Chapter 20: Microevolution

Question 1

What are continuous traits that can be measured?

Answer 1

Quantitative

Question 2

What are discrete character states or categories called?

Answer 2

qualitative

Question 3

What are the two sources of phenotypic variation?

Answer 3

1. environmental
2. genetic

Question 4

What are the two sources of genetic variation?

Answer 4

1. rearrangement of existing alleles
   2.mutations producing new alleles

Question 5

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

Answer 5

genetic

Question 6

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

Answer 6

microevolution

Question 7

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

Answer 7

population genetics

Question 8

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

Answer 8

evolution

Question 9

T or F: Natural populations contain substantial genetic variation

Answer 9

True

Question 10

genetic variation is required for ______ to occur

Answer 10

evolution

Question 11

What are five ways to measure genetic variation?

Answer 11

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

Question 12

What principle predicts genotype frequencies?

Answer 12

Hardy Weinberg principle

Question 13

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

Answer 13

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

Question 14

frequency of first allele is __

Answer 14

p

Question 15

frequency of the second allele is __

Answer 15

q

Question 16

What is the hardy-weinberg principle equation?

Answer 16

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

Question 17

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

Answer 17

change

Question 18

What makes populations vary from Hardy-Weinberg equilibrium?

Answer 18

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

Question 19

What are the five agents of evolutionary change?

Answer 19

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

Question 20

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

Answer 20

mutation

Question 21

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

Answer 21

gene flow

Question 22

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

Answer 22

nonrandom mating

Question 23

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

Answer 23

assortative mating

Question 24

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

Answer 24

disassortative mating

Question 25

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

Answer 25

Genetic drift

Question 26

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

Answer 26

founder effect

Question 27

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

Answer 27

Bottleneck effect

Question 28

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

Answer 28

genetic variability

Question 29

_______ favors some genotypes over others

Answer 29

selection

Question 30

_______ selection- breeder selects desired characteristics

Answer 30

artificial

Question 31

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

Answer 31

natural

Question 32

______ relatives can harbor higher diversity than cultivated crops

Answer 32

wild

Question 33

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

Answer 33

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

Question 34

T or F: Natural selection is a process

Answer 34

TRUE

Question 35

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

Answer 35

evolution

Question 36

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

Answer 36

evolution

Question 37

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

Answer 37

climatic conditions

Question 38

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

Answer 38

pesticide, microbial resistance,

Question 39

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

Answer 39

fitness

Question 40

The most fit phenotype is assigned fitness value of ___

Answer 40

1

Question 41

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

Answer 41

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

Question 42

selection favors phenotypes with the greatest _______

Answer 42

fitness

Question 43

phenotype with greater fitness usually increases in _______

Answer 43

frequency

Question 44

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

Answer 44

fitness

Question 45

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

Answer 45

mate

Question 46

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

Answer 46

parental investment

Question 47

______ have a higher parental investment

Answer 47

females

Question 48

______ face very different selective presssures

Answer 48

sexes

Question 49

in _______ care, mater choice should be more equal

Answer 49

biparental

Question 50

______ selection has competition for mates

Answer 50

sexual

Question 51

________ selection- competitive interactions between members of one sex

Answer 51

intrasexual

Question 52

_______ selection-mate choice

Answer 52

intersexual

Question 53

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

Answer 53

secondary sexual

Question 54

_______ _______- differences between sexes

Answer 54

sexual dimorphism

Question 55

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

Answer 55

sperm competition

Question 56

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

Answer 56

intrasexual

Question 57

_______ selection has the active choice of a mate

Answer 57

intersexual

Question 58

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

Answer 58

handicap hypothesis

Question 59

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

Answer 59

sensory exploitation

Question 60

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

Answer 60

stimuli

Question 61

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

Answer 61

Frequency-dependent

Question 62

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

Answer 62

negative

Question 63

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

Answer 63

positive

Question 64

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

Answer 64

oscillating

Question 65

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

Answer 65

oscillating

Question 66

___________ advantage: Heterozygotes are favored over homozygotes

Answer 66

heterozygote

Question 67

What is an example of heterozygote advantage?

Answer 67

sickle cell allele

Question 68

_______ operates on all the genes for the trait

Answer 68

selection

Question 69

Selection changes the population depending on which ______ are favored

Answer 69

genotypes

Question 70

What are the three types of selection?

Answer 70

1. disruptive 2. directional 3. stabilizing

Question 71

_________ displacement can cause disruptive selection

Answer 71

character

Question 72

______ selection acts to eliminate intermediate types

Answer 72

disruptive

Question 73

_______ selection is where it acts to eliminate one extreme

Answer 73

directional

Question 74

_________ selection is where it acts to eliminate both extremes

Answer 74

stabilizing

Question 75

________ selection often occurs in nature when the environment changes

Answer 75

directional

Question 76

_________ selection makes intermediate more common by eliminating extremes

Answer 76

stabilizing

Question 77

________ and _______ _____ may counter selection

Answer 77

mutations and genetic drift

Question 78

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

Answer 78

mutation

Question 79

_______ is nonrandom

Answer 79

selection

Question 80

_______ _______ is random

Answer 80

genetic drift

Question 81

________ may decrease an allele favored by selection

Answer 81

genetic drift

Question 82

________ usually overwhelms drift except in small populations

Answer 82

selection

Question 83

Gene flow can be 1. 2.

Answer 83

constructive constraining

Question 84

_______ gene flow, spread beneficial mutation to other populations

Answer 84

constructive

Question 85

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

Answer 85

constraining

Question 86

What are the two limits of selection?

Answer 86

1. multiple phenotypic effects of alleles 2. lack of genetic variation

Question 87

________ variation may not genetic basis

Answer 87

phenotypics

Question 88

What are the five agents of Microevolutionary change?

Answer 88

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

Question 89

________ is heritable change in DNA

Answer 89

mutation

Question 90

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

Answer 90

mutation

Question 91

mutation effect on average fitness is:

Answer 91

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

Question 92

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

Answer 92

gene flow

Question 93

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

Answer 93

gene flow

Question 94

speciation can result from long-term _______

Answer 94

microevolution

Question 95

Species limits can be tested by measuring _______ frequencies

Answer 95

allele