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Ecology Of The Elusive: Genome-Informed Investigation Of Soil Microbial Diversity, Lauren Alteio Oct 2019

Ecology Of The Elusive: Genome-Informed Investigation Of Soil Microbial Diversity, Lauren Alteio

Doctoral Dissertations

Soil is considered one of the most diverse ecosystems on Earth, harboring diversity of organisms across the three domains of life. It is spatially and chemically heterogeneous: properties that intertwine in a complex matrix to support organismal diversity and function across different scales. Soil microorganisms both respond to and drive changes in ecosystems through metabolic activities. A single gram of soil is teeming with millions of cells comprised of thousands of species. Much of this diversity remains uncharacterized due to technical and methodological challenges faced by soil ecologists. Due to the complex physicochemical properties of soil and cross-feeding interactions between ...


An Examination Of Tern Diet In A Changing Gulf Of Maine, Keenan Yakola Oct 2019

An Examination Of Tern Diet In A Changing Gulf Of Maine, Keenan Yakola

Masters Theses

The Gulf of Maine is a dynamic ecosystem with rapidly warming sea surface temperatures (SSTs), therefore it is vital to understand how species interactions vary over time and space. In chapter two, I quantify and compare dietary differences among four tern species, across seven islands in the region, over a 32-year period. Multivariate statistical analyses were employed to discern spatial and temporal differences in foraging ecology. Findings suggest there are significant differences between species and islands; however, only three prey species comprise the majority of chick diet for all terns and islands. The reliance on only a few prey items ...


Patterns Of Morphological Plasticity In Metriaclima Zebra And Danio Rerio Suggest Differently Canalized Phenotypes Due To Form-Function Relationships, Dylan Jockel Oct 2019

Patterns Of Morphological Plasticity In Metriaclima Zebra And Danio Rerio Suggest Differently Canalized Phenotypes Due To Form-Function Relationships, Dylan Jockel

Masters Theses

In order to ascertain the degree of compatibility in developmental restructuring and behavioral plasticity between two fish species frequently made subject of laboratory research (Metriaclima zebra & Danio rerio), alternative trophic niche exposure experiments utilizing novel three-prong feeding treatments were conducted to obtain morphometric data, which demonstrated both species do bear some degree of plasticity. The results are somewhat complicated by differences in locality of detectable restructuring, which may be due to disparity in the form-function relationship for each species’ lineage. Each is notable in the manner of respective species’ jaw protrusion, as it is driven by anterior kinethmoid rotation in ...


The Effects Of Social And Physical Interactions On Lizard Morphology, Behavior, And Ecology, Casey Gilman Mar 2019

The Effects Of Social And Physical Interactions On Lizard Morphology, Behavior, And Ecology, Casey Gilman

Doctoral Dissertations

Interactions with the physical and social aspects of an animal’s surroundings direct the trajectory of local adaptation and can lead to tremendous diversity within and across taxa. In my dissertation, I explored how interactions between lizards and their environment lead to morphological, behavioral, and ecological diversity. First, I examined how a common, but unexplored habitat characteristic, perch flexibility, affects jumping performance of an arboreal lizard. I found that in the lab, green anole lizards (Anolis carolinensis) did not take advantage of the natural recoil of the flexible perches, and suffered decreased jump distance and takeoff speed as a consequence ...


Visual Attention In Jumping Spiders, Margaret Bruce Mar 2019

Visual Attention In Jumping Spiders, Margaret Bruce

Masters Theses

The different ways that animals extract and analyze visual information from their environment is of interest to sensory ecologists. Jumping spiders, well-known for visually guided mating and hunting behavior, are an interesting model for the study of visual attention because they quickly and efficiently integrate information from eight eyes with a small brain. Stimuli in front of the spider are examined by two functionally and morphologically distinct pairs of forward-facing eyes. The principal eyes discern fine details and have small retinas and thus a small visual field. However, their position at the back of moveable tubes within the cephalothorax expands ...


Modeling The Abundance And Distribution Of Terrestrial Plants Through Space And Time, Caroline Curtis Nov 2018

Modeling The Abundance And Distribution Of Terrestrial Plants Through Space And Time, Caroline Curtis

Doctoral Dissertations

Anthropogenically-driven changes threaten ecosystems and species over regional to global scales. I addressed several questions related to how species ranges will respond to these changes over large spatial and temporal extents to better understand what determines where a species occurs.

First, I modeled presence and abundance of two widespread invasive plants in the southwest U.S. under current and projected future climatic conditions, from which I inferred impact risk. These results provide more insight than presence modeling alone and highlight the possibility of increased invasion pressure in the future.

Second, I tested the assumption that expert-based climatic tolerance data will ...


An Integrative Approach To Understanding Morphological Novelties: Anatomy, Development, Genetics, And Evolution Of An Extreme Craniofacial Trait In East African Cichlids, Moira R. Conith Nov 2018

An Integrative Approach To Understanding Morphological Novelties: Anatomy, Development, Genetics, And Evolution Of An Extreme Craniofacial Trait In East African Cichlids, Moira R. Conith

Doctoral Dissertations

Phenotypic novelties are an important but poorly understood category of morphological diversity that are often associated with elevated rates of diversification and/or ecological success. The aim of this dissertation is to explore a phenotypic novelty at many levels to contribute to our understanding of how these unique traits can arise (e.g., genetically, developmentally, and evolutionarily) as well as their ecological consequences (e.g., trait function). The extreme snout of the Lake Malawi cichlid fish Labeotropheus is used as a case study. The first chapter establishes the Labeotropheus snout as a model of phenotypic novelty by characterizing the gross ...


Not Gone With The Wind: Addressing Effects Of Offshore Wind Development On Bat Species In The Northeastern United States, Zara Rae Dowling Nov 2018

Not Gone With The Wind: Addressing Effects Of Offshore Wind Development On Bat Species In The Northeastern United States, Zara Rae Dowling

Doctoral Dissertations

Development of coastal and offshore wind energy resources has the potential to add considerable renewable electricity capacity to the United States electrical grid, but could have detrimental impacts on wildlife. Land-based wind energy facilities are estimated to kill hundreds of thousands of bats every year in the United States, and could threaten population viability of some species. Little is known about the potential impacts of offshore wind development on bat populations along the North Atlantic coast, but a number of species are known to frequent marine islands or fly over the ocean during migration. This dissertation helps to characterize risks ...


Cumulative Adverse Effects Of Offshore Wind Energy Development On Wildlife, Morgan Goodale Oct 2018

Cumulative Adverse Effects Of Offshore Wind Energy Development On Wildlife, Morgan Goodale

Doctoral Dissertations

Offshore wind energy development is being pursued as a critical component in achieving a low-carbon energy economy. While the adverse effects of one wind farm on a particular wildlife population may be negligible, the aggregate effect of multiple wind farms through space and time could cause wildlife population declines. The risk of cumulative adverse effects (CAE) of offshore wind farms on wildlife is poorly researched and assessment processes are underdeveloped. Assessments of CAE must first calculate the cumulative exposure of a wildlife population to a hazard and then estimate how the exposure will affect the population. Our research responds to ...


Variation And Evolution Of Fruit Ripening Traits In Tomato Species, Ian M. Gillis Oct 2018

Variation And Evolution Of Fruit Ripening Traits In Tomato Species, Ian M. Gillis

Doctoral Dissertations

As angiosperm seeds mature within their ovaries, ovary tissue tends to grow and transform itself into fruit, which aids the success of the seeds. Fruits that are fleshy provide numerous ways to aid in the protection and the dispersal of seeds. First, they keep seeds hidden, encased in hard walls, surrounded by poisons and unpalatable compounds, and second, they undergo developmental changes that facilitate seeds’ release. Tomatoes, a model fleshy fruit, have all these protective traits, and over the course of ripening they become the familiar fruit that is a staple crop around the world. The wild relatives of cultivated ...


Impact Of Native Natural Enemies On Populations Of The Invasive Winter Moth (Operophtera Brumata L) In The Northeast United States, Hannah J. Broadley Oct 2018

Impact Of Native Natural Enemies On Populations Of The Invasive Winter Moth (Operophtera Brumata L) In The Northeast United States, Hannah J. Broadley

Doctoral Dissertations

Invasive insects increasingly affect forested landscapes and have important ecological and economic impacts. My dissertation focuses on population dynamics of winter moth (Operophtera brumata L.), an invasive pest in the northeastern United States. Native to Europe, this is the species’ fourth accidental introduction to North America. The Elkinton lab established the biological control agent Cyzenis albicans across the range of winter moth in the northeastern U.S. Prior research indicates that C. albicans’ ability to control winter moth likely depends on additional mortality from native natural enemies. My dissertation research evaluates the identity and role of natural enemies already present ...


Gynodioecy And Biotic Interactions: Plant Traits, Insect Preferences, And Population-Level Consequences, Laura A. D. Doubleday Jul 2018

Gynodioecy And Biotic Interactions: Plant Traits, Insect Preferences, And Population-Level Consequences, Laura A. D. Doubleday

Doctoral Dissertations

In species with distinct sexes, differences between the sexes often affect interspecific interactions. In gynodioecious flowering plants, where individuals are female or hermaphrodite, both pollinators and herbivores tend to prefer hermaphrodites. Because pollinators and herbivores affect plant fitness, their preferences have consequences for plant mating patterns, natural selection on mating-related traits, and plant breeding system evolution. Being sessile, the spatial arrangement of females and hermaphrodites in gynodioecious plant populations alters conspecific density and sex ratio locally, which can also have important fitness effects.

My dissertation combines observational studies in natural Silene vulgaris populations and simulation modeling to address questions about ...


Using Stable Isotopes To Examine Carry-Over Effects During The Full Annual Cycle Of A Migratory Bird, The Prairie Warbler, Michael E. Akresh Jul 2018

Using Stable Isotopes To Examine Carry-Over Effects During The Full Annual Cycle Of A Migratory Bird, The Prairie Warbler, Michael E. Akresh

Doctoral Dissertations

To better conserve threatened species, conservationists need to understand the processes that affect species during their entire life cycle, including ‘carry-over effects’ which can occur if individuals’ previous experience influences their current or future performance. We studied prairie warblers (Setophaga discolor) to examine carry-over effects in a Nearctic-Neotropical migratory bird. Using carbon isotopes in birds’ blood as a measure of habitat moisture, we first assessed the effects of rainfall and habitat on the condition of prairie warblers wintering in The Bahamas. Annual variation in rainfall and spatial moisture interacted to influence birds’ condition: during a winter with less rainfall, most ...


Performance Of Floristic Quality Assessment In Massachusetts Forested Wetlands, Carolyn Gorss Jul 2018

Performance Of Floristic Quality Assessment In Massachusetts Forested Wetlands, Carolyn Gorss

Masters Theses

In order to combat the loss of valuable wetland functions and services, federal, state and tribal governments must have the tools to accurately assess and monitor the condition of wetland ecosystems. One particular method of wetland assessment is Floristic Quality Assessment (FQA), which has been growing in popularity throughout the United States since its creation in the 1970s. FQA relies on vegetative indicators of human disturbance to assess the integrity of an ecosystem. FQA calculations are based on Coefficients of Conservatism (C-scores), professionally-assigned scores ranging from 0-10 that denote a local species' tolerance to anthropogenic disturbance. Despite increasing interest in ...


Effects Of Floral Phytochemicals On Growth And Evolution Of A Parasite Of Bumble Bees, Evan Palmer-Young Mar 2018

Effects Of Floral Phytochemicals On Growth And Evolution Of A Parasite Of Bumble Bees, Evan Palmer-Young

Doctoral Dissertations

Background: Nectar and pollen are rich in phytochemicals, some of which can reduce disease in pollinators, including agriculturally important honey and bumble bees. Floral phytochemicals could influence the ecological and evolutionary relationships between plants, their pollinators, and parasites that cause pollinator disease. Antiparasitic effects of phytochemicals could be exploited to ameliorate pollinator disease and decline, and thereby sustain pollinator-dependent agricultural production. However, prior studies showed variable effects of phytochemicals on infection in live bees, where differences in bee genotype, abiotic conditions, and parasite strain could influence results.

Approach: I used cell cultures of the intestinal trypanosome parasite of bumble bees ...


Impacts Of Genome And Nuclear Architecture On Molecular Evolution In Eukaryotes, Xyrus Maurer-Alcalá Mar 2018

Impacts Of Genome And Nuclear Architecture On Molecular Evolution In Eukaryotes, Xyrus Maurer-Alcalá

Doctoral Dissertations

The traditional view of genomes suggests that they are static entities changing slowly in sequence and structure through time (e.g. evolving over geological time-scales). This outdated view has been challenged as our understanding of the dynamic nature of genomes has increased. Changes in DNA content (i.e. polyploidy) are common to specific life-cycle stages in a variety of eukaryotes, as are changes in genome content itself. These dramatic genomic changes include chromosomal deletions (i.e. paternal chromosome deletion in insects; Goday and Esteban 2001; Ross, et al. 2010), developmentally regulated genome rearrangements (e.g. the V(D)J system ...


Tracking Migratory Bird Movements In The Gulf Of Maine With Automated Radio Telemetry And Stable Hydrogen Isotope Markers, Jennifer Smetzer Mar 2018

Tracking Migratory Bird Movements In The Gulf Of Maine With Automated Radio Telemetry And Stable Hydrogen Isotope Markers, Jennifer Smetzer

Doctoral Dissertations

Coastal and offshore areas of the eastern United States provide valuable resources for both migratory songbirds and breeding seabirds, but face some of the most drastic rates of habitat alteration and urbanization. Coastal development can result in loss of significant habitats, and in proliferation of collision hazards that can pose a grave threat to birds. Conserving birds that use these coastal and offshore areas requires better information on how coastal stopover habitats are used, what breeding populations visit these regions during migration, how birds move through these landscapes, and how development can be most sensibly and responsibly directed to minimize ...


Mapping Sandbars In The Connecticut River Watershed Through Aerial Images For Floodplain Conservation, Bogumila Backiel Mar 2018

Mapping Sandbars In The Connecticut River Watershed Through Aerial Images For Floodplain Conservation, Bogumila Backiel

Masters Theses

Active geomorphic features of rivers like sandbars provide habitat for endangered and threatened riparian plant and animal species. However, human development has altered flow and sediment regimes, thus impairing formation of sandbars and islands. Large scale mapping of the fluvial geomorphology in river ecosystems like the Connecticut River is are necessary to understand the dynamics of these features and preserve habitat. Orthophotographs from 2012 from United States Department of Agriculture's Farm Service Agency (FSA), National Agriculture Imagery Program (NAIP) were used to develop a model in ArcGIS Pro to identify fluvial geomorphic features in the Connecticut River and 12 ...


Specialization And Trade-Offs In Plant-Feeding Insects, Daniel Peterson Nov 2017

Specialization And Trade-Offs In Plant-Feeding Insects, Daniel Peterson

Doctoral Dissertations

The immense diversity of life on Earth has been attributed to the partitioning of available resources into ecological niches, but it is not obvious what determines the niche size of each species. For example, most plant-feeding insects consume only one or a few closely-related host-plant species despite the advantages of having a broader diet. Many researchers have therefore suggested that the evolution of broad diets in plant-feeding insects must be constrained by genetic trade-offs between adaptations to alternative host-plants. Despite its intuitive feel, however, little empirical evidence in support of the trade-off hypothesis has emerged from decades of experimental studies ...


Modelling Bird Migration With Motus Data And Bayesian State-Space Models, Justin Baldwin Oct 2017

Modelling Bird Migration With Motus Data And Bayesian State-Space Models, Justin Baldwin

Masters Theses

Bird migration is a poorly-known yet important phenomenon, as understanding movement patterns of birds can inform conservation strategies and public health policy for animal-borne diseases. Recent advances in wildlife tracking technology, in particular the Motus system, have allowed researchers to track even small flying birds and insects with radio transmitters that weigh fractions of a gram. This system relies on a community-based distributed sensor network that detects tagged animals as they move through the detection nodes on journeys that range from small local movements to intercontinental migrations. The quantity of data generated by the Motus system is unprecedented, is on ...


Direct And Indirect Effects Of Climate On Bird Abundance Along Elevation Gradients In The Northern Appalachians, Timothy Duclos Oct 2017

Direct And Indirect Effects Of Climate On Bird Abundance Along Elevation Gradients In The Northern Appalachians, Timothy Duclos

Masters Theses

The stratification of bird species along elevational gradients is widely reported, with montane bird communities typically characterized by distinctive species occurring in relatively small and isolated populations; as such, these species are the subject of considerable interest to ecologists and conservationists. The stratification of species along elevation is largely attributed to compressed climatic zonation. Recent evidence that bird species are shifting up in elevation has fueled speculation that these species are tracking their climactic niches in response to climate change. However, there is also evidence plant communities are shifting in elevation, presenting a potential additional mechanism explaining changes observed in ...


Botswana’S Elephant-Back Safari Industry – Stress-Response In Working African Elephants And Analysis Of Their Post-Release Movements, Tanya Lama Jul 2017

Botswana’S Elephant-Back Safari Industry – Stress-Response In Working African Elephants And Analysis Of Their Post-Release Movements, Tanya Lama

Masters Theses

Understanding how African elephants (Loxodonta africana) respond to human interactions in ecotourism operations is critical to safeguarding animal and human welfare and sustaining wildlife ecotourism activities. We investigated the stress response of elephants to a variety of tourist activities over a 15-month period at Abu Camp in northern Botswana. We compared fecal glucocorticoid metabolite (FGM) concentrations across three elephant groups, including: eight elephants in an elephant-tourism operation (Abu herd), three elephants previously reintroduced back into the wild from the Abu herd, and wild elephants. There were no differences in FGM concentrations between the three groups of elephants. The highest observed ...


Biology, Molecular Systematics, Population Dynamics And Control Of A Stem Gall Wasp, Zapatella Davisae (Hymenoptera: Cynipidae), Monica Davis Jul 2017

Biology, Molecular Systematics, Population Dynamics And Control Of A Stem Gall Wasp, Zapatella Davisae (Hymenoptera: Cynipidae), Monica Davis

Doctoral Dissertations

Gall wasps are phytophagous insects that often go unnoticed, however, when they are released from their natural enemies, they have the capacity to outbreak and cause extensive foliar damage. One such outbreaking pest, Zapatella davisae, causes significant damage and mortality to black oak, Quercus velutina. In recent years, black oak decline has been documented in Long Island, New York and coastal New England. Little is known about the lifecycle, distribution or population dynamics of Zapatella davisae and the taxonomy of the species is still unclear.

My first study described the biology and distribution of Z. davisae. Zapatella davisae completed one ...


The Effects Of Anthropogenic Stress On Nitrogen-Cycling Microbial Communities In Temperate And Tropical Soils, George S. Hamaoui Jr. Jul 2017

The Effects Of Anthropogenic Stress On Nitrogen-Cycling Microbial Communities In Temperate And Tropical Soils, George S. Hamaoui Jr.

Doctoral Dissertations

In this dissertation several research studies are discussed that characterize the effects of anthropogenic, or human-induced, stress on both ammonia-oxidizing and total bacterial soil microbial communities. The disturbances of land-use change in tropical, South American rainforests and artificial warming and nitrogen (N) fertilization in temperate, North American forests were investigated as these disturbances represent past and current disturbances caused by human landscape alteration and climate change. Initially, the response of soil ammonia-oxidizing microbial communities to land-use change from primary rainforest to pasture and, finally, back to secondary forest was determined. Next, these analyses of land-use change effects were expanded to ...


The Role Of Phenotypic Integration In Mammalian Tooth Function And Jaw Morphological Diversity, Andrew Conith Jul 2017

The Role Of Phenotypic Integration In Mammalian Tooth Function And Jaw Morphological Diversity, Andrew Conith

Doctoral Dissertations

Here I investigate how two major components of the mammalian feeding system, teeth and jaws, are influenced by functional, environment, and developmental factors. First, I build physical models of the molars from two early mammals, Morganucodon and Kuehneotherium, and compare their ability to process a proxy food item. Early mammals were under strong selection to reduce metabolic costs, so any savings in energy during feeding would be advantageous. I tested the ability of both mammals to process a hard and soft food item with material properties similar to that of the insects they would have likely consumed. Morganucodon was better ...


Burrowing And Walking Mechanisms Of North American Moles, Yi-Fen Lin Jul 2017

Burrowing And Walking Mechanisms Of North American Moles, Yi-Fen Lin

Doctoral Dissertations

Moles (Family Talpidae) are a classic example of extreme specialization, in their case highly derived forelimb morphologies associated with burrowing. Despite many observations of mole burrows and behaviors gathered in the field, we know very little about how and how well moles use their forelimbs to dig tunnels and to walk within the built tunnels to collect and transport food. The first chapter investigates the effect of soil compactness on two sympatric mole species under controlled laboratory conditions. My results demonstrate that increasing soil compactness impedes tunneling performance as evidenced by reduced burrowing speed, increased soil transport, shorter tunnels, shorter ...


Evaluation Of The Recreational Catch-And-Release Fishery For Golden Dorado Salminus Brasiliensis In Salta, Argentina: Implications For Conservation And Management, Tyler Gagne Mar 2017

Evaluation Of The Recreational Catch-And-Release Fishery For Golden Dorado Salminus Brasiliensis In Salta, Argentina: Implications For Conservation And Management, Tyler Gagne

Masters Theses

Golden dorado (Salminus brasiliensis, Cuvier, 1816) is increasing in popularity as a target for recreational anglers practicing catch-and-release (C&R) in northern Argentina and bordering countries. However, to date no research has looked at the potential social and ecological implications of growth in this recreational fishery. The first manuscript of this thesis assessed the consequences of C&R on golden dorado captured by anglers on the Juramento River in Salta, Argentina. This evaluation examined physical injury, physiological stress, reflex impairment, and short term post-release behavior to develop a clear set of evidence-based best practices for C&R. In addition, the ...


Methods For Incorporating Ecological Impacts With Climate Uncertainty To Support Robust Flood Management Decision-Making, Caitlin M. Spence Mar 2017

Methods For Incorporating Ecological Impacts With Climate Uncertainty To Support Robust Flood Management Decision-Making, Caitlin M. Spence

Doctoral Dissertations

Modern and historic flood risk management involves accommodating multiple sources of sources of uncertainty and potential impacts across a broad range of interrelated sectors. Sources of uncertainty that affect planning include internal climate variability, anthropogenic changes such as land use and system performance expectations, and more recently changes in climatology that affect the resources supporting the system. Flood management systems potentially impact human settlements within and beyond the systems’ scope of planning, local weather patterns, and associated ecological systems. Federal guidelines across nations have called for greater consideration of uncertainty and impacts of water resources planning projects, but methods for ...


Expansion Of And Reclassification Within The Family Lachnospiraceae, Kelly N. Haas Nov 2016

Expansion Of And Reclassification Within The Family Lachnospiraceae, Kelly N. Haas

Doctoral Dissertations

Many of the taxa in the family Lachnospiraceae are currently misclassified as Clostridium spp. Here attempt to rectify many of these issues, beginning with an in-depth genomic and physiologic analysis of Clostridium methoxybenzovorans, culminating in the assertion that is a heterotype of Clostridium indolis, followed by reclassification of the broader group in which this organism resides. We propose two novel genera, Lacriformis and Enterocloster, to reclassify this clade, this includes reclassification of Clostridium sphenoides, Clostridium indolis, Clostridium saccharolyticum, Clostridium celerecrescens, Clostridium xylanolyticum, Clostridium algidixylanolyticum, Clostridium aerotolerans, Clostridium amygdalinum, and Desulfotomaculum guttoideum as Lacriformis sphenoides, comb. nov., Lacriformis indolis, comb. nov ...


Distribution And Population Dynamics Of Ungulates In The Mongolian Gobi, Buuveibaatar Bayarbaatar Dr Nov 2016

Distribution And Population Dynamics Of Ungulates In The Mongolian Gobi, Buuveibaatar Bayarbaatar Dr

Doctoral Dissertations

The Mongolian Gobi is one of the most spectacular and important regions in Central Asia, comprising the largest area of intact grassland in the world. In recent years, a growing human population, expanding exploitation of natural resources, and the development of infrastructure in the region place increasing pressure on these species and their habitats. This dissertation has focused on three species of ungulates such as Mongolian saiga (Saiga tatarica mongolica) in western Mongolia, and Asiatic wild ass (Equus hemionus), and goitered gazelle (Gazella subgutturosa) in Southern Gobi. The study on endangered saiga antelope in western Mongolia found that the calving ...