Simulating Mice Adaptation Due to Natural Selection

Background                         Darwin stated that in the struggle for existence, those variant organisms   

                                                           that are better adapted to their environment will survive and reproduce 

                                                           in greater numbers.  In this laboratory you will simulate the effects of 

                                                           selective forces on a large population of assorted “mice” struggling to 

                                                           survive predation by a “hawk”.

Objectives                             

·         Collect and interpret data of simulated predatory-prey interactions.

·         Describe how natural selection leads to adaptation of a species   

      in a changing environment.

·         Apply simulation as a model for explaining how adaptive

      traits for various species are acquire.

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Materials                             Newspaper                                Container such as a shoebox

                                                          Timer or watch                         Mouse pattern

                                                      Scissors

Procedure                                    1.   Cover a section of the floor with newspaper (1 meter square).

                                                                 This covering represents the black and white desert that is the    

                                                                  habitat of one population of mice.  The various mice living in this  

                                                                  desert have color patterns of black, white, or black and white. 

                                                                  Assume that the mice’s color patterns are inherited.  The mice are

                                                                  prey for daytime-feeding (diurnal) hawks.  These flying hawk

                                                                  predators depend on their keen eyesight and great speed to survive. 

                                                                  The mice population depend on their high reproductive rate and

                                                                  color patterns to survive.

        2.   Take the mouse pattern and trace the mouse outline on the different 

       types of paper so that there are 25 white mice; 25 black mice; 25 

       mice cut out from  large print ads; and 25 mice cut out from the

       classified ads.

3.    Have one person place 100 paper mice in a container, mix the mice

       by gently shaking the container, and then spread the 100 mice on 

       the “desert”.  The person who is playing the role of the “hawk”

       should not look at the “desert” while the 100 mice are randomly  

       scattered.

4.    The person playing the role of the hawk is to capture as many paper mice as possible in one minute.  Use the timer to accurately measure one minute.  The hawk may pick up only one mouse at a time and must stand up straight after each capture.  Each mouse seized by the hawk should be the first mouse seen by the “hawk” from the standing position.

5.    After the minute of predation is over, the person who was the hawk should count the number of each kind (color) of mouse seized and record this data in the following table below.

                                                            Capture Frequency Table

6.    Exchange roles and repeat the experiment.

Analysis                                 1.    How did the data suggest “natural selection” occurred?

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2.   Which adaptation must the hawks develop to increase their 

        chances of survival?

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3.   Which adaptation must the mice develop to increase their chances 

        of survival?   

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GOING FURTHER      

The variation in color and pattern of the paper mice was very obvious.  Variations in traits among living things are not always so obvious.   Unfamiliar grasshoppers may seem to look alike.  So also all silver maple trees may seem to look alike.  Observe these and other species around you.   See if you can detect the slight variations among individual of the same species.  Try to find the variations in: leaf size, leaf shape, pubescence (hairiness), and veining for the maple leaf.  Color, leg length, antennae size, and other traits for a grasshopper.                           

MICE NATURAL SELECTION LAB

                                                                           Group Results

NAME____________________________DATE______________CLASS_________

NATURAL SELECTION LAB

Title Page           Include type of organisms in the experiment and what you were testing.

Introduction        Background paragraph about Charles Darwin (library research) and his theory of 

                            evolution due to natural selection.

Hypothesis          One statement to express what you think will happen.

Methods               “see attached sheet”

Materials             LIST the materials that you used.

Results                Data chart for your individual information.  Table A

                            Data chart for your whole groups information.  Table B

                            Data chart for the class including the class average.  Table C

                            Bar graph of individual, group, and class averages for each type of mice.

Discussion           Answer all questions that listed below in complete sentences.

                             Don’t write the questions in your lab report

Conclusions         Two paragraphs:

                             First paragraph will tell me if your hypothesis was correct and what data you

                             have collected to support it.  Explain fully and in detail.

                             The second paragraph is a source of error section.  Give at LEAST 3 sources of

                             error (mistakes) that you either noticed while doing the lab or mistakes that others

                             made, or possible mistakes that could be made.

QUESTIONS FOR DISCUSSION

1. Describe/explain where exactly natural selection was occurring in this lab.
2. Describe the “newsprint environment” that your mice were placed in.
3. Which type of mouse didn’t survive well in your group?  Why?
4. Which type of mouse survived the best in your group?  Why?
5. Looking at your class data chart, does your individual and group data support what the rest of the class go for results?  Suggest reasons why you data is either the same or different from the others.
6. How do you think this population of mice will change, if this type of natural selection continues in your environment?
7. How do you think the hawks will be affected if the selection you say continues?
8. How might the hawk population become better adapted to it’s environment over time? 

NAME____________________________DATE______________CLASS_________

MICE SELECTION LAB

PRE LAB QUIZ

1. What are the 4 different types of mice you will be using in the lab?

2. In real life, why would mice be different colors?

3. In this lab, who is the predator?  Who is the prey?

4. What must the person playing the predator do in between every capture of a mouse?