Download 300_Breeding_Bunnies_Lab_RGM_15-16

Name _____________________________________
Date _________
Mrs. Geithner-Marron (Biology300)
Period ________
Breeding Bunnies (Allele Frequency & Evolution) Lab

Problem
o To model how natural selection affects the allele frequency of a population over several generations.

Background Information
o Evolution (on a genetic level) can be described as the change in the allele frequencies of a population's
gene pool over time.

"Selective forces" (ex. breeders, predators, etc.) can select for or against specific phenotypes (traits)
and cause a change in the frequencies of the alleles that produce those phenotypes (traits).

Changes in allele frequency (and, therefore, evolution), will in turn, affect how often you see a
particular phenotype (trait) in a population.
o Ex. Breeders of rabbits have long been familiar with a variety of genetic traits that affect the
survivability of rabbits in the wild, as well as in breeding populations. One such trait is the
trait for furless rabbits (naked bunnies). This trait was first discovered in England by W.E.
Castle in 1933. The furless rabbit is rarely found in the wild because the cold English winters
are too harsh for the rabbits and act as a "selective force" against being furless. These rabbits
are not well adapted to their environment and, therefore, die before reproducing (and
passing on their genes).

Vocabulary
o allele _________________________________________________________________________________
______________________________________________________________________________________
o gene pool ______________________________________________________________________________
______________________________________________________________________________________
o allele frequency _________________________________________________________________________
______________________________________________________________________________________
o evolution ______________________________________________________________________________
______________________________________________________________________________________
Name _____________________________________
Date _________
Mrs. Geithner-Marron (Biology300)
Period ________

Pre-Lab Questions
1. Let: F (red/brown bean) = furry
f (white bean) = NO fur (furless)
a. Write the genotype(s) that best fit(s) the description:
i. heterozygous
__________________________
ii. homozygous dominant
__________________________
iii. homozygous recessive
__________________________
iv. have fur
__________________________
v. furless (NO fur)
__________________________
2. Which phenotype is best adapted for the cold climate of Connecticut? _____________________________
3. What will happen to the frequency of the genes of bunnies that are not well adapted to survive in the
cold? _________________________________________________________________________________
4. What does each individual bean represent? __________________________________________________
5. Why do you need to remove two beans for each individual bunny? _______________________________
______________________________________________________________________________________
6. What is the shaking of the bag of beans meant to simulate? _____________________________________
7. What is the best type of graph (bar, circle, line) to show the change in allele frequency over time?
______________________________________________________________________________________

Hypothesis
o If rabbits with fur and NO fur (furless) breed randomly over time in Connecticut, then the allele frequency
for (fur → F / NO fur → f) will (increase / decrease), because ____________________________________
______________________________________________________________________________________
______________________________________________________________________________________
______________________________________________________________________________________.
Name _____________________________________
Date _________
Mrs. Geithner-Marron (Biology300)
Period ________

Experimental Design
o Materials (per group)

50 red/brown beans (to represent the F allele for fur)

50 white beans (to represent the f allele for No fur/furless)

1 paper bag (to represent the countryside where the bunnies randomly mate)

4 cups (labeled FF-furry, Ff-furry, ff-No fur/furless, & “dead bunnies”) (to sort bunnies)

Graph paper (for each person)
o Procedure
1. Place 50 red/brown and 50 white beans (alleles) in the paper bag. (This may have been done for you).
2. Shake the paper bag (to represent the random mating of the rabbits).
3. WITHOUT looking, select TWO (2) beans from the bag (to represent one offspring).
a. The color of the beans will tell you whether you have a homozygous dominant (furry), a
heterozygous (furry), or homozygous recessive (furless/NO fur) bunny.
4. Place the "bunny" in the cup (labeled FF-furry, Ff-furry, & ff-furless/NO fur) representing its genotype.
5. Continue until there are no more beans in the bag.
6. For each cup (FF, Ff, & ff), count how many PAIRS of beans you have & write the number of pairs in
the correct column (FF, Ff, & ff) in the row next to "generation 1".
7. IMPORTANT!!! The ff bunnies are born furless. The cold weather kills them before they reach
reproductive age, so they can't pass on their genes (alleles).
a. Place the beans from the ff container in the “dead bunny” cup before beginning the next
round. Do NOT put them back in the bag or mix them with the beans in the Ff or FF cups!!!
8. To figure out the “Surviving # of ‘F’ alleles”: count the remaining red/brown (F) beans (from the FF
and Ff cups) and record the number in the chart in the column labeled "Surviving # of ‘’F’ Alleles"
(column 4).
9. To figure out the “Surviving # of ‘f’ alleles”: count the remaining white (f) beans (from the Ff cup)
and record the number in the chart in the column labeled "Surviving # of ‘f’ Alleles" (column 5)
a. REMEMBER; don't count the alleles of the ff bunnies that you put aside since they are “dead”.
Name _____________________________________
Date _________
Mrs. Geithner-Marron (Biology300)
Period ________
10. Add the "Surviving # of ‘’F’ Alleles" (column 4) & "Surviving # of ‘f’ alleles" (column 5) for the first
generation. Record this number in (column 6) labeled "Total Number of Surviving Alleles".
11. Place the alleles of the rabbits (FF furry & Ff furry) which have survived, grown, & reached
reproductive age back in the paper bag.
12. Repeat steps 2 through 11 for each generation (until you have finished all 10 generations or you were
told to stop).
a. If working as a team, make sure everyone in the group has a chance to select beans and record
results. Nobody should do the same job the entire time.
13. Using the formulas below, determine the allele frequency of F and f for each generation and record
them in in DECIMAL form on the chart in the columns labeled "Frequency of F alleles" (column 7) and
"Frequency of f alleles" (column 8).
a. To find "Frequency of F alleles" (column 7):
allele frequency of F = "surviving" # of F alleles from column 4
________________________________________________
total # of alleles from column 6
b. To find "Frequency of f alleles" (column 8):
allele frequency of f = "surviving" # of F alleles from column 5
________________________________________________
total # of alleles from column 6
c. Express results in decimal form (rounded to the nearest hundredth).
d. NOTE: The sum of the frequency of column 7 ‘F' + column 8 ‘f’ should = 1 (for each generation).
14. Graph the frequencies in decimal form (rounded to the nearest hundredth) for both alleles on the
same graph.
a. *****Don't forget to include ALL the features of a good graph.
15. Complete the "Analysis and Conclusions".
Name _____________________________________
Date _________
Mrs. Geithner-Marron (Biology300)
Period ________

Observations and Data
Table 1 (Note: columns 7 & 8 should = 1.0)
column column 2 column column 4
1
3
How to
count
count
count
Count all
figure out
PAIRS
PAIRS of
PAIRS
remaining
what to do of red red/white
of
red F
for each
beans
beans
white
beans
column. →
beans (from FF &
Ff cups)
generation
#FF
bunnies
#Ff
bunnies
0
n/a
n/a
1
2
3
4
5
6
7
8
9
10
column 5
column 6
column 7
column 8
Count all
remaining
white
beans
(from Ff
cup)
column 4 +
column 5
column 4 /
column 6
column 5 /
column 6
#ff
"surviving" "surviving" total # of
bunnies # F alleles
# f alleles "surviving"
(red
(white
alleles
beans)
beans)
(F + f
alleles)
frequency
of F alleles
(decimal
rounded to
hundredth)
frequency
of f alleles
(decimal
rounded to
hundredth)
0.50
0.50
n/a
50
50
100
Name _____________________________________
Date _________
Mrs. Geithner-Marron (Biology300)
Period ________

Analysis and Conclusions
1. Graph the frequencies in decimal form (to the nearest hundredth) for both alleles on the same graph.
a. *****Don't forget to include ALL the features of a good graph.
2. How is this lab simulation a model for evolution?
3. What are some limitations (drawbacks) of this type of model?
4. In real life habitats, animals often move in (immigrate) or move out (emigrate). How might immigration and
emigration affect the allele frequencies in a population?
5. In generation 1 on your data table, what was the frequency of “F” alleles? ________ ...of “f” alleles? ________
6. In your last generation on your data table, what was the frequency of “F” alleles? _______ ...of “f” alleles? ______
7. Did either of the alleles totally disappear? __________ Why/why not?
8. Describe the trends you observed in your data for the allele frequencies. (Ex. Which allele increased in frequency?
Which allele decreased in frequency?) (Refer to your data and graph.)
9. Restate your original hypothesis (from the bottom of page 2).
10. Does the data support or refute your hypothesis? Explain your reasoning by referring to your data.
11. How does natural selection (for beneficial traits/against disadvantageous traits) affect allele frequency?
12. Which evolves, individual organisms OR populations/species? Explain your reasoning.
13. If you were to repeat this lab, how could you represent immigration and emigration using beans?
Name _____________________________________
Date _________
Mrs. Geithner-Marron (Biology300)
Period ________
Make your graph here.
Name _____________________________________
Date _________
Mrs. Geithner-Marron (Biology300)
Period ________
Extra graph paper (in case you made a mistake).