Genetics 303 Dr. Joe Staton Fourth exam—take home Answer on separate paper, show all work, and be neat in the reporting of answers. STAPLE YOUR RESULTS! 1. In a human population, the genotype frequencies at one locus are 0.75 AA, 0.2 Aa, and 0.05 aa. What is the frequency of the A allele [f(A)] and a allele [f(a)] for the population? Are they in Hardy-Weinberg equilibrium? 2. Calculate the number of heterozygotes in a population with p = 0.55 and q = 0.45 (at time = 0). After 4 generations of inbreeding between siblings (F = 0.25) in a population of 1000. 3. Human albinism is an autosomal recessive trait. Suppose that you find an isolated village in the Andes where seven people are albino. If the population size of the village was 783 and the population is in Hardy-Weinberg equilibrium with respect to this trait, how many individuals are expected to be carriers (heterozygotes)? 4. A boatload of Swedish tourists, all of whom bear the MM blood group, is marooned on Haldane Island, where they are met by an equally sized population of Islanders, all bearing blood group NN. In time, the castaways become integrated into Island society. Assuming random mating, no mutation, no selection (based on blood group), and no genetic drift, what would you expect the blood group distribution to be among 1500 progeny of the new Haldane Island population? 5. You identify a population of mice (Peromyscus maniculatus) on an island. Their coat color is controlled by a single gene: BB mice are black, Bb mice are gray, and bb mice are white. You take a census of the population and record the following numbers of mice: Black 507 Gray 546 White 147 (a) What are the frequencies of the two alleles? (b) What are the Hardy-Weinberg equilibrium frequencies for these three phenotypes? (c) A heat wave hits the island. All 507 mice with black fur die from heat stroke, but the other mice survive. What are the new allele frequencies for the population? (d) If the population suffers no further cataclysms after the heat wave, and the surviving animals mate randomly, what will be the frequency of mice with black fur in the next generation? (e) If the climate is altered permanently, so that mice with black fur die before reproducing, which following statement is correct? (1) At Hardy-Weinberg equilibrium, f(B) will equal 0.135. (2) The fitness of mice with gray fur (ωBb) must be equal to 0.5. (3) The fitness of mice with black fur (ωBB) is 0. (4) The B allele will disappear from the population in one generation. (5) The B allele will disappear from the population in two generations. 6. Which of the following are requirements for evolution by natural selection? Explain your answer. I Environmental change II Differential survival and reproduction III Heritability of phenotypic variation IV Variation in phenotype V Sexual reproduction A) II, III, V B) II, III, IV C) I, II, IV D) III, IV, V .

1. Genetics 303 Dr. Joe Staton
Fourth exam—take home
Answer on separate paper, show all work, and be neat in the
reporting of answers. STAPLE YOUR RESULTS!
1. In a human population, the genotype frequencies at one locus
are 0.75 AA, 0.2 Aa, and 0.05 aa. What is the frequency
of the A allele [f(A)] and a allele [f(a)] for the population? Are
they in Hardy-Weinberg equilibrium?
2. Calculate the number of heterozygotes in a population with p
= 0.55 and q = 0.45 (at time = 0). After 4 generations of
inbreeding between siblings (F = 0.25) in a population of 1000.
3. Human albinism is an autosomal recessive trait. Suppose that
you find an isolated village in the Andes where seven
people are albino. If the population size of the village was 783
and the population is in Hardy-Weinberg equilibrium
with respect to this trait, how many individuals are expected to
be carriers (heterozygotes)?
4. A boatload of Swedish tourists, all of whom bear the MM
blood group, is marooned on Haldane Island, where they are
met by an equally sized population of Islanders, all bearing
blood group NN. In time, the castaways become
integrated into Island society. Assuming random mating, no
mutation, no selection (based on blood group), and no

2. genetic drift, what would you expect the blood group
distribution to be among 1500 progeny of the new Haldane
Island population?
5. You identify a population of mice (Peromyscus maniculatus)
on an island. Their coat color is controlled by a single
gene: BB mice are black, Bb mice are gray, and bb mice are
white. You take a census of the population and record
the following numbers of mice:
Black 507
Gray 546
White 147
(a) What are the frequencies of the two alleles?
(b) What are the Hardy-Weinberg equilibrium frequencies for
these three phenotypes?
(c) A heat wave hits the island. All 507 mice with black fur die
from heat stroke, but the other mice survive. What are the
new allele frequencies for the population?
(d) If the population suffers no further cataclysms after the heat
wave, and the surviving animals mate randomly, what will
be the frequency of mice with black fur in the next generation?
(e) If the climate is altered permanently, so that mice with black
fur die before reproducing, which following statement is
correct?
(1) At Hardy-Weinberg equilibrium, f(B) will equal 0.135.
(2) The fitness of mice with gray fur (ωBb) must be equal to
0.5.
(3) The fitness of mice with black fur (ωBB) is 0.
(4) The B allele will disappear from the population in one
generation.

3. (5) The B allele will disappear from the population in two
generations.
6. Which of the following are requirements for evolution by
natural selection? Explain your answer.
I Environmental change
II Differential survival and reproduction
III Heritability of phenotypic variation
IV Variation in phenotype
V Sexual reproduction
A) II, III, V B) II, III, IV C) I, II, IV D) III, IV, V E) II, IV,
V
7. Which of the following processes is the source (origin) of
genetic variation within populations?
A) Reproductive Isolation
B) Asexual reproduction
C) Selection
D) Mutation
E) Genetic drift
Explain your answer including a description of what the others
do to variation.
8. If the population (14,926 in 2013) of folks in Perry, GA,
have an f(a) = 0.1 and folks in Valdosta, GA, has a f(a) = 0.7,
then how many people from Valdosta, GA, would have to
migrate to Perry to increase the population to a f(a) =

4. 0.15?
9. What is the Ne of a population with the following annual
censuses, [note the drop in size due to 2005 being an extreme
drought year]?
2001: 10,000
2002: 9,700
2003: 8,800
2004: 4,600
2005: 700
2006: 2,400
2007: 3,800
2008: 7,650
2009: 8,400
2010: 9,700
2011: 10,110
2012: 11,060
10. Consider the following populations that have the genotypes
shown in the following table:
Population AA Aa aa
1 1.0 0.0 0.0
2 0.0 1.0 0.0
3 0.25 0.50 0.25
4 0.25 0.25 0.50
5 0.32 0.36 0.32
6 0.04 0.32 0.64
7 0.64 0.32 0.04
8 0.9025 0.095 0.0025
a. What are p and q for each population?
b. Which of the populations are in Hardy-Weinberg

5. equilibrium?
c. Populations 1 and 2 have a tree fall across their islands so
that individuals can cross. If equal numbers of the
individuals occur on each island, what is the new population’s
allele frequencies and genotype frequencies
after one generation of random mating?
d. In population 3, the a allele is less fit than the A allele, and
the A allele is incompletely dominant. The result
is that AA is perfectly fit (= 1.0), Aa has a fitness of 0.85, and
aa has a fitness of 0.65. With no mutation or
migration, graph the allele frequency of the a allele for 10
generations under selection (e.g., Time 0 = q above,
Time 1 = first generation after selection)
e. In population 8, the population size gets radically reduced to
200 individuals, total. What is the most likely
fate of the “a” allele, and what genetic principle would lead you
to believe that the case?
11. You are given the following genetic data matrix of
distances for crustaceans calculated for a region of the mtDNA
called the 16S rDNA:
Brine Shrimp Striped-leg hermit King Crab Soldier crab Flat-
claw hermit Long-clawed hermit
Brine Shrimp ─
Striped-leg hermit 0.354 ─
King Crab 0.309 0.260 ─
Soldier crab (hermit) 0.321 0.268 0.067 ─
Flat-claw hermit 0.337 0.245 0.108 0.111 ─
Long-clawed hermit 0.312 0.249 0.090 0.096 0.044 ─

6. Calculate the average distance and draw the resulting UPGMA
tree based on these distances. Write a brief interpretation
of the branching pattern in the tree.
12. You digest a linear piece of DNA with two restriction
enzymes, BamH1 & Sma1, and get the following sized
fragments (in kb [kilobases]):
BamHI SmaI BamHI & SmaI
13 kb 11 kb 10 kb
6 kb 5 kb 5 kb
3 kb 3 kb
1 kb
Draw the appropriate restriction fragment map based on this
data labeling all restriction sites.
Extra Credit:
You have a population of gribbets in captivity where the adults
have a genetic frequency of f(A)=0.5 and f(a) = 0.5. When
randomly mated, they have offspring that are represented in the
following frequencies:
f(AA) f(Aa) f(aa)
0.194444 0.555556 0.25
But you notice that the total generational reproduction level is
only 90% that of wild populations (i.e. the ω is only 0.9).
Work backwards to figure out the type of condition from table
25.5, and calculate the equilibrium frequency for the a
allele (q). Give it a try! Partial credit for attempts…