of Populations 21 In evolutionary terms an organisms fitness is measured by its stability in the face of environmental change contribution to the gene pool of the next generation ID: 576115
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Slide1
The Evolution of Populations
21Slide2
In evolutionary terms, an organism’s fitness is measured by its _____.
stability in the face of environmental change
contribution to the gene pool of the next
generation genetic variabilitymutation rate health
© 2016 Pearson Education, Inc.Slide3
In evolutionary terms, an organism’s fitness is measured by its _____.
stability in the face of environmental change
contribution to the gene pool of the next generation
genetic variabilitymutation rate health
© 2016 Pearson Education, Inc.Slide4
Red short-horned cattle are homozygous for the red allele, white cattle are homozygous for the white allele, and roan cattle are heterozygotes. Population A consists of 36% red, 16% white, and 48% roan cattle. What are the allele frequencies?
red
0.36, white 0.16red
0.6, white 0.4red 0.5, white 0.5Allele frequencies cannot be determined unless the population is in equilibrium.
© 2016 Pearson Education, Inc.Slide5
Red short-horned cattle are homozygous for the red allele, white cattle are homozygous for the white allele, and roan cattle are heterozygotes. Population A consists of 36% red, 16% white, and 48% roan cattle. What are the allele frequencies?
red
0.36, white 0.16red
0.6, white 0.4red 0.5, white 0.5Allele frequencies cannot be determined unless the population is in equilibrium.
© 2016 Pearson Education, Inc.Slide6
Indicate which of the Hardy-Weinberg conditions is being violated in the following example: Some moths on a tree are easier to see due to their lighter color and therefore are eaten by predators more often.
large population size
no mutation
no gene flowrandom mating occurringno selection
© 2016 Pearson Education, Inc.Slide7
Indicate which of the Hardy-Weinberg conditions is being violated in the following example: Some moths on a tree are easier to see due to their lighter color and therefore are eaten by predators more often.
large population size
no mutation
no gene flowrandom mating occurringno selection
© 2016 Pearson Education, Inc.Slide8
Indicate which of the Hardy-Weinberg conditions is being violated in this example: Female sailfin
blennies (a fish) tend to choose males with either a large
sailfin
on top of their heads or the best flicking motion of their sailfin.large population sizeno mutation
no gene flowrandom mating occurringno selection© 2016 Pearson Education, Inc.Slide9
Indicate which of the Hardy-Weinberg conditions is being violated in this example: Female sailfin
blennies (a fish) tend to choose males with either a large
sailfin
on top of their heads or the best flicking motion of their sailfin.large population sizeno mutation
no gene flowrandom mating occurringno selection© 2016 Pearson Education, Inc.Slide10
Indicate which of the Hardy-Weinberg conditions is being violated in this example: Due to global warming, a river has dried up, allowing two different rabbit populations, which were
isolated
before, to mate with one another.
large population sizeno mutationno gene flowrandom mating occurringno selection
© 2016 Pearson Education, Inc.Slide11
Indicate which of the Hardy-Weinberg conditions is being violated in this example: Due to global warming, a river has dried up, allowing two different rabbit populations, which were isolated before, to mate with
one
another.
large population sizeno mutationno gene flowrandom mating occurringno selection
© 2016 Pearson Education, Inc.Slide12
The textbook discusses how the conversion of quality habitat into farmland has greatly depleted the greater prairie chicken populations and, as a result, their genetic diversity. Which of the following occurred in this example?
founder effects
mutation
natural selectiongene flowbottlenecking
© 2016 Pearson Education, Inc.Slide13
The textbook discusses how the conversion of quality habitat into farmland has greatly depleted the greater prairie chicken populations and, as a result, their genetic diversity. Which of the following occurred in this example?
founder effects
mutation
natural selectiongene flowbottlenecking
© 2016 Pearson Education, Inc.Slide14
Indicate what type of selection is occurring in the example here: Due to less snowfall in an area, white mice are predated on more than intermediate- or dark-colored mice.
directional selection
disruptive selection
stabilizing selection© 2016 Pearson Education, Inc.Slide15
Indicate what type of selection is occurring in the example here: Due to less snowfall in an area, white mice are predated on more than intermediate- or dark-colored mice.
directional selection
disruptive selection
stabilizing selection© 2016 Pearson Education, Inc.Slide16
Indicate what type of selection is occurring in the example here: During a drought, it was discovered that finches with large beaks and those with small beaks were more successful due to the food sources available.
directional selection
disruptive selection
stabilizing selection© 2016 Pearson Education, Inc.Slide17
Indicate what type of selection is occurring in the example here: During a drought, it was discovered that finches with large beaks and those with small beaks were more successful due to the food sources available.
directional selection
disruptive selection
stabilizing selection© 2016 Pearson Education, Inc.Slide18
The frequency of cystic fibrosis, a recessive genetic disease, is 1 per 2,500 births among Northern Europeans. Assuming random mating, what is the frequency of carriers?
1/2,500, or about 0.04%
1/50, or about 2%
1/25, or about 4%The frequency cannot be calculated because selection violates Hardy-Weinberg assumptions.
© 2016 Pearson Education, Inc.Slide19
The frequency of cystic fibrosis, a recessive genetic disease, is 1 per 2,500 births among Northern Europeans. Assuming random mating, what is the frequency of carriers?
1/2,500, or about 0.04%
1/50, or about 2%
1/25, or about 4%The frequency cannot be calculated because selection violates Hardy-Weinberg assumptions.
© 2016 Pearson Education, Inc.Slide20
Until the 1950s, infants born with cystic fibrosis did not survive longer than a few months. If the frequency of carriers was 4% in the year 1900, what proportion of CF alleles was eliminated in one generation?
100%
50%
4%2% 0.1%
© 2016 Pearson Education, Inc.Slide21
Until the 1950s, infants born with cystic fibrosis did not survive longer than a few months. If the frequency of carriers was 4% in the year 1900, what proportion of CF alleles was eliminated in one generation?
100%
50%
4%2% 0.1%
© 2016 Pearson Education, Inc.Slide22
A high proportion of the cats on Key West have extra toes (polydactyly). What is the most likely explanation?
high rate of mutation
founder effect
bottleneck effectdirectional selection for extra toes© 2016 Pearson Education, Inc.Slide23
A high proportion of the cats on Key West have extra toes (polydactyly). What is the most likely explanation?
high rate of mutation
founder effect
bottleneck effectdirectional selection for extra toes© 2016 Pearson Education, Inc.Slide24
Evolution requires _____ in order to occur.
a large population
heritable variation
nonrandom, differential reproductive successa long time© 2016 Pearson Education, Inc.Slide25
Evolution requires _____ in order to occur.
a large population
heritable variation
nonrandom, differential reproductive successa long time© 2016 Pearson Education, Inc.Slide26
What is the ultimate source of new heritable variation in populations?
sexual reproduction
(e.g
., independent assortment, recombination, random mating)gene flow (e.g., immigration/emigration
)selection (e.g., for favorable traits, against deleterious traits)mutation (e.g., new alleles from errors in replication/recombination)© 2016 Pearson Education, Inc.Slide27
What is the ultimate source of new heritable variation in populations?
sexual reproduction
(e.g
., independent assortment, recombination, random mating)gene flow (e.g., immigration/emigration
)selection (e.g., for favorable traits, against deleterious traits)mutation (e.g., new alleles from errors in replication/recombination)© 2016 Pearson Education, Inc.Slide28
Which of the following is not an example of heritable genetic variation?
a protein translated incorrectly from an mRNA
a base-pair substitution in an exon
a 100-base-pair duplication in an introna 3-base-pair deletion in a promoter
© 2016 Pearson Education, Inc.Slide29
Which of the following is not an example of heritable genetic variation?
a protein translated incorrectly from an mRNA
a base-pair substitution in an exon
a 100-base-pair duplication in an introna 3-base-pair deletion in a promoter
© 2016 Pearson Education, Inc.Slide30
Below are listed genotypic frequencies for four populations at the H locus. Which population(s), if any, are at Hardy-Weinberg equilibrium?
Population HH
Hh
hhA 0 1.0 0B 0.5 0 0.5C 0.33 0.33 0.33D 0.25 0.50 0.25© 2016 Pearson Education, Inc.Slide31
Below are listed genotypic frequencies for four populations at the H locus. Which population(s), if any, are at Hardy-Weinberg equilibrium?
Population
HH
Hh hhA 0 1.0 0
B 0.5 0 0.5C 0.33 0.33 0.33D 0.25 0.50 0.25© 2016 Pearson Education, Inc.Slide32
Below are listed genotypic frequencies for four populations at the W locus. Which population(s), if any, are at Hardy-Weinberg equilibrium?
Population
WW Ww ww
A 0.81 0.18 0.01B 0.16 0.48 0.36C 0.49 0.42 0.09D 0.01 0.18 0.81© 2016 Pearson Education, Inc.Slide33
© 2016 Pearson Education, Inc.
Below are listed genotypic frequencies for four populations at the
W
locus. Which population(s), if any, are at Hardy-Weinberg equilibrium?
Population WW Ww wwA 0.81 0.18 0.01B 0.16 0.48 0.36C 0.49 0.42 0.09D 0.01 0.18 0.81Slide34
Allele frequencies for the ABO blood type among North Americans are estimated at f(I
A
) = 0.27; f(
IB) = 0.06; f(i) = 0.67. Assuming HWE conditions for this locus, what is the expected frequency of blood type O?
0.67 0.1340.4491.0© 2016 Pearson Education, Inc.Slide35
Allele frequencies for the ABO blood type among North Americans are estimated at f(IA
) = 0.27; f(
I
B) = 0.06; f(i) = 0.67. Assuming HWE conditions for this locus, what is the expected frequency of blood type O?0.67
0.1340.4491.0© 2016 Pearson Education, Inc.Slide36
Allele frequencies for the ABO blood type among North Americans are estimated at f(I
A
) = 0.27; f(
IB) = 0.06; f(i) = 0.67. Assuming HWE conditions for this locus, what is the expected frequency of blood type A?
0.27 0.0730.3620.435© 2016 Pearson Education, Inc.Slide37
Allele frequencies for the ABO blood type among North Americans are estimated at f(IA
) = 0.27; f(
I
B) = 0.06; f(i) = 0.67. Assuming HWE conditions for this locus, what is the expected frequency of blood type A?0.27
0.0730.3620.435© 2016 Pearson Education, Inc.Slide38
In some regions where malaria is endemic, the frequency of the sickle-cell allele is maintained as high as 10% due to heterozygous advantage.
If modern technology were to completely eradicate malaria but not alleviate sickle-cell disease, what would be expected to happen to the sickle-cell allele frequency in subsequent generations?
remain
near 10
%gradually drop toward zerodrop slightly, then restabilizerise slightly, then restabilize© 2016 Pearson Education, Inc.Slide39
© 2016 Pearson Education, Inc.
In some regions where malaria is endemic, the frequency of the sickle-cell allele is maintained as high as 10% due to heterozygous advantage.
If modern technology were to completely eradicate malaria but not alleviate sickle-cell disease, what would be expected to happen to the sickle-cell allele frequency in subsequent generations?
remain
near 10%gradually drop toward zerodrop slightly, then restabilizerise slightly, then restabilize