Name:
Population Genetics Review WS
Vocab
Population
Age structure diagram
Logistic model
Density-dependent limiting
factors
Mutations
Gene flow
Stabilizing selection
Geographic isolation
Gradualism
Population size
Survivorship curve
Carrying capacity
Population density
Growth rate
Limiting factors
Population genetics
Bell curve
Population distribution
Exponential model
Density-independent
limiting factors
Gene pool
Genetic drift
Non-random mating
Directional selection
Allopatric speciation
Punctuated equilibrium
Founder effect
Sexual selection
Disruptive selection
Reproductive isolation
Bottleneck effect
Natural selection
Speciation
Sympatric speciation
Questions
1. How are population sizes measured?
2. What is the difference between a type I, type II, and type III survivorship curve? What is an example of an
organism that represents each type of curve?
a. Draw what a survivorship curve looks like (see ppt for details)
3. What are some of the disadvantages of small populations?
4. What are the causes of variation that is observed in populations of different organisms?
5. What are the two equations used to calculate Hardy-Weinberg allele frequencies? Why is Hardy-Weinberg
useful?
6. What conditions are needed for Hardy-Weinberg equilibrium to exist? What is the significance of HardyWeinberg?
7. How is genetic drift different in a small population vs. a large population (think about the lab you did in class)
Hardy-Weinberg Practice problems
1. A population of rabbits may be brown (the dominant phenotype) or white (the recessive phenotype). Brown
rabbits have the genotype BB or Bb. White rabbits have the genotype bb. The frequency of the BB genotype is
.35.
a. What is the frequency of heterozygous rabbits?
b. What is the frequency of the B allele?
c. What is the frequency of the b allele?
2. A population of birds contains 16 animals with red tail feathers and 34 animals with blue tail feathers. Blue tail
feathers are the dominant trait.
a. What is the frequency of the red allele?
b. What is the frequency of the blue allele?
c. What is the frequency of heterozygotes?
d. How many birds are carriers for the red allele?
3. If 51% of a population of male deer has at least one copy of the dominant allele for fuzzy antlers:
a. What is the predicted frequency of individuals in the population that are homozygous dominant for
fuzzy antlers?
b. What is the predicted frequency of the recessive allele?
4. In corn, yellow kernel color is govered by a dominant allele; white, by its recessive allele. A random sample of
1,000 kernels from a population that is in equilibrium reveals that 910 are yellow.
a. How many kernels are white?
b. What are the frequencies of the yellow and white alleles in this population?
c. How many kernels are heterozygous in this population?
5. A rare disease, which recessive and lethal when homozygous, occurs with a frequency of one in a million.
a. How many individuals in a town of 14,000 can be expected to carry this allele?
Diagrams
Age Structure
 Look at the graphs below and answer the following questions
1. Identify in the age structure diagrams below which one represent the population exhibiting rapid growth, which
one represents slow growth, and which one represents zero growth. Explain how you know this.
Exponential vs. Logistical Growth Model
 Look at the graphs below and answer the following questions
1.
2.
3.
4.
5.
Which type of population growth is shown in each of the graphs shown above?
Which graph would most likely illustrate the growth of a deer population living in New Jersey?
Which graph illustrates a population that has reached carrying capacity?
Which graph illustrates the growth of a microbial population living in the most hospitable environment?
Why don’t populations of organisms grow indefinitely?
Types of Natural Selection
Look at the pictures below and then answer the following questions
1. Identify which bell curve diagram is showing the original population, which one is showing directional selection,
which is showing disruptive selection, and which is showing stabilizing selection.
2. Hypothesize what might influence each type of population to cause this type of natural selection.
Speciation of California Salamanders
1. Identify in the picture to the
right where geographic
isolation plays a role in the
speciation of the population
of salamander. What type of
speciation is demonstrated?
2. Identify in the picture to the
right where reproductive
isolation plays a role in the
speciation of salamander.
What type of speciation is
demonstrated?
3. How does reproductive
isolation prevent similar
organisms from reproducing
with each other?
4. What does speciation mean?
5. Observe the ancestral
salamander, which is dark
blue in color, and the western
population, which get
progressively lighter in blue
color. If these species were formed from a single type of natural selection, which type is it most likely to be?
Explain.
6. Competition for resources plays a key role in natural selection. Describe one way that competition might have
influenced the evolution of salamander color.