Natural Selection Feeding Adaptations

 

Background:  One of the principle aspects of the theory of evolution is the concept of natural selection.  The theory states that living things change over time and certain changes will be successful, thereby showing up in greater numbers in the population.  Given enough time, a change may be so successful that the original condition will disappear altogether, and the organism will evolve with regards to that one aspect of its nature.  Natural selection states that as change occurs, nature will select for the most advantageous condition for the organism, and we call this condition an adaptation.

 

Problem:  How can you model natural selection for feeding adaptations?

 

Materials:

 

8 forceps

8 spoons

8 test tube holders

8 scoopulas

32 paper cups

Approximately 200 pinto beans

 

Procedure:

a.         Divide the class into groups of four members.  The 4 members represent animals with 4 different feeding strategies.  The are called the spoonies, zeeters, pelcamps and skoopers.

 

  1. Every participate receives a paper cup.  Every zeeter receives forceps.  Every spoonie receives a plastic spoon.  Every pelcamp receives a test tube holder.  Every scooper receives a scoopula.
  2. Each member will receive 30 seconds to demonstrate how efficient their feeding strategy is.  The beans are spread out on a given area.  Each member is given 30 seconds to pick up beans with their special adaptation and place them in a paper cup.
  3. At the end of the 30 seconds, team members will count their beans on the data table.
  4. The member with the fewest beans becomes extinct, and are out of the competition.
  5. Repeat steps two more times, until only one member is left.
  6. Repeat the entire procedure again, but allow all the members to compete at the same time.  There is no physical interference allowed (i.e. pushing out of the way.)

 

 

 

 

Results  Data Table – Part 1

                                                Total Number of beans per member

            Zeeters                       Spoonies                     Pelcamps                    Scoopulas

Trial 1

Trial 2

Trial 3

 

Results  Data Table – Part 2

                                                Total Number of beans ALL members

            Zeeters                       Spoonies                     Pelcamps                    Scoopulas

Trial 1

Trial 2

Trial 3

 

Summary of the Results – Make a graph showing the results of both Data Tables.

 

Conclusions
Answer the following questions in complete sentences.

 

  1. When each member participated independently for 30 seconds, who became extinct first?  Why do you think this happened?
  2. When each member participated independently for 30 seconds, who survived to the end?  Why do you think this happened?
  3. How did your results differ when ALL members participated?  Why do you think this different occurred?