Other Ecology and Evolutionary Biology Commons^™

Cell Volume As A Determinant Of Virus-Mediated Population Growth In Ciliates, Jace Miller, John Paul Delong Phd

Honors Theses

Many protists and other small aquatic organisms consume virus particles, a behavior known as virovory. Some species of protists, such as the ciliate Halteria grandinella, can grow and divide using viruses as their sole food source. Other ciliate species have previously been shown to consume large quantities of viral particles, but it is unclear if they are able to support population growth with viruses alone. Because large ciliates have a higher energy demand, we hypothesize that they will be unable to support population growth on a virus-only diet. We fed nine ciliate species a diet of chloroviruses and found …

Hybrid Viability: An Analysis Of Drosophila Hybrid Competition And Mating Success Amongst Its Parental Species, Konrad Drzymalski

Honors Theses

The topic of hybrid offspring viability and mating preference between the two parental species of Drosophila athabasca (West Northern) and Drosophila mahican (Eastern A) is a still largely unexplored avenue of study. While the two aforementioned parental Drosophila species exist in distinct geographical regions across North America, they occupy a sympatric zone in the North East. Due to the absence of hybrid offspring in nature and the high levels of sexual isolation between these two parental species, it is necessary to establish if, and how hybrid offspring suffer in nature. By utilizing no choice mating systems involving audio playback of …

An Experiment To Test For Rapid Evolution In An Introduced Ectomycorrhizal Symbiosis, Valerie Rewa

Honors Theses

The rapid evolution of introduced ectomycorrhizal-plant partnerships is an under- explored topic that may have immense impacts on ecosystems around the world. This experiment sought to identify and quantify this evolution and its impacts on both fungal colonization as well as plant growth. I used a laboratory experiment to analyze these factors in native and exotic genotypes of Suillus cothurnatus and Pinus species. Much of the data was not able to be collected, but that which was did not support the presence of rapid evolution in the mutualistic partnership. Pine species was seen to have a significant effect on plant …

Density Dependent Growth Of Pseudomonas Fluorescens In The Presence And Absence Of C. Elegans Predation In Liquid Media, Jack Landmann

Honors Theses

The purpose of this study was to understand the predator-prey relationship between C. elegans worms and P. fluorescens bacteria in liquid media. We were aiming to create a predation model of the relationship between these two species.

This study was performed through three experiments. Using 96-well plates, we were able to measure the change in optical density (OD) of these wells and calculate the growth rate. This growth rate was then graphed and analyzed. The first experiment contained P. fluorescens and KB liquid media, this study demonstrated that the bacterial population has a carrying capacity. We were also able to …

Warming Stimulates Sporulation Rates And Alters Community Structure Of Litter-Associated Fungi In Streamside Channel Experiment, Kaitlin D. Beasley-Polko

Honors Theses

Fungi, such as aquatic hyphomycetes, are important decomposers of plant litter in temperate forested headwater streams providing energy and nutrients for the higher trophic levels in these ecosystems. According to current climate change predictions, stream water temperatures are expected to rise significantly in the near future. This project addressed the effects of temperature on sporulation rates and community structure of aquatic hyphomycetes on substrates of different carbon quality (maple and rhododendron leaf litter and wood veneers). The experiment was conducted in streamside channels fed with stream water (ambient, +2°C and +4°C) and set up to mimic small streams. We found …

Impact Of The North American Monsoon On Molt Migrant Passerines, Liuqingqing Yang

Honors Theses

Breeding, molt, and migration place considerable yearly demands on migrating passerines in North America. Due to conflicts in energy allocation, many species have evolved migration strategies that prevent temporal overlap in these processes. However, there is recent evidence that some passerines which breed in western North America migrate to intermediate stopover sites to carry out molt, conflating molt and migration. Factors influencing the evolution of such a strategy are believed to include both aridity on breeding grounds and dependable flushes of late-summer productivity in the southwestern United States and northwestern Mexico. This productivity occurs due to the brisk rainfall of …

An Analysis Of Social Dominance In The Feeding Of Ex Situ Humboldt Penguins (Spheniscus Humboldti), Robert Gabel

Honors Theses

In the field of ecology, complex social structures, including dominance hierarchies, have been demonstrated in a variety of fauna, including bird species. While wild Humboldt Penguins (Spheniscus humboldti) do not exhibit a feeding hierarchy, captive penguins are under very different conditions. Humboldt penguins feed on schooling fish in the wild, but in captivity are hand fed from a zookeeper. I investigated whether there is a nonrandom pattern of dominance in the feeding order of the penguins at the Lincoln Children’s Zoo, in Lincoln, NE, USA. Using a camera and tripod, with assistance from four of the zookeepers, I …

Predation Effects On Mid-Marsh Ribbed Mussel Mortality, Cluster Size, And Facilitation Of Cordgrass Growth, Colten Winter, Keith Walters

Honors Theses

Reciprocal facilitation between Geukensia demissa, ribbed mussels, and Sporobolus alterniflorus, cordgrass, has a positive effect on salt marsh ecosystems. Mussel clusters enhance cordgrass growth and drought resistance and cordgrass provides attachment and shade for mussel aggregations. Along with benefits for both mussels and cordgrass, the mutualism facilitates increased biodiversity and shoreline stabilization and enhances marsh ecosystem functions. Aspects of mussel patch configuration including cluster size, perimeter and connectivity modulate the reciprocal facilitation effects of cordgrass and mussels on marsh ecosystems. In a northern South Carolina marsh system, mussel patch configuration positively influenced cordgrass biomass. Predation affected mussel patch …

Biological Soil Crusts In A Northeastern Pine Barren: Composition And Ecological Effects, Jessica Gilbert

Honors Theses

Biological soil crusts (BSCs), otherwise known as cryptogamic soil crusts, biocrusts, or cyanobacterial crusts, are soil aggregations hosting diverse biotic communities. They are composed of cyanobacteria and algae, and generally have a covering of moss and/or lichen. BSCs are typically found in arid to semi-arid regions throughout the world, and are integral soil stabilizers, moisture retainers, and nitrogen fixers in these communities. Along with these factors, BSCs are able to impact germination and establishment of plants, either as an accompanying influence, or direct result of those listed above. BSCs have yet to be formally described in the inland northeastern United …

Sibship Reconstruction For Inferring The Number Of Breeders Of Gulf Sturgeon In The Apalachicola River, Robbilyn Verges

Honors Theses

The Gulf sturgeon is an anadromous fish that inhabits the Gulf of Mexico and its neighboring river drainages. The species is currently listed as threatened due to habitat alterations and overfishing. In this study, we focused on the Apalachicola River in Florida, which has had several historic spawning locations of the sturgeon blocked by the Jim Woodruff Lock and Dam. Age-1 juvenile sturgeon from the year 2013 (n=31) and 2014 (n=131) were genotyped using fourteen microsatellite loci. Sibship reconstruction and parentage assignment was performed in order to determine the effective number of breeders (Nb) and the total number of spawning …

Olfactory Learning Capabilities Of Paraphrynus Laevifrons, John Perez

Honors Theses

Amblypygids, a species of nocturnal arachnids from the tropics and subtropics are incredibly intelligent and are able to not only navigate through difficult tropical terrain but also, it is believed, possess olfactory learning capabilities that aid in navigation and recollection of environments. It is hypothesized that through sensitive olfactory receptors on their antenniform legs and highly developed mushroom bodies, Amblypygi can not only learn smells but also learn to associate smells with certain stimuli such as a crevice to take refuge in. To test this hypothesis, Paraphrynus laevifrons, a species of amplypygid was subjected to four different learning treatment groups …

Biomass Energy At Colby College, Rachel E. Baron

Honors Theses

In light of growing concern regarding the effects of global climate change, Colby College signed the American College and University Presidents’ Climate Commitment (ACUPCC) in 2008. Through this pledge, Colby has committed to reducing carbon emissions in its Climate Action Plan (IPCC 2007; CCAP 2010). The College seeks to be carbon neutral by 2015 (CCAP 2010). This will be accomplished through a variety of mechanisms, one of which includes the construction of a biomass facility to replace most of the oil currently used for heating (CCAP 2010).

Anthropogenic global climate change has been documented by many scientists, but was widely …