Comparative and Convergent Aspects of Natural Selection

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A key issue in evolutionary biology concerns whether similar environmental conditions in different areas will result in similar phenotypes of animals. If one can show that natural selection operates in the same manner in independent but environmentally similar areas, then this would represent strong evidence for the power of adaptive forces overcoming stochastic or randomizing forces. Caribbean Anolis lizards provide an excellent opportunity for investigating this issue because the same phenotypes have independently arisen on different Greater Antillean islands, but no studies have investigated whether natural selection operates in the same manner on these independently evolved species. The strength of natural selection on both locomotor performance and morphology will be quantified for six different species of Anolis lizard on two different islands (Jamaica and the Bahamas). Locomotor performance is particular appropriate for testing the above ideas because lizards must run quickly to avoid predators and to capture prey. The six study species are ideal for long-term studies of selection because of their abundance, small home-ranges, and the ease with which individuals can be captured and manipulated in the laboratory. On each island, lizards will be captured, marked, and measured for both morphology and locomotor performance. If the same phenotypes on different islands experience the same selection pressures, then this would provide strong evidence for adaptive forces being important in shaping the community structure of Anolis lizards. Local high school teachers from Orleans Parish (New Orleans, LA) will participate in the proposed research. Specifically, these school teachers will conduct field research on selection in Anolis lizards, analyze the resulting data, and also participate in the publishing process. This additional component could have a profound impact on the educational opportunities of a large number of minority students from disadvantaged areas via secondary education for their teachers.