Evolution Commons^™

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 …

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 …

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 …

Quantified Lives: Data, Bias, And The Cost Of Categorization, Colin F. Geraghty

Dissertations, Theses, and Capstone Projects

This project critically examines how statistical methods and data visualization have historically been used to categorize, rank, and control human populations. By exploring the works of key figures like Francis Galton, Karl Pearson, and R.A. Fisher, it traces the evolution of categorization frameworks from their eugenic roots to modern applications in artificial intelligence and global metrics like the World Happiness Report. Through interactive visualizations and historical analysis, the project invites users to question the legitimacy of these frameworks and reflect on their impact on society. At its core, this work emphasizes the need to move beyond rigid classification systems, challenging …

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 …

Adaptive Evolution Of Surface Proteins In Microbial Pathogens: Lyme Disease Pathogens (Borreliella Sp.) And Human Immunodeficiency Virus Type 1 (Hiv-1), Li Li

Dissertations, Theses, and Capstone Projects

Cell and virion surface proteins are key to the survival and adaptation of microbial pathogens by enabling them to evade host immune responses and to persist in diverse environments. Pathogens respond to host immune pressures with genetic changes in surface proteins through mechanisms including point mutations, recombination, gene duplication and loss, and lateral gene transfer, resulting in novel antigenic variants and antigenic diversity. This continuous adaptation helps pathogens evade host immunity, leading to chronic infections and recurrent disease outbreaks. Understanding these mechanisms is vital for developing effective strategies to combat infectious diseases.

This dissertation comprises three chapters exploring the adaptive …

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 …

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 …

Statistical And Biological Analyses Of Acoustic Signals In Estrildid Finches, Moises Rivera

Dissertations, Theses, and Capstone Projects

Acoustic communication is a process that involves auditory perception and signal processing. Discrimination and recognition further require cognitive processes and supporting mechanisms in order to successfully identify and appropriately respond to signal senders. Although acoustic communication is common across birds, classical research has largely disregarded the perceptual abilities of perinatal altricial taxa. Chapter 1 reviews the literature of perinatal acoustic stimulation in birds, highlighting the disproportionate focus on precocial birds (e.g., chickens, ducks, quails). The long-held belief that altricial birds were incapable of acoustic perception in ovo was only recently overturned, as researchers began to find behavioral and physiological evidence …

Elucidating Mechanisms Of Biofluorescence And Bioluminescence In Marine Organisms, Andrew M. Guarnaccia

Dissertations, Theses, and Capstone Projects

Biofluorescence and bioluminescence are two methods of light emission that entail separate mechanisms of action but end at the same process: a colorful display that have tremendous ecological and behavioral benefits, whether it be used to communicate with conspecifics, camouflage into a multicolored background, attract unsuspecting prey, or alert others to a predator. In biofluorescence, higher-energy, shorter wavelength light is absorbed then re-emitted as lower-energy, longer-wavelength light. Bioluminescence on the other hand entails a chemical reaction in which a small molecule is oxidized by an enzyme, creating a high-energy intermediate that sheds the excess energy in the form of visible …

Genomic Insights Into Mechanisms Of Microbial Evolution And Evolution-Inspired Strategies To Combat Pathogen Diversity, Saymon Akther

Dissertations, Theses, and Capstone Projects

We live in an era of emerging infectious diseases that are increasingly common, rapidly spreading, and gravely devastating. Lyme disease, caused by bacteria belonging to the genus Borreliella, is rapidly rising in the Northern Hemisphere because of geographic range expansion of both the tick vectors and the pathogens. Evolutionary comparative analysis of Borreliella genomes is a key to understanding the phylogeographic history and mechanisms of their global diversification. Moreover, genomic variations in Borreliella associated with human pathogenicity, e.g., at loci encoding cell-surface antigens interacting with the vertebrate hosts, have not been fully identified. Similarly, the ongoing COVID-19 pandemic, caused …

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 …

The Evolution Of Reproductive Complexity In Fishes, Frieda Benun

Dissertations, Theses, and Capstone Projects

How does reproductive complexity evolve? In this dissertation, I investigate the evolution of parental investment and mating behavior, using both macro- and microevolutionary lenses. I use fishes, the most diverse group of vertebrates, comprising over 30,000 species, as a model to study the evolution of these traits.

In Chapter 1, I introduce the evolution of parental behaviors in fishes. I present a systematic review of parental care for 294 families (close to 60%) of bony fish and show that male-only care is the predominant form of care in this group. I summarize current theories on parental care, emphasizing external fertilization, …

The Evolution Of Spinosad Resistance In Colorado Potato Beetles (Leptinotarsa Decemlineata), Coby Michael Klein

Dissertations, Theses, and Capstone Projects

Colorado potato beetles (Leptinotarsa decemlineata) are a major pest of cultivated potato plants worldwide. They are well-known for their ability to rapidly evolve resistance to all major classes of pesticides. Defoliation of potato plants by L. decemlineata can reduce potato yields by a considerable margin. The damage done by resistant beetles is steep and much research is focused on developing new chemical controls, especially those derived from naturally occurring compounds. Spinosad is a relatively new natural product insecticide, introduced approximately a decade ago, suitable for use in organic farming. Potato beetles on Long Island, NY developed very strong …

Innate Antibodies, Murine Models, And Evolution: A Study Of Trypanosome Lytic Factor Functions And Their Translational Applications, Joseph P. Verdi

Dissertations, Theses, and Capstone Projects

Trypanosome lytic factors (TLFs) are primate-specific antimicrobial protein complexes that lyse African trypanosome parasites by delivering the channel-forming toxin APOL1 to the invading microorganisms. Human serum contains two TLFs that are delivered to the parasite by separate mechanisms, only one of which has been characterized. TLF1 is endocytosed by a receptor that is typically blocked by other serum factors in vivo, suggesting that TLF2 is the more relevant lytic factor in the context of trypanosome immunity. TLF2 is non-covalently associated with polyclonal immunoglobulin M (IgM) antibodies, which we report here to be involved in the uptake mechanism. The TLF2-IgMs …

The Functional Morphology Of Ingestion In The Platyrrhine Sclerocarpic Harvesters (Platyrrhini, Primates), Zachary Stoffel Klukkert

Dissertations, Theses, and Capstone Projects

The identification of anatomical correlates of diet and feeding behavior in nonhuman primates is an important area of research in biological anthropology. The morphology of the jaws and teeth reflects the phylogeny and adaptations that distinguish taxa and their different ecological niches. Studying the form-function relationships of jaws and teeth in modern species provides a framework for interpreting the diets of extinct species and for inferring the ecological pressures that may have contributed to the evolutionary diversification of primate craniodental morphology. Previous work on modeling primate jaw mechanics has focused largely on the functional context of a closed jaw. Little …

The Morphology And Evolution Of The Primate Brachial Plexus, Brian M. Shearer

Dissertations, Theses, and Capstone Projects

Primate evolutionary history is inexorably linked to the evolution of a broad array of locomotor adaptations that have facilitated the clade’s invasion of new niches. Researchers studying the evolution of primates and of their individual locomotor adaptations have traditionally relied on bony morphology – a practical choice given the virtual non-existence of any other type of tissue in the fossil record. However, this focus downplays the potential importance of the many other structures involved in locomotion, such as muscle, cartilage, and neural tissue, which may each be influenced by separate selective forces because of their different roles in facilitating movement. …

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 …

Convergent Evolution Of Biochemical Innovations In Polychaetes: Characterizing The Molecular Basis Of Bioluminescence And Venom Production, Aida E. Verdes Gorín

Dissertations, Theses, and Capstone Projects

The convergent evolution of phenotypic traits is a widespread phenomenon across the tree of life and is explained as the outcome of different taxa facing similar selective forces or environmental conditions. A longstanding question in evolutionary biology is whether the evolution of convergent phenotypes in unrelated lineages is driven by similar or different molecular processes. The research presented here investigates this question by characterizing the molecular basis of two biochemical innovations, bioluminescence and venom production, that have evolved independently in different lineages of polychaetes worms (Annelida). We use an integrative approach, combining next-generation sequencing, phylogenetics and computational tools to evaluate …

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 …

Comparative Phylogeographic, Population Genomic, And Selection Inference With Development Of Hierarchical Co-Demographic Models, Alexander Xue

Dissertations, Theses, and Capstone Projects

Comparing demographic histories across assemblages of populations, species, and sister pairs has been a focus in phylogeography since its inception. Initial approaches utilized organelle genetic data and involved qualitative comparisons of genetic patterns for evaluating hypotheses of shared evolutionary responses to past environmental changes. This endeavor has progressed with coalescent model-based statistical techniques and advances in next-generation sequencing, yet there remains a need for methods that can analyze aggregated genomic-scale data from non-model organisms within a unified framework that considers individual taxon uncertainty and variance. To this end, the aggregate site frequency spectrum (aSFS), an expansion of the site frequency …

Ecology, Evolution, And Sexual Selection In The Invasive, Globally Distributed Small Indian Mongoose (Urva Auropunctata), M. Aaron Owen

Dissertations, Theses, and Capstone Projects

Introduced species provide rare opportunities to test evolutionary hypotheses in situ by creating so-called natural experiments. Natural experiments are situations in nature that resemble laboratory studies by allowing for comparisons of a “control” group (i.e., a species’ native range) with “experimental” groups (i.e., a species’ introduced range). In particular, introduced animals allow us to investigate evolutionary dynamics in complex, long-lived organisms in ways that would otherwise be impossible in a laboratory setting. One such introduced animal is the small Indian mongoose (Urva auropunctata, formerly Herpestes auropunctatus). Native to South Asia, the small Indian mongoose’s introduction to more …

Comparative Population Genomics And Speciation Of Snakes Across The North American Deserts, Edward A. Myers

Dissertations, Theses, and Capstone Projects

Understanding the process of speciation is of central interest to evolutionary biologists. Speciation can be studied using a phylogeographic approach, by identifying regions that promote lineage divergence, addressing whether speciation has occurred with gene flow, and when extended to multiple taxa, addressing if the same patterns of speciation are shared across codistributed groups with different ecologies. Here I examine the comparative phylogeographic histories and population genomics of thirteen snake taxa that are widely distributed and co-occur across the arid southwest of North America. I first quantify the degree to which these species groups have a shared history of population divergence …

Models And Methods In Cultural And Social Evolution, Elliot G. Aguilar

Dissertations, Theses, and Capstone Projects

Chapter 1 The mathematical study of genealogies has yielded important insights in population biology, such as the ability to estimate the time to the most recent common ancestor (MRCA) of a sample of genetic sequences or of a group of individuals. Here we introduce a model of cultural genealogies that is a step toward answering similar questions for cultural traits. In our model individuals can inherit from a variable, potentially large number of ancestors, rather than from a fixed, small number of ancestors (one or two) as is typical of genetic evolution. We first show that, given a sample of …

Phylogeny, Systematics And Biogeography Of Short-Tailed Opossums (Didelphidae: Monodelphis), Silvia E. Pavan

Dissertations, Theses, and Capstone Projects

Short-tailed opossums (genus Monodelphis) comprise the most species-rich genus of New World marsupials, with 25 currently recognized species. Monodelphis comprise small, terrestrial species collectively widespread in South America, which makes the group potentially informative about biogeographic processes that have shaped the continental fauna. The genus exhibits striking variation in several phenotypic characters, notably pelage coloration, behavior, and reproductive strategies. This diversity is unique among Neotropical marsupials, and makes the group particularly interesting to investigate the evolution and the adaptive significance of phenotypic trait variation. Despite this potential, missing knowledge on phylogeny and basic taxonomy precludes broader studies on evolution …

The Evolution Of The Viral Rna Sensor Oas1 In Old World Monkeys And Cetartiodactyls, Ian Fish

Dissertations, Theses, and Capstone Projects

Animals produce an array of sensors patrolling the intracellular environment poised to detect and respond to viral infection. The oligoadenylate synthetase family of enzymes comprises a crucial part of this innate immune response, directly signaling endonuclease activity responsible for inhibiting viral replication. Oligoadenylate synthetase 1 plays a vital role in animal susceptibility to pathogens including flaviviruses such as dengue, West Nile, and hepatitis c virus. This thesis includes a population level analysis of OAS1 diversity within macaque and baboon species followed by a broader survey of the gene in nineteen Old World monkeys. My research found that at the species …