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Full-Text Articles in Biodiversity

Diversification And Convergence Following The Transition From Saltwater To Freshwater In Stingrays., Autumn D. Magnuson May 2023

Diversification And Convergence Following The Transition From Saltwater To Freshwater In Stingrays., Autumn D. Magnuson

College of Arts & Sciences Senior Honors Theses

One of the most fundamental questions in biology is why some groups of organisms are more diverse than others. Classic hypotheses for explaining differences in diversity consider distinctions in time, place, resources, and competitors as the staging grounds for differential diversification. Freshwater and saltwater environments have similar levels of diversity despite significant differences in size, so studying transitions between the two systems can provide insights into evolutionary processes. Despite the challenges associated with this transition, stingrays have invaded freshwater habitats multiple times across different continents, making them useful for better understanding these systems. In this study, I evaluated the frequency …


Diversification And Convergence Following The Transition From Saltwater To Freshwater In Stingrays, Autumn D Magnuson Mar 2023

Diversification And Convergence Following The Transition From Saltwater To Freshwater In Stingrays, Autumn D Magnuson

2023 Midwest Ecology & Evolution Conference

One of the most fundamental questions in biology is why some groups of organisms are more diverse than others. Classic hypotheses for explaining differences in diversity consider distinctions in time, place, resources, and competitors as the staging grounds for differential diversification. Freshwater and saltwater environments have similar levels of diversity despite significant differences in size, so studying transitions between the two systems can provide insights into evolutionary processes. Despite the challenges associated with this transition, stingrays have invaded freshwater habitats multiple times across different continents, making them useful for better understanding these systems. In this study, we evaluated the frequency …


Environmental Factors Shaping A Sawfly-Associated Community Of Parasitoids, Carson Kephart, Robin K. Bagely Mar 2023

Environmental Factors Shaping A Sawfly-Associated Community Of Parasitoids, Carson Kephart, Robin K. Bagely

2023 Midwest Ecology & Evolution Conference

A major goal of evolutionary biology is to understand the mechanisms that shape biodiversity, especially amongst highly speciose lineages such as parasitic wasps. However, most of these lineages are poorly described, with very little available natural history information. This lack of information limits our ability to uncover the environmental factors that contribute to their patterns of divergence, distribution, and abundance. To that end, here we take advantage of a community of hymenopteran parasites that has an unusually large amount of available information since they attack an economically important pine sawfly species, Neodiprion lecontei. We build upon a set of …


Ecological And Phenotypic Diversification After A Continental Invasion In Neotropical Freshwater Stingrays, Matthew Kolmann, Fernando Pl Marques, James C. Weaver, Mason N. Dean, Joao Pedro Fontenelle, Nathan R. Lovejoy Aug 2022

Ecological And Phenotypic Diversification After A Continental Invasion In Neotropical Freshwater Stingrays, Matthew Kolmann, Fernando Pl Marques, James C. Weaver, Mason N. Dean, Joao Pedro Fontenelle, Nathan R. Lovejoy

Faculty Scholarship

Habitat transitions are key potential explanations for why some lineages have diversified and others have not—from Anolis lizards to Darwin's finches. The ecological ramifications of marine-to-freshwater transitions for fishes suggest evolutionary contingency: some lineages maintain their ancestral niches in novel habitats (niche conservatism), whereas others alter their ecological role. However, few studies have considered phenotypic, ecological, and lineage diversification concurrently to explore this issue. Here, we investigated the macroevolutionary history of the taxonomically and ecologically diverse Neotropical freshwater river rays (subfamily Potamotrygoninae), which invaded and diversified in the Amazon and other South American rivers during the late Oligocene to early …


Nitrogen Availability In Dune Systems And Its Effect On Root Fungal Endophyte Communities., Haley E. Sage May 2022

Nitrogen Availability In Dune Systems And Its Effect On Root Fungal Endophyte Communities., Haley E. Sage

College of Arts & Sciences Senior Honors Theses

As global change persists, changes in resource availability can influence plant-microbe interactions. To understand how resource availability can influence these interactions and species diversity, I focused this research on how varying nitrogen (N) levels affect root endophyte communities in the plant species Ammophila breviligulata, an ecosystem engineer in the dune system. I analyzed the relationship between nitrogen addition and microbial community composition across 60 plots treated with three nitrogen addition levels (control, low, and high) in a long-term experimental field site in the Lake Michigan dunes. I identified Ammophila breviligulata's root endophyte community after creating a culture collection and …


Community Structure And Dynamics Of Benthic Macroinvertebrates In A Recreated Headwater Stream System On A Valley Fill In A Retrofitted Watershed Located In The Appalachian Coalfields Of Southeastern Kentucky (U.S.A.), Steven W. Bailey Aug 2021

Community Structure And Dynamics Of Benthic Macroinvertebrates In A Recreated Headwater Stream System On A Valley Fill In A Retrofitted Watershed Located In The Appalachian Coalfields Of Southeastern Kentucky (U.S.A.), Steven W. Bailey

Electronic Theses and Dissertations

The extraction of coal from steep-gradient surface mining sites such as in the Appalachian Coalfields of the U.S. produces excess debris that is often placed in adjacent valleys resulting in the creation of valley fills. Not only are headwater streams buried in the process, but watershed functions are either destroyed outright, or become fragmented and disconnected from adjacent ecosystems resulting in adverse effects to downstream biological communities. In this dissertation, the dynamics of stream macroinvertebrate community structure, composition, diversity, and biotic integrity are assessed at a “proof of concept” stream system recreated on a retrofitted valley fill. For comparison, two …


Approaches To Arthropod Conservation : Landscape Genetics, Community Assessment, And Prediction Of Extinction Risk., Victoria Annette Prescott Dec 2016

Approaches To Arthropod Conservation : Landscape Genetics, Community Assessment, And Prediction Of Extinction Risk., Victoria Annette Prescott

Electronic Theses and Dissertations

Although urbanization is a leading cause of species extinction throughout the world, the impact of urban development on arthropods is little studied and, as a result, poorly understood. I used three distinct approaches to studying arthropod conservation in North America. First, I used landscape genetics techniques to study the impact of urbanization on gene flow among populations of Rabidosa rabida, the rabid wolf spider. While gene flow was not detrimentally reduced, urban development correlated with a reduction in migration rates among populations, and to my knowledge, this is the first study to document isolation by resistance in spiders. Next, …


Effects Of Invasive Shrub Honeysuckle (Lonicera Maackii) And Forest Composition On Bird Communities In Woodland Stands., Katie Rae Lynch Aug 2016

Effects Of Invasive Shrub Honeysuckle (Lonicera Maackii) And Forest Composition On Bird Communities In Woodland Stands., Katie Rae Lynch

Electronic Theses and Dissertations

Invasive species pose a threat to aquatic and terrestrial ecosystems by decreasing biodiversity (Didham et al. 2005). Amur bush honeysuckle (Lonicera maackii) has typically reduced native plant diversity and altered animal communities by influencing animal abundance and activity (Collier and Vankat 2002). This study was intended to determine whether honeysuckle density or other characteristics of forested stands influence avian diversity, whether impacts are seasonally dependent, and whether correlations exist between attributes of forested stands and honeysuckle density. In order to test the hypotheses, thirteen forest stands within the Louisville Metropolitan Area were selected. They had similar tree composition …


Earthworm, Microbial Biomass, And Leaf Litter Decay Responses After Invasive Honeysuckle Shrub Removal From Urban Woodlands., Robert Preston Pipal Dec 2014

Earthworm, Microbial Biomass, And Leaf Litter Decay Responses After Invasive Honeysuckle Shrub Removal From Urban Woodlands., Robert Preston Pipal

Electronic Theses and Dissertations

Invasive species are one of the leading causes of biodiversity loss and their presence can significantly impact the structure and function of native ecosystems. In this dissertation, the impacts of the invasive honeysuckle shrub, Lonicera maackii, on exotic earthworm populations, leaf litter decay responses, and inorganic and organic nutrient pools in an urban woodland park are assessed. Chapter 1 provides a brief review of honeysuckle's effects on forest ecosystems. Chapter 2 describes honeysuckle’s effects on exotic earthworm populations and the seasonal importance of macroinvertebrates to leaf litter decomposition in urban woodlands. This study revealed that L. maackii promoted higher exotic …