Exam (elaborations) Student Exploration Natural Selection

Student Exploration: Natural Selection Vocabulary:biological evolution, camouflage, Industrial Revolution, lichen, morph, natural selection, peppered moth Prior Knowledge Questions (Do these BEFORE using the Gizmo.) The peppered moth (Biston betularia) is a common moth found in Europe, Asia, and North America. It is commonly found in two forms, or morphs: a dark morph and a light, speckled morph. Birds are a frequent predator of the peppered moth. 1. Which morph do you think would be easier to see on a dark tree trunk? The light morph 2. Which morph do you think would be easier to see on a light tree trunk? The dark morph Gizmo Warm-up The Natural Selection Gizmo™ allows you to play the role of a bird feeding on peppered moths. The initial population of 40 moths is scattered over 20 tree trunks. Click on moths to capture them. Click the Next tree button or hit the spacebar on your keyboard to advance to the next tree. 1. Check that LIGHT TREES is selected. Click Start and hunt moths for one year. A. How many dark moths did you capture? 4 B. How many light moths did you capture? 5 C. Camouflage is coloring or patterns that help an organism to blend in withthe background. Which type of moth is better camouflaged on light bark? The lighter moth is better 2. If a forest contained mostly light-colored trees, which type of moth would you expect to be most common? I’d expect light-colored moths to be more common because of evolution. Activity A: Light trees Get the Gizmo ready:  Click Reset.  Check that the LIGHT TREES tab is selected. Introduction: Before the 19th century in England, the air was very clean. The bark on trees was usually light in color. Abundant lichens growing on tree trunks also lightened their appearance.