November 8 2018

5:00 pm 1100 TLSB

This seminar is sponsored by EEB

EcoEvoPub Series

Graduate Student Presentation


Christian Henry
Department of Ecology and Evolutionary Biology, ULCA

The Control of Stomata by Leaf Water Status: Trade-Off between Safety and Efficiency

For plants and ecosystems, greater stomatal apertures result in higher stomatal conductance (gs), a major determinant of photosynthetic productivity, water use, and drought response. Stomatal closure with declining plant water status dynamically influences gas exchange and productivity in ecosystems worldwide. Based on biophysical mechanisms and life history theory, we hypothesized that across species, this response would be constrained by a trade-off between gs in hydrated leaves (gmax) and the leaf water potential at which gs is reduced by 50% (Ψgs50). We tested for thegmax- Ψgs50 trade-off in a controlled experiment on 15 diverse species of southern California determining the response of gs to dehydration, and in novel analyses of a compiled database of published stomatal responses for diverse species. We additionally tested hypotheses that might singly or in combination explain the trade-off.

Tyler McCraney
Department of Ecology and Evolutionary Biology, UCLA

Phylogenomic Systematics of Gobiiformes: Small Fishes Show Some Backbone
Gobiiformes comprise a global radiation of small, mostly marine fishes characterized by extraordinary species richness and ecological diversity. Molecular phylogenetics has been crucial to advancing gobiiform systematics, but classification remains unsettled due to disagreements on clade relationships and poor bootstrap support; especially along the backbone of the tree subtending lineages of goby families Gobionellidae and Gobiidae. Here I use a phylogenomic approach to infer gobiiform phylogeny from 855 ultraconserved element loci sequenced on a broadly sampled set of 50 taxa. Consistent with early mitochondrial work and recent phylogenomic studies, my results support successive sister group relationships of families Kurtidae, Apogonidae, Odontobutidae, Eleotridae, Butidae, Gobionellidae and Gobiidae. I also recover monophyly of all goby lineages sampled with complete bootstrap support. These results support the classification of Gobiiformes inclusive of Kurtiformes (Kurtidae and Apogonidae), provide improved resolution along the gobioid backbone, and advance systematics of goby lineages.






































































































































































































































































































































































































































































































































































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