chance alone
-magnitude of genetic drift is inversely related to population size
-can lead to the loss of alleles in isolated populations and uncommon alleles are more vulnerable
-founder effect
-bottleneck effect

A

Genetic drift

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26
Q

What type of genetic drift is
-one or a few individuals disperse and become the founder of a new, isolated population

A

founder effect

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27
Q

What type of genetic drift is where a drastic reduction in population size due to drought, disease, other natural forces

A

Bottleneck effect

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28
Q

Endangered species experience severe population bottlenecks, which result in the loss of ______ _______

A

genetic variability

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29
Q

_______ favors some genotypes over others

A

selection

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30
Q

_______ selection- breeder selects desired characteristics

A

artificial

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31
Q

_______ selection- environmental conditions determine which individuals produce the most offspring

A

natural

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32
Q

______ relatives can harbor higher diversity than cultivated crops

A

wild

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33
Q

What three conditions must be met for evolution by natural selection to occur
1.
2.
3.

A
  1. variation must exist among individuals in a population
  2. variation among individuals must result in differences in the number of offspring surviving in the next generation
  3. variation must have a genetic basis
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34
Q

T or F: Natural selection is a process

A

TRUE

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35
Q

_______ is the historical record, or outcome, of change through time

A

evolution

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36
Q

result of ______ driven by natural selection is that populations become better adapted to their environment

A

evolution

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37
Q

selection to match _______ _______
is where :
- enzyme allele frequencies often vary with latitude
- allele frequencies of enzyme lactate dehydrogenase in fish vary geographically
- enzyme formed by these alleles function differently at different temperatures

A

climatic conditions

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38
Q

Selection for ______ and ______ ________
is where evolution of resistance to antibiotics in many disease-causing pathogens

A

pesticide, microbial resistance,

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39
Q

_________ is where individuals with one phenotype leave more surviving offspring in the next generation than individuals with an alternative phenotype

40
Q

The most fit phenotype is assigned fitness value of ___

41
Q

What are the four components of fitness:
1.
2.
3.
4.

A

1.survival
2. sexual selection
3. number of offspring per mating
4. traits favored for one component may be a disadvantage for others

42
Q

selection favors phenotypes with the greatest _______

43
Q

phenotype with greater fitness usually increases in _______

44
Q

males and females usually differ in how they attempt to maximize ______

45
Q

reproductive strategies:
females evaluate a male’s quality and then decide whether to ____

46
Q

______ ________ refers to the energy and time each sex invests in producing and rearing offspring

A

parental investment

47
Q

______ have a higher parental investment

48
Q

______ face very different selective presssures

49
Q

in _______ care, mater choice should be more equal

A

biparental

50
Q

______ selection has competition for mates

51
Q

________ selection- competitive interactions between members of one sex

A

intrasexual

52
Q

_______ selection-mate choice

A

intersexual

53
Q

______ _____ characteristics used to combat other males or to persuade members of opposite sex

A

secondary sexual

54
Q

_______ _______- differences between sexes

A

sexual dimorphism

55
Q

______ ______- selects for features that increase probability that a male’s sperm will fertilize theeggs

A

sperm competition

56
Q

________ selection- individuals of one sex ( usually males) compete with each other for the opportunity to mate

A

intrasexual

57
Q

_______ selection has the active choice of a mate

A

intersexual

58
Q

______ ______ - only genetically superior mates survive with a handicap such as a long tail that is a hinderance in flying

A

handicap hypothesis

59
Q

______ _______- evolution in males of signal that exploits preexisting biases

A

sensory exploitation

60
Q

some courtship displays appear to have evolved from a predisposition in females to respond to certain ______

61
Q

__________-________ selection: is where fitness of a phenotype depends on its frequency within the population

A

Frequency-dependent

62
Q

__________ frequency-dependent selection:
-rare phenotypes favored by selection
-rare forms may not be in “search image”; preyed upon less frequently

63
Q

__________ frequency-dependent selection
- favors common form
-tends to elimante variation

64
Q

_______ selection is where selection favors one phenotype at one time and another phenotype at another time

A

oscillating

65
Q

________ selection’s effect will be to maintain genetic variation in the population

A

oscillating

66
Q

___________ advantage:
Heterozygotes are favored over homozygotes

A

heterozygote

67
Q

What is an example of heterozygote advantage?

A

sickle cell allele

68
Q

_______ operates on all the genes for the trait

69
Q

Selection changes the population depending on which ______ are favored

70
Q

What are the three types of selection?

A
  1. disruptive
  2. directional
  3. stabilizing
71
Q

_________ displacement can cause disruptive selection

72
Q

______ selection acts to eliminate intermediate types

A

disruptive

73
Q

_______ selection is where it acts to eliminate one extreme

A

directional

74
Q

_________ selection is where it acts to eliminate both extremes

A

stabilizing

75
Q

________ selection often occurs in nature when the environment changes

A

directional

76
Q

_________ selection makes intermediate more common by eliminating extremes

A

stabilizing

77
Q

________ and _______ _____ may counter selection

A

mutations and genetic drift

78
Q

In nature, _______ rates are rarely high enough to counter selection

79
Q

_______ is nonrandom

80
Q

_______ _______ is random

A

genetic drift

81
Q

________ may decrease an allele favored by selection

A

genetic drift

82
Q

________ usually overwhelms drift except in small populations

83
Q

Gene flow can be
1.
2.

A

constructive
constraining

84
Q

_______ gene flow, spread beneficial mutation to other populations

A

constructive

85
Q

_______ gene flow can impede adaptation by continual flow of inferior alleles from other populations

A

constraining

86
Q

What are the two limits of selection?

A
  1. multiple phenotypic effects of alleles
  2. lack of genetic variation
87
Q

________ variation may not genetic basis

A

phenotypics

88
Q

What are the five agents of Microevolutionary change?

A
  1. mutation
  2. gene flow
  3. genetic drift
  4. natural selection
  5. nonrandom mating
89
Q

________ is heritable change in DNA

90
Q

_________ effect on genetic variation is that introduces new genetic variation into population; does not change allele frequencies quickly,

91
Q

mutation effect on average fitness is:

A

unpredictable effect on fitness; most mutations in protein-coding genes lower fitness

92
Q

________ is the change in allele frequencies as individuals caused by chance

93
Q

The _____ ______effect on genetic variation is where it may introduce genetic variation from another population

94
Q

speciation can result from long-term _______

A

microevolution

95
Q

Species limits can be tested by measuring _______ frequencies

Bio 214 (23 decks)

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