Survival of the Fittest

Introduction:

  Within a population, organisms will vary.  Charles Darwin stated that in the struggle for existence, those variant organisms that have favorable variations are "better adapted" to their environment and will survive and reproduce in greater numbers.  Favorable variations may mean that they are faster, or stronger, or able to eat different types of food, or better camouflaged to avoid predators.  In this lab you will simulate the effect of predation by a hawk on a large population of assorted mice.  Your population of mice will consist of black, white, and speckled mice.  You will represent the hawk.

Objectives:

  -to simulate the effect of hawk predation on the appearance of mice
  -to simulate the natural selection of traits

Materials:

 large sheet of newspaper  4 hawks (students)
 30 white mice (paper squares) 1 petri dish
 30 speckled mice (paper squares)
 30 black mice (paper squares)

Procedure:

  1. Open your sheet of newspaper and place it on the lab table.  This will serve as the environment for your mice.
  2. Place the petri dish on the other side of the lab table.  This will be the nest.
  3. Select one person from your group to act as a hawk.  This person should stand by the nest.
  4. Spread the mice on their environment evenly.
  5. The hawk now swoops over and has 1 minute to pick up as many mice as possible. The hawk may only pick up one mouse at a time, and must place it in their nest (a petri dish) before flying back to pick up another.  The goal is to pick up as many mice as possible in the time period.
  6. When the time is up record the number of mice left in the environment in the data table below.
  7. Repeat this procedure for each person in the lab group or 4 times. 
  8. After all data is collected, construct a bar graph. Be sure to label the graph and its axes.
  9. Data:
     
 
White
mice
Speckled mice
Black
mice
Hawk #1  

 

   
Hawk #2  

 

   
Hawk #3  

 

   
Hawk #4  

 

   

Total

 

 

   

Conclusion:
 Write a paragraph describing;

* the purpose of the lab

* what you thought the results would be

* what the results were (discussing numbers from data)

*how the mouse population and hawk population may change over time from natural selection