November 29 2012

5:00 pm BSRB 154

EcoEvoPub Series

Graduate Student Presentations


Jonathan Drury
Dept of Ecology and Evolutionary Biology

"The Intersection between Reproductive Interference and Interspecific Territoriality in Rubyspot Damselflies (Hetaerina spp.)"

Abstract: Male rubyspot damselflies (Hetaerina spp.) defend territories that they use solely for accessing females. In rivers throughout the southern U.S. and Mexico with two or more Hetaerina spp., there is much variation in whether species pairs engage in interspecific territoriality. Previous research has unearthed mechanisms by which some species pairs avoid competing with conspecifics, but until now we had not investigated species pairs that do engage in interspecific territoriality. New field data and simulations that quantify the cost of sharing a territory with heterospecifics demonstrate that interspecific territoriality occurs in species pairs that exhibit heterospecific reproductive interference (i.e., when males clasp heterospecific females). This pattern occurs across several different sites and species pairs, and even within-site as levels of reproductive interference vary, suggesting that between-species aggressive interactions are the adaptive outcome of selection on males competing for access to conspecific females.

Sergio Nigenda
Dept of Ecology and Evolutionary Biology

"Association between Environmental and Phenotypic Variables in the Virginia Opossum"

Abstract: Natural environments present several biotic and abiotic challenges. How organisms react to environmental challenges involve both short-term ecological and long-term evolutionary responses. Species distributed through large geographic ranges may exhibit strong phenotypic variation, especially when inhabits various habitats, which may be a signal of genetic adaptation to those environments. The Virginia opossum is a widely distributed marsupial that inhabits different environments along its geographic range from Northern Costa Rica to Southern Canada. This species also shows different pigmentation and body size phenotypes throughout its range. This study aimed to find if environmental variables could explain some of the phenotypic variation observed. We found that environmental variables related to low temperature and temperature stability are explaining much of the phenotypic variation. These findings set the basis for future studies on the phenotypic evolution and adaptation to different environments in marsupial mammals.

THURSDAY, November 29, 2012











































































































































































































































































































































































































































































































































































































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