1. How did the occurrences of the different traits change over the 30-year period? Use evidence from the graph to support your answer. Using what you know about natural selection and adaption, what generalization can you make based on these changes? 2. What might be the correlation between the clarity of the Lake water and the occurrence of The water from 1950 to 1980 based on this correlation?

3. Both the full body plate type and a half body plate trait are also present in an ocean near the lake. Where would you expect a higher occurrence of the full body plate trait, in the lake or the ocean? Explain your answer.