Question 1

How are the neutral theory of molecular evolution and the Hardy-Weinberg equilibrium similar?

Accepted Answer

Both are used as null models in evolutionary biology.

Question 2

The effective population size is often lower than the census size of a population because

Accepted Answer

A)  inbreeding depression decreases the fitness of inbred progeny. 
B)  populations cannot recover from decreases in heterozygosity. 
C)  scientists cannot accurately count the number of individuals in a population. 
D)  individuals contribute unequally to future generations. 
A)  inbreeding depression decreases the fitness of inbred progeny. 
B)  populations cannot recover from decreases in heterozygosity. 
C)  scientists cannot accurately count the number of individuals in a population. 
D)  individuals contribute unequally to future generations. D

Question 3

Consider a collection of 50 distinct alleles, each at equal frequency in a population. The time before the first coalescent event will be shortest if

Accepted Answer

A)  Ne = 100. 
B)  Ne = 100,000. 
C)  Ne = 100,000,000. 
D)  Ne = the census population size. 
A)  Ne = 100. 
B)  Ne = 100,000. 
C)  Ne = 100,000,000. 
D)  Ne = the census population size. A

Question 4

A researcher examines a microsatellite locus in a wild population of D. melanogaster. She finds that in a sample of 50 individuals, 20 different alleles are segregating. According to the neutral theory, these alleles are most likely experiencing

Accepted Answer

A)  balancing selection. 
B)  directional selection. 
C)  genetic drift. 
D)  neutral selection. 
A)  balancing selection. 
B)  directional selection. 
C)  genetic drift. 
D)  neutral selection.

Question 5

The neutral theory predicts a constant rate of substitutions per generation; however, molecular clock estimates show that substitutions accumulate annually regardless of the generation time. What explanation for this discrepancy is illustrated in the figure?

Accepted Answer

Species with longer generation times ten

Question 6

Population bottlenecks occur when

Accepted Answer

A)  a large number of genetically diverse individuals found a new population. 
B)  population size dramatically increases. 
C)  a consistently large population experiences a brief period of small size. 
D)  inbreeding is high. 
A)  a large number of genetically diverse individuals found a new population. 
B)  population size dramatically increases. 
C)  a consistently large population experiences a brief period of small size. 
D)  inbreeding is high.

Question 7

Consider a population with an effective size of 4,000 and 32 segregating alleles. On average, how many generations would it take for all 32 alleles to coalesce to a single, ancestral allele?

Accepted Answer

A)  32 
B)  128 
C)  1,000 
D)  16,000 
A)  32 
B)  128 
C)  1,000 
D)  16,000

Question 8

A founder event changes allele frequencies because

Accepted Answer

A)  only a subset of alleles in the original population are represented in the newly founded population. 
B)  selection in the newly founded population differs from selection in the original population. 
C)  coalescent processes generate alleles that share a common history. 
D)  mutation is higher in the newly founded population than in the original population. 
A)  only a subset of alleles in the original population are represented in the newly founded population. 
B)  selection in the newly founded population differs from selection in the original population. 
C)  coalescent processes generate alleles that share a common history. 
D)  mutation is higher in the newly founded population than in the original population.

Question 9

Consider a population of lizards living on the coast of Africa. A storm creates piles of debris that the lizards use to raft to a faraway uninhabited island. Which evolutionary process is happening?

Accepted Answer

A)  mutation selection balance 
B)  frequency-dependent selection 
C)  the founder effect 
D)  coalescence 
A)  mutation selection balance 
B)  frequency-dependent selection 
C)  the founder effect 
D)  coalescence

Question 10

Consider a series of island populations each founded by a single individual that is heterozygous at a particular locus. If the alleles at this locus are neutral, and there is no mutation or migration, describe what the variation will look like after many generations within each population and between populations. Why?

Accepted Answer

After many generations, genetic drift wi

Question 11

A rancher genotypes all of her 150 head of cattle. In her herd, 25 are A1A1, 75 are A1A2, and 50 are A2A2. Assuming there is random mating, no selection, no mutation, and no new cattle are introduced into the population, what is the probability that the A1 allele will be fixed?

Accepted Answer

A)  0 
B)  0.4167 
C)  0.6588 
D)  1 
A)  0 
B)  0.4167 
C)  0.6588 
D)  1

Question 12

In the figure, assuming all evolutionary processes are similar in A-D, which genealogy is expected to carry the largest number of neutral alleles?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
A)  A 
B)  B 
C)  C 
D)  D

Question 13

Why might a wind-pollinated plant experience different levels of diversity in mitochondrial versus nuclear loci following a postglacial recolonization event?

Accepted Answer

After glaciers recede, the newly uncover

Question 14

The graphs show the results of simulations of changes in the frequency of a neutral allele. Each graph shows 10 different runs of the simulation. What is the most likely difference between these simulations? Explain your reasoning. A

B

C

Accepted Answer

Graph A has the smallest population size

Question 15

Explain why the probability of fixation of a new beneficial allele is independent of population size
in Haldane's model of selection and drift.

Accepted Answer

In a large population, allele frequencie

Question 16

Consider two species, 1 and 2, that experience different mutation rates with m1 2, and have populations sizes of Ne1 e2. Which species would you expect to have a lower frequency of heterozygotes at a neutral locus? Explain your reasoning.

Accepted Answer

Species 1 will have lower heterozygosity

Question 17

If neutral mutations occur at the rate of 0.5 per individual per generation, the rate of neutral substitutions per generation in that population will equal

Accepted Answer

A)  2Ne F1F1F1S1F1F1F10 0.5. 
B)  (1/2Ne) F1F1F1S1F1F1F10 0.5. 
C)  2Ne. 
D)  0.5. 
A)  2Ne F1F1F1S1F1F1F10 0.5. 
B)  (1/2Ne) F1F1F1S1F1F1F10 0.5. 
C)  2Ne. 
D)  0.5.

Question 18

In a diploid population, the threshold at which selection will outweigh drift occurs when s (the selective advantage) is greater than

Accepted Answer

A)  1/2Ne. 
B)  Ne. 
C)  Ne/2. 
D)  4Ne. 
A)  1/2Ne. 
B)  Ne. 
C)  Ne/2. 
D)  4Ne.

Question 19

Refer to the figure of the genetic code shown to answer the following question. Which of the following mutations to a codon is most likely to be selectively neutral?

Accepted Answer

A)  UUG F1F1F1S1F1F1F10 CUG 
B)  AUA F1F1F1S1F1F1F10 AUG 
C)  AAC F1F1F1S1F1F1F10 AAA 
D)  UGC F1F1F1S1F1F1F10 UGA 
A)  UUG F1F1F1S1F1F1F10 CUG 
B)  AUA F1F1F1S1F1F1F10 AUG 
C)  AAC F1F1F1S1F1F1F10 AAA 
D)  UGC F1F1F1S1F1F1F10 UGA

Question 20

Gene trees and species trees both depict evolutionary relationships. What is the difference between these two types of trees?

Accepted Answer

Species trees represent the hi

How are the neutral theory of molecular evolution and the Hardy-Weinberg equilibrium similar?

The effective population size is often lower than the census size of a population because

Consider a collection of 50 distinct alleles, each at equal frequency in a population. The time before the first coalescent event will be shortest if

A researcher examines a microsatellite locus in a wild population of D. melanogaster. She finds that in a sample of 50 individuals, 20 different alleles are segregating. According to the neutral theory, these alleles are most likely experiencing

The neutral theory predicts a constant rate of substitutions per generation; however, molecular clock estimates show that substitutions accumulate annually regardless of the generation time. What explanation for this discrepancy is illustrated in the figure?

Population bottlenecks occur when

Consider a population with an effective size of 4,000 and 32 segregating alleles. On average, how many generations would it take for all 32 alleles to coalesce to a single, ancestral allele?

A founder event changes allele frequencies because

Consider a population of lizards living on the coast of Africa. A storm creates piles of debris that the lizards use to raft to a faraway uninhabited island. Which evolutionary process is happening?

A rancher genotypes all of her 150 head of cattle. In her herd, 25 are A₁A₁, 75 are A₁A₂, and 50 are A₂A₂. Assuming there is random mating, no selection, no mutation, and no new cattle are introduced into the population, what is the probability that the A₁ allele will be fixed?

In the figure, assuming all evolutionary processes are similar in A-D, which genealogy is expected to carry the largest number of neutral alleles?

Why might a wind-pollinated plant experience different levels of diversity in mitochondrial versus nuclear loci following a postglacial recolonization event?

The graphs show the results of simulations of changes in the frequency of a neutral allele. Each graph shows 10 different runs of the simulation. What is the most likely difference between these simulations? Explain your reasoning. A B C

Explain why the probability of fixation of a new beneficial allele is independent of population size in Haldane's model of selection and drift.

Consider two species, 1 and 2, that experience different mutation rates with m₁< m₂, and have populations sizes of N_e1< N_e2. Which species would you expect to have a lower frequency of heterozygotes at a neutral locus? Explain your reasoning.

If neutral mutations occur at the rate of 0.5 per individual per generation, the rate of neutral substitutions per generation in that population will equal

In a diploid population, the threshold at which selection will outweigh drift occurs when s (the selective advantage) is greater than

Refer to the figure of the genetic code shown to answer the following question. Which of the following mutations to a codon is most likely to be selectively neutral?

Gene trees and species trees both depict evolutionary relationships. What is the difference between these two types of trees?

An Overview of Evolutionary Biology

Early Evolutionary Ideas and Darwin S Insight

Natural Selection

Phylogeny and Evolutionary History

Inferring Phylogeny

Transmission Genetics and the Sources of Genetic Variation

The Genetics of Populations

Evolution at Multiple Loci

Genome Evolution

The Origin and Evolution of Early Life

Major Transitions

Evolution and Development

Species and Speciation

Extinction and Evolutionary Trends

The Evolution of Sex

The Evolution of Sociality

Coevolution

Human Evolution

Evolution and Medicine

Filters

Exam 8: Evolution in Finite Populations

How are the neutral theory of molecular evolution and the Hardy-Weinberg equilibrium similar?

The effective population size is often lower than the census size of a population because

Consider a collection of 50 distinct alleles, each at equal frequency in a population. The time before the first coalescent event will be shortest if

A researcher examines a microsatellite locus in a wild population of D. melanogaster. She finds that in a sample of 50 individuals, 20 different alleles are segregating. According to the neutral theory, these alleles are most likely experiencing

The neutral theory predicts a constant rate of substitutions per generation; however, molecular clock estimates show that substitutions accumulate annually regardless of the generation time. What explanation for this discrepancy is illustrated in the figure?

Population bottlenecks occur when

Consider a population with an effective size of 4,000 and 32 segregating alleles. On average, how many generations would it take for all 32 alleles to coalesce to a single, ancestral allele?

A founder event changes allele frequencies because

Consider a population of lizards living on the coast of Africa. A storm creates piles of debris that the lizards use to raft to a faraway uninhabited island. Which evolutionary process is happening?

A rancher genotypes all of her 150 head of cattle. In her herd, 25 are A1A1, 75 are A1A2, and 50 are A2A2. Assuming there is random mating, no selection, no mutation, and no new cattle are introduced into the population, what is the probability that the A1 allele will be fixed?

In the figure, assuming all evolutionary processes are similar in A-D, which genealogy is expected to carry the largest number of neutral alleles?

Why might a wind-pollinated plant experience different levels of diversity in mitochondrial versus nuclear loci following a postglacial recolonization event?

The graphs show the results of simulations of changes in the frequency of a neutral allele. Each graph shows 10 different runs of the simulation. What is the most likely difference between these simulations? Explain your reasoning. A B C

Explain why the probability of fixation of a new beneficial allele is independent of population size in Haldane's model of selection and drift.

Consider two species, 1 and 2, that experience different mutation rates with m1 < m2, and have populations sizes of Ne1 < Ne2. Which species would you expect to have a lower frequency of heterozygotes at a neutral locus? Explain your reasoning.

If neutral mutations occur at the rate of 0.5 per individual per generation, the rate of neutral substitutions per generation in that population will equal

In a diploid population, the threshold at which selection will outweigh drift occurs when s (the selective advantage) is greater than

Refer to the figure of the genetic code shown to answer the following question. Which of the following mutations to a codon is most likely to be selectively neutral?

Gene trees and species trees both depict evolutionary relationships. What is the difference between these two types of trees?

An Overview of Evolutionary Biology

Early Evolutionary Ideas and Darwin S Insight

Natural Selection

Phylogeny and Evolutionary History

Inferring Phylogeny

Transmission Genetics and the Sources of Genetic Variation

The Genetics of Populations

Evolution at Multiple Loci

Genome Evolution

The Origin and Evolution of Early Life

Major Transitions

Evolution and Development

Species and Speciation

Extinction and Evolutionary Trends

The Evolution of Sex

The Evolution of Sociality

Coevolution

Human Evolution

Evolution and Medicine

Filters

A rancher genotypes all of her 150 head of cattle. In her herd, 25 are A₁A₁, 75 are A₁A₂, and 50 are A₂A₂. Assuming there is random mating, no selection, no mutation, and no new cattle are introduced into the population, what is the probability that the A₁ allele will be fixed?

Consider two species, 1 and 2, that experience different mutation rates with m₁< m₂, and have populations sizes of N_e1< N_e2. Which species would you expect to have a lower frequency of heterozygotes at a neutral locus? Explain your reasoning.