Name: _____________________________ Class: __________________ Date: __________________
The Evolution of Populations
Vocabulary Practice
Answer Key
A. Who Am I?
1. temporal isolation
2. normal distribution
3. geographic isolation
4. Hardy-Weinberg equilibrium
5. punctuated equilibrium
6. behavioral isolation
3.
4.
5.
6.
7.
8.
normal distribution
extinction
gene flow
allele frequency
gene pool
geographic isolation
B. Word Origins
1. evolving together
2. evolution in which two species
“come together” becoming more similar,
from different directions
3. evolution in which two species evolve in
different directions from a common point, or
common ancestor
4. evolution on a small scale
C. Choose the Correct Word
1. stabilizing selection
2. normal distribution
3. directional selection
4. disruptive selection
5. geographic isolation
6. reproductive isolation
7. behavioral isolation
8. temporal isolation
9. coevolution
10. convergent evolution
11. divergent evolution
12. microevolution
D. Do-It Yourself Matching
1. Sample answer: many species evolving
from one
2. Sample answer: all the alleles in a
population
3. Sample answer: favors one extreme
phenotype
4. Sample answer: favors the intermediate
phenotype
5. Sample answer: favors both extreme
phenotypes
6. Sample answer: the rise of a new species
E. Analogies
1. punctuated equilibrium
2. genetic drift
Copyright © McDougal Littell/Houghton Mifflin Company.
Biology
1
The Evolution of Populations
Name ______________________________ Class __________________ Date __________________
The Evolution of Populations
Study Guide B
Answer Key
SECTION 1. GENETIC VARIATION WITHIN POPULATIONS
1. genetic variation
2. A wide range of phenotypes increases the likelihood that some individuals will have traits that allow
them to survive in new environmental conditions.
3. gene pool
4. the combined alleles of all individuals in a population
5. allele frequency
6. dividing the number of times an allele occurs by the total number of alleles
7. Can produce new alleles. Mutations in reproductive cells can be passed on to offspring.
8. Forms new genetic combinations that are passed on to offspring.
9. New genetic information can be introduced into populations when species mate with other closely-related
species.
10. it contains all of the genes/alleles of all the individuals in a population
11. how common a certain allele is in a gene pool
Be Creative: Share the most creative responses with the class.
SECTION 2. NATURAL SELECTION IN POPULATIONS
1. graph that shows the frequency of each phenotype for a trait in a population
2. how common each phenotype is in the population; whether or not the population is undergoing natural
selection for that trait
3. a normal distribution or a bell-shaped curve
Phenotypic Distribution: Graph should resemble a bell-shaped curve. X-axis should be labeled “range”
or “range of phenotypes”; y-axis should be labeled “frequency.” Mean phenotype should be labeled in the
center of the curve, which is also the peak of the curve.
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Biology
Study Guide B
2
The Evolution of Populations
Name ______________________________ Class __________________ Date __________________
4. Favors phenotypes at one extreme of a trait’s range; graph should show a normal distribution shifted
either to the right or left.
5. Favors intermediate phenotypes/selects against phenotypes at both extremes; graph should show
distribution with sharp peak in center at the mean.
6. Favors phenotypes at both extremes of a trait’s range/selects against intermediate phenotypes; graph
should show distribution with one peak at each extreme.
7. allele frequencies
8. stabilizing
9. disruptive
10. directional
SECTION 5. SPECIATION THROUGH ISOLATION
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
gene flow
gene pools
environments, genetic drift
mate
speciation, species
mutation
behavioral, geographic, and temporal barriers
Behavioral isolation: changes in behavior between two populations can act as barriers that prevent
mating. Examples: Fruit flies in the ds2 experiment which evolved different pheromones, firefly species
with different flash patterns.
Geographic isolation: physical barriers can divide populations. Example: Isthmus of Panama divides
populations of marine species in the Atlantic and Pacific Oceans.
Temporal isolation: differences in mating periods or times of day when individuals
are active can prevent mating between populations. Example: Plant species that shed pollen during
different times of
the year.
the rise of two or more species from one existing species
temporal
behavioral
geographic
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Biology
Study Guide B
3
The Evolution of Populations