Exams PCB4674
Study online at https://quizlet.com/_e9dheg
1. A population of wobbly-brown wombats was screened for the bi-allelic gene
Tsp6. These were the genotypes. Is the population in HW equilibrium? Show
work and explain.
A1A1: 0.30
A1A2: 0.60
A2A2: 0.10: p = (0.3) + (1/2)(0.6) = 0.6
q = 1 - p = 1 - (0.6) = 0.4
A1A1 = p^2 = (0.6)^2 = 0.36
A1A2 = 2pq = 2(0.6)(0.4) = 0.48
A2A2 = q^2 = (0.4)^2 = 0.16
Since the A1A1, A1A2, and A2A2 values do not match the given genotypes frequencies, the frequencies did change due
to a HW violation. The population is NOT in HW.
2. Describe two important symbioses; be sure to identify the participants: 1.
endosymbioses of aerobic and cyanobacteria led to mitochondria/chloroplasts
2. lichens are the symbiotic association between fungi and cyanobacteria
3. If persistent directional selection is applied to a population, it is expected that
variation in the population will eventually be exhausted and all individuals will
be the same. Name three mechanisms other than point mutations that might
help maintain variation in the population.: 1. migration
2. natural selection
3. heterozygote advantage
4. Which of the following provide evidence for evolution?
- Phylogenies produced by unrelated data sets (e.g. different genes or genes
and morphology) are very similar
- Coelacanth fish have no fossils recorded from the last 63 million years
- Fruit flies can be found all over the world
- the Vagus Nerve in giraffes wraps under the aorta, even though that is a >12
foot detour: - Phylogenies produced by unrelated data sets (e.g. different genes or genes and morphology) are
, Exams PCB4674
Study online at https://quizlet.com/_e9dheg
very similar
- the Vagus Nerve in giraffes wraps under the aorta, even though that is a >12 foot detour
5. An isolated, oceanic island was colonized by a small number of psychedelics
lizards that were carried to the island by clinging to a log during a hurricane.
Assume that is a very rare event (probably will not happen again). Two color
morphs are present, purple and gold. The purple allele (A1) is dominant and
present at frequency p=0.34; the recessive gold allele (A2) id present at q=0.66.
On the mainland, p=0.71. The two morphs have equal fitness, so there is no
selection. There are 200 lizards on the island.
What is the probability that the gold allele (A2) will become fixed in the island
population?: q=0.66 so 66%
6. Circle each of the violations to HW equilibrium that will usually promote
the evolutionary divergence of two populations from each other over multiple
generations.
- selection
- mutation
- migration
- genetic drift: - selection
- mutation
- genetic drift
7. Which statements about natural selection are true?
- always results in adaptations that are perfectly designed for their function
- selects for traits that do not currently enhance fitness, but could be favorable
in the future
- acts on individuals, not species
- is a random process
- increases the mean fitness of a population: - selects for traits that do not currently enhance
fitness, but could be favorable in the future
- increases the mean fitness of a population
, Exams PCB4674
Study online at https://quizlet.com/_e9dheg
8. Which of the following statements about genetic drift are true?
- drift will eventually lead to fixation of one allele
- drift can produce adaptations if enough time passes
- founder effect usually result in a steep decrease in genetic diversity
- the probability of fixation depends on population size
- the ate of neutral evolution due to drift depends on population size: - drift will
eventually lead to fixation of one allele
- founder effect usually result in a steep decrease in genetic diversity
9. Write the word that describes the type of selection and the mode of inheri-
tance for the fitness landscape: stability (heterozygote advantage)
mode: overdominance
10. Write the word that describes the type of selection and the mode of inheri-
tance for the fitness landscape: directional
mode: additivity
11. Write the word that describes the type of selection and the mode of inheri-
tance for the fitness landscape: disruptive (heterozygote disadvantage)
mode: underdominance
12. Which type of fitness landscape leads to fixation?: disruptive (heterozygote disadvantage)
and directional
13. Which type of fitness landscape leads to stable equilibrium?: stability (heterozygote
advantage)
14. Calculate the absolute fitness of each genotype. Show work.
A1A1 A1A2 A2A2
# young 100 80 30
# breeding adults 45 64 27: Absolute: (# breeding)/(#young)
, Exams PCB4674
Study online at https://quizlet.com/_e9dheg
A1A1: 0.45
A1A2: 0.8
A2A2: 0.9
15. Calculate the relative fitnesses of each genotype. Show work.
A1A1 A1A2 A2A2
# young 100 80 30
# breeding adults 45 64 27
Absolute Fitness Values
A1A1: 0.45
A1A2: 0.8
A2A2: 0.9: Relative: divide all of the absolute fitness values by the highest absolute fitness value
Highest absolute fitness value: 0.9
A1A1: 0.5
A1A2: 0.889
A2A2: 1.0
16. Name two mechanisms that have created opportunities for the great radia-
tions that have occurred since the origin of life: all possible correct answers: key innovation,
geographic opportunities, climate change, mass extinction
17. What did Darwin demonstrate in his origin of species?
- how to classify species
- the principle of Uniformitarianism for the first time
- the process of natural selection
- the merger of science with religion
- life was characterized by common descent with modifications: - the process of natural
selection
- life was characterized by common descent with modifications
18. Underdominance and overdominance are two scenarios in which heterozy-
gotes have different fitness than homozygotes. What kind of equilibrium does
Study online at https://quizlet.com/_e9dheg
1. A population of wobbly-brown wombats was screened for the bi-allelic gene
Tsp6. These were the genotypes. Is the population in HW equilibrium? Show
work and explain.
A1A1: 0.30
A1A2: 0.60
A2A2: 0.10: p = (0.3) + (1/2)(0.6) = 0.6
q = 1 - p = 1 - (0.6) = 0.4
A1A1 = p^2 = (0.6)^2 = 0.36
A1A2 = 2pq = 2(0.6)(0.4) = 0.48
A2A2 = q^2 = (0.4)^2 = 0.16
Since the A1A1, A1A2, and A2A2 values do not match the given genotypes frequencies, the frequencies did change due
to a HW violation. The population is NOT in HW.
2. Describe two important symbioses; be sure to identify the participants: 1.
endosymbioses of aerobic and cyanobacteria led to mitochondria/chloroplasts
2. lichens are the symbiotic association between fungi and cyanobacteria
3. If persistent directional selection is applied to a population, it is expected that
variation in the population will eventually be exhausted and all individuals will
be the same. Name three mechanisms other than point mutations that might
help maintain variation in the population.: 1. migration
2. natural selection
3. heterozygote advantage
4. Which of the following provide evidence for evolution?
- Phylogenies produced by unrelated data sets (e.g. different genes or genes
and morphology) are very similar
- Coelacanth fish have no fossils recorded from the last 63 million years
- Fruit flies can be found all over the world
- the Vagus Nerve in giraffes wraps under the aorta, even though that is a >12
foot detour: - Phylogenies produced by unrelated data sets (e.g. different genes or genes and morphology) are
, Exams PCB4674
Study online at https://quizlet.com/_e9dheg
very similar
- the Vagus Nerve in giraffes wraps under the aorta, even though that is a >12 foot detour
5. An isolated, oceanic island was colonized by a small number of psychedelics
lizards that were carried to the island by clinging to a log during a hurricane.
Assume that is a very rare event (probably will not happen again). Two color
morphs are present, purple and gold. The purple allele (A1) is dominant and
present at frequency p=0.34; the recessive gold allele (A2) id present at q=0.66.
On the mainland, p=0.71. The two morphs have equal fitness, so there is no
selection. There are 200 lizards on the island.
What is the probability that the gold allele (A2) will become fixed in the island
population?: q=0.66 so 66%
6. Circle each of the violations to HW equilibrium that will usually promote
the evolutionary divergence of two populations from each other over multiple
generations.
- selection
- mutation
- migration
- genetic drift: - selection
- mutation
- genetic drift
7. Which statements about natural selection are true?
- always results in adaptations that are perfectly designed for their function
- selects for traits that do not currently enhance fitness, but could be favorable
in the future
- acts on individuals, not species
- is a random process
- increases the mean fitness of a population: - selects for traits that do not currently enhance
fitness, but could be favorable in the future
- increases the mean fitness of a population
, Exams PCB4674
Study online at https://quizlet.com/_e9dheg
8. Which of the following statements about genetic drift are true?
- drift will eventually lead to fixation of one allele
- drift can produce adaptations if enough time passes
- founder effect usually result in a steep decrease in genetic diversity
- the probability of fixation depends on population size
- the ate of neutral evolution due to drift depends on population size: - drift will
eventually lead to fixation of one allele
- founder effect usually result in a steep decrease in genetic diversity
9. Write the word that describes the type of selection and the mode of inheri-
tance for the fitness landscape: stability (heterozygote advantage)
mode: overdominance
10. Write the word that describes the type of selection and the mode of inheri-
tance for the fitness landscape: directional
mode: additivity
11. Write the word that describes the type of selection and the mode of inheri-
tance for the fitness landscape: disruptive (heterozygote disadvantage)
mode: underdominance
12. Which type of fitness landscape leads to fixation?: disruptive (heterozygote disadvantage)
and directional
13. Which type of fitness landscape leads to stable equilibrium?: stability (heterozygote
advantage)
14. Calculate the absolute fitness of each genotype. Show work.
A1A1 A1A2 A2A2
# young 100 80 30
# breeding adults 45 64 27: Absolute: (# breeding)/(#young)
, Exams PCB4674
Study online at https://quizlet.com/_e9dheg
A1A1: 0.45
A1A2: 0.8
A2A2: 0.9
15. Calculate the relative fitnesses of each genotype. Show work.
A1A1 A1A2 A2A2
# young 100 80 30
# breeding adults 45 64 27
Absolute Fitness Values
A1A1: 0.45
A1A2: 0.8
A2A2: 0.9: Relative: divide all of the absolute fitness values by the highest absolute fitness value
Highest absolute fitness value: 0.9
A1A1: 0.5
A1A2: 0.889
A2A2: 1.0
16. Name two mechanisms that have created opportunities for the great radia-
tions that have occurred since the origin of life: all possible correct answers: key innovation,
geographic opportunities, climate change, mass extinction
17. What did Darwin demonstrate in his origin of species?
- how to classify species
- the principle of Uniformitarianism for the first time
- the process of natural selection
- the merger of science with religion
- life was characterized by common descent with modifications: - the process of natural
selection
- life was characterized by common descent with modifications
18. Underdominance and overdominance are two scenarios in which heterozy-
gotes have different fitness than homozygotes. What kind of equilibrium does
