Patterns of Differentiation Among Allopatric Drosophila mettleri Populations
AuthorCastrezana, Sergio Javier
AdvisorMarkow, Therese A.
Committee ChairMarkow, Therese A.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractSonoran Desert Drosophila mettleri breeds in soil soaked by the necrotic cacti juices from saguaro (Carnegiea gigantea) and cardon (Pachycereus pringlei). An isolated population on Santa Catalina Island, 300 kilometers NW of the Sonoran Desert limit, was discovered breeding in several Opuntia cacti species. Host shifts are associated with the speciation process in phytophagous insects. I tested for evidence of premating isolation, postmating isolation, and ecological differences among allopatric populations of Drosophila mettleri using a variety of approaches. No sexual isolation was detected. However, Drosophila mettleri from Santa Catalina Island shows significant behavioral and physiological differences compared with Sonoran Desert populations. Furthermore, Drosophila mettleri from Santa Catalina Island was significantly genetically differentiated from all other populations in the study. Finally, I observed sufficiently significant F1 male sterility in crosses involving the Santa Catalina Island population to consider it indicative of early postzygotic isolation.
Degree ProgramEcology & Evolutionary Biology