Exam 6 Practice Exam
1. Darwin and Wallace postulated that:
a. The species inhabiting the earth have changed through time
b. The mechanism by which descent with modification occurs is natural selection
c. Genetic variation is heritable
d. Natural selection is random
e. All of the above
f. B & D
g. A & B
2. The mechanism of evolution, natural selection, is not a random process.
a. True (Selects for the individuals who are successful at reproducing in the
environment that they are in)
b. False
3. Explain in your own words why “survival of the fittest” is a misleading phrase, and why
“reproduction of the fittest” is more accurate.
If one is able to reproduce in a given environment successfully, then that individual is
demonstrating their fitness. You must reproduce and generate viable offspring in order for
your genes to be passed on- aka – in order for your species to survive.
4. Which of the following is evidence in support of the theory of evolution?
a. Genetic homology
b. Fossil record
c. Developmental homology
d. Morphological homology
e. All of the above
f. B & D
g. A & B
5. Which of the following is a misconception of the theory of evolution?
a. Evolution is both a theory and a fact
b. The theory of evolution is an explanation for the origin of life on Earth
c. The theory of evolution does not explain the beginning of the universe
d. There are many known and well documented transitional fossils in the fossil record
6. Which of the following is TRUE about the theory of evolution?
a. Evolution can occur in individuals
b. All species are clearly distinct from one another
c. Immunity to infections and disease within an individual is NOT conferred through
evolution
d. Wild species are perfectly adapted to their environments
7. Evolution always leads to more complex species as a part of a progression towards the best
species.
a. True
b. False
8. Does meiosis and sexual reproduction change allele frequencies?
a. Yes, cellular division alters the gene pool
b. Yes, meiosis results in different combinations of alleles
c. No, cellular division alters the gene pool
d. No, meiosis only results in the different recombination of alleles
9. List the five conditions that must be met in order for a population to remain in Hardy-Weinberg
equilibrium:
a. No mutation
b. No natural selection
c. No genetic drift
d. No gene flow (migration)
e. Random mating must occur
10. Do natural populations ever satisfy all five of these conditions? Why or why not? Because of
this, what becomes of the allele frequencies?
No. There is no perfect environment where all 5 of these conditions are met. Therefore,
allele frequencies change through future generations.
11. Define microevolution. What does it lead to?
Microevolution is the change in allele frequency over short time spans (few generations).
This leads to macroevolution the production of new species and groups of new species.
12. What are the causes of evolution? (Hint: what are the five conditions that need to be met for
HWE? What needs to happen to them?)
a.
b.
c.
d.
e.
Mutations (random change in allele frequencies)
Natural selection (leads to the change in alleles frequencies; this is non-random)
Genetic drift
Gene flow (migration in and out of other populations must happen)
Non-random mating (sexual selection)
13. Why is natural selection likely better to adapt a population to its environment compared to the
other causes of evolution?
It maintains favorable alleles while removing unfavorable alleles for a given
environment. (Page 6 of pop genetics slides.)
14. For the following, assume that the population is undergoing random mating, no gene flow, no
mutations, no genetic drift, as well as not mutating. In a large population of beetles, the allele for
a metallic exoskeleton is dominant to that for a black exoskeleton. The frequency of the allele for
metallic exoskeletons in the population is 0.38.
a. What is P representing in this problem? The dominant alleles in the gene pool (the
total alleles of the metallic exoskeleton)
b. What is q representing in this problem? The recessive alleles in the gene pool (the total
alleles of the black exoskeleton)
c. What is the allele frequency of P? 0.38
d. What is the allele frequency of q? 0.62
e. In percent form (%), what is the genotype frequency of the:
i. Homozygous dominants beetles? P2= 0.382= 0.144= 14%
ii. Heterozygote individuals? 2pq= 2(0.38)(0.62)= 0.471= 47%
iii. Homozygous recessive individuals? q2= (0.62)(0.62)= 0.384= 38% (*a really
good check- be sure your final answers/ calculations all add up close to 1 or
100%)
15. The bottleneck effect:
a. Results from environmental/ human calamity and leads to a loss in the allelic
variability of the population
b. Involves the colonization of a new area due to migration
c. Results in the loss of all genetic diversity from the gene pool of a population
d. Promotes the shifting of alleles among different loci within a population
16. The founder effect:
a. Results from environmental/ human calamity and leads to a loss in the allelic variability
of the population
b. Involves the colonization of a new area due to migration
c. Results in the loss of all genetic diversity from the gene pool of a population
d. Promotes the shifting of alleles among different loci within a population
17. Which of the following are mechanisms of reproductive isolation?
a. Post-zygotic barriers
b. Allopatric speciation
c. Pre-zygotic barriers
d. Sympatric speciation
e. All of the above
f. A & C
g. B & D
18. The biological species concept:
a. Focuses on the idea of reproductive isolation
b. Eludes to the idea that members of one species does not/ cannot successfully interbreed
with members of any other species
c. Suggests that individual species do not maintain their genetic identity
d. Leads to the idea of morphology being the primary source of distinguishing between
species
e. All of the above
f. A & C
g. A & B
19. Two major requirements must be met in order for speciation to occur. Describe the following and
how each relates to speciation:
1) Genetic Isolation: Requires that gene flow between populations of a species is
interrupted/ halted
2) Genetic Divergence: Enough time must pass to allow the accumulation of sufficient
phenotypic characteristics to prevent interbreeding between the two newly distinct
populations
20. Allopatric speciation requires geographic barriers to promote genetic divergence and genetic
isolation, whereas sympatric speciation involves the development of new species within the same
geographical area.
a. True
b. False
21. Where is the fossil missing link between humans and chimps?
a. Scientists have not uncovered it yet
b. Scientists have uncovered it, yet require more fossilized samples before definitively
declaring the link between humans and apes
c. There exists so such thing since humans and chimps have evolved extensively since
our last shared common ancestor
d. Scientists have uncovered it- the hominid we call “Lucy”
22. Which of the following is CORRECT regarding evidence in support of the “out of Africa” idea?
a. Humans probably first reached the western hemisphere by ~100,000 years ago (no,
20,000)
b. The oldest known fossil remains of our species are from the Middle East
c. All the available evidence supports the idea that our species evolved in mid-central
Africa and reach other parts of the world by migration
d. The last common ancestor between humans and chimps was found to have migrated out
of Africa
Be able to define these terms:
Genetic homology
Developmental homology
Morphological homology
Natural selection
Evolution
Population
Gene pool
P
q
p+q=1
p2+2pq+q2=1
Allele frequency
Genotype frequency
Non-random mating
Genetic drift
The founder effect
The bottleneck effect
Speciation
Sympatric speciation
Allopatric Speciation
Reproductive isolation
Pre-zygotic barriers
Post-zygotic barriers
Biological Species Concept
Reproductive Isolation