Story #1 Once upon a time, there lived a population of mountain people whose members all had wings but different
types-either bat wings or bird wings. 40% of the population had bat wings and 60% of the population had bird
wings. One day, a storm hit that lasted for several weeks. Those with bat wings were able to fly around and
find food because their wings were water resistant, while those with bird wings were not able to get food
because their feathers were not water resistant and got soaked through. Many of the bird-winged people starved
and did not survive, so their alleles decreased in the gene pool, lowering the frequency of the bird wings in
future generations. Over many generations, the environment had more and more long periods of rain and the
genetic makeup of the population shifted to 10% with bird wings and 90% with bat wings.
What is the trait being described?
What are the variations that exist in this population?
3. How did the event lead to the change in allele frequency?
Alleles?
4. What type of evolutionary mechanism did this story show?
5. Was there an adaptation in this story? If so, identify it.
6. Did the change make the population more or less similar to other populations?
7. Would this increase or decrease reproductive isolation?
Increase or decrease speciation?
8. Did the new population change for the better, worse, or have no effect? Why?