Question 1

Explain how landscape genetics can influence the evolution of populations.

Accepted Answer

Landscape genetics is the study of how landscape features and environmental factors influence the genetic structure and evolution of populations. By examining the relationship between genetic variation and landscape features, researchers can gain insights into how populations are shaped by their environment.

One way in which landscape genetics can influence the evolution of populations is by identifying barriers to gene flow. Landscape features such as rivers, mountains, or human-made structures can act as barriers that limit the movement of individuals between different areas. This can lead to genetic isolation and the formation of distinct populations, which can ultimately drive the evolution of new species or subspecies.

Additionally, landscape genetics can help identify corridors or pathways that facilitate gene flow between populations. These connections can promote genetic exchange and prevent the loss of genetic diversity, which is important for the long-term survival and adaptability of populations.

Furthermore, landscape genetics can also provide insights into how environmental changes, such as habitat fragmentation or climate change, can impact the genetic diversity and adaptive potential of populations. By understanding how landscape features influence gene flow and genetic diversity, conservation efforts can be better informed to protect and manage populations in the face of environmental challenges.

Overall, landscape genetics plays a crucial role in understanding the evolutionary processes that shape populations, and can inform conservation and management strategies to ensure the long-term viability of species.

Question 2

Compare two examples of genetic drift: the genetic bottleneck and the founder effect.

Accepted Answer

Genetic drift is a mechanism of evolution that occurs when there is a change in the frequency of certain alleles in a population due to random chance. Two examples of genetic drift are the genetic bottleneck and the founder effect.

The genetic bottleneck occurs when a population undergoes a drastic reduction in size, leading to a significant loss of genetic diversity. This can happen as a result of natural disasters, disease outbreaks, or human activities such as habitat destruction. The smaller population that emerges from the bottleneck will have a limited gene pool, and certain alleles may be overrepresented or lost entirely. This can lead to an increase in genetic disorders and a decrease in overall fitness.

On the other hand, the founder effect occurs when a small group of individuals establishes a new population in a different location. These individuals may not represent the full genetic diversity of the original population, and as a result, the new population will have a gene pool that is different from the original population. Over time, this can lead to the fixation of certain alleles and the loss of others, resulting in genetic differences between the two populations.

In both cases, genetic drift can lead to changes in allele frequencies and a loss of genetic diversity within a population. However, the genetic bottleneck is the result of a population size reduction, while the founder effect is the result of a small group of individuals founding a new population. Both processes can have significant impacts on the genetic makeup of a population and its ability to adapt to changing environments.

Question 3

A genetic bottleneck occurs when

Accepted Answer

A)  there is a temporary dip in population size. 
B)  a population is very small. 
C)  a few individuals begin a new isolated population. 
D)  a and b 
E)  all of the above 
A)  there is a temporary dip in population size. 
B)  a population is very small. 
C)  a few individuals begin a new isolated population. 
D)  a and b 
E)  all of the above A

Question 4

The probability of an allele being lost during a genetic bottleneck depends on

Accepted Answer

A)  the beginning frequency of that allele in the population. 
B)  the severity of the bottleneck. 
C)  the size of the population before the bottlenecking event. 
D)  a and b 
E)  a, b, and c 
A)  the beginning frequency of that allele in the population. 
B)  the severity of the bottleneck. 
C)  the size of the population before the bottlenecking event. 
D)  a and b 
E)  a, b, and c

Question 5

The graphs below show the results of simulations of the effect of selection on deleterious alleles. Population size is infinite in both simulations, and the starting frequency and the strength of selection are the same.   (a) Based on the shape of the curves, why do the results of the simulations differ? Explain your answer.
(b) The allele in the second simulation is not eliminated entirely from the population. Would this change if the population was finite in size? Why or why not?

Accepted Answer

The answer of The graphs below show the results of...

Question 6

A mosquito that has the genotype Ester1Ester1 is considered ____ and is ____ at the esterase locus.

Accepted Answer

A)  homozygous dominant; diploid 
B)  heterozygous; haploid 
C)  homozygous; diploid 
D)  heterozygous; diploid 
A)  homozygous dominant; diploid 
B)  heterozygous; haploid 
C)  homozygous; diploid 
D)  heterozygous; diploid

Question 7

The sickle-cell anemia allele, S, experiences strong negative selection because of its deleterious effect on homozygotes, yet the allele is maintained at frequencies higher than expected because having only one copy can increase survival in areas where malaria is prevalent. This is an example of

Accepted Answer

A)  heterozygote advantage. 
B)  antagonistic pleiotropy. 
C)  balancing selection. 
D)  a and c 
E)  a, b, and c 
A)  heterozygote advantage. 
B)  antagonistic pleiotropy. 
C)  balancing selection. 
D)  a and c 
E)  a, b, and c

Question 8

Inbreeding

Accepted Answer

A)  increases heterozygosity in populations. 
B)  creates deleterious recessive alleles. 
C)  increases homozygosity in populations. 
D)  all of the above 
E)  b and c 
A)  increases heterozygosity in populations. 
B)  creates deleterious recessive alleles. 
C)  increases homozygosity in populations. 
D)  all of the above 
E)  b and c

Question 9

The graph below depicts the rise in resistance to warfarin in a rat population. Notice that after reaching a peak of 100% resistance, resistance in the population declined. Please provide a plausible evolutionary explanation for this.

Accepted Answer

The answer of The graph below depicts the rise in...

Question 10

A bowl of beads has 500 red and 500 white beads. In a random sample of two beads, you select two white beads; if you took a random sample of 100 beads, you would expect

Accepted Answer

A)  mostly white beads again because it is obviously easier to draw white beads. 
B)  mostly red beads this time; it is actually easier to draw red beads. 
C)  approximately 50 red beads and 50 white beads because it is a larger sample. 
D)  none of the above; there is not enough information given to make a prediction. 
A)  mostly white beads again because it is obviously easier to draw white beads. 
B)  mostly red beads this time; it is actually easier to draw red beads. 
C)  approximately 50 red beads and 50 white beads because it is a larger sample. 
D)  none of the above; there is not enough information given to make a prediction.

Question 11

Which of the following is the best evidence for a genetic bottleneck in northern elephant seals?

Accepted Answer

A)  They were nearly hunted to extinction. 
B)  They have low genetic variation within a mitochondrial DNA sequence that has a high mutation rate. 
C)  Their populations rebounded. 
D)  all of the above 
A)  They were nearly hunted to extinction. 
B)  They have low genetic variation within a mitochondrial DNA sequence that has a high mutation rate. 
C)  Their populations rebounded. 
D)  all of the above

Question 12

If a population is in Hardy-Weinberg equilibrium and the frequency of homozygous recessive individuals is 0.49, what is the frequency of the recessive allele?

Accepted Answer

A)  0.51 
B)  0.49 
C)  0.7 
D)  0.3 
E)  none of the above 
A)  0.51 
B)  0.49 
C)  0.7 
D)  0.3 
E)  none of the above

Question 13

Although the Ester1 allele confers a selective advantage to mosquitoes exposed to DDT on the coast of France, carriers of Ester1 in inland populations are more likely to be caught by spiders and other predators. This is an example of

Accepted Answer

A)  positive selection. 
B)  antagonistic pleiotropy. 
C)  genetic drift. 
D)  average excess of fitness. 
E)  none of the above 
A)  positive selection. 
B)  antagonistic pleiotropy. 
C)  genetic drift. 
D)  average excess of fitness. 
E)  none of the above

Question 14

An example of a phenotype is _____, while a genotype would be _____.

Accepted Answer

A)  homozygous; Ester1Ester1 
B)  heterozygous; EsterEster 
C)  esterase production; Ester1Ester 
D)  esterase production; Ester1 
A)  homozygous; Ester1Ester1 
B)  heterozygous; EsterEster 
C)  esterase production; Ester1Ester 
D)  esterase production; Ester1

Question 15

How is a null hypothesis useful in studying how allele frequencies change?

Accepted Answer

A)  It serves as a baseline for change. 
B)  It explains what happens when there is no change. 
C)  It explains what happens when there is change. 
D)  a and b 
E)  a and c 
A)  It serves as a baseline for change. 
B)  It explains what happens when there is no change. 
C)  It explains what happens when there is change. 
D)  a and b 
E)  a and c

Question 16

In the Hardy-Weinberg equation, what does 2pq refer to?

Accepted Answer

A)  the frequency of heterozygotes in a population 
B)  the frequency of both alleles in a population 
C)  the frequency of homozygotes in a population 
D)  none of the above 
A)  the frequency of heterozygotes in a population 
B)  the frequency of both alleles in a population 
C)  the frequency of homozygotes in a population 
D)  none of the above

Question 17

How did Buri's experiments illustrate populations deviating from the assumptions of Hardy-Weinberg equilibrium?

Accepted Answer

A)  Each population started with only eight males and eight females. 
B)  Reproducing flies were chosen at random. 
C)  Populations of flies were kept isolated in their own vials. 
D)  all of the above 
E)  none of the above 
A)  Each population started with only eight males and eight females. 
B)  Reproducing flies were chosen at random. 
C)  Populations of flies were kept isolated in their own vials. 
D)  all of the above 
E)  none of the above

Question 18

In comparison with genetic drift, evolution by natural selection is

Accepted Answer

A)  random. 
B)  adaptive. 
C)  random and adaptive. 
D)  nonrandom and adaptive. 
A)  random. 
B)  adaptive. 
C)  random and adaptive. 
D)  nonrandom and adaptive.

Question 19

Which of the following is not an assumption of the Hardy-Weinberg theorem?

Accepted Answer

A)  The population is infinitely large. 
B)  There is no selection in the population. 
C)  There is no immigration, but individuals can emigrate out of a population. 
D)  There are no mutations. 
A)  The population is infinitely large. 
B)  There is no selection in the population. 
C)  There is no immigration, but individuals can emigrate out of a population. 
D)  There are no mutations.

Question 20

Discuss the effectiveness of genetic drift and natural selection in small versus large populations. Please be sure to explain why each process is stronger or weaker depending on the population size.

Accepted Answer

Genetic drift and natural selection are

Explain how landscape genetics can influence the evolution of populations.

Compare two examples of genetic drift: the genetic bottleneck and the founder effect.

A genetic bottleneck occurs when

The probability of an allele being lost during a genetic bottleneck depends on

A mosquito that has the genotype Ester¹Ester¹ is considered and is at the esterase locus.

The sickle-cell anemia allele, S, experiences strong negative selection because of its deleterious effect on homozygotes, yet the allele is maintained at frequencies higher than expected because having only one copy can increase survival in areas where malaria is prevalent. This is an example of

Inbreeding

The graph below depicts the rise in resistance to warfarin in a rat population. Notice that after reaching a peak of 100% resistance, resistance in the population declined. Please provide a plausible evolutionary explanation for this.

A bowl of beads has 500 red and 500 white beads. In a random sample of two beads, you select two white beads; if you took a random sample of 100 beads, you would expect

Which of the following is the best evidence for a genetic bottleneck in northern elephant seals?

If a population is in Hardy-Weinberg equilibrium and the frequency of homozygous recessive individuals is 0.49, what is the frequency of the recessive allele?

Although the Ester¹ allele confers a selective advantage to mosquitoes exposed to DDT on the coast of France, carriers of Ester¹ in inland populations are more likely to be caught by spiders and other predators. This is an example of

An example of a phenotype is _, while a genotype would be _.

How is a null hypothesis useful in studying how allele frequencies change?

In the Hardy-Weinberg equation, what does 2pq refer to?

How did Buri's experiments illustrate populations deviating from the assumptions of Hardy-Weinberg equilibrium?

In comparison with genetic drift, evolution by natural selection is

Which of the following is not an assumption of the Hardy-Weinberg theorem?

Discuss the effectiveness of genetic drift and natural selection in small versus large populations. Please be sure to explain why each process is stronger or weaker depending on the population size.

The Whale and the Virus: How Scientists Study Evolution

From Natural Philosophy to Darwin: a Brief History of Evolutionary Ideas

What the Rocks Say: How Geology and Paleontology Reveal the History of Life

The Tree of Life: How Biologists Use Phylogeny to Reconstruct the Deep Past

Raw Material: Heritable Variation Among Individuals

Beyond Alleles: Quantitative Genetics and the Evolution of Phenotypes

The History in Our Genes

From Genes to Traits: the Evolution of Genetic Networks and Development

Natural Selection: Empirical Studies in the Wild

Sex: Causes and Consequences

After Conception: the Evolution of Life History and Parental Care

The Origin of Species

Macroevolution: the Long Run

Intimate Partnerships: How Species Adapt to Each Other

Brains and Behavior

Human Evolution: a New Kind of Ape

Evolutionary Medicine

Filters

Exam 6: The Ways of Change: Drift and Selection

Explain how landscape genetics can influence the evolution of populations.

Compare two examples of genetic drift: the genetic bottleneck and the founder effect.

A genetic bottleneck occurs when

The probability of an allele being lost during a genetic bottleneck depends on

A mosquito that has the genotype Ester1Ester1 is considered ____ and is ____ at the esterase locus.

The sickle-cell anemia allele, S, experiences strong negative selection because of its deleterious effect on homozygotes, yet the allele is maintained at frequencies higher than expected because having only one copy can increase survival in areas where malaria is prevalent. This is an example of

Inbreeding

The graph below depicts the rise in resistance to warfarin in a rat population. Notice that after reaching a peak of 100% resistance, resistance in the population declined. Please provide a plausible evolutionary explanation for this.

A bowl of beads has 500 red and 500 white beads. In a random sample of two beads, you select two white beads; if you took a random sample of 100 beads, you would expect

Which of the following is the best evidence for a genetic bottleneck in northern elephant seals?

If a population is in Hardy-Weinberg equilibrium and the frequency of homozygous recessive individuals is 0.49, what is the frequency of the recessive allele?

Although the Ester1 allele confers a selective advantage to mosquitoes exposed to DDT on the coast of France, carriers of Ester1 in inland populations are more likely to be caught by spiders and other predators. This is an example of

An example of a phenotype is _____, while a genotype would be _____.

How is a null hypothesis useful in studying how allele frequencies change?

In the Hardy-Weinberg equation, what does 2pq refer to?

How did Buri's experiments illustrate populations deviating from the assumptions of Hardy-Weinberg equilibrium?

In comparison with genetic drift, evolution by natural selection is

Which of the following is not an assumption of the Hardy-Weinberg theorem?

Discuss the effectiveness of genetic drift and natural selection in small versus large populations. Please be sure to explain why each process is stronger or weaker depending on the population size.

The Whale and the Virus: How Scientists Study Evolution

From Natural Philosophy to Darwin: a Brief History of Evolutionary Ideas

What the Rocks Say: How Geology and Paleontology Reveal the History of Life

The Tree of Life: How Biologists Use Phylogeny to Reconstruct the Deep Past

Raw Material: Heritable Variation Among Individuals

Beyond Alleles: Quantitative Genetics and the Evolution of Phenotypes

The History in Our Genes

From Genes to Traits: the Evolution of Genetic Networks and Development

Natural Selection: Empirical Studies in the Wild

Sex: Causes and Consequences

After Conception: the Evolution of Life History and Parental Care

The Origin of Species

Macroevolution: the Long Run

Intimate Partnerships: How Species Adapt to Each Other

Brains and Behavior

Human Evolution: a New Kind of Ape

Evolutionary Medicine

Filters

A mosquito that has the genotype Ester¹Ester¹ is considered and is at the esterase locus.

Although the Ester¹ allele confers a selective advantage to mosquitoes exposed to DDT on the coast of France, carriers of Ester¹ in inland populations are more likely to be caught by spiders and other predators. This is an example of

An example of a phenotype is _, while a genotype would be _.