Sur vival of th e
Fitte st
Purpose – To observe and experience forces that may lead to natural selection.
Materials
Natural Variation
Peanuts
Ruler
Feeding Mechanisms
Stopwatch
Beans
Graduated Cylinder
Beaker
Spoon
Forceps (tweezers)
Predator & Prey
Stopwatch
Red Paper
White Paper
Newspaper
Red Squares
White Squares
Newspaper Squares
Opposable Thumbs
Tape
Paper
Scissors
Popsicle Stick
Peanut Butter
Crackers
Bottle
Glue Stick
Stopwatch
Colored Pencil
Procedure
Natural Variation
1. Obtain a sample of 10 peanuts in shells.
2. Examine the external structure (color, texture, size, shape, etc.) for each of your ten
specimens.
3. Record your observations on your student data sheet.
Feeding Mechanisms
1. In your lab kit you will find a bag containing beans. Count out 100 beans and place them in
the 50mL beaker also found in your kit.
2. Count out an additional 100 beans and place them in the 50mL-graduated cylinder.
3. The beaker and graduated cylinder represent two different species of flowers.
4. For this activity you will need to make use of three different tools to obtain the beans from
each of your “flowers:” a spoon, forceps, and your fingers. Each tool represents a different
bird beak types. The beans represent the birds’ food.
5. Allow each group member to try to obtain beans from each container using the tools
provided.
6. In your group, select a timekeeper and a group member to remove the seeds.
7. For each feeding mechanism, or beak type, allow 15 seconds to remove as many beans as
possible from the beaker. The beaker must remain stationary during this activity.
8. Record the number of beans collected on your student data sheet.
9. Return beans obtained after each trial.
10. Repeat step 7 using the beans in the graduated cylinder and record your data.
Predator & Prey
1. In your lab kit you will find a bag containing 25 red squares, 25 white squares and 25
newspaper squares. These colored squares represent different variations of the same prey
species. You will also find 3 sheets of paper, one red, one white and newspaper. These sheets
represent different environments.
2. In your group, select a timekeeper, a predator, and prey keeper.
3. The prey keeper will scatter the prey squares on the white paper when the predator is not
looking. When the time keeper says go, the predator will have 10 seconds to collect as many
prey squares as possible. Record the number and color of the prey collected on your student
data sheet.
4. Repeat step 3 using the other two colored “environment” papers and record your data.
Opposable Thumbs
1. One of the distinctive characteristics of primates is the use of their opposable thumbs. In this
section you will perform a series of simple tasks both with and without the use of your
thumbs.
2. Each group member will have the opportunity to perform each of the activities.
3. With normal use of your hands, perform the following tasks and record the time required to
complete the tasks.
a. Handwrite (in cursive) your full name (first, middle and last)
b. Open a bottle
c. Cut a triangle out of a sheet of notebook paper (tape or glue this sample to your data
sheet)
d. Find the image on your data sheet and color within the lines
e. Spread peanut butter on a cracker
f. Tie your shoe
4. Ask your instructor to tape your thumb to your hand.
5. Repeat steps 3a-f as directed above without the use of your thumbs and record the time
required to complete the tasks.
6. Please dispose of all used materials in the trashcan.
Conclusion
Restate the purpose of this laboratory exercise. What is natural variation and how was it observed in
the peanuts? Is it possible for certain traits to be favorable in situations yet unfavorable in another?
Use evidence from the “Feeding Mechanisms” section of this lab to explain your answer. How does
the environment affect an organism’s fitness or ability to survive? Support your statement with
evidence from the “Predator & Prey” section of this exercise. What are the advantages to having an
opposable thumb? Give examples, other than those in lab, of activities that would be significantly
more difficult if humans did not have opposable thumbs. What can affect an organism’s fitness and
what factors can lead to the progression of natural selection?
Survival of the Fittest -
Student data
sheet
Natural Variation
Peanut
#
1
2
3
4
5
6
7
8
9
10
Observations
Did you find any peanut shells that were exactly alike?
What characteristics seemed to show the greatest variation?
Feeding Mechanisms
Number of Beans Collected
Forceps (tweezers)
Spoon
Fingers
Beaker
Graduated Cylinder
Which strategy or mechanism was most successful for obtaining food in each “flower type”?
Which strategy or mechanism was least successful for obtaining food in each “flower type”?
Were more beans obtained from the beaker or the graduated cylinder?
Predator & Prey
Environment
Red Prey
White Prey
Newspaper Prey
White
Group Data
Class Data
Red
Group Data
Class Data
Newspaper Group Data
Class Data
What pattern or trend did you observe when comparing environment to prey type?
How did your group data compare with the class data?
Opposable Thumbs
Task
Sample (using thumbs)
Time (using Sample (w/o
thumbs)
thumbs)
use
Name
Open Bottle
(no sample required)
(no sample required)
Could you do it?
Could you do it?
Peanut Butter
(no sample required)
(no sample required)
Tie Shoe
Could you do it?
(no sample required)
Could you do it?
(no sample required)
Cut Paper
Color Image
of Time
(w/o
use of thumbs)
Could you do it?
Could you do it?
Which task was most affected by the absence of the opposable thumb?