Download Purpose:

Lab G – Jelly bellicus Shipwreck!
Name:______________
Purpose:
In this activity you’ll explore the effects of natural selection on the phenotype frequency of a
population of imaginary creatures (Jelly bellicus).
Background:
Hardy-Weinberg genetic equilibrium states that a population’s phenotype frequency will change
from one generation to the next but the allele frequency will remain unchanged under the following
conditions. (5 pts)
1.
2.
3.
4.
5.
If the Hardy-Weinberg genetic equilibrium is a hypothetical and not realistic model, how is it helpful in
the study of population genetics and the creation of new species? (2 pts)
PART One: Stabilizing Selection
Procedure:
1. Find the bag of jelly beans with three colors of jelly beans in it (they should be blue, red, and
light speckled). Put the other bag off to the side, you’ll use it later. You should have 30 light
speckled jelly beans and 15 each of the red and blue. (DO NOT EAT THEM)
2. Create a line graph in the “Graph 1- Stabilizing Selection” with the color of beans on the
horizontal axis in the order red, light, blue and number of beans on the y-axis. Draw a line in
read to connect the points. Label the red line “Genetic Equilibrium”. (It should look like a bell
curve.)
3. Add the jelly beans to your pan. Mix them into the shavings to make them harder to find.
STOP HERE – DO NOT CONTINUE UNTIL INSTRUCTED
4. As a class, we’ll take 15 seconds to find as many jelly beans as you can. Your teacher will call
out when to start and stop. All crew members should search at the same time. Only one hand
may be used to collect the beans and you may NOT grab a handful of shavings and sort
through it.
5. Record the number and color of jelly beans that were not eaten in the Data Table 1.
6. For every two surviving jelly beans you’ll add 1 offspring of the same color. If there is an odd
number of blue, light speckled or red ones they can make a pair and their offspring will be light
speckled. Pull the offspring from the ones you’ve “eaten”; ask for additional ones if needed.
Lab G – Jelly bellicus Shipwreck!
Name:______________
Data Table: (4 pts)
Generation
1
Starting
Red
15
Data Table 1 – Stabilizing Selection
Number of each surviving Jelly bellicus color
Starting Light
Starting Ending
Ending Light
Speckled
Blue
Red
Speckled
30
15
Ending
Blue
2
3
Analysis:
1. On “Graph 1 – Stabilizing Selection” plot the “Ending” numbers from generation 3 (shaded
boxes) in blue and connect the points with a blue line. Label the line “Stabilizing Selection”.
2. Based on this activity and the graph you’ve created (without looking it up in the book) come up
with a possible definition for “stabilizing selection.” (2 pts)
3. Now, look up “stabilizing selection” in your book and put the definition here: (2 pts)
4. Which trait is “favored” (survived in the greatest numbers) by natural selection in this activity?(2
pts) Why do you think this trait favored? (4 pts)
PART Two: Disruptive Selection
Procedure:
1. We have discovered that the brightly colored Jelly bellicus are poisonous!
2. Place the original jelly beans back in the pan (15 blue, 15 red, and 30 light speckled).
3. Create a line graph in the “Graph 2 – Disruptive Selection” with the color of beans on the
horizontal axis in the order red, light, blue and number of beans on the y-axis. Draw a line in
read to connect the points. Label the red line “Genetic Equilibrium”. It will look like a bell curve.
4. On the instructor’s cue search for 15 seconds. Avoid the blue and red ones! If you pick up a
“poisonous” jelly bean, you must stop and skip the rest of the meal since you became sick. (If
you pick it up you can’t put it back – you are just out for this round.)
5. Record the number and color of jelly beans that were not eaten in the Data Table 2 – Disruptive
Selection.
6. For every two surviving jelly beans you’ll add 1 offspring of the same color. If there is an odd
number of blue, light speckled, or red ones they can make a pair and their offspring will be light
speckled. Pull the offspring from the ones you’ve “eaten”; ask for additional ones if needed.
7. Return the original jelly beans to their bag (15 red, 15 blue, 30 light speckled). Return extras to
the teacher.
Lab G – Jelly bellicus Shipwreck!
Name:______________
Data Table: (4 pts)
Generation
1
Starting
Red
15
Data Table 2 – Disruptive Selection
Number of each surviving Jelly bellicus color
Starting Light
Starting Ending
Ending Light
Speckled
Blue
Red
Speckled
30
15
Ending
Blue
2
3
Analysis:
5. On “Graph 2 – Disruptive Selection” plot the “Ending” numbers from generation 3 (the shaded
boxes) in blue and connect the points with a blue line. Label the line “Disruptive Selection”.
6. Based on this activity and the graph you’ve created (without looking it up in the book) come up
with a possible definition for “disruptive selection.” (2 pts)
7. Now, look up “disruptive selection” in your book and put the definition here: (2 pts)
8. Describe what happened to the population when we realized the bright ones were poisonous?
(2pts) Extrapolate what might happen to the population over several more generations. (4 pts)
PART three: Directional Shift
Procedure:
1. Find the bag with the gradient of jelly bean colors. Organize the jelly beans into their various
colors. Follow the colors listed on “Data Table 3 – Directional Shift” below to be sure you have
the correct number of jelly beans for each color.
2. Create a line graph in the “Graph 3 – Directional Shift” box with the color of beans on the
horizontal axis in the order they appear on your data table and number of beans on the y-axis.
Draw a line in red to connect the points. Label the red line “Genetic Equilibrium”.
3. On the instructor’s cue search for 15 seconds. The lighter colored jelly beans (those on the left of
the data table) taste disgusting like hot, day old frog guts and the darker ones taste sweet and
yummy, like your favorite candy. You want the darker yummy ones and try to pick those.
4. Determine the number and color of the survivors left in the pan.
5. For every two surviving jelly beans you’ll add 1 offspring of the same color. If there are an odd
number of beans they can make a pair with the color closest to them. Their offspring will be like
the lighter color of the pair. Pull the offspring from the ones you’ve “eaten”; ask for additional
ones if needed.
6. Repeat the process two more times to simulate the next 2 generations.
Lab G – Jelly bellicus Shipwreck!
Name:______________
Data Tables: (6 pts)
Totals
Starting Number
Number of
survivors
Number of
offspring
Starting Number
for next
generation
Totals
Starting Number
Generation 1 – Directional Shift
Number of each Jelly bellicus color
Dark
Yellow Light
Yellow-Green Light
Yellow
Yellow
w/ spots
Green
5
9
12
16
12
Generation 2 – Directional Shift
Number of each Jelly bellicus color
Dark
Yellow Light
Yellow-Green Light
Yellow
Yellow
w/ spots
Green
Green
9
Dark
Green
5
Green
Dark
Green
Green
Dark
Green
Number of
survivors
Number of
offspring
Starting Number
for next
generation
Totals
Starting Number
Generation 3 – Directional Shift
Number of each Jelly bellicus color
Dark
Yellow Light
Yellow-Green Light
Yellow
Yellow
w/ spots
Green
Number of
survivors
Number of
offspring
Starting Number
for next
generation
Analysis:
1. On “Graph 3 – Directional Shift” plot the “Starting Number for Next Generation” numbers from
generation 3 (the shaded boxes) in blue and connect the points with a line. Label the line
“Directional Shift”.
Lab G – Jelly bellicus Shipwreck!
Name:______________
2. Based on this activity and the graph you’ve created (without looking it up in the book) come up
with a possible definition for “Directional Shift”. (2 pts)
3. Now, look up “Directional Shift” in your book and put the definition here: (2 pts)
4. Describe what happened to the “bell curve” after three generations. (2 pts)
5. Overall, the jelly bean genetic diversity has declined. How might this affect the future of the jelly
bean population? (4 pts)
6. In the natural word, the environment is constantly changing. How did the trait of being tasty or
not affect the population? (4 pts)
7. Create a hypothesis about what would happen to the population if a new predator moved in that
preferred the lighter colored beans? (4 pts)
Pulling it all together:
Read pages 324 – 325 and answer the following questions:
8. In all of these examples how is “fitness” related to natural selection? (4 pts)
9. According to your book which form of natural selection is the most common? (2 pts) Come up
with a possible explanation why this is true. (4 pts)
10. Give a real life example for each type of natural selection: (6 pts)
Lab G – Jelly bellicus Shipwreck!
Graph 1 – Stabilizing Selection
Graph 3 – Directional Selection
Name:______________
Graph 2 – Disruptive Selection