Breeding Bunnies

On thursday's biology class, we learned that, to evolve, a population needs some sort of genetic variation, memory of previous generations, and a selecting factor. We looked at the example of a population of bunnies that lived in the middle of a mountain. It was neither at the very top nor at the very bottom. Then, a hurricane came and took some bunnies to the bottom and some to the top. What genes would allow the most bunnies to survive at each location, FF (dominant, thicker hair), Ff (heterozygous, thicker hair), or ff (recessive, thinner hair)?
Our group explored the possibilites of survival of those rabbits at the very top of the mountain. Here is what we did. Our group recieved 5 plastic cups. One had fifty beans; 25 black and 25 red, the others were marked; "FF", "Ff", "ff" and ":(". We should draw two beans at a time, placing them at the corresponding plastic cup. Each set of two beans stood for an individual, where black beans meant dominant alleles and red beans meant recessive alleles. Every time we picked a "Ff" bean couple, we flipped a coin to see whether this individual would live or die. If it lived, the beans would go to the "Ff" cup, and if it died, they would go to the ":(" cup. At the end of a generation, we "killed off" the beans in the "ff" cup, since the rabbits with thin hair would not survive in the cold climate of the mountaintop. All the beans that were of surviving individuals went back to the clear cup and were drawn to find the statistics of the next generation.
Before starting to experiment we came up with a hypothesis:
"If a population of rabbits with equal number of dominant and recessive alleles is placed at the top of a mountain, then those with thicker hair (dominant alleles) will survive more than those with thinner hair (recessive alleles)."
If our hypothesis were right, we wrote that the rabbits of "ff" alleles would die off and the ones with "FF" alleles would live on after 10 generations.
Here is our data chart.

As one can observe, the "ff" individauls completely died off at the 5th generation.
Here are the questions we were supposed to answer after completing the experiment:

• What was your original hypothesis?

Our hypothesis stated that FF bunnies would survive and dominate over ff bunnies when placed on a mountaintop (see above).

• Based on your lab data, do you need to change your hypothesis? Explain

No, we do not have to change our hypothesis because it was correct.

• Compare the number of alleles for the dominant characteristic with the number of alleles for the recessive characteristic.

By the second generation, the FF bunnies already had a 4:1 ratio over the ff bunnies, and by the fifth, the ff bunnies had already died off.

• Compare the frequencies of the dominant allele to the frequencies of the recessive allele.

The dominant allele was more common because it was the one that was best suited for that enviornment.

• In a real habitat new animals often come into the habitat (immigrate), and other s leave the area (emigrate). How might emigration and immigration affect gene frequency of F and f individuals in this population of rabbits? How might you simulate this effect if you were to repeat this activity?

In our population, immigration and emmigration would have an impact only on the generation directly after that, due to the fact that new alleles would be added into the gene pool, but, in the long run, they would not present much difference, since the thick-hair alleles would dominate. The rabbits with "FF" genes would survive the most because they would be the most adapted to the enviornment, regardless of immigration and emigration.

• How do your results compate with the class data? If significantly different, why were they different?

Our results were different because we gathered information while selecting for FF bunnies, against ff bunnies. Some other groups were selecting for either ff or FF alleles, and therefore our results vary. However, the first generation was very similar in all the groups in our class.

• How are the results of this simulation an example of evolution?

Our results are an example of evolution because our mock population adapted to conditions exterior to themselves (which was the weather at the peak of the mountain). Eventually the population grew thicher fur in order to adapt to its conditions. There was variation (genes: FF, Ff. and ff), memory of the previous generation (the gene pool was changed over the years) and a selecting factor (weather, which selected for FF genes). Therefore, this experiment is a simulation of evolution!