Natural Selections Lab —Text Version
Introduction:
In this lab, we will explore the scientific theory of evolution by recognizing and explaining ways in which genetic variation and environmental factors contribute to evolution by natural selection and diversity of organisms. Predators will act as agents of selection on the prey, a species whose members vary in color.
Objective:
In this lab, you will learn to:
identify different types of evolutionary adaptations such as camouflage, mimicry, body shape, and teeth/beak types
explain ways in which genetic variation and environmental factors contribute to evolution by natural selection and diversity
simulate the effects of natural selection and genetic variation under specific environmental conditions
Let's learn how rabbits adapted to predation.
Brown and white rabbits are very different when it comes to survival in the environment. White rabbits are better suited to survive in the winter when their fur camouflages with the snow. This allows them to blend in with their environment and hide from predators. Brown rabbits are better suited in the other seasons when their fur matches the rocks, tree bark, and dirt. The ability of the rabbits to blend in with their environment helps them to be less of a target for predators. The difference in color is due to genetic variation.
There would be nowhere for the brown rabbit to hide without being seen by the predator. The white rabbit could easily hide from any predator since it blends in with the snow. In the summer months, the white rabbit would have a difficult time hiding from predators.
Predator Background Information:
Now we will take a closer look at how the rabbits camouflage with their environment.
First, drag the white rabbit on each type of background shown on the screen. Then drag the brown rabbit on each background. Observe the differences.
As you can see, the white-colored rabbit is camouflaged on the white snow, hence making it hard for predators to see and attack it.
Due to the fact that the white rabbit can easily be seen on the brown bark, it is vulnerable to attacks from predators. This makes the brown rabbit more suited for that environment.
There are many predators that prey on rabbits. Some examples of predators are wolves, fox, wild cats, hawks.
Hypothesis:
What do you think will happen to the rabbit population when put in different environments?
The environment with snow will have an increase in population of white rabbits over time.
The environment with snow will have a decrease in population of the light-colored rabbits over time.
The wooded environment will have an increase in population of light-colored rabbits over time.
The wooded environment will have a decreased in population of light-colored rabbits over time.
Simulation:
Get ready, get set! Rabbits will be released on your chosen environment. The predatory bird can be controlled and will eat the rabbits that are visible in that environment. The rabbits will be eaten for 5 generations. At the end of each generation, record the remaining rabbit percentages.
Data Table
Generation White Rabbit Brown Rabbit
1
2
3
4
5
Conclusion:
The rabbit simulation should have given you a good idea of how natural selection works. Let's summarize your observations from this lab:
identify different types of evolutionary adaptations such as camouflage, mimicry, body shape, and teeth/beak types
explain ways in which genetic variation and environmental factors contribute to evolution by natural selection and diversity
simulate the effects of natural selection and genetic variation under specific environmental conditions
Now you have come to the end of the lab.
Remember to copy the data table into your lab report or print your data table.Natural Selection Virtual Lab Report
Instructions: As you complete each slide of the Natural Selection Virtual Lab Activity, please fill in this lab report with the appropriate information and data.
Title:
Include your name, instructor’s name, and the name of the lab
Objective(s):
What is the purpose of the lab
Hypotheses:
Include the if/then statement you developed during the virtual lab.
Variables:
Materials:
The Natural Selection Virtual Lab Activity
Natural Selection Virtual Lab Report
Procedures:
The procedures are listed in Natural Selection Virtual Lab Activity. You do not need to include them here.
Data and Observations:
Table 1: Rabbits in the light-colored environment
Generation Rate of Survival for White Rabbits Rate of Survival for Brown Rabbits
1
2
3
4
5
Table 2: Rabbits in the dark-colored environment
Generation Rate of Survival for White Rabbits Rate of Survival for Brown Rabbits
1
2
3
4
5
Data Analysis:
Part 1: In your data tables, you recorded the percentage of the rate of survival for both the white and brown rabbit in both the light-colored and the dark-colored environments.
Part 2: Using your percentages in part 1, create a graph that represents the rate of survival for the white and brown rabbits in each type of environment.
Insert chart [Hint: don’t forget to consider the relationship between your data and the type of graph to best represent your data. A bar graph would be the best option to analyze this data.]
Conclusion:
Include the following as a summary paragraph in the conclusion of your lab report:
Analysis of the results of the experiment
Using Table 1, which color rabbit had the higher rate of survival in the light-colored (white) environment? Explain why this occurred.
Using Table 2, which color rabbit had the higher rate of survival in the dark-colored (brown) environment? Explain why this occurred.
Look at your data for both environments. Which color of rabbit seemed to camouflage best overall? Explain your answer using data.
Rationale for the support or rejection of the hypothesis
Questions:
Using what you have learned from the lesson and the virtual lab activity, answer the following questions in complete sentences.
How did the colors of each type of prey affect its population size over time?
How do you predict the data would change if you continued? Explain your answer.
What traits could help a predator be more "fit" to survive in each environment? Be specific.
Describe other adaptations besides color that could affect an individual's survival.
Explain what will happen if there are not enough resources to support the individuals in a species.
This experiment tested natural selection. What could be another possible mechanism of evolution for the rabbits to evolve? Be specific.