It is suitable for an introductory biology class. It would also be suitable for more advanced classes where you could go into more detail on important principles such as the role of variation and mutation. This is the last lab in our majors' Introductory Biology course and the first lab in Ecology. The exercise reinforces the students' understanding of the experimental method, while at the same time emphasizing the importance of careful observation of nature. As a group they develop hypotheses to explain this pattern and then discuss experimental design.
Students then repeat the exercise on their own, first in pairs and then individually.
This lab is based on my research . The ecology class counts the number of aphid galls on individual witch hazel leaves and determines if they are randomly distributed. It could be easily adapted to labs looking at the distribution of other organisms. This page has been accessed 4,100 times since November 1, 1996.