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Biogeographic Relationships of Pocket Gophers (Geomys breviceps and Geomys bursarius) in the Southeastern Portion of Their RangesElrod, Douglas Allen 08 1900 (has links)
This research utilized population genetic analyses (protein starch-gel electrophoresis and DNA sequencing of the cytochrome b mtDNA gene), host-parasite specificity (lice coevolution), remote sensing of satellite data, and geographic information systems (GIS) to characterize newly discovered populations of pocket gophers (genus: Geomys) in Arkansas. These populations are isolated and occur in seemingly unsuitable habitat in the Ozark Mountains of Arkansas. Analyses of electrophoretic and ectoparasite data suggested the populations in the Ozark Mountains represented isolates allied to Geomys bursarius, a species not known to occur in Arkansas. Comparison of mitochondrial DNA sequence data of the cytochrome b gene with that of other taxa and morphometric analyses confirmed that these populations are most closely allied to G. bursarius occurring to the north in Missouri. Moreover, these mtDNA sequence analyses indicated a degree of differentiation typical of that between other subspecies of pocket gophers. Therefore, these populations represent a distinct genetic entity in an intermediate stage of speciation and should be designated as a new subspecies, Geomys bursarius ozarkensis. Molecular clock analysis revealed a time of lineage divergence for this new subspecies as approximately 511,000 YBP. Due to the isolated nature and limited distribution of this subspecies, an evaluation of critical habitat needs was initiated. Remote sensing and GIS technologies were used to identify and describe suitable habitat Computerized classification of satellite imagery of suitable vegetation, integrated with ancillary digital information on soil associations, roads, and water systems, revealed that human activity had played a positive role in the establishment and dispersal of pocket gophers in this area. This research represents an initial combination of classical systematic tools with remote sensing and GIS to investigate biogeographic patterns and evolution. This project establishes a framework for using an interdisciplinary approach to studying organisms with limited distributions, determining evolutionary status, and providing recommendations for conservation.
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Geographic variation in transposable elements and isozymes in Southern African populations of drosophila melanogaster.Getz, Chonat Greer Louise January 1990 (has links)
A thesis submitted to the Faculty of Science,
University of the Witwatersrand, Johannesburg
for the Degree of Doctor of Philosophy. / This thesis reports on the investigation of two genetic aspects of Southern African populations of Drosophila Melanogaster:
the " family of transposable elements and the allelic variation
present in several enzyme systems. (Abbreviation abstract) / Andrew Chakane 2018
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Distribution change in South African frogsBotts, Emily Anne 01 February 2013 (has links)
Range change is a common species response to global change. Comparing historical species distribution data with recent biological surveys has the potential to quantify changes to species geographic ranges. However, the broad-scale sampling strategies typically employed to acquire primary species distribution data are prone to errors of omission. The aim of this study was to evaluate the South African Frog Atlas Project (SAFAP) as a means for detecting changes in amphibian species distributions and to relate observed range changes to extrinsic environmental factors and intrinsic species characteristics. The SAFAP provided historical (1905 – 1995) and recent (1996 – 2003) species distributions of the amphibians of South Africa. Geographic sampling bias in the dataset was assessed by relating collection density and species richness to hypothesised sources of bias. Several methods for managing differing sampling intensity were tested on hypothetical ranges. The best methods were applied to the South African species to investigate range dynamics. Changes to the size of species ranges and shifts in mean range centre were assessed. An Ecological Niche Factor Analysis provided comparative measures of climate and habitat niche breadth for each species. SAFAP sampling was concentrated around cities, roads and protected areas, resulting in relatively overestimated species richness and range sizes near to these features. Large parts of the arid northwestern regions were under-sampled. An increase in sampling intensity over time resulted in the false detection of range expansions. The most reliable method to correct for increased sampling was a mathematical correction factor, according to which, 60.2% of South African frog species have undergone range contractions. Upslope shifts of 47.6 m were found for South African species and species of the Bushveld region shifted towards an area of Savanna Biome resilience. While several of the observed changes to species ranges were consistent with global change predictions, southern hemisphere amphibians may show a differing response to global change to that which is commonly predicted. Small range size, habitat specialisation and climate specialisation were significant predictors of range contractions for all species. Contracting habitat specialists were concentrated within two areas of endemism that also had high levels of land transformation. The use of methods that correct for sampling variation has allowed the SAFAP to be valuable in investigating species range change.
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Foraging ecology of wading birds in a sub-tropical intertidal zoneUnknown Date (has links)
The first of five chapters describe the study area and study species, including a short description
about the impetus for this research. The second chapter describes a unique hydrologic model for application
in tidal ecosystems. The second chapter represents new information on the effects of various abiotic and
biotic factors on foraging wading birds in this highly dynamic environment. The third chapter identifies
important factors affecting the abundance of foraging wading birds in intertidal environments. The fourth
chapter presents a study of the foraging habitat preferences of two wading bird species in intertidal
environments. The fifth chapter describes a conceptual model of wading bird foraging ecology and a
predictive model of foraging habitat in intertidal zones. The conceptual model captures the major drivers
and linkages between the abiotic and biotic variables thought to affect wading bird foraging abundance in
intertidal habitats. The conceptual model also identifies major knowledge gaps in our understanding of
foraging ecology of wading birds in coastal intertidal areas. The predictive model of foraging habitat is
meant to be used by resource managers, but its framework may be useful for ecological studies in general.
The final and sixth chapter provides a summary of all the major findings. Each chapter has been written so
as to be independent of the other chapters. As such, a full background, along with a discussion of the
relevance of the chapter's findings is provided for each chapter. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
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Morphology of Astarte borealis (Mollusca: bivalvia) of Camden bay, northern AlaskaUnknown Date (has links)
The genus Astarte is known for variable shell morphology and polymorphism
within living and fossil species. Astarte borealis, the most common living species, is
recognizable and common among mid-to-high latitude North Pacific, Arctic Ocean and
North Atlantic waters, and has been divided into many subspecies and varieties based on overall shell shape. A collection of recent A. borealis specimens from Camden Bay,
northern Alaska (641 specimens) with outline intact were used for analyses. Bivariate
analysis of height vs. length and morphometric analysis of shell outline determined
variants within a population of A. borealis, and then compared to Pliocene A. borealis
and Oligocene A. martini. The computer program SHAPE uses elliptic Fourier
coefficients of shell outline to evaluate and visualize shape variations. The multivariate outline analysis indicates that A. borealis intraspecies variation is based upon a common
shape that grades into other shapes, rather than grade between two or more end-forms. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2013.
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Spatial and temporal distributions of sea turtles within the Florida current and surrounding watersUnknown Date (has links)
Assessing the spatial and temporal distributions of marine turtles in an open
system poses both observational and analytical challenges due to their migratory nature
and use of large current systems. Concentrations of animals can shift because turtles
undergo large-scale migrations and habitat shifts seasonally as well as a function of lifestage.
Surface counts of marine turtles in waters off Florida’s east coast were made in
and adjacent to the Florida Current using standard aerial surveys. While it is understood
that marine turtles use waters off the eastern coast of Florida, here we document the
magnitude of the shift in turtle presence each season throughout a two year study and
identify habitat characteristics where turtles occur most frequently. Our assessment of
marine turtles in the waters off southeast Florida provide valuable metrics describing the
in-water biology of sea turtles in this area to inform future management strategies of
these endangered species. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
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Análise do índice de instalação de empresas no município de Osasco utilizando sistemas de informação geográfica e análise envoltória de dados - DEA. / Instalation index analysis of companies in Osasco\'s municipal district using geographical information system and Data Envelopment Analysis -DEA.Almeida, George Eduardo Serra 28 August 2006 (has links)
Este estudo apresenta uma análise sobre a aplicação do geoprocessamento integrado à técnica de Análise Envoltória de Dados (Data Envelopment Analysis - DEA), relacionada a distribuição espacial de empresas em unidades produtivas representadas por áreas de zoneamento do solo urbano, utilizando dados socioeconômicos multitemporais. O trabalho tem como área de estudo o Município de Osasco, localizado na Região Metropolitana de São Paulo, que faz parte do trecho Oeste do Sistema Viário Rodoanel Mário Covas. Desta forma, a análise de instalação de empresas nos períodos anterior e posterior a implantação do sistema viário Rodoanel, poderá servir de apoio na avaliação de mudanças ou transformações empresariais (indústria, comércio e serviços) no uso e ocupação do solo no Município de Osasco. De uma forma mais específica, o estudo buscou avaliar a influência dos fatores espaciais no processo de localização e migração de empresas, focando em alterações no uso do solo com ênfase no zoneamento do município e em função da melhoria de infra-estrutura relacionada à construção de uma grande obra viária e tomando como base períodos de tempo e situações urbanas distintas. Para traçar este panorama foram utilizadas informações sócioeconômicas, dados cadastrais de empresas e o zoneamento municipal associadas a dados geográficos, os quais permitiram compor cenários multitemporais de cada momento urbano. Estes cenários foram representados e analisados no capítulo de resultados utilizando o índice de instalação de empresas em conjunto com as analises espaciais do SIG, que proporcionou uma análise temporal quantitativa da distribuição de empresas no Município de Osasco. / This study presents an analysis on GIS application integrated to Data Envelopment Analysis - DEA, related to spatial distribution of companies in productive units represented by zoning areas of the urban land and using socioeconomic data of different time periods. The work has Osasco\'s Municipal district as the area of study, located in São Paulo\'s Metropolitan Region, it makes part of the west section of the Mário Covas Rodoanel road system. Thus, the analysis will support in the changes evaluation or managerial transformations (industries, commerce and services) in the Osasco\'s Municipal district land use, current of the Rodoanel road system implantation. In a more specific way, the study sought to evaluate the influence of the space factors in the companies location and migration process, focusing on alterations in the land use with emphasis in the municipal district zoning and in infrastructure improvement function related to construction of a big road and taking as time\'s base periods and distinct urban situations. To trace this panorama were used socioeconomic information, cadastral data of companies and the municipal zoning associated to geographical data, to compose urban scenarios in different time periods. These scenarios were represented and analyzed in the results chapter using the companies installation index together with Spatial GIS Analysis, who provided a quantitative temporal analysis of distribution of companies in Osasco\'s Municipal distritct.
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Plant conservation in space, time and a changing world : forecasting the fate of Coffea arabica in EthiopiaMoat, Justin January 2018 (has links)
We are facing an ever-increasing environmental crisis on our planet, with multiple threats from humankind. Industrialisation, deforestation, overpopulation and exploitation of our natural resources is driving species to extinction and changing the environment we live in. We need to plan for the future in order to adapt or mitigate these risks. Recent advances in computing and analytical techniques, plus the rise of readily available spatial data, provide us with a means to understand the complex interactions between species, environmental change and human activity. Coffea arabica (Arabica coffee) is a critically important crop species in several tropical countries. Globally its export value is over $13 billion dollars per year. Wild populations of this species are of immense importance to the global coffee sector, due to the traits associated with the standing genetic diversity, such as disease resilience, new flavour profiles, and agronomically favourable morphological variation (root length; compact habit). In its countries of origin, Ethiopia and South Sudan, the wild species provides the planting stock for a multi-million-dollar export sector. Arabica coffee is well known across the globe, as the increasingly popular beverage coffee. The ubiquitous cultural nature of coffee drinking means that coffee acts as a flagship species for demonstrating science and the benefits of conservation and sustainable use, enabling the findings of this thesis to gain traction with a wider audience, who might otherwise not engage with research and social and environmental issues. Coffea arabica is greatly influenced by climate. The wild and cultivated variants of this species are restricted to a relatively narrow climate niche, within Ethiopia and anywhere where it is cultivated. Coffee production is considerably influenced by changes in rainfall, temperature or seasonality. Ethiopia has already experienced climate change; mean temperatures from the 1960s onwards show an average increase of 0.28 °C per decade, a shortening wet season, and an increase in the number of hot days. The continuation of this rapid change in climate will influence both wild populations and production of Arabica coffee in Ethiopia. Within this thesis I forecast the fate of wild and cultivated Arabica coffee in Ethiopia, under climate change, reviewing risks and opportunities from the recent past until the end of the century. To do this I developed several novel methods, which are initially used to project the future of wild and cultivated coffee cultivation in Ethiopia. For the wild species, I have developed several new spatial techniques, particularly dealing with the issue of the “modifiable areal unit problem” within species extinction risk assessments. I have updated and refined existing techniques into one package, allowing multiple future climate scenarios/projections to be processed and assessed quickly. I present my scientific findings in the form of five submitted manuscripts (see ‘List of original articles’, on p.8). Using the findings, results and recommendations from these papers, I repurpose the outputs and impact of the science, graphically and within various media (including two more manuscripts, media and social media), for multiple audiences. Using these spatial techniques and visualisations, I show the impact climate change will have on Arabica coffee in Ethiopia, both as a crop and as a wild species within the humid forests of the country. I show that the present coffee-growing areas could be reduced by up to 60% if no interventions are made, but conversely, that there is an opportunity to increase the coffee growing area of Ethiopia four-fold if the right actions are taken. For wild Arabica coffee I show that the species is threatened with extinction due to climate change. Specifically, I show that wild Arabica coffee would be assessed as Least Concern (under little or no risk; IUCN Extinction Red List) if climate change is not factored in, as opposed to Endangered (threatened with extinction) if climate change is included in an extinction risk assessment. The work in this thesis demonstrates the power of spatial analysis, modelling, and high data quality, for plant conservation.
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Biogeographical History of North American Wood Warblers and the Assembly of the North American Avian BiotaSanin, Camilo January 2017 (has links)
Differences in patterns of species richness and taxonomic composition across continents are well documented. However, less is known about how these patterns originate from the fundamental processes that contribute to the assembly of continental biotas: speciation, extinction, immigration, and emigration. To truly decipher how these processes operate at a continental scale, it is crucial to understand how Earth-history events and environmental change shaped the biogeographical history of the taxa occurring in a region.
The Pleistocene glacial cycles have been hypothesized to be a significant geological event which affected the Earth’s biota over the past three million years. During this period, multiple cycles, in which ice sheets covered a large portion of the Northern Hemisphere, have been hypothesized to facilitate allopatry and ecological differentiation. The central goal of this dissertation is to understand the assembly of continental biotas by integrating the role of Earth’s geological and environmental history and recent (late Quaternary) changes in distributions.
Here, I studied the North American wood-warblers, which are passerine birds belonging to the family Parulidae. In the first chapter of this dissertation, I examined the extent to which recent diversification is underestimated by ignoring recently diverged taxa. To do so, I evaluated the effect of taxonomic delimitation on the inferred temporal patterns of diversification of wood-warblers in the genus Setophaga. My results show that species-level taxonomic delimitation in ecological and evolutionary studies is crucially important but is often ignored. Evaluating the effect of taxonomic delimitation in the genus Setophaga is particularly relevant because it has been widely cited as an ideal example of niche saturation, and previous studies suggested that lineages in this particular radiation exhibited an asymptotic accumulation of diversity through time. In this chapter, however, I demonstrate that this pattern was likely a consequence of the ways in which taxonomic diversity was sampled.
In the second chapter, I examined how biotic and abiotic factors limit the distribution of species of the genus Oreothlypis at a continental scale. For most of the taxa examined, climatic- and biotic-based areas of suitability were equivalent, and therefore the relative importance of these factors could not be disentangled. However, in some cases, biotic variables limited the distribution in areas climatically suitable, and vice versa. The results of this chapter highlight the importance of considering potential effects of biotic interactions in the study of climate-driven range shifts. This paper is also an important methodological contribution to the general field of ecological niche modeling (ENM) by integrating climatic and palynological data to empirically estimate both abiotically and biotically suitable areas which that has only been done theoretically so far.
In the third chapter, I integrated phylogenetic data, biotic and climatic ENMs, and reconstructions of environments during the LGM to test how cycles of fragmentation, differentiation, and expansion during the Pleistocene shaped the biogeographical patterns of the genus Oreothlypis in North America. Based on a time-calibrated phylogeny I identified two groups of taxa that diversified during the last million years and therefore were potentially affected by glacial cycles. My analyses suggest that there were rapid switches in the environmental conditions in which species of the genus occur and that glacial cycles resulted in dramatic range shifts from glacial maxima to interglacials. Distribution patterns during the LGM suggest that divergence in areas isolated by glaciers presumably contributed to the geographical structuring of Oreothlypis, as well as to their taxonomic and ecological diversity in the present.
In summary, this work illustrates how wood-warblers are an ideal model system for examining the large-scale history of the North America biota and environment, particularly over the Pleistocene. They are highly diverse, have endemics in virtually all of North America's areas of endemism and ecosystems, and many of these patterns are repeated within and across clades. Furthermore, distributional patterns in warblers show high congruence with those of other organisms; thus inferences made about the history of this group likely have implications for understanding the biotic history of North America in general. In addition, many warblers have narrow ecological preferences in that they occupy forest environments with specific tree compositions. As a consequence, ecological models of their distributions, integrated with the North American pollen record of forest change, provide a new perspective on ecosystem change during glacial cycles, and its impact on the origin and maintenance of biodiversity in the continent.
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Composição, distribuição batimétrica e estrutura da assembleia de ermitões (Crustacea, Anomura) em uma área do litoral sudeste brasileiro influênciada pelo fenômeno da ressurgênciaLima, Israel Fernandes Frameschi de. January 2015 (has links)
Orientador: Adilson Fransozo / Banca: Katia Aparecida Nunes Hiroki / Banca: Aridiane Cristine Almeida / Banca: Rogério Caetano da Costa / Banca: Antonio Leão Castilho / Resumo: Não disponivel / Abstract: Not avaliable / Doutor
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