Biology - HOT Science Lab

Teacher
Additional instructions/Handouts:
Rules of the Island
success of each beak variation throughout the six rounds. Plot rounds
1–6 on the x-axis. Plot the percent frequency of each variation on the y-
axis. Be sure to title your graph and label the axes and the three graph
lines. Check graphs for correct labeling of axes and title. Graphs should
represent their data.
3. Describe the pattern of change for each beak type as displayed in your
graph. Identify the most successful beak type or types and suggest
reasons for success. Discuss how the beak shapes enabled them to
efficiently capture the different types of food.
4. Did the frequency of the different beak variations change when the food
supply changed Relate this to what you learned about the finches on
Daphne Major. Yes, when the food supply changed, the knife variation
was especially affected. While the forks and spoons could scoop up the
food, the knives could barely carry back one piece at a time. On Daphne
Major during dry years, many of the finches with small beaks did not
survive because they were unable to crack open harder seeds and
expand their food supply.
5. How do you think the results of the Grants‘ research might have been
different if the beak-depth variations were not genetically based traits
(were not passed on from the generation to generation) If beak depth
were not a genetic trait, then the percent frequencies of the variations in
depth would not change after a dry year.
6. Competition and variation are two factors that play key roles in the
natural selection in the population of ground finches on Daphne Major
during the drought years. There are variations in the depth of beaks
among medium ground finches. During drought years, finches with
deeper beaks have more access to food. These finches are more apt to
survive and reproduce than finches with less deep beaks.
1. You may not use your hands except to hold the plastic utensil (your ―beak‖) and open the
plastic bag (the ―nest‖).
2. You may not push other ―birds,‖ deliberately knock the food out of the other ―birds‘ beaks,‖ or
steal food from the other ―birds‘ nests.‖
3. You must put your nest in the same general area as the other birds‘ nests.
4. When your teacher says that time is up, stop where you are. If you have food held securely
in your beak, you may bring it to your nest.
5. Do not eat any of the food.
Biology HSL Page 75
Curriculum and Instruction