Experimental Design Diagram
Title: The Effect of Isolation on the Genes in a Population
Hypothesis: If two populations become isolated then…..
Independent Variable: Interbreeding vs Isolated Populations
and Time
Levels of Independent Variable
Generations 1-5
# of Repeated Trials
5 Per Population
Control: Interbreeding Population
Dependent Variable: Percent of Genotypes AA, Aa, and aa
Constants: Gene letters (alleles), breeding time,
recombination times
Materials Needed:
1.
Four cards (2 A’s and 2 a’s)
2.
Paired desks
3.
Data Sheet
4. Music
Procedure Outline:
1.
Record your Initial Genotype as Aa
2.
Taking your cards and your data sheet with you, move around the desks as
directed when the music starts.
3.
Quickly find a seat when the music stops.
4.
Shuffle your cards.
5.
Each person of the pair lays down one card.
6.
The person on the right records that genotype in Round 1.
7.
Shuffle the cards again and repeat the process for the person on the left.
8.
If your new genotype is Aa, keep 2 A and 2 a cards. If your genotype is AA, you will
need 4 A cards. If your genotype is aa, you will need 4 a cards.
9.
Repeat steps 2-7 for a total of 5 rounds.
10.
Repeat the entire process for two isolated populations.
11.
Determine the percent of each genotype at the end of the 5th round for each
population. Fill in the data tables, then make a graph.
Conclusion:
1. Summarize the data and state whether or not it
supports your hypothesis.
2. Explain why you think it turned out the way it did.
3. Explain some way that this data could be useful to
someone?
4. Give an example of another experiment we could do
to show how speciation occurs.
5. What could we have done to improve on this
activity?