1. Using an example that's not in the book, describe how a population evolves by natural selection.
2. You have noticed in your greenhouse that your plants are covered by a pest, so you decide to apply a chemical pesticide. The first time you spray the pesticide, 90% of the pests are eliminated, but you have noticed that subsequent spraying of the pesticide has resulted in a smaller reduction of the pest population. What is happening in the pest population?