May 9 2013

5:00 pm BSRB 154

EcoEvoPub Series

Graduate Student Presentations


Laurie Sorenson
Department of Ecology and Evolutionary Biology

"Species-level phylogenetic analysis of a coral reef fish family, the surgeonfishes (Acanthuridae; Percomorpha)"

Fishes are an important component of coral reef ecosystems; about 40% of the approximately 17,000 marine fish species live in close association with coral reefs. A fundamental understanding of the evolution of these reef fish groups is therefore essential to expanding our knowledge of the processes that led to extant reef biodiversity; however, we still have relatively limited understanding of the evolutionary relationships within and among reef fish groups. The surgeonfishes (Family: Acanthuridae) are primarily herbivores that are abundant members of reef communities worldwide. They have been the subject of numerous morphological and molecular phylogenetic studies, but we still have not resolved intra-familial relationships and the timing of their evolution. We generated the first comprehensive time-calibrated, species-level molecular hypothesis of the tempo of Acanthuridae evolution, including 76% of the extant diversity. We recovered two major acanthurid clades, the Nasinae and Acanthurinae. Our results support a paraphyletic Acanthurus and Ctenochaetus, and suggest that a single origin for the evolution of a muscular gizzard-like stomach morphology, which helps with algal and detrital digestion, occurred within the family.

Evan McCartney-Melstad
Department of Ecology and Evolutionary Biology

"A Landscape Genetic Approach to Predicting Pesticide Impacts on the California Tiger Salamander"

The California Tiger Salamander (Ambystoma californiense) is a federally-protected species facing threats on multiple fronts. These salamanders live in some of the most heavily-farmed regions in the country, and pesticides are impacting their survival and ability to stave off a hybrid invasion from the introduced barred tiger salamander (Ambystoma tigrinum mavortium). There are thousands of chemicals being applied every year, however, so it is not feasible to test the impacts of each of these chemicals on animals in the laboratory. To create a short list of candidate harmful chemicals, this project integrates spatial pesticide application data as resistive elements in landscape genetic models. I will be testing to see if incorporation of pesticide information improves landscape genetic models of population connectivity. Chemicals that correlate strongly with reduced movement through the landscape will be prioritized for further experimental testing in the lab.

THURSDAY, May 9, 2013











































































































































































































































































































































































































































































































































































































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