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Full-Text Articles in Life Sciences

Population Structure Of The Lizard Ecpleopus Gaudichaudii Coincides With A Biogeographic Barrier - The Doce River, Alexander J. Garretson Jan 2022

Population Structure Of The Lizard Ecpleopus Gaudichaudii Coincides With A Biogeographic Barrier - The Doce River, Alexander J. Garretson

Dissertations and Theses

Intraspecific genetic variation is an integral component of diversification and the accumulation of biodiversity. The degree to which isolated populations of the same species are genetically structured in geographical space is impacted by a variety of mechanisms. In this study, I document patterns and discuss possible drivers of genetic structure within Ecpleopus gaudichaudii, a lizard species endemic to the Atlantic Forest of Brazil. For that, I assembled ddRadseq sequences from 48 individuals across much of the range of the E. gaudichaudii and analyzed its population structure. I created an intraspecific phylogeny for this group utilizing RAxML and conducted a …


Spatial And Non-Spatial Patterns Of Genetic Diversity In Neotropical Bats, Andrea J. Calderon Brito Jan 2021

Spatial And Non-Spatial Patterns Of Genetic Diversity In Neotropical Bats, Andrea J. Calderon Brito

Dissertations and Theses

Macroecological studies that predict genetic diversity and its correlation with other biodiversity dimensions are essential to conservation in a rapidly changing environment. However, in bats (order Chiroptera), studies associating abiotic or ecological traits that could help to predict genetic diversity are scarce, even for singular species. In the Neotropics, the highest concentration of mammal and amphibian genetic diversity has been found in the Andes mountains and the Amazon Rainforest, yet it is an open question whether bat genetic diversity is also higher in these regions, or even if any abiotic factors are correlated with bat genetic diversity. Additionally, it is …


Evolution Of Floral Morphology And Symmetry In The Miconieae (Melastomataceae), Maria Gavrutenko Jan 2018

Evolution Of Floral Morphology And Symmetry In The Miconieae (Melastomataceae), Maria Gavrutenko

Dissertations and Theses

Analyses of evolution of floral morphology and symmetry broaden our understanding of the drivers of angiosperm diversification. Integrated within a flower, labile floral characters produce different phenotypes that promote variable interactions with pollinators. Thus, investigation of floral evolution may help infer potential historic transitions in pollinator modes and ecological pressures that generated present diversity. This study aims to explore morphological evolution of flowers in Miconieae, a species-rich Neotropical tribe within family Melastomataceae. Despite a constrained floral plan, Melastomataceae manage to achieve a variety of floral traits appealing to diverse pollinator types, with majority of the species requiring specialized “buzz pollination” …


Effects Of Increased Nitrogen Deposition On The Dominance Of Hedera Helix In The Pacific Northwest, Bianca Christine Dolan Mar 2013

Effects Of Increased Nitrogen Deposition On The Dominance Of Hedera Helix In The Pacific Northwest, Bianca Christine Dolan

Dissertations and Theses

Increased nitrogen deposition has been shown to promote the dominance of invasive species, and nitrogen deposition rates have steadily increased in most of the Western United States in recent years due to population increases. The purpose of this study was to determine if increased rates of nitrogen deposition are contributing to the success of Hedera helix in the Pacific Northwest. Plots were established in Lesser Park in Portland, Oregon and received monthly treatments of ammonium nitrate for one year. Growth, measured as change in percent cover, was compared between treated and untreated plots for both H. helix and native species. …


Where Is The Rain-On-Snow Zone In The West-Central Washington Cascades?: Monte Carlo Simulation Of Large Storms In The Northwest, Matthew John Brunengo Jan 2012

Where Is The Rain-On-Snow Zone In The West-Central Washington Cascades?: Monte Carlo Simulation Of Large Storms In The Northwest, Matthew John Brunengo

Dissertations and Theses

Rain-on-snow (ROS) occurs when warm, wet air moves into latitudes and/or elevations having vulnerable snowpacks, where it can alter water inputs to infiltration, runoff and erosion. The Pacific Northwest is particularly susceptible: winter storms off the Pacific cause locally heavy rain plus snowmelt almost annually, and disastrous flooding and landsliding intermittently. In maritime mountainous terrain, the effects seem more likely and hydrologically important where warm rains and seasonal snowpacks are liable to coincide, in middle elevations. Several questions arise: (1) In the PNW, does ROS affect the long-term frequency and magnitude of water delivery to the ground, versus total precipitation …


Relative Heart Ventricle Mass And Cardiac Performance In Amphibians, Gregory Joseph Kluthe Jan 2012

Relative Heart Ventricle Mass And Cardiac Performance In Amphibians, Gregory Joseph Kluthe

Dissertations and Theses

This study used an in situ heart preparation to analyze the power and work of spontaneously beating hearts of four anurans (R. marina, L. catesbeianus, X. laevis, P. edulis) and three urodeles (N. maculosus, A. tigrinum, A. tridactylum) in order to elucidate the meaning of relative ventricle mass (RVM) in terms of specific cardiac performance variables. This study also tests two hypotheses: 1) the ventricles of terrestrial species (R. marina, P. edulis, A. tigrinum) of amphibians are capable of greater maximum power outputs (Pmax) compared to aquatic species (X. laevis, A. tridactylum, N. maculosus, L. catesbeianus) and, 2) …