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Population Biology Commons

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University of Nebraska - Lincoln

School of Biological Sciences: Dissertations, Theses, and Student Research

Evolution

Articles 1 - 2 of 2

Full-Text Articles in Population Biology

Multilocus And Parametric Analyses Of The Evolutionary History Of The Amazonian Peacock Cichlids, The Genus Cichla (Teleostei: Cichlidae), Stuart Willis Apr 2011

Multilocus And Parametric Analyses Of The Evolutionary History Of The Amazonian Peacock Cichlids, The Genus Cichla (Teleostei: Cichlidae), Stuart Willis

School of Biological Sciences: Dissertations, Theses, and Student Research

Accurate knowledge of species boundaries and species phylogeny are fundamental to testing hypotheses of recent evolutionary processes, but the estimation of these partitions is challenging due both to inherent confusion about what is being estimated as well as the data available to estimate them. Using multilocus data from mtDNA, microsatellites, and nuclear locus sequences of over 1100 individuals, we delimited eight separately evolving species of Cichla rather than the 15 described. Among species we found evidence of rare but widespread introgressive hybridization, while within these species we observed evidence of long-term gene exchange and constrained evolutionary trajectories. In most cases …


Ecological Effects Of Virus-Resistant Transgenic Squash, Holly R. Prendeville Nov 2010

Ecological Effects Of Virus-Resistant Transgenic Squash, Holly R. Prendeville

School of Biological Sciences: Dissertations, Theses, and Student Research

Two ecological risks associated with the use of transgenic crops include the effects of transgene products on non-target organisms and the effects of a transgene after it moves from crops into a wild plant population. In work presented here, we specifically investigate the ecological risks of virus-resistant transgenic squash. We observed pollinator behavior to determine if pollinators are affected by nontarget effects of the virus-resistant transgene. We found that pollinator behavior did differ between conventional and virus-resistant transgenic squash due to pleiotropic effects of the transgene. This difference in pollinator behavior can affect plant mating patterns, thereby affecting crop-wild hybridization …