Population Biology Commons^™

Historical Diversification Of Montane Herpetofauna Within And Between The Sierras Of Mexico, Robert William Bryson Jr.

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Mexican highlands consist of four major mountain ranges spanning most of mainland Mexico. The evolutionary history of the Mexican highlands has been shaped by various geological and climatic events over the past several million years. The relative impacts of these historical events on diversification in montane taxa, however, remains uncertain. I used mitochondrial DNA data from three widely distributed species complexes of lizards as a model system to exemplify the potential roles of Neogene mountain formation and Quaternary climate change on timing and tempo of diversification across the Mexican highlands. My results suggested strong geographic partitioning of genetic variation …

Phylogeography Of A Vanishing North American Songbird: The Painted Bunting (Passerina Ciris), Connie Ann Herr

UNLV Theses, Dissertations, Professional Papers, and Capstones

Studies of genetic variation within and between species can provide insights into their evolutionary history as well as important information for conserving biodiversity. An understanding of population processes can assist in the conservation of biodiversity by contrasting current versus historical patterns, and the processes that have generated these patterns. Genetic differentiation often coincides with significant geological or climatic changes that have shaped the sizes and locations of the species geographic range and altered the connectivity between populations over time. Phylogenetic and population genetic analyses can also provide a statistical framework for the investigation of how human processes such as habitat …

The Distribution And Life Cycle Of Alliaria Petiolate In Lincoln, Nebraska, Caleb Pharris

Department of Environmental Studies: Undergraduate Student Theses

Alliaria petiolata (Garlic Mustard) is a biennial alien invasive plant species of the Brassicacea family. It is responsible for displacing native plant species throughout North America and its management has proven to be extremely difficult. Recently several populations of Alliaria petiolata have been discovered in southwestern Lincoln, Nebraska. The spread of Alliaria petiolata is a concern for natural resource managers and the general public. Due to the difficulty of its control, Alliaria petiolata is capable of creating monocultures which diminish the aesthetic value of an ecosystem. While most commonly found in the understory of hardwood forests, it is capable of …

Herbicide-Resistant Risk Assessment: Response Of Common Nebraska Weeds To Dicamba Dose, Roberto J. Crespo

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Dicamba-resistant soybeans are being developed to provide an additional herbicide mechanism of action that can be used in soybean, and to provide a tool to help manage or mitigate the evolution of other herbicide-resistant weed populations. The objectives of this thesis were to assess the risk of common Nebraska weeds developing resistance to dicamba, quantify baseline dose-response to dicamba of high-risk weed species, and survey the variability in dicamba dose-response among populations of those species. Twenty-five weed scientists were asked to estimate the risk likelihood of ten weed species evolving resistance to dicamba following the commercialization of dicamba-resistant soybean. Palmer …

Phylogeography Of The Reef Fish Cephalopholis Argus(Epinephelidae) Indicates Pleistocene Isolation Across The Indo-Pacific Barrier With Contemporary Overlap In The Coral Triangle, Michelle R. Gaither, Brian W. Bowen, Tiana-Rae Bordenave, Luiz A. Rocha, Stephen J. Newman, Juan A. Gomez, Lynne Van Herwerden, Matthew T. Craig

Fisheries Research Articles

Background

The Coral Triangle (CT), bounded by the Philippines, the Malay Peninsula, and New Guinea, is the epicenter of marine biodiversity. Hypotheses that explain the source of this rich biodiversity include 1) the center of origin, 2) the center of accumulation, and 3) the region of overlap. Here we contribute to the debate with a phylogeographic survey of a widely distributed reef fish, the Peacock Grouper (Cephalopholis argus; Epinephelidae) at 21 locations (N = 550) using DNA sequence data from mtDNA cytochrome b and two nuclear introns (gonadotropin-releasing hormone and S7 ribosomal protein).

Results

Population structure was significant …

Patterns Of Transience, Sex Bias, And Body Mass In Open-Habitat Rodent Populations, Stephen Edward Rice

Biological Sciences Theses & Dissertations

Rodents are assumed to live their lives in circumscribed (natal) areas with males being more prone to disperse than females and juveniles more prone to disperse than adults. To test these assumptions we examined the initial captures of geographic populations of hispid cotton rat, meadow vole, prairie vole, and marsh rice rat obtained through capture-mark-recapture methods. Capture records were obtained from Kansas and Illinois from long-term studies, and through live-trapping in Chesapeake, Virginia. I evaluated proportions of residents and transients, adults and juveniles, and males and females for significant differences among seasons, years, and geographic locations. The overall body masses …

Biology, Systematics, Phylogenetic Analysis And Dna Character-Based Species Diagnosis Of The False Root-Knot Nematode Nacobbus Aberrans (Thorne, 1935) Thorne & Allen 1944 (Nemata: Pratylenchidae), Angel Ramirez-Suarez

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The False Root-Knot nematode Nacobbus aberrans is a plant parasitic nematode that causes yield losses in several crops and plant protection agencies have established regulations to prevent infestations from spreading to new agricultural areas. The taxonomic status of the nematode has been the subject of controversy due to wide degree of variation exhibited by the species. This variability has led to the suggestion that N. aberrans is actually a species complex rather than a single species. In order to test this hypothesis, we compared twelve N. aberrans populations, which include isolates from western Nebraska, two distinct regions of Mexico and …

Influence Of Wave Action On Mytilus Californianus Mussel Beds, Jaclyn Mann

Biological Sciences

No abstract provided.

Life History Benefits Of Residency In A Partially Migrating Pond-Breeding Amphibian, Kristine L. Grayson, Larissa L. Bailey, Henry M. Wilbur

Biology Faculty Publications

Species with partial migration, where a portion of a population migrates and the other remains residential, provide the opportunity to evaluate conditions for migration and test mechanisms influencing migratory decisions. We conducted a five-year study of two populations of red-spotted newts (Notophthalmus viridescens), composed of individuals that either remain as residents in the breeding pond over the winter or migrate to the terrestrial habitat. We used multistate mark-recapture methods to (1) test for differences in survival probability between migrants and residents, (2) determine if migrants breed every year or skip opportunities for reproduction, and (3) estimate the frequency …

Botteri's Sparrow (Peucaea Botterii) Occurs In Northern Coahuila, Mexico, Paul Van Els, Ricardo Canales-Del-Castillo, John Klicka

Ornithology Program (HRC)

Botteri’s Sparrow (Peucaea botterii) occurs widely in the shrub-grasslands of southern North America. We report a breeding population of the species in the Sierra de la Encantada of northern Coahuila, Mexico, ~80 km from the Big Bend area of Texas and >300 km from the nearest previously known breeding range in southern Coahuila and central Chihuahua. We captured three individuals, which show a mostly gray dorsal coloration, suggestive of the texana subspecies, occurring from southern Texas to northern Veracruz. The exact affinity of the northern Coahuila population still needs to be ascertained. The presence of Botteri’s Sparrow in northern Coahuila …

Population Dynamics Of The Western Prickly Pear, Opuntia Macrorhiza (Cactaceae), Kathleen H. Keeler, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

Although most cacti that have been studied are long lived, following individually marked plants in Boulder County, Colorado, for >7 years, we determined that average life span of Opuntia macrorhiza, the western prickly pear, is 3 years. A few individuals probably live >10 years. Vegetative reproduction, produced by rooting of cladodes, exceeded reproduction by germination and establishment from seeds. Both types of new recruits, from vegetative reproduction and seeds, had higher death rates than established plants. Size and frequency of flowering increased with age, although size both increased and decreased, sometimes dramatically, between years. Flowering correlated more strongly with …

The Role Of Historical And Contemporary Processes On Phylogeographic Structure And Genetic Diversity In The Northern Cardinal, Cardinalis Cardinalis, Brian T. Smith, Patricia Escalante, Blanca E. Hernandez-Banos, Adolfo G. Navarro-Siguenza, Sievert Rohwer, John Klicka

Ornithology Program (HRC)

Background

Earth history events such as climate change are believed to have played a major role in shaping patterns of genetic structure and diversity in species. However, there is a lag between the time of historical events and the collection of present-day samples that are used to infer contemporary population structure. During this lag phase contemporary processes such as dispersal or non-random mating can erase or reinforce population differences generated by historical events. In this study we evaluate the role of both historical and contemporary processes on the phylogeography of a widespread North American songbird, the Northern Cardinal, Cardinalis cardinalis …

A Mark–Recapture Technique For Monitoring Feral Swine Populations, Matthew M. Reidy, Tyler A. Campbell, David G. Hewitt

United States Department of Agriculture Wildlife Services: Staff Publications

Techniques to monitor populations of feral swine (Sus scrofa) relative to damage control activities are needed on rangelands. Our objectives were to describe and assess a mark–recapture technique using tetracycline hydrochloride (TH) for monitoring feral swine populations. We established bait stations at study sites in southern and central Texas. During 1 d, we replaced normal soured corn bait with bait containing TH and counted the number of feral swine that consumed bait with observers. We conducted feral swine removal using box-style traps and helicopters, at which time we collected teeth for TH analysis. In southern Texas, we estimated …

The Decline And Conservation Status Of North American Bumble Bees, Jonathan Berenguer Koch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Several reports of North American bumble bee (Bombus Latreille) decline have been documented across the continent, but no study has fully assessed the geographic scope of decline. In this study I discuss the importance of Natural History Collections (NHC) in estimating historic bumble bee distributions and abundances, as well as in informing current surveys. To estimate changes in distribution and relative abundance I compare historic data assembled from a >73,000 specimen database with a contemporary 3-year survey of North American bumble bees across 382 locations in the contiguous U.S.A. Based on my results, four historically abundant bumble bees, B. …

Does Thermal Stress Cause Females Of The Plant Bryum Argenteum To Manipulate The Sex Ratios Of Their Offspring?, Elisha Rhodes, Lloyd Stark

Festival of Communities: UG Symposium (Posters)

About half of all moss taxa exhibit female-biased sex ratios, and bryophyte male rarity remains largely unexplained. One possible explanation is differential stress tolerance of spores due to maternal sporophyte manipulation during stress. To test this hypothesis, sporophytes of the species Bryum argenteum were subjected to thermal stress and observed for growth abnormalities and sporophyte abortions. Data display a correlation between increased temperature and increased sporophyte abortions as well as increased time to complete meiosis, possibly indicating decreased fitness. Continued global warming may create more stressful environments for sporophytes resulting in the elimination of males from local populations.

Review Of Nature's Ghosts: Confronting Extinction From The Age Of Jefferson To The Age Of Ecology. By Mark V. Barrow, Jr., Peter A. Bednekoff

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

The saving of bison occupies a central place in Nature's Ghosts, but Mark Barrow's chronicle extends over a century both before and after. The story starts with Thomas Jefferson and fossils that came to be recognized as mastodons, mammoths, and giant ground sloths. "Jefferson and most of his contemporaries were certain that the natural world was orderly, static, and new." In such a worldview, extinction was unthinkable. Fossil evidence plus the historical extinctions of dodos, moas, and great auks forced reconsideration.

This book ranges across centuries and continents, and only a few parts of it are explicitly about the Great …

Health And Fertility Implications Related To Seasonal Changes In Kidney Fat Index Of White-Tailed Jackrabbits In South Dakota, Dustin Schaible, Charles D. Dieter

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

White-tailed jackrabbit (Lepus townsendii) populations in the Northern Plains have been in a general decline for the past decade or longer. A suggested reason for this population decline was reduced body condition of individual jackrabbits due to habitat changes. In order to evaluate body condition, we determined the kidney fat index of 314 white-tailed jackrabbits harvested in 44 counties throughout South Dakota. We removed and weighed kidneys and all perirenal fat associated with the kidneys from collected jackrabbits. We measured kidney weight to determine times of high metabolic activity as indicated by an increase in mass. Body condition was …

Governance Of The Western Rock Lobster Fishery And Marine Stewardship Council Principle 3 Effective Management, Department Of Fisheries

Fisheries Occasional Publications

No abstract provided.

Multilocus And Parametric Analyses Of The Evolutionary History Of The Amazonian Peacock Cichlids, The Genus Cichla (Teleostei: Cichlidae), Stuart Clayton Willis

School of Biological Sciences: Dissertations, Theses, and Student Research

Accurate knowledge of species boundaries and species phylogeny are fundamental to testing hypotheses of recent evolutionary processes, but the estimation of these partitions is challenging due both to inherent confusion about what is being estimated as well as the data available to estimate them. Using multilocus data from mtDNA, microsatellites, and nuclear locus sequences of over 1100 individuals, we delimited eight separately evolving species of Cichla rather than the 15 described. Among species we found evidence of rare but widespread introgressive hybridization, while within these species we observed evidence of long-term gene exchange and constrained evolutionary trajectories. In most cases …

Effects Of Water Quality On Genetic Variation On The Brackish-Water Rotifer Brachionus Plicatilis, Kayla I. Hinson^, Elizabeth J. Walsh*

COURI Symposium Abstracts, Spring 2011

Impacts of water quality on the genetic structure of aquatic organisms have not been well characterized. Unfavorable conditions may result in loss of species diversity and/ or select for tolerant genotypes. We investigated whether aquatic pollutants affect the genetic diversity of the rotifer Brachionus plicatilis, common in saline systems. We predict that the genetic diversity of B. plicatilis will decrease with lower water quality. An urban population (Ascarate Lake, El Paso Co., TX) was compared with a non-impacted population (Figure 8 Lake, Bottomless Lakes, NM). Basic water chemistry parameters were measured along with heavy metals concentrations. Genetic variation is …