Download How Can Natural Selection Be Modeled? Learning Targets

Name: __________________________________ Period: ___ Date: ___ / ___ / ___
How Can Natural Selection Be Modeled?
Learning Targets:

Students will describe the role that natural selection plays in evolution.

Students will know that the driving force of evolution is genetic variation caused by mutation.

Students will discuss the environmental conditions that account for the evolution of species.

Students will use the concepts of evolution and heredity to account for the changes in species and
diversity of life.

Students will apply the concept of natural selection to the evolution of populations.
Pre-lab Questions:
Read through the introduction on the left hand side of your screen, and answer the following
questions.
1. Define populations.
2. What does natural selection mean? (Be sure to talk about the main points of natural selection.)
a.
b.
c.
d.
3. What does variation mean?
4. What is the driving force of this variation?
5. Explain how a variation (that results from a mutation) can be beneficial.
Lab Instructions:
1. Follow the procedure on the screen.
2. Fill out the following data table from the population graph.
Trial 1: Mutation: _______________________
Condition: _______________________
Number of Animals in Population
Generation
Number of Normal Animals
Number of Mutant Animals
0
1
2
3
4
5
3. Run a second experiment, picking a different mutation and/or condition.
4. Fill out the following data table from the population graph.
Trial 2: Mutation: _______________________
Condition: _______________________
Number of Animals in Population
Generation
Number of Normal Animals
Number of Mutant Animals
0
1
2
3
4
5
5. Share your data with your lab partner, and answer the conclusion questions on the next page.
Conclusion Questions:
1. Looking at the information you recorded for a particular mutation/condition, describe how the
population of animals changed over time. (Be sure to state what particular mutation/condition you
are talking about).
2. Using your understanding of natural selection, explain why the population changed the way it did.
3. Invent a new type of mutation and environmental condition. How might natural selection operate
on a population with this mutation and environmental condition? How would the population
change over time?
4. Scientists have discovered by looking at fossil records that the ancestors of giraffes had shorter
necks than giraffes today. Make a hypothesis of how long necks have evolved in giraffes through
the process of natural selection.