The Acetate Animal Hunt

Carter, Linda                    DuSable High School
                                 536-8600
                      
                      

Objective:

Students should be able to determine which variations (adaptations) 
would allow an organism to survive and reproduce in a certain 
environment.

Apparatus needed:

25 clear acetate discs
25 yellow acetate discs
25 red acetate discs
25 blue acetate discs
Discs should be about 1 cm in diameter.

Recommended strategy:

This activity uses acetate discs of different colors to determine 
which variations may help an organism to survive in a given 
environment.
Use the entire floor area of the classroom as a habitat for a 
population of acetate "animals."  These "animals" are all of the same 
species.  The variation in the color of the discs representing the 
"animals" is due to different genetic inheritance.  The following are 
the genotypes for each "animal."

COLOR                       GENOTYPE

clear                       ccrr
red                         ccRR
blue                        CcRr
yellow                      CCrr

     Each individual in the class will act as a predator searching for 
food.  The prey will be the acetate animals.  They will be given 2 
minutes to search the area for "food."  Collect as many acetate 
animals as possible.  When the time is up, reassemble and count the 
total number of acetate discs found by all members of the class.  
Chart your findings for each color disc.  List number originally used, 
number found, number left on floor,and frequency of genes left.  
Students may prepare a bar graph indicating the frequency of color 
genes remaining in the acetate population.  Determine gene frequency 
by dividing the total number of each color organism by the number of 
surviving organisms.  Then multiply by 100 to find the percentage. 

Evaluation:

1. Which animals were most difficult to find?  Explain.
2. Explain which acetate animals were the most fit?
3. Which were the most poorly adapted?  Why?
4. What will eventually happen to genes of the most poorly adapted 
   animals?
5. As far as the predators (you) are concerned, which of you will live 
   and which of you will die?
6. List several factors that make the predators better adapted for 
   hunting.

Summary:

1. What does it mean for an organism to be adapted to its environment?
2. Explain the concept of "survival of the fittest."  
3. Give the students several scenes in which they must determine which 
   organisms within a population would most likely survive if their 
   environment was to change.  Have them explain why.  Example: 
   Imagine a population of species of giraffe living on an African 
   plain for hundreds of years.  Assume that the variation in this 
   species is such that neck length ranges from short to very long. 
   Most individuals have average-length necks, but some have short 
   necks and some have very long necks.  Assuming that this population 
   of giraffes has been at genetic equilibrium for centuries, what 
   would happen if another species, such as leaf-eating deer, entered 
   the area?  Would the species of giraffes change? 


NOTE: This paper has been modified from the original by the SMILE Staff.