Research Abstracts Online
January 2010 - March 2011
University of Minnesota Twin Cities
College of Food, Agricultural, and Natural Resource Sciences
PI: Ralph W. Holzenthal
Evolution of Endemism in Biodiversity Hotspots
The goal of this project was to elucidate past and present patterns of diversification and speciation in an endemic-rich group of insects in a temperate South American biodiversity hotspot. Results were compared with studies from Europe and North America. It has recently become apparent that aquatic organisms in Europe and North America responded differently to past climate change than terrestrial organisms; there is ample evidence that aquatic insects survived in cryptic northern refugia and the periglacial during the Pleistocene. This project tested whether similar patterns could be observed in a temperate region in South America, which was heavily influenced by late Pleistocene glaciations.
The researchers used the caddisfly genus Smicridea, which includes many local endemics in Chile and several species with sky-island distributions, as a model. They analyzed microsatellite and mitochondrial sequence data in a population genetic and phylogenetic framework to: study the comparative phylogeography of two Smicridea species with sky-island distribution; examine interspecific gene flow and hybridization between closely related sympatic species; explore phylogenetic patterns of lineage divergence within the genus; and use DNA-based life stage associations to provide a key to the larval sage of Chilean Smicridea for water-management purposes. The project allowed the researchers to formulate general hypotheses on the processes driving speciation and local endemism in subtropical and temperate South America and how these differ from temperate Europe and North America.
Roger Blahnik, Research Associate
Steffan Pauls, Research Associate
Desiree Roberts, Graduate Student