Literaturdatenbank
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Coghill, L. M. (2013). Statistical and comparative phylogeography of mexican freshwater taxa in extreme aquatic environments. Unpublished thesis , University of New Orleans.
Added by: Sarina Wunderlich (06 Jul 2014 16:10:36 UTC) |
| Resource type: Thesis/Dissertation BibTeX citation key: anon2013.15935 View all bibliographic details  |
Categories: General Keywords: Habitat - habitat, Nordamerika - North America, Podocnemididae, Podocnemis expansa, Podocnemis unifilis, Schildkröten - turtles + tortoises, Systematik - taxonomy Creators: Coghill Publisher: University of New Orleans |
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Views index: 18% Popularity index: 4.5% |
| URLs http://scholarworks.uno.edu/td/1724 |
| Abstract |
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Terrapene coahuila Phylogeography aims to understand the processes that underlie the distribution of genetic variation within and among closely related species. Although the means by which this goal might be achieved differ considerably from those that spawned the field some thirty years ago, the foundation and conceptual breakthroughs made by Avise are nonetheless the same and are as relevant today as they were two decades ago. Namely, patterns of neutral genetic variation among individuals carry the signature of a species’ demographic past, and the spatial and temporal environmental heterogeneity across a species’ geographic range can influence patterns of evolutionary change. Aquatic systems throughout Mexico provide unique opportunities to study phenotypic plasticity and evolution in relation to climatic and environmental selective forces. There are several unique, often isolated aquatic environments throughout Mexico that have a history of geographic isolation and reconnection. The first study presented herein shows significant mitochondrial sequence divergence was also discovered between L. megalotis populations on either side of the Sierra de San Marcos that bisects the valley of Cuatro Ciénegas and that the populations in the valley are genetically distinct from those found outside of the valley. The second study recovered signals of two divergence events in Cuatro Ciénegas for six codistributed taxa, and reveals that both events occured in the Pleistocene during periods of increased aridity suggesting that climatic effects might have played a role in these species’ divergence. The final study presents an Illumina-based high-resolution species phylogeny for Astyanax mexicanus providing added support that there are multiple origins to cave populations and further clarifying the uniqueness of the Sabinos and Rio Subterráneo caves.
Added by: Sarina Wunderlich |