Biology ETDs


Tracy Diver

Publication Date



Aim: Determine evolutionary events that have shaped observed patterns of diversity in Red Shiner within the Rio Grande Basin, New Mexico. Location: Pecos, Delaware, Rio Grande and Canadian Rivers, New Mexico, United States. Methods: We used DNA sequence data from two mitochondrial genes (cytochrome b and ND4), nuclear RAG-1 intron, and geometric-morphometric and meristic data to test alternative hypothesis regarding the evolutionary history of native populations of Red Shiner in New Mexico. Results: MtDNA gene trees revealed deeply divergent lineages (Great Plains and Coastal) with in situ diversification within each geographic lineage between the Rio Grande and Pecos River. Nuclear DNA showed no support for assortative mating between lineages. In concordance with nuclear DNA, results of morphological analyses indicated no phenotypic divergence with respect to geographic lineage. Main conclusions: The presence of deeply divergent, co-occurring lineages of Red Shiner in New Mexico is the result of geologic events that separated and later reconnected the upper and lower Rio Grande Basins during the late Miocene, Pliocene, and Pleistocene. There is also evidence of recent anthropogenic movement of Red Shiner from the adjacent Arkansas Basin to the Rio Grande. This study demonstrates that multiple lines of evidence are required to accurately infer effects of historical and recent events that shape genetic diversity.




Miocene, Pliocene, divergent lineage, Red Shiner, Rio Grande, Coastal, Great Plains

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Degree Name


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Department Name

UNM Biology Department

First Committee Member (Chair)

Osborne, Megan

Second Committee Member

Kodric-Brown, Astrid