Biodiversity Commons^™

Computational And Functional Characterization Of Terebrid Venom Peptides, Favour T. Achimba

Dissertations, Theses, and Capstone Projects

Venom peptides represent a natural repertoire of bioactive compounds that are potent modulators of ion channels. Teretoxins, venom peptides from terebrid snails, remain underexplored despite their structural and functional diversity. This thesis is the first to comprehensively explore the structure and function of teretoxins using a comparative computational sequence and structure model followed by experimental assays. The majority of the functional focus has been on identifying the ion channel molecular targets of uncharacterized teretoxins. Teretoxins, like other venom peptides, are hypothesized to manipulate the cellular function of a diversity of ion channels. Dysregulation of ion channels leads to several …

Systematics, Biogeography, And Comparative Morphology Of Emerald And Tigertail Dragonflies (Anisoptera: Synthemistidae & Corduliidae), Aaron M. Goodman

Dissertations, Theses, and Capstone Projects

Dragonflies and damselflies (Odonata Fabricius, 1793) are among the most widely recognized and charismatic insect groups, whose significance have permeated throughout artwork, culture, and religion. They are highly mobile predators, currently consisting of ~ 6,500 species, and possessing some of the complex visual color systems, visual acuity, and flight patterns on Earth. Odonata are the among the earliest flying insects, with proto-odonates (Griffinflies) dating back to the Carboniferous (~360mya), with crown-odonata fossils stretching back to the Triassic (~250mya). Overall, dragonflies and damselflies are considered models of ecological and evolutionary research due to their long evolutionary history, range of habitats, and …

The Evolution And Reproduction Of Andean Miconia (Melastomataceae), Juan Angulo

Dissertations, Theses, and Capstone Projects

Understanding the factors that shape diversification and distribution in tropical plant lineages is central to explaining the origins of Neotropical biodiversity. Assessing evolutionary history with trait evolution and climatic niche dynamics provides key insights into the drivers of diversification and biogeography, while natural history data remains critical for these evolutionary studies. The Tropical Andes, with its exceptional biodiversity and environmental heterogeneity, offers an ideal setting to explore these processes. In this dissertation, I investigate how reproductive systems, climatic niche dynamics, and pollination strategies influence the evolution and biogeography of Miconia III, a large and ecologically diverse clade in the …

Exploring The Role Of Ecological Traits In Shaping Spatial Patterns Of Genetic Diversity, Rilquer Mascarenhas Da Silva

Dissertations, Theses, and Capstone Projects

The field of comparative phylogeography aims at uncovering common underlying causes for shared patterns of diversity and diversification at the population level. However, it is now widely accepted that intraspecific genetic diversity patterns can differ considerably across co-occurring taxa due to ecological processes acting at the population level (and influencing individual movement and abundance). To model the processes underlying lineage diversification and demographic shifts in response to environmental changes, phylogeographers and population geneticists are now faced with the challenge of incorporating measurements of species ecological traits into their molecular studies. This dissertation aimed at investigating how different types of ecological …

Origin And Maintenance Of The Andean Bird Fauna, Elkin A. Tenorio

Dissertations, Theses, and Capstone Projects

The origin and maintenance of the tropical montane diversity have been evaluated over multiple decades using various techniques and perspectives. Despite major progress in understanding phylogenetic relationships, diversification patterns, distributional data, and general ecology in the Andean biota, large gaps in our understanding remain, particularly in the synthesis across scales. To fill these gaps, I aimed to explore patterns and processes that underlie species diversification in birds of the tropical Andes of South America by combining different approaches using phenotypic, phylogenetic, and genomic data in multiple temporal and spatial scales.

In the first chapter, I examined the macroevolutionary patterns of …

The Influence Of Environmental Change On Genetic Diversity Across Spatial And Taxonomic Scales, Connor M. French

Dissertations, Theses, and Capstone Projects

The spatial distribution of genetic diversity is of interest to biodiversity scientists and conservationists and is a fundamental metric of biodiversity. Genetic diversity patterns across spatial and taxonomic scales contain information about population and assemblage dynamics that can convey their resilience to environmental change. Ectotherms are especially linked to their environments and may be especially sensitive to fluctuations in the environment over time. Herein, I investigate global and regional patterns of genetic diversity in two groups of ectotherms, insects and lizards, to understand the relationship between environmental change and genetic diversity, from populations to assemblages. Overall, my research aims to …

The Effects Of Environmental Changes On The Biodiversity And Macroecological Patterns Of Bird Assemblages In The United States, Marlen Acosta Alamo

Dissertations, Theses, and Capstone Projects

The current restructuring of species assemblages and global loss of biodiversity result from species-specific responses to anthropogenic changes in climate and land cover. I investigated the effect of these two drivers on the seasonal distribution and biodiversity of birds in the United States and how human-induced habitat loss impacts macroecological patterns such as the species-area and the abundance-occupancy relationships. In Chapter 1, I examined the existence of a correlation between breeding and wintering geographic distributions of birds with different migratory strategies and the effect of changes in climate and the proportion of crop-pasture and urban land cover on this correlation. …

Using Leaf Spectra To Elucidate The Taxonomy And Ecology Of Living And Dried Plants, Natalia L. Quinteros Casaverde

Dissertations, Theses, and Capstone Projects

Identifying plants and understanding of changes in plant communities are crucial to the conservation and management of nature. The shortwave spectral reflectance of leaves is a promising tool for rapidly identifying species at different taxonomic ranks and predicting important plant functional traits. However, the spectral reflectance of leaves changes in response to biotic and abiotic conditions.

The aim of this dissertation is to investigate the potential of shortwave spectral reflectance to investigate (Chapter 1) how its variation affects the accuracy of methods used to predict plant taxonomies and what environmental factors most influence biophysically predicted traits, (Chapter 2) what are …

Towards Sociobiogeochemistry: Critical Perspectives On Anthropogenic Alterations To Soil Nitrogen Chemistry Via U.S. Urban And Suburban Development, Christopher D. Ryan

Dissertations, Theses, and Capstone Projects

The ecological impacts of changes to land use are relevant to concerns about climate change, eutrophication of waterbodies, and reductions in biodiversity. As a foundational component of ecosystem functioning, changes to soil biogeochemistry have significant effects on overall ecosystem health. With cities continuing to grow and develop in extent, the impacts of urbanization and suburbanization on soils are of particular concern. Despite a wide range of natural climatic and geologic conditions, several factors have driven similar patterns of land transformation and management across the United States. In particular, federal initiatives including the Home Owners Loan Corporation, the Federal Housing Administration, …

Avian Symbionts Of Sulawesi: Identifying And Correlating Malaria Parasites And The Microbiome In Communities Of Endemic Avian Hosts, Rachael Joakim

Dissertations, Theses, and Capstone Projects

Since the evolution of complex organisms, there have been communities of symbionts inhabiting them. Thanks to the development of parallel sequencing techniques, DNA of entire microbial communities can be sequenced from a single sample. Some microbes can be parasitic in nature, such as Haemosporida, an order of eukaryotes causing malaria. While most symbionts form a more commensal host relationship in wild systems, host-symbiont dynamics can vary in pathogenicity based on biotic and abiotic factors. In vertebrates, microbial communities in the gut play a major role in host function, including immune responses to Haemosporida. Though this relationship is most commonly explored …

Expanding The Role Of The Temporal Dimension In Ecological Niche Models: A Study On Mexican Montane Small Mammals, Gonzalo E. Pinilla Buitrago

Dissertations, Theses, and Capstone Projects

Ecological niche models (ENMs) are commonly used to estimate the potential geographic distributions of species and have various uses, such as predicting invasive species' potential distribution, assessing vulnerability to climate change, or estimating paleodistributions. However, ENM developments have primarily focused on solving spatially related issues, underemphasizing the temporal dimensionality of occurrence and environmental data collected over the last century. One limitation of ENMs is the common practice of using recent environmental averages that fail to capture the gradual environmental change over the time span of the occurrence records and can hide trends in environmental variables, a critical piece of information …

Population Genomics, Ecology And Conservation Of Asterias Sea Stars In The North Atlantic, Melenia I. Giakoumis

Dissertations, Theses, and Capstone Projects

Uncovering how species respond to environmental change is a central question in biology (Ehrlén & Morris 2015; Habibullah et al. 2022). It is the key to elucidating the past, understanding the present and predicting the future of species’ population dynamics. This dissertation investigates the influence of environmental change on intertidal species’ distributions and genomics at several timescales, with implications for conservation.

Environmental changes have occurred throughout history, on a geological scale, and have shaped the global patterns of species’ distributions and population sizes. Biologists have long studied how geological history has shaped species distributions (Sanmartín 2012) in both terrestrial (Liu …

Remote Sensing Characterization Of Ecosystem Structure And Functional Types To Inform On Biodiversity Conservation In The Lowland Chocó Rainforest, Derek Tesser

Dissertations, Theses, and Capstone Projects

This dissertation focuses on the utilization of remote sensing techniques to characterize ecosystem structure and functional types to inform on biodiversity conservation. This work is motivated by a guiding hypothesis that increased degradation of tropical forest biodiversity due to human activity results in in measurable changes in ecosystem processes that can be detected using remote sensing technologies. Throughout this dissertation, testing of aspects of this hypothesis involve comparing areas with varying degrees of human-induced degradation in a biodiverse tropical ecoregion, the lowland Chocó rainforest of Ecuador. Remote sensing data is used to evaluate changes in vegetation structure, thermal regimes, and …

Illuminating The Drivers Of Genomic Diversification In Lamprologine Cichlids Of The Lower Congo River, Naoko P. Kurata

Dissertations, Theses, and Capstone Projects

Freshwater fishes are extraordinarily diverse, considering their available habitats represent a tiny proportion of the earth’s surface. Rivers connect heterogeneous habitats in a linear form and provide excellent simplified models to understand how aquatic biodiversity evolves. In particular, the lower Congo River (LCR) in west Central Africa consists of a dynamic hydroscape exhibiting extraordinary aquatic biodiversity, endemicity, and morphological and ecological specialization. This system is thus an excellent natural laboratory for understanding complex speciation and population diversification processes. In my research, I explore various drivers of diversification, and adaptive evolution in rheophilic lamprologine cichlids endemic to the LCR, including Lamprologus …

American Eel (Anguilla Rostrata) And Other Fishes As Surveyed By Environmental Dna In The Bronx River And Hudson River Watershed, Sam C. Chin

Dissertations, Theses, and Capstone Projects

Mounting an effective response to the threats faced by freshwater fish may require expansions to aquatic biomonitoring in excess of what is feasible using the capture-based survey techniques currently relied upon by natural resource managers. Methods for analyzing environmental DNA (eDNA) are emerging as a minimally invasive and cost-effective approach for surveying fish and other organisms. By detecting taxon-specific DNA sequences recovered from environmental samples (e.g. water, sediment), eDNA methods are able to infer species presence from samples that can be collected rapidly with simple equipment. In many cases, eDNA detection rates of fish species have been shown to meet …

Nutrient Dynamics And Ecosystem Development Of Urban Forests, Gisselle A. Mejía

Dissertations, Theses, and Capstone Projects

Urban growth and expansion are a major component of global environmental change, with impacts on climate, air and water quality, biodiversity, and human well-being. Forests embedded in urban landscapes are critical in mitigating these impacts at local, regional, and continental scales. However, assessing urban forests is difficult because cities are heterogenous in physical, chemical, biological, and social dimensions. This heterogeneity has constrained how urban forests are defined, and therefore, how they are studied. The objective of this dissertation is to determine how these biophysical and social factors drive ecological processes in urban forests and will address three outstanding challenges in …

Vertebrate Scavenger Diversity And Ecosystem Services Along An Elevational Gradient In Central Nepal, Aishwarya Bhattacharjee

Dissertations, Theses, and Capstone Projects

A growing number of studies recognize the ecological significance of vertebrate scavengers, and several species belonging to this diverse, functional guild are of high conservation importance around the globe. Studies on taxonomic and functional components of biodiversity often use elevation gradients to comprehensively examine patterns and drivers across multiple spatial scales. Yet, there are relatively few elevational studies on large vertebrates or multi-taxa guilds, and the related variation of their ecosystem services. In particular, scavenger research has largely focused on local-scale studies or regional/global comparisons of local-scale investigations. Moreover, these studies primarily consider taxonomic community characteristics and the patterns of …

Understanding And Predicting The Distribution Of Biodiversity In The Atlantic Forest, Andrea Paz Velez

Dissertations, Theses, and Capstone Projects

Understanding how biodiversity is distributed in geography is essential for conservation. This requires an understanding of the multiple dimensions of biodiversity: species, their ecological functions, and their evolutionary history. For my Ph.D. dissertation, I devised a study to explore the environmental drivers of biodiversity patterns in Neotropical species. I first investigated broad macroecological patterns in the Brazilian Atlantic Forest, combining occurrence data and phylogenetic information from multiple clades of animals and plants (Chapter 1). I discovered that one can accurately predict the accumulation of species richness and phylogenetic diversity based on current climatic descriptors – particularly precipitation – but not …

Genomic And Ecological Dimensions Of Malagasy Reptile And Amphibian Biodiversity, Arianna L. Kuhn

Dissertations, Theses, and Capstone Projects

A long history of isolation coupled with complex topographic and ecological landscapes makes Madagascar ideal for exploring the historical factors that have shaped patterns of population diversity and endemism. Many species-level studies have suggested Late Quaternary climate change may have influenced population dynamics in the tropics, but Madagascar’s ecologically unique biomes or individual species properties may have driven idiosyncratic responses to these shifts. Using community-scale population genetic data I implement a hierarchical approximate Bayesian computation (hABC) approach to evaluate the degree of synchronous population expansion during glacial cycles across herpetofaunal assemblages both within and across discrete biomes and taxonomic groups. …

On The Distribution Of Genetic Variation In Ecological Communities, Isaac Overcast

Dissertations, Theses, and Capstone Projects

Biodiversity in ecological communities is structured hierarchically across spatial and temporal scales. Many open questions remain as to how this structure accumulates. For example, what are the relative contributions of dispersal versus in situ speciation? Or, how important are stochastic drift versus deterministic processes? Up to this point, these questions have been investigated by isolated disciplines (e.g. macroecology, comparative phylogeography, macroevolution) using tools and data that tend to focus on only one axis of community scale data (e.g. phylogenies, relative abundances, and/or trait information). Yet we know that there are feedbacks among processes that respond on short, medium, and long …

Systematics Of Carex Section Laxiflorae (Cyperaceae), Jenna Dorey

Dissertations, Theses, and Capstone Projects

Carex, with more than 2100 species, is the most species-rich genus of flowering plants in temperate regions of the world. Members of the family Cyperaceae are colloquially known as sedges, and members of the genus Carex are called “true sedges.” Carex occur on every continent except for Antarctica, they thrive in a panoply of habitats, and are ecologically important as a forage source for wildlife, carbon sequestration, prevention of soil erosion, and providing habitat for fresh water invertebrates. Despite their importance many sedges are still poorly known, such as the woodland sedges in Carex section Laxiflorae, which is …

Cultural Heritage Preservation In The Context Of Climate Change Adaptation Or Relocation: Barbuda As A Case Study, Martha B. Lerski

Dissertations, Theses, and Capstone Projects

This case study introduces an arts camp methodology of engaging communities in identifying their key cultural heritage features, thus serving as a meta study. It presents original research based on field studies on the climate-vulnerable Caribbean island of Barbuda during 2017 and 2018. Its Valued Cultural Elements survey, enabling precise identification of key tangible and intangible art forms and biocultural practices, may serve as a basis for further studies. Such approaches may facilitate future research or planning as climate-vulnerable communities harness Local or Indigenous Knowledge for purposes of biocultural heritage preservation, or towards adaptation or relocation. I report on findings …

Distribution And Population Structure Of The Invasive Nitellopsis Obtusa (Desv. In Loisel.) J. Groves And Native Species Of Characeae In The Northeast U.S.A., Robin Sleith

Dissertations, Theses, and Capstone Projects

Freshwater ecosystems are some of the most biologically diverse environments on Earth. Billions of humans rely on functioning freshwater ecosystems for drinking water and many other services. These ecosystems are increasingly threatened by human impacts including nutrient pollution, invasive species, and climate change. Here I contribute four research chapters that investigate freshwater diversity and ecosystem threats using the Characeae, a family of freshwater green macroalgae, as a study system. Characeae are a diverse and ancient group with more than 500 extant species and a fossil history spanning at least 250 million years. These algae are macrophytes in freshwater ecosystems, and …

Using Molecular Markers To Trace The Population History Of Volant Organisms At Differing Temporal Scales, Noah A. Burg

Dissertations, Theses, and Capstone Projects

Using molecular markers to test phylogenetic and phylogeographic hypotheses is critical for tracking the population origin of invasive, introduced species (Chapter 2, Chapter 4) and to identify the systematic relationships of disparate lineages at both shallow and deep evolutionary time scales (Chapters 3, Chapter 4). In this thesis, Sanger Sequencing was used to generate datasets based on fresh and preserved tissue from specimens collected in the field, as well as museum tissue vouchers granted from various institutions in the US and Europe. In combining these source materials, data were generated for three focal studies: 1) In the first research section …

Niche Shifts, Species Distributions, And Genetic Diversity In Gymnophthalminae Lizards, With A Focus On Microclimates And Thermophysiology, Maria Strangas

Dissertations, Theses, and Capstone Projects

The environmental niche is a central organizing concept in the study of ecology and evolution, as the environmental conditions in which species can persist (their fundamental niches) and the conditions in which they occur (their realized niches) can shape spatial and temporal patterns of biodiversity at multiple scales. How organisms at different levels of biological organization are affected by environmental heterogeneity has consequences for the distribution of genetic and phenotypic diversity, yet the mechanisms through which this occurs are poorly studied. In this dissertation, I present three research chapters that explore how species’ traits and their microclimatic environments shape biodiversity …

A Contribution Toward A Global Monograph Of Gyroporus: Taxonomy, Phylogeny, Biogeography, Naveed Davoodian

Dissertations, Theses, and Capstone Projects

Gyroporus (Sclerodermatineae, Boletales, Agaricomycetes, Basidiomycota, Fungi) is a genus of ectomycorrhizal mushroom-forming fungi distributed throughout the world in suitable habitats. Previous attempts to untangle the diversity of this genus proved difficult due to the presence of semi-cryptic species and equivocal results from phylogenetic analysis of ribosomal RNA markers. To overcome these obstacles, a combined taxonomic and phylogenetic (emphasizing protein-coding genes) approach is used here to delimit species and elucidate geographic and evolutionary patterns of Gyroporus. Careful study of relevant literature and herbarium specimens was augmented by field work in North America, Australia, and East Asia for observation and collection …

Militarization Of Conservation, Daniel Ryan Michel

Dissertations, Theses, and Capstone Projects

The world is facing biological diversity extinction of its wildlife solely caused by humans. One of the leading causes of the extinction crisis is attributed to poaching and the illegal trade of wildlife products. In search of finding suitable methods to curb the crisis, a dichotomy of overarching solutions has arisen: those who have advocated for community-based natural resource management and those who support militarized conservation. The focus of this paper is to delineate which method is, if any, the most appropriate when combatting poaching and the illegal wildlife trade. Concentrating on elephants (both African and Asian) and the rhinoceros, …

Walking As Ontological Shifter: Thoughts In The Key Of Life, Bibi (Silvina) Calderaro

Dissertations, Theses, and Capstone Projects

With walking as ontological shifter I pursue an alternative to the dominant modernist episteme that offers either/or onto-epistemologies of opposition and their reifying engagements. I propose this type of walking is an intentional turning towards a set of radical positions that, as integrative aesthetic and therapeutic practice, brings multiplicity and synchronicity to experience and being in an expanded sociality. This practice facilitates the conditions of possibility for recurring points of contact between the interiority perceived as ‘body’ and the exteriority perceived as ‘world.’ While making evident the self’s at once incoherence with it-self, it opens to a space beyond the …

Climate-Driven Habitat Shifts In South America: Biogeography, Historical Demography, And Population Genomics Of Anole Lizards, Ivan Prates

Dissertations, Theses, and Capstone Projects

Shifts in the geographic distribution of habitats over time can promote dispersal and vicariance, thereby influencing large-scale biogeographic patterns and ecological processes. The establishment of corridors of suitable habitat across previously disjunct yet ecologically similar regions has been widely linked to climate change over time. Such climate-mediated habitat changes may have played a key role in the assembly of tropical biotas, including those of Amazonia and the coastal Atlantic Forest in South America, two of the most diverse ecosystems on Earth. The history of biogeographic associations between tropical rainforest habitats in response to former climatic shifts, as well as their …

Lichen Conservation In Eastern North America: Population Genomics, Climate Change, And Translocations, Jessica Allen

Dissertations, Theses, and Capstone Projects

Conservation biology is a scientific discipline that draws on methods from diverse fields to address specific conservation concerns and inform conservation actions. This field is overwhelmingly focused on charismatic animals and vascular plants, often ignoring other diverse and ecologically important groups. This trend is slowly changing in some ways; for example, increasing number of fungal species are being added to the IUCN Red-List. However, a strong taxonomic bias still exists. Here I contribute four research chapters to further the conservation of lichens, one group of frequently overlooked organisms. I address specific conservation concerns in eastern North America using modern methods. …