LAB: Natural Selection
Group Members:
Problem Statement:
What is the effect of environment on the
survival of a population?
Introduction: Read and write a 1 page
summary paragraph.
Hypothesis: If the background is __________,
then the __________ bean would be most fit for
survival in the environment.
Materials/Procedure: see lab handout (don’t
write it out)
Variables:
independent – environment
dependent – survival of bean population
constants – size of initial population, # prey, #
predator, time of predation, size of environment
Procedures:
1. Each group will, pick 1 game warden and 3 predators.
2. Game warden will gather supplies and record data.
- Pick 20 beans from each population of supply beakers
(pinto, white, red, black, lentils, yellow split peas) and add
to ziploc bag labeled “beginning population”
- Each type represents a different species
- Lay a piece of white poster paper in center of lab table
(represents light-colored habitat)
- Tell predators to turn away from habitat, and spread the
prey in the “beginning population” across the habitat.
- Predators gets 20 seconds to gather prey (ONLY ONE AT A
TIME) using forceps. TEACHER WILL KEEP THE TIME!
3. Recording Data- Determining # prey for each generation
- Count the # of each type of prey that the predators captured
- Subtract the # of captured prey from the starting #, (write # under
“surviving #” in Data Table 1
4. Simulate Reproduction:
‐
‐
Add 1 beans for each remaining bean of every type (game
warden should get these from supply beakers)
Record new “Start # for Gen. 2” in Table 1 (should be 2 times the
amount of beans that survived)
5. Generation 2:
‐ Repeat predation & reproduction (steps 1 – 5)
6. Class Data:
‐ -Record your group data “# surviving” by prey(bean) and
generation on board and calculate average # on Table 3 for each
habitat type.
6. Change of Environment
‐ Game warden should remove light background (poster
board) and use the black table tops as new darkcolored habitat
7. Repeat steps 1-5 with new environment.
8. After all data has been collected, all beans MUST
be returned to their appropriate bean supply
locations (groups will lose 10% of their lab grade
for not doing this).
Light
Dark
Graph:
Analysis:
Conclusion: