Seminars

April 12 2012

5:00 pm 154 BSRB

EcoEvoPub Series

Graduate Student Presentations

Summary

SARA SIMMONDS
Department of Ecology and Evolutionary Biology
UCLA

“Ecological Speciation via Host Switching in Coral Associated Gastropods”

Evolutionary biologists have long viewed allopatry as the principal mode of speciation. However, recent studies are demonstrating that sympatric speciation via divergent selection, also known as ecological speciation, may be much more common in the ocean than previously thought. First, absolute dispersal barriers are exceedingly rare. As a result, speciation must proceed with varying levels of gene flow and this process is aided by divergent selection. Secondly, strong interspecific interactions believed to promote ecological speciation are ubiquitous in the marine realm. My dissertation research seeks to reevaluate the importance of allopatric speciation in generating marine biodiversity in the Coral Triangle by examining the speciation process and host switching in a group of coralliovorous gastropods.

JONATHAN CHANG
Department of Ecology and Evolutionary Biology
UCLA

“Phylogenetic Clustering of Commercially Exploited Fish Species”

Currently, over three-quarters of the world’s fish stocks are depleted, overexploited, or fully exploited. Typical marine fishing practices tend to target the largest species in the food web and move downwards. This selective harvesting could change the trait distribution of important fish stocks. To test its impact, we collected exploitation data from Fishbase.org for 7,159 ray-finned fishes on a megaphylogeny containing 7,958 species. Here we show that commercial exploitation of fishes tends to be clustered at both tree-wide scales and towards younger lineages. Our results indicate that overfishing irrevocably alters the evolutionary history of important lineages through size-selective exploitation, potentially selecting against traits that are necessary for the continued ecological health of the ocean.

THURSDAY, APRIL 12, 2012
5PM IN 154 BIOMEDICAL SCIENCES RESEARCH BLDG

 

 

 

 

 

 

 

 

 

 

 



 

 

 

 

 

 

 

 

 

 

 

 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



 



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