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Articles 1 - 16 of 16
Full-Text Articles in Life Sciences
Diversification On Continents And Islands: A Herpetological Perspective, Kyle Anthony O'Connell
Diversification On Continents And Islands: A Herpetological Perspective, Kyle Anthony O'Connell
Biology Dissertations
This dissertation seeks to understand the geological and climatological processes that have promoted diversification on continental and island systems. Using molecular genetic data generated using Sanger sequencing and Next Generation Sequencing platforms, I conduct phylogenetic and biogeographic analyses, estimate gene flow, and conduct species delimitation. Using these analyses, I explore diversification processes on continents and islands using reptile and amphibian systems. In Chapter 2 I evaluate the role of geographical features to whipsnake diversification. Chapter 3 resolves the taxonomy of several poorly understood whipsnakes species and tests the effect of missing data on species delimitation. Chapter 4 investigates the biogeographical …
Tracing The Genetic Footprints Of The Redbelly Yellowtail Fusilier, Caesio Cuning, Across Multiple Spatial And Evolutionary Scales, Amanda Susanne Ackiss
Tracing The Genetic Footprints Of The Redbelly Yellowtail Fusilier, Caesio Cuning, Across Multiple Spatial And Evolutionary Scales, Amanda Susanne Ackiss
Biological Sciences Theses & Dissertations
Overfishing is one of the most pervasive threats to coral reef ecosystems, and management of these multi-species resources is hampered by limited species-specific population level information. The reefs in the western tropical Pacific Ocean, including the Coral Triangle, are the most bio-diverse in the world. Home to more than 400 million people, this region contains some of the most threatened coral reef ecosystems. Presented here is the first comprehensive analysis of the genetic structure of Caesio cuning, planktivorous fish inhabiting reefs in the Coral Triangle and western Pacific Ocean. Data from both classical Sanger and next-generation sequencing were analyzed …
Big Brains Stabilize Populations And Facilitate Colonization Of Variable Habitats In Birds, Trevor S. Fristoe, Andrew N. Iwaniuk, Carlos A. Botero
Big Brains Stabilize Populations And Facilitate Colonization Of Variable Habitats In Birds, Trevor S. Fristoe, Andrew N. Iwaniuk, Carlos A. Botero
Biology Faculty Publications & Presentations
The cognitive buffer hypothesis posits that environmental variability can be a major driver of the evolution of cognition because an enhanced ability to produce flexible behavioural responses facilitates coping with the unexpected. Although comparative evidence supports different aspects of this hypothesis, a direct connection between cognition and the ability to survive a variable and unpredictable environment has yet to be demonstrated. Here, we use complementary demographic and evolutionary analyses to show that among birds, the mechanistic premise of this hypothesis is well supported but the implied direction of causality is not. Specifically, we show that although population dynamics are more …
Beringian Biogeography: Patterns Of Intercontinental Dispersal And The Structuring Of A Holarctic Tapeworm Genus, Genevieve M. Haas
Beringian Biogeography: Patterns Of Intercontinental Dispersal And The Structuring Of A Holarctic Tapeworm Genus, Genevieve M. Haas
All NMU Master's Theses
The opening and closing of the Bering Land Bridge due to Pleistocene climate fluctuations facilitated the exchange of taxa between the Palearctic and Nearctic. While many studies have worked toward elucidating the role of Beringia in assembling northern faunas, relatively little work has focused on parasites. Here I examine the number and direction of transberingian colonization events within the Holarctic tapeworm genus, Arostrilepis Mas-Coma & Tenora, 1997. I performed maximum likelihood and multi-locus coalescent phylogenetic reconstructions using mitochondrial and nuclear DNA sequences. Biogeographic ancestral range estimations were conducted on the resulting species phylogeny. My systematic reconstructions reveal as many as …
Negative Density Dependence Mediates Biodiversity–Productivity Relationships Across Scales, Joseph A. Lamanna, R Travis Belote, Laura A. Burkle, Christopher P. Catano, Jonathan A. Myers
Negative Density Dependence Mediates Biodiversity–Productivity Relationships Across Scales, Joseph A. Lamanna, R Travis Belote, Laura A. Burkle, Christopher P. Catano, Jonathan A. Myers
Biology Faculty Publications & Presentations
Regional species diversity generally increases with primary productivity whereas local diversity–productivity relationships are highly variable. This scale-dependence of the biodiversity–productivity relationship highlights the importance of understanding the mechanisms that govern variation in species composition among local communities, which is known as β-diversity. Hypotheses to explain changes in β-diversity with productivity invoke multiple mechanisms operating at local and regional scales, but the relative importance of these mechanisms is unknown. Here we show that changes in the strength of local density-dependent interactions within and among tree species explain changes in β-diversity across a subcontinental-productivity gradient. Stronger conspecific relative to …
Exploring The Biogeography Of South American Rainforest Understory Birds Using Morphological Variation In The Wedge-Billed Woodcreeper ( Glyphorynchus Spirurus ), Gregory Tito
Theses and Dissertations
Tropical rainforests in the Amazon Basin show an extraordinarily high degree of biodiversity, the reasons for which are poorly understood. A number of biogeographical models have been proposed to account for the variation present within and among species, including birds. This study tests the predictive ability of six major historical vicariant biogeographical models (Andean uplift, marine incursion, Amazonian lake, river barrier, refuge, and river refuge) using a large data set of morphological characters in the Wedge-billed Woodcreeper (Glyphorynchus spirurus), a small understory songbird found mostly in terra firme tropical rain forest. It also characterizes variation in key morphological characters and …
Marine Tardigrades From South Carolina, Usa, Paul J. Bartels, Lilvia J. Bradbury, Diane R. Nelson
Marine Tardigrades From South Carolina, Usa, Paul J. Bartels, Lilvia J. Bradbury, Diane R. Nelson
Journal of the South Carolina Academy of Science
Until now, there have been only three studies of marine tardigrades from South Carolina, USA. The Fall 2015 invertebrate zoology class from Warren Wilson College collected four sediment samples from Huntington Beach State Park: shallow beach sand, deep beach sand, shallow salt marsh sediment, and deep salt marsh sediment. No tardigrades were found in the salt marsh, but two species were found in the beach samples. Batillipes pennaki Marcus, 1946 was found in shallow and deep beach sand, and three specimens of a potentially new species of Stygarctus Schulz, 1951 were found in the deep beach sand at groundwater level. …
The Effects Of Environmental Variability And Latitude On Breeding Behaviors And Life History Traits Of Aves In North America, Elizabeth E. Tharman
The Effects Of Environmental Variability And Latitude On Breeding Behaviors And Life History Traits Of Aves In North America, Elizabeth E. Tharman
Master's Theses
Breeding systems among Aves have garnered attention in the last several decades as many species considered monogamous have been found to exhibit an alternative breeding system such as polygyny, polyandry, cooperative breeding, or colonial nesting. My thesis focuses on assessing the correlations between type of breeding system and resource availability by using environmental variables as proxy variables. It also assess the correlations between life history trait variables and environmental variables. Both breeding system and life history traits are analyzed at the species and population levels while controlling for phylogenetic relationships and geographic location when appropriate. Breeding system among species was …
A Longitudinal Cline Characterizes The Genetic Structure Of Human Populations In The Tibetan Plateau, Choongwon Jeong, Benjamin M. Peter, Buddha Basnyat, Maniraj Neupane, Geoff Childs, Sienna Craig, John Novembre, Anna Di Rienzo
A Longitudinal Cline Characterizes The Genetic Structure Of Human Populations In The Tibetan Plateau, Choongwon Jeong, Benjamin M. Peter, Buddha Basnyat, Maniraj Neupane, Geoff Childs, Sienna Craig, John Novembre, Anna Di Rienzo
Dartmouth Scholarship
Indigenous populations of the Tibetan plateau have attracted much attention for their good performance at extreme high altitude. Most genetic studies of Tibetan adaptations have used genetic variation data at the genome scale, while genetic inferences about their de- mography and population structure are largely based on uniparental markers. To provide genome-wide information on population structure, we analyzed new and published data of 338 individuals from indigenous populations across the plateau in conjunction with world- wide genetic variation data. We found a clear signal of genetic stratification across the east- west axis within Tibetan samples. Samples from more eastern locations …
Where The Wild Things Are: Investigating Body Size As A Mechanism For Persistence, Meghan A. Balk
Where The Wild Things Are: Investigating Body Size As A Mechanism For Persistence, Meghan A. Balk
Biology ETDs
Body size is a trait under selection. Genetic drift, climate, diet quality, and biotic interactions all select upon body size at the population, species, and community levels. These factors can be important in the context of rapidly changing climate. One of the ways an animal can persist in its environment is through morphological adaptation in situ. Here, I investigate four questions relating to the evolution of body size: (1) what is the limit in body size change in response to climatic change; (2) how does body size influence the thermal tolerances of animals; (3) how does body size evolve …
Phylogenetics, Biogeography, And Patterns Of Diversification Of Geckosacross The Sunda Shelf With An Emphasis On The Genuscnemaspis (Strauch, 1887), Perry Lee Wood
Theses and Dissertations
In my dissertation I investigate two genera of geckos (Cyrtodactylus and Cnemaspis) that are distributed across Southeast Asia with an emphasis on Cnemaspis. In Chapter 1 I use a multilocus dataset, ancestral area analyses, and molecular clock dating to generate a species level time calibrated phylogeny to test the monophyly of Cyrtodactylus and to identify major biogeographical patterns. I identified that Cyrtodactylus is monophyletic only if the the Sri Lankan genus often recognized as Geckoella is included. The results of the Biogeographical analyses reveal a west to east pattern of diversification. Chapter 2 I use a traditional morphological dataset to …
Phylogenetics, Biogeography, And Patterns Of Diversification Of Geckosacross The Sunda Shelf With An Emphasis On The Genuscnemaspis (Strauch, 1887), Perry Lee Wood
Theses and Dissertations
In my dissertation I investigate two genera of geckos (Cyrtodactylus and Cnemaspis) that are distributed across Southeast Asia with an emphasis on Cnemaspis. In Chapter 1 I use a multilocus dataset, ancestral area analyses, and molecular clock dating to generate a species level time calibrated phylogeny to test the monophyly of Cyrtodactylus and to identify major biogeographical patterns. I identified that Cyrtodactylus is monophyletic only if the the Sri Lankan genus often recognized as Geckoella is included. The results of the Biogeographical analyses reveal a west to east pattern of diversification. Chapter 2 I use a traditional morphological dataset to …
Biotic And Abiotic Factors Predicting The Global Distribution And Population Density Of An Invasive Large Mammal, Jesse S. Lewis, Mathew L. Farnsworth, Christopher L. Burdett, David M. Theobald, Miranda Gray, Ryan S. Miller
Biotic And Abiotic Factors Predicting The Global Distribution And Population Density Of An Invasive Large Mammal, Jesse S. Lewis, Mathew L. Farnsworth, Christopher L. Burdett, David M. Theobald, Miranda Gray, Ryan S. Miller
Other Publications in Wildlife Management
Biotic and abiotic factors are increasingly acknowledged to synergistically shape broad-scale species distributions. However, the relative importance of biotic and abiotic factors in predicting species distributions is unclear. In particular, biotic factors, such as predation and vegetation, including those resulting from anthropogenic land-use change, are underrepresented in species distribution modeling, but could improve model predictions. Using generalized linear models and model selection techniques, we used 129 estimates of population density of wild pigs (Sus scrofa) from 5 continents to evaluate the relative importance, magnitude, and direction of biotic and abiotic factors in predicting population density of an invasive large mammal …
Rapid Turnover Of Ciliate Community Members In New England Tide Pools, Mary Badger, Sarah J. Tucker, Jean-David Grattepanche, Laura A. Katz
Rapid Turnover Of Ciliate Community Members In New England Tide Pools, Mary Badger, Sarah J. Tucker, Jean-David Grattepanche, Laura A. Katz
Biological Sciences: Faculty Publications
The rocky intertidal zone represents a dynamic habitat marked by considerable species richness, which has been well-documented for invertebrates and macroalgae. This high biodiversity exists in the context of extreme fluctuations in abiotic factors such as temperature, salinity and pH that occur during each tidal cycle. Despite these attributes, few studies have focused on microbial diversity in tide pools, including analyses of the ciliate communities that are the focus of this study. We investigated the spatial and temporal distributions of ciliate species across the intertidal environment at sites in Maine and Connecticut, USA. Our study used a DNA fingerprinting technique, …
Comparative Floristic Studies Of Georgian Sandhill Ecosystems Reveals A Dynamic Composition Of Endemics And Generalists, James M. Long, John Schenk
Comparative Floristic Studies Of Georgian Sandhill Ecosystems Reveals A Dynamic Composition Of Endemics And Generalists, James M. Long, John Schenk
Honors College Theses
Sandhill habitats are characterized by sandy, xeric soils that contain a unique assemblage of plants and animals. Similar to the broader long-leaf pine (Pinus palustris) and wire grass (Aristida stricta) ecosystem that sandhills are a subset of, agriculture, development, and habitat modifications have caused sandhill ecosystems to become degraded, putting many species at risk of extinction. Previous studies have focused on diversity within individual sandhills, leaving us with an incomplete understanding of how these communities form, what species are endemic, whether endemics are widespread across sandhills, and how species have adapted to these communities. To gain a more comprehensive understanding …
Diversity And Evolution Of Fruits In Cuscuta (Dodders; Convolvulaceae), Anna Ho
Diversity And Evolution Of Fruits In Cuscuta (Dodders; Convolvulaceae), Anna Ho
Theses and Dissertations (Comprehensive)
Cuscuta (dodder) is a genus of roughly 200 species of obligate stem parasites with sub-cosmopolitan distribution. The fruit, generally regarded as a capsule, has a thin pericarp containing one to four seeds and opening at the base (circumscissile dehiscence; DE), or remaining closed (indehiscent; IN). IN has evolved multiple times in Cuscuta from DE, and is most common in the North American clades of subgenus Grammica. In addition, some species produce fruits that open irregularly. Characteristics pertaining to the fruits of Cuscuta are important as their seeds contribute most to their distribution and prevalence across the globe, and their reduced …