For this actiivty the students will watch a Nova documentary called "The Four-Winged Dinosaur." The documentary follows two teams of scientists as they create replicas of microraptor, a dinosaur with four feathered wings, in an attempt to determine how flight evolved in birds (from the ground up or from the trees down). As the students watch the video, they should think about each hypothesis and pay attention to the lines of evidence presented on both sides of the argument. The students are given specific questions to answer while watching the video that will help them pay attention to key ideas. Outside of class they are responsible for writing a short essay (~1 page, typed) describing which origin of flight hypothesis that they believe is the most plausible and why. Students must support their argument with evidence presented in the video.