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Evolutionary Biology > EXAM 2 > Flashcards

EXAM 2 Flashcards

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1
Q

founded the field of population genetics
use of mathematical theory and hypothesis testing which are components of scientific inquiry

A

modern synthesis

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2
Q

Darwin’s postulate 1 restated in population genetics terms

A

allelic variation exists among individuals

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3
Q

Darwin’s postulate 2 restated in population genetics terms

A

alleles are passed down from parent to offspring (through meiosis and fertilization)

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4
Q

Darwin’s postulate 3 restated in population genetics terms

A

more young are born than can survive

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5
Q

Darwin’s postulate 4 restated in population genetics terms

A

some allelic combinations are more fit than others (these can survive to reproduce more often) based on allelic variants

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6
Q

change in frequency of alleles in a population over generations

A

new definition of evolution

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7
Q

evolution at the population level, the level at which evolution acts

A

microevolution

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8
Q

a null model for the behavior of genes in a population, specifies what will happen to frequencies of alleles and genotypes
applies to all diploid sexual organisms

A

Hardy-Weinberg Equilibrium

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9
Q

group of interbreeding individuals and their offspring
adults produce gametes
gametes combine to make zygotes
zygotes grow up to become next generation of adults

A

population in HWE

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10
Q

HWE- tracks the fate of _____ across generations in a population
find out if particular alleles become more or less common over time

A

mendelian genes

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11
Q

imagine 60% of eggs and sperm received allele A and 40% received allele a
frequency of A allele in the gene pool = 0.6, and the a allele= 0.4
when egg and sperm meet what proportion of genotypes will be AA?

A

60% egg will be A, 60% sperm will be A
0.6 X 0.6 = 0.36
so 36% of zygotes will have genotype AA

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12
Q

imagine 60% of eggs and sperm received allele A and 40% received allele a
frequency of A allele in the gene pool = 0.6, and the a allele= 0.4
when egg and sperm meet what proportion of genotypes will be aa?

A

0.4 X 0.4 = 0.16
16% will be aa

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13
Q

imagine 60% of eggs and sperm received allele A and 40% received allele a
frequency of A allele in the gene pool = 0.6, and the a allele= 0.4
when egg and sperm meet what proportion of genotypes will be Aa?

A

0.6 X 0.4 X 2 = 0.48
(Aa = 0.6 X 0.4, aA = 0.4 X 0.6 therefore multiplied by 2)
48% homozygous

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14
Q

what is the trick to know your genotypic frequencies are correct?

A

they should add up to 1

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15
Q

determine frequencies in the next generation

A

multiply the heterozygote proportion by 1/2 and add this to the homozygote proportion

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16
Q

if a population is in Hardy Weinberg equilibrium it will never ____ regardless of starting frequencies

A

evolve

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17
Q

allele frequencies are in equilibrium and are the same as the first generation

A

numerical example shows what in HWE?

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18
Q

p+q =

A

1

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19
Q

Frequency of allele A
(AA, AB, BB)

A

p

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20
Q

Frequency of allele B
(AA, AB, BB)

A

q

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21
Q

HWE equation 1

A

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

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22
Q

HWE equation 2

A

(p+q)^2 = p^2 +2pq+ q^2

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23
Q

individuals homozygous for dominant

A

p2

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24
Q

individuals heterozygous for both alleles (EX N and n)

A

2pq

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25
Q

individuals homozygous for recessive

A

q^2

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26
Q

the allele frequencies in a population will not change generation after generation

A

conclusion 1 of HWE

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27
Q

if the allele frequencies in a population are given by p and q, the genotype frequencies will be given by p^2, 2pq, and q^2
expected values

A

conclusion 2 of HWE

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28
Q

there is no selection and all members contribute equally to the gene pool

A

HWE assumptions 1

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29
Q

there is no mutation
no new alleles are created

A

HWE assumptions 2

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30
Q

there is no migration
all alleles stay in the gene pool

A

HWE assumptions 3

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31
Q

there is an infinitely large population size
no random events = no genetic drift

A

HWE assumptions 4

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32
Q

panmixia
mates are chosen randomly

A

HWE assumptions 5

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33
Q

allows prediction of genotypic frequencies given allele frequencies
allele and genotypic frequenciess will not change as long as the assumptions are met

A

why use HWE?

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34
Q

HWE phenotypic example with dominance

A

polydactyl cats is from an autosomal dominant trait caused by a variant

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35
Q

polydactyl cat example: if a population of 100 cats has 60 polydactl and 40 normal individuals. Then the frequencies of polydacryl and normal phenotypes are:

A

0.60 and 0.40

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36
Q

by having explicit assumptions (HWE) the violations of assumptions can be used to determine which forces are causing

A

disequilibrium or evolution

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37
Q

a change in allele frequency over time, allele frequencies do not change in a HWE population and therefore it does not have:

A

evolution (in terms of HWE)

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38
Q

what happens when assumptions are broken

A

no selection
no mutation
no migration
large population size
random mating

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39
Q

differential reproductive success

A

individuals with particular phenotypes survive to reproduce more than others

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40
Q

Cavener and Clegg used two alleles for alcohol dehydrogenase locus (Adhf and Adhs) to break down alcohol at different rates. They maintained two populations of flies spiked with alcohol and two controls without alcohol
determined genotypes at each generation with random samples.

A

empirical study of drosophila

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41
Q
A
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42
Q

in the empirical study of drosophila, which populations appeared to be in Hardy Weinberg equilibrium where the alleles did not change

A

control populations

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43
Q

in the empirical study of drosophilia populations under seletion pressure showed a decline in:

A

Adhs allele

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44
Q

the populations evolved in the study of drosophila because of selection which favored:

A

better ability to break down alcohol

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45
Q

allele frequencies do nto change but genotype frequencies cannot be calculated by HWE

A

conclusion 2 being violated

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46
Q

Pregnant women are more susceptible to malaria
invades the placenta
Causes placental inflammation and usually death of the child
*Influences placenta development and inflammation
*SS and SL produce more of the protein than LL
Malaria season (76 infants SS=16,SL=50,LL=10)

A

malaria example of selection

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47
Q

test if HWE holds or is broken, how to determine whether the difference between the actual genotype frequencies and HWE expected genotype frequencies is significant

A

chi-squared test

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48
Q

X^2 = sum (observed – expected)^2 /expected

A

Chi-squared equation

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49
Q

frequency of allele 20% 1/4 of people with genotype +/+ or +/delta32 die before reproducing
all delta32/delta32 individuals survive
after 40 gens (1000yrs) the delta32 allele is nearly 100%
(graph with an upward slope increase and leveling of at 1.0)

A

CCR5-delta 32 model 1

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50
Q

frequency of allele 20%
HIV infection rate less than 1%
all delta32/delta 32 individuals survive
after 40 gens (1000yrs) the delta32 allele is still at 20%
selection is too weak to cause a large change in allele frequencies
(graph with a horizontal line at 0.2)

A

CCR5-delta 32 model 2

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51
Q

frequency of allele 1%
1/4 of people with genotype +/+ or +/delta32 die before reproducing
all delta32/delta32 individuals survive after 40 gens (1000yrs) the delta32 allele is still at 1%
most copies of delta32 would be heterozygotes and hidden from selection
(graph with horizontal line at 0.1)

A

CCR5-delta 32 model 3

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52
Q

two alleles + and l
individuals with genotype +/+ or +/l are normal
individuals with genotype l/l do not survive
this is a recessive lethal allele

A

Flour beetle selection example

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53
Q

in the flour beetles with the l locus because they have ____ expect populations to evolve to lower l frequencies

A

lower fitness

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54
Q

flour beetle selection ex: frequency of allele l dropped as expected but was not eliminated altogether

A

l frequency over 12 generations

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55
Q

if recessive is common, evolution is rapid
when recessive is rare, evolution is very slow
when rare, the recessive allele is usually hidden from selection- the allele is maintained even if it is negative toward the population

A

dominance and allele frequency interaction

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56
Q

selection coefficient: fitness of an allele, ranges from 0-1

A

w

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57
Q

selection coefficient: strength of selection of an allele
gives strength of selection on homozygous recessive phenotype
amount of strength against the phenotype

A

s

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58
Q

selection in favor of the phenotype

A

positive S

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59
Q

selection against the phenotype

A

negative S

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60
Q

w++ = 1 - s, w+l = 1 - s, wll = 1

A

negative selection on dominant phenotypes

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61
Q

the fixation point of selection, a mechanism of evolution

A

genetic drift

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62
Q

when one allele is dominant and one is recessive _____ is equal to that of one kind of homozygote

A

heterozygote fitness

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63
Q

changes rate of evolution
eventually one allele may become fixed and the other is lost

A

heterozygote fitness is intermediate to two homozygotes

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64
Q

different evolutionary outcomes are produced

A

heterozygote fitness is superior or inferior to homozygotes

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65
Q

heterozygote has an advantage over homozygote
fitness advantage for homozygote

A

overdominance

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66
Q

example with drosophila melanogaster
single locus
homozygotes for V allele viable
homozygotes for L allele lethal
initial V allele frequency is 0.5
initial L allele frequency is 0.975
Rate slowed and viable allele reached equilirbium at 0.79
what happens to the lethal allele

A

lethal should decrease in frequency overtime but not completely disappear

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67
Q

what is present in the drosophila melanogaster example of selection
meaning heterozygotes have higher fitness than either homozygote
this maintains genetic diversity
benefits of heterozygosity outweighs the benefits from the homozygotes

A

Heterozygote superiority or Overdominance

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68
Q

heterozygotes may have lower fitness than either homozygote
so the homozygote is preferred over heterozygote

A

under dominance

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69
Q

compound chromosomes

A

C(2)

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70
Q

normal chromosomes

A

N(2)

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71
Q

if Wc(2)C(2) how many survive

A

0.25

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72
Q

if Wc(2)n(2) how many survive

A

0

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73
Q

if Wn(2)n(2) how many survive

A

1

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74
Q

reduces genetic diversity within a population by pushing alleles to fixation

A

heterozygote inferiority

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75
Q

for the second example with fruit flies: Within the population, it is _____ diversity but outside it is ______ diversity

A

eliminating, maintaining

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76
Q

in this graph: heterozygote has the advantage of fitness increases and moves towards an optimum in the middle- increase diversity, to get the most heterozygotes in a population you need the most mix of alleles

A

overdominance graph

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77
Q

in this graph: homozygote has the advantage -fitness will increase and reduce diversity

A

under dominance graph

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78
Q

in nature, selection changes over time this maintains genetic diversity

A

frequency-dependent selection

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79
Q

fish that attack other fish for food by attacking them from behind grabbing their scales and darting away

A

perissodus microlepis (scale-eating fish)

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80
Q

left-handed and right-handed determines which side of the fish its mouth will be which allele is dominant and which is recessive
right always attack the left side
left always attack the right side (means for selection depending on preferred side)

A

right-handed (dominant)
left-handed (recessive)

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81
Q

in frequency-dependent selection, the population is always evolving for a ____ frequency of rarer type because it is a more successful predator and is more fit, leaving more offspring

A

higher

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82
Q

when one form becomes more popular and common the other decreases- selection and fitness changes

A

oscillating effect

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83
Q

introduces new alleles into a population, not a potent evolutionary force alone

A

mutation

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84
Q

model mouse population mutation example: The frequency in the new population is calculated by

A

calculating how much A is lost

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85
Q

mutation can cause evolution but it usually happens

A

slowly

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86
Q

____ alone cannot cause great changes in allele frequencies but it is still important in evolution
but
in combination with selection it can be a potent evolutionary force

A

mutation

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87
Q

studied a strain of E. coli incapable of conjugation, the mutation is the only form of genetic variation
frozen ancestors are compared with the newer generations to see which is better in fitness
fitness and cell size increased in response to natural selection (occurred in jumps)
mutations caused bacteria to divide faster and increase in size

A

lenski’s E. coli study

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88
Q

when the rate of deleterious alleles being eliminated by selection quals rate of creation by mutation

A

mutation-selection balance

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89
Q

when mutation is low and selection is high

A

q hat is low

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90
Q

when mutation is high and selection is low

A

q hat is high

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91
Q

in the q hat equation for deleterious recessive allele equilibrium m is the ____ and s is the ____

A

mutation rate, selection coefficient

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92
Q

cystic fibrosis example: CTFR causes chronic lung infection and few individuals survive the disease this is because a ______mutation occurs

A

loss of function

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93
Q

if the selection coefficient is ____ then the mutation rate is not high enough to maintain the recessive allele

A

strong

94
Q

researchers discovered cystic fibrosis still has a high frequency because it is maintained by _____ meaning it is not selected against

A

heterozygote advantage

95
Q

cystic fibrosis is maintained by

A

mutation and overdominance

96
Q

the movement of alleles among populations

A

migration

97
Q

transfer of alleles from one gene pool to another gene pool of a different population

A

gene flow

98
Q

movement into a population

A

immigration

99
Q

movement out of a population

A

emigration

100
Q

model of migration that has two populations, mainland and island
migration of alleles to the continent is insignificant
migration of alleles to the island could have a large impact on allele and genotype frequencies
gene flow is effectively one-way

A

one-island model

101
Q

in the one-island model gene flow changed the

A

allelic frequency

102
Q

population of the island

A

Pi

103
Q

migration rate

A

m

104
Q

population of the mainland or source

A

p

105
Q

Lake Erie water snake example is an example of ____ because the unbanded allele is not fixed and diversity is maintained on the island

A

migration

106
Q

given enough time gene flow will make two populations more _____

A

similar

107
Q

early succession species, each island has different aged individuals, seed dispersal by wind or water, eventually will die off when outcompeted by another species

A

red bladder campion

108
Q

when there is no similarities between the population and they are completely different Fst=

A

1

109
Q

when the populations are the same or identical Fst=

A

0

110
Q

in Fst ____ values represent more variation in allele frequencies

A

larger

111
Q

extremes have _____ diversity

A

more

112
Q

intermediate populations have _____ diversity

A

less

113
Q

genetic drift is also known as _____ and this violates the idea that an infinite population is assumed in HWE

A

random chance

114
Q

_____ populations do not work for HWE

A

smaller

115
Q

genetic drift 10 zygote example: this example did not work because it (small size)

A

broke both HWE conclusions

116
Q

because of drift, one allele can rise to ____ over time

A

fixation

117
Q

random discrepancy between theoretical expectations and actual results can be called ____
also known as genetic drift when involved in the production of zygotes

A

sampling error

118
Q

a small group of individuals start a new population and allelic frequencies are by chance different from the source population, by chance not all alleles will be represented (ladybug example)

A

founder effect

119
Q

the Pennsylvania Amish have a higher frequency of dwarfism and polydactyl recessive alleles due to the

A

founder effect

120
Q

random events cause a population to crash to a very low level, many alleles are eliminated from the population, the remaining population has different allelic and genotypic frequencies than the beginning

A

bottleneck effect

121
Q

low genetic diversity of cheetahs due to several mass extinction events is an example of

A

bottleneck effect

122
Q

when a population goes to fixation ____ also declines because of genetic drift (important if trying to manage an endangered species) a
also a good measure of diversity in a population

A

heterozygosity

123
Q

demonstrated that the probability of fixation for a particular allele is the same as its original frequency
(EX if the initial frequency of an allele is 0.8, 80% will drift to fixation)

A

sewall wright

124
Q

a study in the ozark mountains where a specific type of lizard exists because it can thrive in the desert like habitat

A

Templeton’s natural study of Crotaphytus lizards

125
Q

average number of alleles per loci

A

allelic richness

126
Q

a collection of genes that tend to be inherited together

A

haplotype

127
Q

fraction of loci that have at least two alleles with frequencies above 0.01

A

genetic polymorphism

128
Q

two measures of genetic diversity used in youngs study of plants

A

genetic polymorphism and allelic richness

129
Q

genes that have more alleles show more ____ in a population

A

diversity

130
Q

proportion of the variance in the subpopulation contained in an individual, also known as the inbreeding coefficient

A

Fis

131
Q

differentiation among a set of populations

A

Fst

132
Q

total expected heterozygosity among all populations

A

Ht

133
Q

when an Fst value is small and closer to 0 it means the populations are relatively _____

A

similar

134
Q

the size of an idealized population that would lose genetic diversity at the same rate as the actual population

A

effective population size

135
Q

three primary factors of effective population size

A

unequal sex ratio
high variance in family size
fluctuations in pop size over generations

136
Q

effective population size equation (unequal sex ratio)

A

Ne=4(Nef)(Nem)/(Nef+Nem)

137
Q

variance in family size

A

Vk

138
Q

effective population size equation
(variation in family size)

A

Ne= (4N-2) / (Vk + 2)

139
Q

effective population size equation
(fluctuation in population size)
where t=number of generations
Nei=effective size in the ith gen

A

Ne=t/sum of (1/Nei)

140
Q

effective population size

A

Ne

141
Q

advantageous mutations are very rare and most mutations are selectively neutral

A

neutral theory

142
Q

advantageous mutations are more common, rate of substitution determined by natural selection on advantageous mutation

A

selectionist theory

143
Q

negative selection (synonymous)

A

purifying

144
Q

positive selection (nonsynonymous)

A

diversifying

145
Q

there is a higher rate of substitutions with ____ or silent mutations (neutral theory graph)

A

synonymous

146
Q

____ is the greatest at DNA positions that, when altered, are least likely to affect function and therefore least likely to alter the organism’s fitness (support for neutral theory)

A

rate of evolution

147
Q

when replacements are deleterious

A

dn/ds < 1

148
Q

when replacements are neutral

A

dn/ds=0

149
Q

when replacements are advantageous

A

dn/ds>1

150
Q

codon usage random vs nonrandom, it is often nonrandom, highly expressed genes

A

codon

151
Q

can lead to an increase in frequency of neutral or even deleterious genes

A

hitchhiking (selective swap)

152
Q

a method that allows the calculation of effective population size in previous generations using phylogenetic comparisons, estimate what our ancestral populations would have been by using genetic drift

A

coalescence

153
Q

___ mating is necessary for conclusion 2 of HWE to hold

A

random

154
Q

non random mating, females choose males with a particular phenotype

A

assortative mating

155
Q

individuals choose mates similar to themselves, increase in homozygosity decrease in heterozygosity

A

positive assortative mating

156
Q

disassortative mating, individuals choose mates different from themselves, increases heterozygosity

A

negative assortative mating

157
Q

most common type of nonrandom mating, mating among genetic relatives, increases homozygosity at all loci

A

inbreeding

158
Q

in the case of inbreeding homozygous can only produce

A

homozygous

159
Q

in the case of inbreeding heterozygous can produce (frequency of heterozygote is halved in every generation

A

half homozygote, half heterozygote

160
Q

we cannot predict allele frequencies from ____ frequencies

A

genotype

161
Q

probability that two alleles in an individual are identical by descent, coefficient of inbreeding

A

F

162
Q

signifies 100% homozygote

A

f=-1

163
Q

the population is panmictic

A

f=0

164
Q

some kind of inbreeding is occurring

A

f>0

165
Q

the population is selfing

A

f=0.5

166
Q

entire population are homozygotes, locus is fixed for one allele

A

f=1

167
Q

to calculate F in terms of probability just

A

multiply each probability for both populations then add those final probabilities together

168
Q

exposure of deleterious alleles as homozygotes, loss of function mutations are usually hidden as heterozygotes, increased frequency at which deleterious alleles affect phenotypes

A

inbreeding depression

169
Q

as a plant grows it is more likely to ___ when it is created from selfing

A

die

170
Q

mortality rate in inbreeding individuals is ____ than those who are distantly related

A

higher

171
Q

mate choice, self incompatibility, dispersal, different phenologies of male and female organs

A

mechanisms to avoid inbreeding depression

172
Q

small populations cannot avoid

A

inbreeding

173
Q

this population was reduced to a very low number because of hunting and habitat destruction, the population, isolated from other puma populations, problems of migration, genetic drift, and non-random mating all causing them to become extinct

A

Florida panther example

174
Q

synergistic effects on drift, population size, and accumulated mutations

A

mutational meltdown

175
Q

mutational meltdown and inbreeding depression combined result in a

A

extinction vortex

176
Q

Accumulation of deleterious recessives leads to reduction in population size
Effectiveness of genetic drift is increased
Speed and proportion of deleterious mutations going to fixation increases
Population size decreases more

A

conservation genetics

177
Q

sex is beneficial due to genetic drift

A

hypothesis 1 to why sex is important

178
Q

sex is beneficial due to variable selection in changing environments

A

hypothesis 2 to why sex is important

179
Q

disrupted by sex because it disrupts the accumulation of mutations (lack of recombination heightens mutation and resets the rachet), proves the first hypothesis

A

Muller’s Rachet

180
Q

the world is changing so much individuals need to evolve to keep up, proves the second hypothesis

A

red queen hypothesis

181
Q

the frequency of one allele does not affect the frequency of another allele, they are not close together on the genome, therefore they do not get inherited together

A

linkage disequilibrium

182
Q

in linkage disequilibrium, one locus can predict or influence the evolution of another due to

A

genetic linkage

183
Q

predicts how tightly loci are linked

A

physical distance between one another

184
Q

linkage disequilibrium is created by

A

genetic drift, population admixture, selection on multi-locus genotype

185
Q

linkage disequilibrium is eliminated by _____ because of meiosis, crossing over (genetic recombination) , and outbreeding

A

sex

186
Q

rate of linkage disequilibrium decline is proportional to the

A

rate of recombination

187
Q

clegg study: documented decay of linkage disequilibrium in fruit flies maintained populations for 50 generations, linkage disequilibrium ______ with sexual reproduction

A

declined to almost zero

188
Q

as the rachet clicks, overall fitness ___ due to the accumulation of mutations

A

decreases

189
Q

trematodes eat the snail gonads so that they have 0 fitness, hypothesis 2 on why sex is important, Lively found higher sexual proportion in areas with high trematode infection

A

trematode and snail example

190
Q

inherited as dominant and recessive, each genotype has one phenotype

A

mendelian traits

191
Q

polygenic, multifactorial, continuous
each phenotype is determined by many genes, often these genes are unknown

A

quantitative

192
Q

examines discrete genotypes
allele and genotype frequencies of populations

A

population genetics

193
Q

examines continuously distributed phenotypes
mean and variance of populations
individuals phenotypic values

A

quantitative genetics

194
Q

most traits are ____ and determined by multiple genes in our genome

A

suppressed

195
Q

traits that show continuous variation
ex) human height, cheetah sprint speed, flower size

A

quantitative traits

196
Q

used for quantitative traits to understand the variation in a population

A

descriptive statistics

197
Q

quantitative traits often occur in a

A

normal distribution

198
Q

one allele masks another

A

dominance

199
Q

alleles combine to create a phenotype

A

additive

200
Q

separate loci interact to create a phenotype

A

epistasis

201
Q

uses for quantitative genetics

A

measure heritable variation
measure differences in fitness
predict evolutionary response to selection

202
Q

statistical creation that identifies a particular region of the genome as containing a gene associated with the trait of interest

A

QTL

203
Q

if statistically significant ____ will be found in QTL mapping
these are indicated spikes on an LOD graph

A

neutral markers

204
Q

linkage example with mice

A

cross two homozygotes for two different traits- F1 gen will be heterozygous for both, when f1 gen reproduces you will have a mix of alleles, to determine trait of interest backcross F1 gen with a parent

205
Q

how often the traits were shuffled in the progeny
used to make linkage maps

A

frequency of recombination

206
Q

map distances between markers is calculated in

A

centimorgans

207
Q

if neutral markers appear significantly more often than chance with certain phenotypic values a____ that is linked to the marker may be affecting the trait

A

QTL

208
Q

long odds ratio
plots for each phenotypic trait
likelihood that there is a QTL linked to the particular neutral marker

A

LOD score

209
Q

in an LOD score anything that surpasses the ____ of 95th percentile, indicates linkage

A

threshold

210
Q

if QTLS are detected it

A

indicates that a locus in the region affects the phenotype, which exact locus is still unknown

211
Q

what can you use to test if a particular gene in the region affects the phenotype?

A

knock out mutations or CRISPR

212
Q

QTLs are mapped in which fields

A

agriculture, biomedicine, evolution

213
Q

P= G + E what is G

A

value determined by genotype

214
Q

P= G + E what is E

A

value determined by environment

215
Q

phenotypic variation

A

Vp

216
Q

genetic variation

A

Vg

217
Q

environmental variation

A

Ve

218
Q

measuring heritable traits equation

A

Vp=Vg+Ve

219
Q

if you know the heritability and the selection differential you can predict the

A

evolutionary response

220
Q

what distribution is common for quantitative traits

A

normal

221
Q

evolutionary response equation

A

R=H^2S

222
Q

R=H^2S what does R=

A

predicted response to selection

223
Q

R=H^2S what does H^2=

A

heritability

224
Q

R=H^2S what does S =

A

selection differential

225
Q

multiple genes are contributing to the genotypes

A

polygenic

226
Q

three patterns of selection

A

Directional
Stabilizing
Disruptive

227
Q

fitness increases with the value of a trait, shift in heritable phenotype frequency in a consistent direction

A

directional selection

228
Q

individuals with intermediate values of a trait have highest fitness means the population stays the same, curve narrow

A

stabilizing selection

229
Q

individuals with extreme values of a trait have highest fitness

A

disruptive selection

230
Q

fitness graph for directional selection

A

a constant increase from o

231
Q

fitness graph for stabilizing selection

A

normal distribution favor intermediate

232
Q

fitness graph for disruptive selection

A

Evolutionary Biology (1 decks)

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