Name ____________________________________________
Date ______________________________
Natural Selection: Crash Course
Biology #14
Subject: Science
Directions: Follow along with the video and complete the questions below.
1. (1:16) What else do you already know about how species change over time to adapt to
their environment?
2. (1:39) Which of the following correctly explains why the black trait rose from 2% to 95% in
moths during the Industrial Revolution in England?
A. As the soot concentration increased in the air, dark-colored moths were better equipped to find
their mates, making it more likely for them to thrive and multiply.
B. As trees became darker, dark-colored moths were less likely to be found and eaten by birds,
making it more likely for them to thrive and multiply.
C. As the darker trees made conditions more favorable for darker species of moths, dark-colored
moths ate light-colored moths more often.
3. (2:19) Which of the following correctly ranks natural selection's role in evolution?
A. Natural selection is the chief cause of evolutionary change, ahead of mutation, migration, and
genetic drift.
B. Natural selection and genetic drift are the two chief causes of evolutionary change, ahead of
mutation and migration.
C. Natural selection, genetic drift, mutation, and migration are all equally important in dictating
evolutionary change.
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Name ____________________________________________
Date ______________________________
4. (5:17) Which of the following correctly describes a principle of natural selection?
A. Variation in phenotype is what distinguishes one species from another.
B. Individual members of a species are only able to pass down favorable traits.
C. Populations produce more offspring than the environment can support.
D. Only individuals that don't have unfavorable traits are able to reproduce.
5. (5:59) Which of the following is key to Darwin's theory?
A. Individuals evolve over their lifetime as their environments change.
B. Species evolve over generations as certain individuals reproduce.
C. Humans evolve over their lifetime while animals evolve over generations.
6. (10:13) In your own words, explain the difference between directional selection, stabilizing
selection, and disruptive selection.
7. (11:24) In your own words, explain how sexual selection also contributes to evolution.
8. (12:21) What is one question you still have about natural selection?
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