Use this as a student directed learning activity. Each scenario describes a mechanism of evolution (not natural selection). They will attempt to match the scenario with the correct mechanism from the word bank. You can use this before formally teaching the topics. Scenario 4 should be customized to apply to your local geography/fauna allowing a more personal connection to the information. Explain task to students, allow them to read and fill out in pairs without the aid of Internet or text (~15-20 min), go over as a class when complete while describing the formal definitions of the mechanisms (~15-20 min). Fun way to introduce mechanisms.