PCB4674 Evolution Exam 2 - Questions with Correct
Answers (Verified Update)
172 questions with answers
Topic: PCB4674 Evolution Exam 2
1. Migration (gene flow) differentiation among population
Answer: reduces
2. Drift is 1/N. Where N, is the population size.
Answer: directly proportional
3. if 1/N is greater than selection differential (s) then
Answer: genetic drift is more important
4. is the greater force and more important than drift
Answer: if differential selection (s) is greater selection than 1/N, then
5. In 2 islands of N=100,000, how many migrants per generation will prevent
divergence by drift?
Answer: 1
6. In 2 islands of N=10, how many migrants per generation will prevent divergence
by drift?
Answer: 1
7. four fundamental mechanisms of microevolution
Answer: drift, selection, migration, and mutation
8. is the rate of neutral evolution affected by population size?
Answer: no
9. is the loss of genetic variation affected by population size?
Answer: yes
10. is the probability of fixation affected by population size?
Answer: no
11. is the amount of time for an allele to work towards fixation affected by
population size?
Answer: yes
12. Migration (gene flow)
Answer: movement of alleles from one population to another
13. Gene Flow: Island model
Answer: single parameter of (m) from mainland to island because movement from and to
mainland is so much larger island population is small
14. Gene Flow: Stepping Stone Model This
Answer: model expands on the island model but having comparing the migration between
multiple populations, such as island archipelagos 1/2m
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, 15. prevents divergence
Answer: gene flow
16. symbol for migration
Answer: m the proportion of the population that are migrants
17. individuals that stayed on the island equation
Answer: = 1 - m Where m is the percentage of individuals that moved to the island
18. Gene Flow: Isolation by distance Model
Answer: You can have migration between any populations despite distance, where the rate
between close islands will be high and the rate will be low between far islands most common
situation
19. m (-Pi +Pc) must equal m: migration Pc: A1 allele on continent Pi: Ai allele on
island
Answer: 0
20. Lake Erie Watersnake: Nerodia sipedon insularum
Answer: a case where selection acts upon the migrants since they are not the most favored
on the island Mainland: banded favored Middle, Isolated island: unbanded favored
21. consequences of gene flow
Answer: - serves to homogenize ('make the same') allele frequencies between populations.
22. Homogenization
Answer: A trend toward uniformity as a result of gene flow .
23. cline
Answer: change in population properties over space/geographic region A gradual change in
a trait along a geographic axis
24. delta P (selection) is equal to
Answer: negative delta P (migration)
25. disruption of gene flow is usually a requirement for .
Answer: speciation
26. and can have profound impacts on gene flow and population size thus on
evolutionary dynamics
Answer: ecology ... behavior
27. how are clines maintained?
Answer: ditterential selection
28. differential selection
Answer: occurs when certain individuals have ditterent characteristics/phenotypes that are
better suited for a region, producing nonequivalent groups
29. is migration a weak or strong forces?
Answer: strong
30. mating systems and population structure can effective population size (Ne)
Answer: reduce
Page 2
Answers (Verified Update)
172 questions with answers
Topic: PCB4674 Evolution Exam 2
1. Migration (gene flow) differentiation among population
Answer: reduces
2. Drift is 1/N. Where N, is the population size.
Answer: directly proportional
3. if 1/N is greater than selection differential (s) then
Answer: genetic drift is more important
4. is the greater force and more important than drift
Answer: if differential selection (s) is greater selection than 1/N, then
5. In 2 islands of N=100,000, how many migrants per generation will prevent
divergence by drift?
Answer: 1
6. In 2 islands of N=10, how many migrants per generation will prevent divergence
by drift?
Answer: 1
7. four fundamental mechanisms of microevolution
Answer: drift, selection, migration, and mutation
8. is the rate of neutral evolution affected by population size?
Answer: no
9. is the loss of genetic variation affected by population size?
Answer: yes
10. is the probability of fixation affected by population size?
Answer: no
11. is the amount of time for an allele to work towards fixation affected by
population size?
Answer: yes
12. Migration (gene flow)
Answer: movement of alleles from one population to another
13. Gene Flow: Island model
Answer: single parameter of (m) from mainland to island because movement from and to
mainland is so much larger island population is small
14. Gene Flow: Stepping Stone Model This
Answer: model expands on the island model but having comparing the migration between
multiple populations, such as island archipelagos 1/2m
Page 1
, 15. prevents divergence
Answer: gene flow
16. symbol for migration
Answer: m the proportion of the population that are migrants
17. individuals that stayed on the island equation
Answer: = 1 - m Where m is the percentage of individuals that moved to the island
18. Gene Flow: Isolation by distance Model
Answer: You can have migration between any populations despite distance, where the rate
between close islands will be high and the rate will be low between far islands most common
situation
19. m (-Pi +Pc) must equal m: migration Pc: A1 allele on continent Pi: Ai allele on
island
Answer: 0
20. Lake Erie Watersnake: Nerodia sipedon insularum
Answer: a case where selection acts upon the migrants since they are not the most favored
on the island Mainland: banded favored Middle, Isolated island: unbanded favored
21. consequences of gene flow
Answer: - serves to homogenize ('make the same') allele frequencies between populations.
22. Homogenization
Answer: A trend toward uniformity as a result of gene flow .
23. cline
Answer: change in population properties over space/geographic region A gradual change in
a trait along a geographic axis
24. delta P (selection) is equal to
Answer: negative delta P (migration)
25. disruption of gene flow is usually a requirement for .
Answer: speciation
26. and can have profound impacts on gene flow and population size thus on
evolutionary dynamics
Answer: ecology ... behavior
27. how are clines maintained?
Answer: ditterential selection
28. differential selection
Answer: occurs when certain individuals have ditterent characteristics/phenotypes that are
better suited for a region, producing nonequivalent groups
29. is migration a weak or strong forces?
Answer: strong
30. mating systems and population structure can effective population size (Ne)
Answer: reduce
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