Lizard-Predation-Student (Look Whos Coming to Dinner)

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LOOK WHO’S COMING FOR DINNER: SELECTION BY PREDATION PART I: INTRODUCTION In the film The Origin of Species: Lizards in an Evolutionary Tree, you met the anole lizards of the Caribbean islands. F... or well over 20 years, Dr. Jonathan Losos has studied these lizards to understand how the different species and their traits have evolved. In this activity, you will examine the results from an experiment that involves another type of lizard, the much larger curly-tailed lizard that hunts and feeds on anoles! Figure 1: This map of the Caribbean Islands features Cuba, Jamaica, Hispaniola (Haiti and the Dominican Republic), Puerto Rico, and the Bahamas. The inset shows Great Abaco Island in the northern Bahamas. (Adapted from MapMaker Interactive maps, National Geographic Society, http://mapmaker.education.nationalgeographic.com/) Dr. Losos and his colleagues conducted an experiment in a group of small islands near Abaco in the northern Bahamas (Figure 1), where a single species of anole, Anolis sagrei, lives. A. sagrei is a long-legged species of anole that spends most of its active time on the ground or on the lower parts of tree trunks, where it hunts for prey and mates with other A. sagrei lizards. Although in general A. sagrei lizards have relatively long legs compared to other species of anole lizards, leg length varies among individuals in a population. On some islands, A. sagrei coexists with Leiocephalus carinatus, a large, curly-tailed lizard that hunts for prey, including anoles, on the ground. On these islands, Dr. Losos and his colleagues noticed that A. sagrei lizards tend to spend more time on bushes and small trees where L. carinatus cannot climb (Figure 2) [Show More]

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