How Can We Show That It Takes Many Generations for the Population of Piloses to Change?
Data and the process of natural selection can explain how a beneficial trait variant becomes more common in an animal population over multiple generations when the environment changes.
Students count thicker, medium, and thinner trunks in pictures of three generations of a pilose population. They record and graph their data. They reason with the process of natural selection to explain how the sequence of graphs shows change in trunk width over many generations.
Materials to Have Ready
For each student:
Notebook pages 10-12
For each small group of students:
A packet of pilosa cards (Generation 1)*
Printed pictures of Generation 3 and Generation 5
*Adaptation teachers will need to cut out sets of Generation 1 cards and print pictures of Generations 3 and 5 for each small group.