Ecology and Evolutionary Biology Commons^™

Editorial: Systems Biology And Ecology Of Microbial Mat Communities, Martin G. Klotz, Donald A. Bryant, Jim K. Fredrickson, William P. Inskeep, Michael Kühl

Publications and Research

No abstract provided.

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 …

When Human-Leopard Conflict Turns Deadly: A Cross-Country Situational Analysis, Julie S. Viollaz

Dissertations, Theses, and Capstone Projects

Habitat destruction and pollution are two of the main causes for the decline of the planet’s biodiversity. Yet environmentalists are now recognizing that illegal wildlife killings, both poaching and retaliatory killings due to human-wildlife conflict, are perhaps the next major threat. Biologists have researched illegal killings and their effect on species conservation, but few researchers have applied criminological principles of crime reduction to them. This research will explore the situational factors that drive retaliatory leopard killings in parts of South Africa, Kenya, and India. These factors, human and environmental, include local expectations from wildlife, sensitivity to environmental issues, communication between …

Are We Overestimating The Niche? Removing Marginal Localities Helps Ecological Niche Models Detect Environmental Barriers, Mariano Soley-Guardia, Eliécer E. Gutiérrez, Darla M. Thomas, José Ochoa-G, Marisol Aguilera, Robert P. Anderson

Publications and Research

Correlative ecological niche models (ENMs) estimate species niches using occurrence records and environmental data. These tools are valuable to the field of biogeography, where they are commonly used to infer potential connectivity among populations. However, a recent study showed that when locally relevant environmental data are not available, records from patches of suitable habitat protruding into otherwise unsuitable regions (e.g., gallery forests within dry areas) can lead to overestimations of species niches and their potential distributions. Here, we test whether this issue obfuscates detection of an obvious environmental barrier existing in northern Venezuela – that of the hot and xeric …

Comparative Phylogeography Of Ethiopian Anurans: Impact Of The Great Rift Valley And Pleistocene Climate Change, Xenia Freilich, Jose D. Anadon, Jolanta Bukala, Ordaliza Calderon, Ronveer Chakraborty, Stephanie Boissinot

Publications and Research

Background: The Ethiopian highlands are a biodiversity hotspot, split by the Great Rift Valley into two distinct systems of plateaus and mountains. The Rift Valley is currently hot and dry and acts as a barrier to gene flow for highland-adapted species. It is however unlikely that the conditions in the Rift were inhospitable to highland species during the entire Pleistocene. To assess the significance of the Ethiopian Rift as a biogeographic barrier as well as the impact Pleistocene climatic changes have had on the evolution of Ethiopian organisms, we performed phylogeographic analyses and developed present and past niche models on …

Homo Naledi, A New Species Of The Genus Homo From The Dinaledi Chamber, South Africa, Lee R. Berger, John Hawks, Darryl J. De Ruiter, Steven E. Churchill, Peter Schmid, Lucas K. Delezene, Tracy L. Kivell, Heather M. Garvin, Scott A. Williams, Jeremy M. Desilva, Matthew M. Skinner, Charles M. Musiba, Noel Cameron, Trenton W. Holliday, William Harcourt-Smith, Et Al.

Publications and Research

Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is characterized by body mass and stature similar to small-bodied human populations but a small endocranial volume similar to australopiths. Cranial morphology of H. naledi is unique, but most similar to early Homo species including Homo erectus, Homo habilis or Homo rudolfensis. While primitive, the dentition is generally small and simple in occlusal morphology. H. naledi has humanlike manipulatory adaptations of the hand and wrist. It also exhibits a humanlike foot and lower …

A Generalist Brood Parasite Modifies Use Of A Host In Response To Reproductive Success, Matthew I M Louder, Wendy M. Schelsky, Amber N. Albores, Jeffrey P. Hoover

Publications and Research

Avian obligate brood parasites, which rely solely on hosts to raise their young, should choose the highest quality hosts to maximize reproductive output. Brown-headed cowbirds (Molothrus ater) are extreme host generalists, yet female cowbirds could use information based on past reproductive outcomes to make egg-laying decisions thus minimizing fitness costs associated with parasitizing low quality hosts. We use a long-term (21 years) nest box study of a single host, the prothonotary warbler (Protonotaria citrea), to show that local cowbird reproductive success, but not host reproductive success, was positively correlated with the probability of parasitism the following …

Suitability Of Great South Bay, New York To Blooms Of Pfiesteria Piscicida And P. Shumwayae Prior To Superstorm Sandy, October 29, 2012, Pawel Tomasz Zablocki

Theses and Dissertations

Pfiesteria piscicida and P. shumwayae are toxic dinoflagellates implicated in massive fish kills in North Carolina and Maryland during 1990s. A set of physical, chemica l, and biological factors influence population dynamics of these organisms. This study employs i nformation gathered from relevant literature on temperature, salinity, dissolved oxygen, pH, turbulent mixing, and dissolved nutrients, bacteria, algae, microzooplankton, mesozooplankton, bivalve m ollusks, finfish, and other toxic dinoflagellates, which influence Pfiesteria population dynamics. The research focused on whether conditions in the Great South Bay, Long Island, New York were suitable to blooms of Pfiesteria species prior to the passage of superstorm …

Population Genetic Structure Of The Dwarf Seahorse (Hippocampus Zosterae) In Florida, Nathan Fedrizzi, Melanie L. J. Stiassny, J. T. Boehm, Eric R. Dougherty, George Amato, Martin Mendez

Publications and Research

The dwarf seahorse (Hippocampus zosterae) is widely distributed throughout near-shore habitats of the Gulf of Mexico and is of commercial significance in Florida, where it is harvested for the aquarium and curio trades. Despite its regional importance, the genetic structure of dwarf seahorse populations remains largely unknown. As an aid to ongoing conservation efforts, we employed three commonly applied mtDNA markers (ND4, DLoop and CO1) to investigate the genetic structuring of H. zosterae in Florida using samples collected throughout its range in the state. A total of 1450 bp provided sufficient resolution to delineate four populations of dwarf seahorses, as …

Common Cell Shape Evolution Of Two Nasopharyngeal Pathogens, Frédéric J. Veyrier, Nicolas Biais, Pablo Morales, Nouria Belkacem, Cyril Guilhen, Sylvia Ranjeva, Odile Sismeiro, Gérard Péhau-Arnaudet, Eduardo P. Rocha, Catherine Werts, Muhamed-Kheir Taha, Ivo G. Boneca

Publications and Research

Respiratory infectious diseases are the third cause of worldwide death. The nasopharynx is the portal of entry and the ecological niche of many microorganisms, of which some are pathogenic to humans, such as Neisseria meningitidis and Moraxella catarrhalis. These microbes possess several surface structures that interact with the actors of the innate immune system. In our attempt to understand the past evolution of these bacteria and their adaption to the nasopharynx, we first studied differences in cell wall structure, one of the strongest immune-modulators. We were able to show that a modification of peptidoglycan (PG) composition (increased proportion of pentapeptides) …

Estimates Of Micro-, Nano-, And Picoplankton Contributions To Particle Export In The Northeast Pacific, B. L. Mackinson, S. B. Moran, M. W. Lomas, Gillian M. Stewart, R. P. Kelly

Publications and Research

The contributions of micro-, nano-, and picoplankton to particle export were estimated from measurements of size-fractionated particulate 234Th, organic carbon, and phytoplankton indicator pigments obtained during five cruises between 2010 and 2012 along Line P in the subarctic northeast Pacific Ocean. Sinking fluxes of particulate organic carbon (POC) and indicator pigments were calculated from 234Th;238U disequilibria and, during two cruises, measured by a sediment trap at Ocean Station Papa. POC fluxes at 100m ranged from 0.65 to 7.95 mmolm2 d1, similar in magnitude to previous results at Line P. Microplankton pigments dominate indicator pigment fluxes (averaging 6919% of total pigment …

Molecular Diversity And Gene Evolution Of The Venom Arsenal Of Terebridae Predatory Marine Snails, Juliette Gorson, Girish Ramrattan, Aida Verdes, Elizabeth M. Wright, Yuri Kantor, Ramakrishnan Rajaram Srinivasan, Raj Musunuri, Daniel Packer, Gabriel Albano, Wei-Gang Qiu, Mandë Holford

Publications and Research

Venom peptides from predatory organisms are a resource for investigating evolutionary processes such as adaptive radiation or diversification, and exemplify promising targets for biomedical drug development. Terebridae are an understudied lineage of conoidean snails,which also includes cone snails and turrids. Characterization of cone snail venompeptides, conotoxins, has revealed a cocktail of bioactive compounds used to investigate physiological cellular function, predator-prey interactions, and to develop novel therapeutics. However, venom diversity of other conoidean snails remains poorly understood. The present research applies a venomics approach to characterize novel terebrid venom peptides, teretoxins, from the venom gland transcriptomes of Triplostephanus anilis and Terebra …

Using 3d Printed Eggs To Examine The Egg-Rejection Behaviour Of Wild Birds, Branislav Igic, Valerie Nunez, Henning U. Voss, Rebecca Croston, Zachary Aidala, Analía V. López, Aimee Van Tatenhove, Mandë E. Holford, Matthew D. Shawkey, Mark E. Hauber

Publications and Research

The coevolutionary relationships between brood parasites and their hosts are often studied by examining the egg rejection behaviour of host species using artificial eggs. However, the traditional methods for producing artificial eggs out of plasticine, plastic, wood, or plaster-of-Paris are laborious, imprecise, and prone to human error. As an alternative, 3D printing may reduce human error, enable more precise manipulation of egg size and shape, and provide a more accurate and replicable protocol for generating artificial stimuli than traditional methods. However, the usefulness of 3D printing technology for egg rejection research remains to be tested. Here, we applied 3D printing …

Teaching Evolution: A Students’ Perspective, Abdullah Allaoa, Tyniqua Hinton

Publications and Research

Many may wonder “where do we come from?” Over time, scientists have pondered and tested the concept of evolution. Simply put, evolution is gradual change over time. A major tenet of evolution is natural selection, which includes three principles which are variation in population, differential reproduction due to competition, and heredity. These principles are supported by multiple lines of evidence, including biochemical, geographical, fossil, and anatomical evidence. By providing tangible, real-world examples of evolution, we hope to provide a clear understanding of this long-studied scientific breakthrough, while at the same time showing how animals (including us) are related to each …

Climate And Changing Winter Distribution Of Alcids In The Northwest Atlantic, Richard R. Veit, Lisa L. Manne

Publications and Research

Population level impacts upon seabirds from changing climate are increasingly evident, and include effects on phenology, migration, dispersal, annual survivorship, and reproduction. Most population data on seabirds derive from nesting colonies; documented climate impacts on winter ecology are scarce. We studied interannual variability in winter abundance of six species of alcids (Charadriiformes, Alcidae) from a 58-year time series of data collected in Massachusetts 1954–2011. We used counts of birds taken during fall and winter from coastal vantage points. Counts were made by amateur birders, but coverage was consistent in timing and location. We found significant association between winter abundance of …

Experimental Shifts In Intraclutch Egg Color Variation Do Not Affect Egg Rejection In A Host Of A Non-Egg-Mimetic Avian Brood Parasite, Rebecca Croston, Mark E. Hauber

Publications and Research

Avian brood parasites lay their eggs in the nests of other birds, and impose the costs associated with rearing parasitic young onto these hosts. Many hosts of brood parasites defend against parasitism by removing foreign eggs from the nest. In systems where parasitic eggs mimic host eggs in coloration and patterning, extensive intraclutch variation in egg appearances may impair the host’s ability to recognize and reject parasitic eggs, but experimental investigation of this effect has produced conflicting results. The cognitive mechanism by which hosts recognize parasitic eggs may vary across brood parasite hosts, and this may explain variation in experimental …

Now You See It, Now You Don’T: Flushing Hosts Prior To Experimentation Can Predict Their Responses To Brood Parasitism, Daniel Hanley, Peter Samas, Josef Heryán, Mark E. Hauber, Tomáš Grim

Publications and Research

Brood parasitic birds lay their eggs in other birds’ nests, leaving hosts to raise their offspring. To understand parasite-host coevolutionary arms races, many studies have examined host responses to experimentally introduced eggs. However, attending parents often need to be flushed from their nests to add experimental eggs. If these birds witness parasitism events, they may recognize and reject foreign eggs more readily than parents who did not. We found that, after being flushed, female blackbirds, Turdus merula, remained close to their nests. Flushed females were more likely to eject foreign eggs and did so more quickly than females that …

Evolution Of Bat-Trypanosome Associations And The Origins Of Chagas Disease, Christian Miguel Pinto

Dissertations, Theses, and Capstone Projects

Trypanosoma cruzi is a genetically diverse parasite that causes Chagas disease, one of the most important zoonoses in the Americas. This generalist parasite of mammals belongs to a clade mostly comprised of bat parasites, the T. cruzi clade. The origins (i.e., biogeographic history and evolution of hosts associations) of this parasite are far from being understood, and the main areas that need further study are: species limits within T. cruzi sensu lato, further studies on the diversity of T. cruzi clade members and their hosts, and research on adaptations of the hosts to trypanosome infections. In this dissertation I explore …

Integrating Phylogenomics, Biogeography And Systematics To Explore The Taxonomy And The Rise Of The Ratsnakes, Xin Chen

Dissertations, Theses, and Capstone Projects

Understanding the evolutionary processes that create the spectacular diversity of organisms, both in species numbers and form, is a primary goal for biologists. Global ratsnakes are a species-rich assemblage with high morphological and ecological diversity and a distribution that encompasses both the Old World (OW) and the New World (NW). To explore the mechanism leading to the divergence of the ratsnakes, I tested the hypotheses regarding the area of origin and global dispersal, and examined the patterns of diversification and trait evolution. Given adaptive radiation via ecological opportunity, a diversity-dependent diversification pattern and an early burst trait evolutionary pattern are …

Striking The Balance: Challenges And Perspectives For The Protected Areas Network In Northeastern European Russia, Svetlana V. Degteva, Vasily I. Ponomarev, Sasha W. Eisenman, Vyacheslav Dushenkov

Publications and Research

Increasing anthropogenic pressure on the largest remaining tracts of old-growth boreal forest in Europe necessitates additional conservation of ecosystems and biodiversity in northeastern European Russia. In a regional network comprising 8 % of the Nenets Autonomous District and 13.5 % of the Komi Republic, 248 areas have varying protected statuses as state nature reserves (zapovedniks), national parks, reserves/sanctuaries (zakazniks), or natural monuments. Due to increased natural resource extraction in this relatively pristine area, designation of additional protected areas is critical for the protection of key ecological sites. The history of ecological preservation in these regions is herein described, and recent …

High Intralocus Variability And Interlocus Recombination Promote Immunological Diversity In A Minimal Major Histocompatibility System, Anthony B. Wilson, Camilla M. Whittington, Angela Bahr

Publications and Research

Background: The genes of the major histocompatibility complex (MHC/MH) have attracted considerable scientific interest due to their exceptional levels of variability and important function as part of the adaptive immune system. Despite a large number of studies on MH class II diversity of both model and non-model organisms, most research has focused on patterns of genetic variability at individual loci, failing to capture the functional diversity of the biologically active dimeric molecule. Here, we take a systematic approach to the study of MH variation, analyzing patterns of genetic variation at MH class IIα and IIβ loci of the seahorse, which …

Paleoecology Of Late Cretaceous Methane Cold-Seeps Of The Pierre Shale, South Dakota, Kimberly Cynthia Handle

Dissertations, Theses, and Capstone Projects

Most investigations of ancient methane seeps focus on either the geologic or paleontological aspects of these extreme environments. In contrast, this thesis encompasses both disciplines to evaluate the paleoecology of these systems with greater detail than previously published either within the Western Interior Basin or elsewhere. This thesis addresses the following questions: 1) Are the changes in mineralogy of a seep discernable and predictable as a seep shifts from a clay-based environment to a carbonate-based environment? 2) What are the foundation organism(s) of Late Cretaceous methane cold-seeps? 3) Is there a correlation to the mineralogic changes and shifts in community …

Ecological Niches, Species Distributions, And Biogeographic Processes In Rodents On Neotropical Sky Islands, Mariano Soley

Dissertations, Theses, and Capstone Projects

This dissertation focused on the methodological and theoretical improvement of correlative ecological niche models (ENMs) to better understand the processes governing species distributions and associated evolutionary divergence in rodents inhabiting mesic conditions in the Neotropics. Focusing on a widespread rodent from northern South America (Heteromys anomalus), in the first chapter I proposed and tested a methodological approach to surmount the challenge of incorporating environmental information from the margins of species geographic ranges into ENMs. In so doing, I argue how populations that exist on the borders of species' local ranges (spatial margins) can lead to exaggerated estimates of their niches …

Age-Related Aspects Of Mirror-Use By Bottlenose Dolphins (Tursiops Truncatus), Rachel A. Morrison

Dissertations, Theses, and Capstone Projects

Bottlenose dolphins are neuroanatomically different and evolutionarily divergent from primates yet they exhibit mirror self-recognition (MSR), a rare cognitive ability in non-human animals. This research investigated the developmental and age-related aspects of MSR in this species. During a longitudinal study, a social group of bottlenose dolphins at the National Aquarium, Baltimore, MD were exposed to a mirror and their behavioral responses were recorded to: 1) further confirm the presence of MSR in this species, 2) determine the age of emergence of MSR and 3) draw comparisons with data documenting the emergence of this ability in humans and great ape species. …

Foraging Ecology Of Shorebirds At A Stopover Site: Niche Dynamics, Aggression And Resource Use In Delaware Bay, Ivana Novcic

Dissertations, Theses, and Capstone Projects

Classical ecological theory predicts that generally similar species ought to partition resources in order to minimize competition amongst themselves. This basic idea becomes complex when one is dealing with species that migrate over thousands of miles and forage in a broad diversity of habitats and geographical locations. I studied a suite of migratory sandpipers, and asked whether they partitioned niches at a major migratory stopover in Delaware Bay. During migration, shorebirds form large, usually mixed-species flocks, which forage on marshes, mudflats, beaches or similar two-dimensional habitats where all individuals are distributed on the same horizontal plane. These habitats are often …

High Local Diversity Of Trypanosoma In A Common Bat Species, And Implications For The Biogeography And Taxonomy Of The T. Cruzi Clade, Veronika M. Cottontail, Elisabeth K. V. Kalko, Iain Cottontail, Nele Wellinghausen, Marco Tschapka, Susan L. Perkins, C. Miguel Pinto

Publications and Research

The Trypanosoma cruzi clade is a group of parasites that comprises T. cruzi sensu lato and its closest relatives. Although several species have been confirmed phylogenetically to belong to this clade, it is uncertain how many more species can be expected to belong into this group. Here, we present the results of a survey of trypanosome parasites of the bat Artibeus jamaicensis from the Panama´ Canal Zone, an important seed disperser. Using a genealogical species delimitation approach, the Poisson tree processes (PTP), we tentatively identified five species of trypanosomes – all belonging to the T. cruzi clade. A small monophyletic …

Nesting Behaviour Influences Species-Specific Gas Exchange Across Avian Eggshells, Steven J. Portugal, Golo Maurer, Gavin H. Thomas, Mark E. Hauber, Tomáš Grim, Phillip Cassey

Publications and Research

Carefully controlled gas exchange across the eggshell is essential for the development of the avian embryo. Water vapour conductance (GH2O) across the shell, typically measured as mass loss during incubation, has been demonstrated to optimally ensure the healthy development of the embryo while avoiding desiccation. Accordingly, eggs exposed to sub-optimal gas exchange have reduced hatching success. We tested the association between eggshell GH2O and putative life-history correlates of adult birds, ecological nest parameters and physical characteristics of the egg itself to investigate how variation in GH2O has evolved to maintain optimal water loss across a diverse set of nest environments. …

Naïve Hosts Of Avian Brood Parasites Accept Foreign Eggs, Whereas Older Hosts Fine-Tune Foreign Egg Discrimination During Laying, Csaba Moskát, Miklós Bán, Mark E. Hauber

Publications and Research

Background: Many potential hosts of social parasites recognize and reject foreign intruders, and reduce or altogether escape the negative impacts of parasitism. The ontogenetic basis of whether and how avian hosts recognize their own and the brood parasitic eggs remains unclear. By repeatedly parasitizing the same hosts with a consistent parasitic egg type, and contrasting the responses of naïve and older breeders, we studied ontogenetic plasticity in the rejection of foreign eggs by the great reed warbler (Acrocephalus arundinaceus), a host species of the common cuckoo (Cuculus canorus).

Results: In response to experimental parasitism before the …

Comparative Population Assessments Of Nautilus Sp. In The Philippines, Australia, Fiji, And American Samoa Using Baited Remote Underwater Video Systems, Gregory Jeff Barord, Frederick Dooley, Andrew Dunstan, Anthony Ilano, Karen N. Keister, Heike Neumeister, Thomas Preuss, Shane Schoepfer, Peter D. Ward

Publications and Research

The extant species of Nautilus and Allonautilus (Cephalopoda) inhabit fore-reef slope environments across a large geographic area of the tropical western Pacific and eastern Indian Oceans. While many aspects of their biology and behavior are now well-documented, uncertainties concerning their current populations and ecological role in the deeper, fore-reef slope environments remain. Given the historical to current day presence of nautilus fisheries at various locales across the Pacific and Indian Oceans, a comparative assessment of the current state of nautilus populations is critical to determine whether conservation measures are warranted. We used baited remote underwater video systems (BRUVS) to make …

Early Back-To-Africa Migration Into The Horn Of Africa, Jason A. Hodgson, Connie J. Mulligan, Ali Al-Meeri, Ryan L. Raaum

Publications and Research

Genetic studies have identified substantial non-African admixture in the Horn of Africa (HOA). In the most recent genomic studies, this non-African ancestry has been attributed to admixture with Middle Eastern populations during the last few thousand years. However, mitochondrial and Y chromosome data are suggestive of earlier episodes of admixture. To investigate this further, we generated new genome-wide SNP data for a Yemeni population sample and merged these new data with published genome-wide genetic data from the HOA and a broad selection of surrounding populations. We used multidimensional scaling and ADMIXTURE methods in an exploratory data analysis to develop hypotheses …