This handout goes along with the slide show linked at the top of the of the resource. Depending on the computer availability in your school, this could be a WebQuest in which learners go through the slide show at their own pace, or you could project it in class and add some discussion to each slide. For example, there is a slide about the black rhinoceros; the western black rhinoceros was recently declared extinct, so this could be an interesting place to share with your budding biologists just how quickly an organism can go from critically endangered to extinct. This activity would be easy for a substitute to present, as well.