No description available.

No description available.

Alligatorines are a diverse clade of crocodylians whose history spans the entire Cenozoic. They are suited to answer a variety of questions with far‐reaching impacts due to their physiology and preservation potential, and have been the subject of several phylogenetic, biogeographic, and diversity analyses. However, prior phylogenetic analyses had poor resolution and several putative alligatorines have never been included, while other analyses would be more informative and accurate if viewed through the context of evolutionary history. Here, I analyze the phylogenetics, taxonomy, biogeography, ecomorphology, and diversity dynamics of alligatorines. An almost fully resolved phylogenetic hypothesis returns two major clades within Alligatorinae and includes several putative alligatorines not previously analyzed. The clade originated in North America and dispersed to Europe and Asia three to five times via at least three different corridors at high latitudes when climate—and potentially salinity—were favorable, likely including the recently discovered subaerial Lomonosov Ridge. The modern American alligator is a dietary generalist, but evolved from a durophagous specialist, contrary to the intuitive reasoning of the “Law of the Unspecialized”. It was able to do so by entering the generalist niche vacated by basal crocodyloids following their extirpation from mid‐latitude North America. Alligatorine diversity only weakly tracks climate change and does not track the rock record excepting swampy environments. Alligatorine diversity correlates with climate change. Climate change correlates with rocks, though in a more complicated pattern. Some diversity metrics correlate with some aspects of the rock record, but predominantly do not. There is more support for the common‐cause hypothesis than for rock record bias driving apparent alligatorine diversity. Overall, alligator evolution exhibits a pattern of being more diverse taxonomically and morphologically when the climate is warmer, and dispersing during the warmest and wettest of those times.

Literature is a deeply personal and interpersonal act from the author to the reader. In some way the author is attempting to capture their interpretation of space and time inside the vehicle of language. Through metaphor and enjambment, syntax and imagery, this thesis attempts to render the contemporary experience of the artist as he is grounded in location and interpretation. The lens used in inspecting the world is biological and philosophical, seeking and hiding from the truth. Nature and science are used as linking languages in the collections of poems, seeking to be united with emotion based in the bedrock of Kentucky. Poetry is ephemeral in its brevity, but concrete in the impressions it can leave with the reader. The author has attempted to render the facts as he observed them in language which is specifically universal. No one else could have participated in the experiment of research, but all are welcome to share in the observations. Kentucky is the pivotal element in this research. Experimentation was made with other locations, but the sense of place that can only be found in these hills provides the fertilizer for the elements of literary art to flourish. The author seeks to enrich the landscape that has created him, and to provide a snapshot of this land and its people.

Population genetic structure is difficult to assess in blow flies (Diptera: Calliphoridae) due to high connectivity and genetic diversity of subpopulations. Previous studies revealed high relatedness among individuals within wild samples of blow fly populations, however broad geographic structure was absent. The aim of this research was to determine if blow fly genetic structure exists at a fine spatiotemporal resolution and, if so, to elucidate the influence of environmental factors and resource availability on fly genetics. Specifically, blow fly population genetic patterns were tested against anull hypothesis that flies adhere to a patchy population model with high genetic diversity (i.e. no structure) and high resource availability. Samples of the black blow fly, <i>Phormia regina</i> Meigen (Diptera: Calliphoridae), were collected at six urban parks in Indiana, USA (=urban) in 2016 and 2017 (N = 14 and 16 timepoints, respectively). Additional sampling in different ecoregions was performed to determine if trends observed at a high-resolution scale were also present at a broad geographic scale. Therefore, <i>P. regina</i> were also collected at four sites within two national parks (the Great Smoky Mountains and Yellowstone National Parks) over a three-day period. Randomly selected females (N = 10) from each sample underwent the following analyses: 1) gut DNA extraction, 2) molecular analysis at 6 microsatellite loci, 3) vertebrate-specific 12S and 16S rRNA sequencing, and, 4) vertebrate fecal metabolite screening. Flies from the national parks and a comparable subset of urban data also underwent stable isotopeanalysis (SIA) to determine larval food source. Overall, strong seasonal population genetic structure was observed over both years in the urban environment (2016 F’_ST= 0.47, 2017 F’_ST0.34), however spatial structure was lacking, as seen in previous studies (2016 F’_ST= 0.04, 2017 F’_ST0.03). Weather conditions prior to and on the day of blow fly collections, interspecific competition, and resource availability greatly impacted the genetic diversity and kinship of <i>P. regina</i>. A total of 17 and 19 vertebrate species were detected by flies in 2016 and 2017, respectively, and many flies tested positive for vertebrate feces, suggesting that many varied resources are important for maintaining high gene flow among geographic locations. Genetic diversity was non-existent in flies collected from the Smokies (F’_ST= 0.00), while very slight spatial structure existed in the Yellowstone populations (F’_ST= 0.07). Environmental factors such as temperature, humidity, and wind speed were all statistically relevant in maximizing fly collections with vertebrate resources. In 720 min of total sampling time in the national parks and a subset of urban data, 28 vertebrate species were identified, and fecal resources appeared to be the most abundant in Yellowstone. Stable isotopeanalysis revealed a majority of larval resources in the national parks were herbivores, with a more even distribution of carnivore and herbivore carcasses present in the urban environment, which likely explains the high genetic diversity of adult flies in these regions. Overall, the null hypothesis that <i>P. regina</i> adheres to a patchy population model could not be rejected for the Smokies populations. However, the urban and Yellowstone populations appear to adhere to a Levins metapopulation model in which variable availability in resources leads to random bottleneck events in the local populations. Overall, environmental conditions, competition, and resource availability are all important factors influencing <i>P. regina </i>population genetic structure in different environments.

Recent theoretical and technological advances in ecosystem science have dramatically expanded the ways in which scientists can pursue and explore ecological questions. For my thesis research, I integrated the recent theoretical concept of organisms as ecosystem engineers with the relatively recent development of stable isotope tracer tests to ask the question: how does the invasive common carp affect stream ecosystem structure and function? To investigate the structuring role of carp, I measured autotroph seasonal distribution and abundance and macroinvertebrate seasonal abundance and diversity within two stream reaches in Spring Creek, Utah, USA; one with low carp biomass (LCB) and one with high carp biomass (HCB). I installed a series of carp exclosures in the HCB reach to examine the response of the stream to carp exclusion. To explore the effects of carp on stream nitrogen dynamics, I performed a three week, continuous injection of 15N as ammonium chloride. The macrophyte and macroinvertebrate community was severely depauperate in the HCB reach compared to the LCB reach. The observed rapid colonization of a relatively abundant and diverse macrophyte and macroinvertebrate community at the carp exclusion sites in the HCB reach not only indicates that carp engineering reduces the abundance and diversity of these communities, but also highlights the importance of the spatial distribution of engineered and non-engineered patches in dictating the temporal scale of re-colonization. Carp engineering had a simplifying effect on stream N dynamics that ultimately limited the uptake and retention capacity of the HCB reach. For example, macrophytes played a dominant role in the N dynamics of the LCB reach by directly assimilating NH4, retaining N rich FBOM, and by providing habitat necessary to support an abundant and relatively diverse macroinvertebrate community that facilitated greater trophic transfer of nitrogen. Conversely, carp reduction of macrophytes in the HCB reach resulted in an overall reduction in areal uptake rates of NH4, reduced trophic transfer of N, and significantly reduced N retention. These results clearly indicate that carp engineering reduces macrophyte and macroinvertebrate abundance and diversity in streams and that N dynamics are simplified in carp engineered patches.

No description available.

No description available.

The goal of this study was to undertake a microbial investigation of the Historic Huts areas on Ross Island, to gain knowledge of the fungal biodiversity and biochemical framework, focusing on the wood degrading potential of these fungi at both psychrophilic (cold) and mesophilic (moderate) temperatures. Eight hundred and forty nine samples were collected from three Heroic Era Historic Huts of Antarctica, from a variety of substrates but predominantly structural wood. The huts, Discovery Hut at Hut Point, Terra Nova Hut at Cape Evans and Nimrod Hut at Cape Royds, are located on Ross Island and were all assembled in the early 20th century by the Heroic Era explorers to house the expeditions, stores and animals. These wooden huts were abandoned when the expeditions left. The introduction of wood and other organic material to a pristine environment along with the creation of a microclimate within the harsh Antarctica environment created interesting sites for studying fungal diversity, wood decay and fungal cellulase enzymes in an extreme environment. Each hut can be classified as offering different conditions and circumstances for fungal propagules. Of the three huts, Terra Nova Hut is the only hut where there are visible fungal blooms within the hut and it, with Discovery Hut, had the greatest number of samples that contained fungi compared to Nimrod Hut which had the least. Discovery Hut, at less than 500 metres from the United States McMurdo Station, is the most visited by scientist and base staff and has been the most demonstrably affected by human impact of the three huts due to its closeness to the research stations on Ross Island To ensure a full understanding of the fungal diversity of the Historic Hut sites, a variety of sampling techniques were used along with a variety of culture media. Two thousand and seventy six isolates consisting of 1177 filamentous fungi and 899 single celled microorganisms (yeast and bacteria) were isolated; all these cultures were frozen and now form the University of Waikato Antarctic Culture Collection. Five genera dominated the fungal isolates that were identified and these were Cladosporium, Geomyces, Cadophora, Penicillium and Thelebolus. The fungal diversity of these Historic Huts' communities is low but the members present are metabolically active, consistent with other microbial communities in the Antarctic. The Historic Huts and surroundings contain a diverse array of provision in the way of wood and supplies, which provide nutrient sources for fungal growth. Endemic organisms present in the soil could have been enriched by using the introduced nutrient sources as primary and/or second metabolic substrates. In addition, fungi could have been introduced with the wooden huts and supplies when they were brought to Antarctica by the Heroic Era explorers, or introduced in the subsequent years with visitors and conservation work conducted at the sites. These introduced organisms, though, would have had to adapt to the change in climate and conditions posed by the Antarctic in order to survive and be subsequently isolated in this study. A screen for carboxymethylcellulase (CMCase) activity was done on a selection of the fungal isolates as the first step to understand the cellulytic potential of the Antarctica fungal community inhabiting the huts. One hundred and six fungal isolates from a total of 404, that were screened were deemed to be CMCase positive, 27 fungal isolates were chosen for further study including quantifying the activity of extracellular endo-1,4-β-glucanase at psychrophilic and mesophilic incubation temperatures. All but one isolate could produce endo-1,4-β-glucanase activity at 4 C and many produced more endo-1,4-β-glucanase activity at 4 C than at 15 C. Cadophora malorum 182, Cadophora malorum 242, Penicillium roquefortii 405, Penicillium roquefortii 408, Geomyces sp. 711, Geomyces sp. 824 and Cladosporium oxysporium 805 were selected for in-depth study of growth characteristics including growth temperature preferences, growth on a variety of cellulose substrates, water activity, and carbon sources, the latter done by using a commercially available microtitre plate containing 95 carbon sources. All seven of the fungal isolates were classified as psychrotolerant and produced, when cultured at either 4 C or at 15 C, cellulase, protease, amylase, xylanase, and pectinase and mannanase enzyme activities. The range of water activity that the Antarctic Penicillium roquefortii isolates could grow at was distinctive when compared with food Penicillium roquefortii isolates. The utilisation of different carbon sources showed that like many studies of Antarctica organism they have a diverse range of enzymatic activity, but interestingly the activity does not differ greatly with incubation temperature with most carbon sources being used or not used at both incubation temperatures tested. Although it took longer for the fungi to grow at the psychrophilic temperatures, the range of carbon sources they utilised was not reduced. The protein composition of the extracellular supernatants was visualised using various electrophoretic and staining techniques. The cellulase activity of the protein bands was visualised by cellulose-containing zymograms, which illustrated that the cellulase complex in all fungi tested was multi-enzyme and differed between species, isolates and temperatures of culturing. The cellulase activity of Cadophora malorum 182 was enriched by purification techniques including ion exchange chromatography and native preparative electrophoresis. The protein complex was not purified to homogeneity, but enriched for a mixture of proteins and the mixture was described as having the following properties; a temperature range of β-1,4-glucan cellobiohydrolase activity from 20 C to 80 C with the optimum activity seen at 60 C, β-1,4-glucan cellobiohydrolase activity that is stable at 4, 25 and 40 C for at least 24 hrs, lost at 50 C and 80 C within 24 hrs and 2 minutes respectively. Along with β-1,4-glucan cellobiohydrolase activity, the protein mixture contained Avicelase, CMCase, xylanase and mannanase activity. The thesis research showed that there was limited fungal diversity in the Historic Huts and artefacts (a total of five dominant genera were identified) but the fungi are actively growing and producing viable spores in the cold of Antarctica and producing the necessary enzymes for degradation of wood. Although the metabolism and growth rate is slower at psychrophilic temperatures, the fungal isolates studied as part of this thesis research could still function enzymatically at cold temperatures and this includes the degradation of wood as evidenced by in vitro wood decay studies examined by scanning electron microscopy where two isolates of one species demonstrated the ability to degrade wood. The cellulase complex of the investigated fungal isolate was multi-enzymed and although the components were not purified to homogeneity, an enriched mixture of proteins had enzyme activity and stability in a broad temperature range, and activity to a variety of cellulosic substrates. This thesis research adds to the knowledge of the fungal biodiversity in the Antarctic and increases the understanding of the biochemical framework, participating in relation to wood decay potential of these Antarctic fungal isolates.

Of all anthropogenic pressures, urbanisation is one of the most damaging, and is expanding in its influence throughout the world. In Australia, 90% of the human population live in urban centres along the eastern seaboard. Before European settlement in the early 1800s, much of the Australia's East coast was dominated by forests. Many of the forest dependent fauna have had to adapt to forest fragmentation and habitat loss resulting from clearing for urbanisation. However, relatively few studies have investigated the impact of urbanisation on biodiversity. This is especially true for the remaining fauna in large metropolitan areas, such as Melbourne, Sydney and Brisbane. The physical and conceptual context of this thesis is the increasing impact of urbanisation and the potentially threatening factors to forest dependent fauna. Bats were selected because they comprise a third of Australia's mammal species, and therefore form a major component of Australia's biodiversity. Very little is known about the ecology and conservation biology of hollow-dependent bats in general, but particularly in urban environments. The study was conducted in Brisbane, south-east Queensland, one of Australia's most biodiverse regions. More than a third of Australia's bat species occur in this region. A large insectivorous bat, the white-striped freetail bat (Tadarida australis), was selected to study two key resources in this urban area - hollow availability and foraging habitat. This thesis also examined if artificial roost habitat could provide temporary roosts for white-striped freetail bats and other insectivorous bats and assessed whether these bat boxes can be used as a conservation tool in urban environments where natural hollow-availability is limited. The white-striped freetail bat is an obligate hollow-dweller and roosted largely in hollows of old or dead eucalypts throughout Brisbane's urban matrix. These roost trees harboured significantly more additional hollow-dependent species compared to control trees of similar age, height, and tree diameter. Roost cavities inside trees often exceeded 30 cm in diameter. Furthermore, maternity colonies used cavities of hollow trunks, which often extended into major branches, to roost in big numbers. Therefore artificial alternatives, such as small bat boxes, may provide temporary shelter for small roosting groups, but are unlikely to be suitable substitutes for habitat loss. Although five bat species used bat boxes during this study, the white-striped freetail bat was not attracted into bat boxes. Roost-switching behaviour was then used to quantify associations between individual white-striped freetail bats of a roosting group. Despite differences in gender and reproductive seasons, the bats exhibited the same behaviour throughout three radio-telemetry periods and over 500 bat-days of radio-tracking: each roosted in separate roosts, switched roosts very infrequently, and associated with other tagged bats only at a communal roost. Furthermore, the communal roost exhibited a hub of socialising between members of the roosting group especially at night, with vocalisation and swarming behaviour not found at any of the other roosts. Despite being spread over a large geographic area (up to 200 km2), each roost was connected to others by less than three links. One roost (the communal roost) defined the architecture of the network because it had the most links. That the network showed scale-free properties has profound implications for the management of the habitat trees of this roosting group. Scale-free networks provide high tolerance against stochastic events such as random roost removals, but are susceptible to the selective removal of hub nodes, such as the communal roost. The white-striped freetail bat flew at high speed and covered large distances in search for food. It foraged over all land-cover types found in Brisbane. However, its observed foraging behaviour was non-random with respect to both spatial location and the nature of the ground-level habitat. The main feeding areas were within three kilometers of the communal roost, predominantly over the Brisbane River flood plains. As the only mammal capable of flight, bats can forage above fragmented habitats. However, as this study showed, hollow-dependent insectivorous bats, including free-tailed bats, are specialised in their roosting requirements. The ongoing protection of hollow-bearing trees, and the ongoing recruitment of future hollow-bearing trees, is essential for the long-term conservation of these animals in highly fragmented landscapes. Furthermore, loss of foraging habitat is still poorly understood, and should be considered in the ongoing conservation of bats in urban environments.