Segui questo link per vedere altri tipi di pubblicazioni sul tema: Biogeography.
Tesi sul tema "Biogeography"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-50 saggi (tesi di laurea o di dottorato) per l'attività di ricerca sul tema "Biogeography".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi le tesi di molte aree scientifiche e compila una bibliografia corretta.
1
Billing, Ian Michael. "British carboniferous Bryozoan biogeography". Thesis, Durham University, 1991. http://etheses.dur.ac.uk/6289/.
Testo completoAbstract (sommario):
The geographical and temporal distributions of the British Carboniferous Bryozoa have been determined, incorporating data from fieldwork (including localities in Scotland, North England, North Wales, South Wales, and Avon), museum collections, and literature searches. A total of 126 species has been recognised, though further work may reveal some synonymies within this list. The forty species collected during the fieldwork have been identified by reference to previous taxonomic work; most species can be assigned to established taxonomic descriptions, but two new species, Rhombopora bancrofti and Polypora hexagonaria, are proposed, and the descriptions of Rhombopora incrassata and Rhombopora similis are emended. The applicability of Student's t-test to the morphometric analysis of Carboniferous bryozoan species has been studied, and a computer program written to perforin this task, incorporating a database of species measurements. A new statistical method, the division t-test, is presented in this thesis; this method is useful in comparing the relative ratios of bryozoan colony parameters. Both the t-test and the division t-test were found to be of use in identifying bryozoan species. Analysis of the bryozoan faunas in nine regional areas of Britain has been made using the Simpson and Jaccard coefficients of similarity. The resulting coefficients are consistent with the limited distribution capability of many bryozoan taxa, and also match with the known palaeogeography and palaeocurrents of the Carboniferous of northwest Europe. Plots of species diversity against geographical distribution show a similar pattern to that produced by Tertiary non-planktotrophic larvae-bearing neogastropods. Further, additional plots of species diversity against species longevity produced a pattern consistent with normal background extinction events. A study of bryozoan morphology between different areas and different stages within the Carboniferous indicated that species showed no measurable temporal evolutionary or lateral geographical changes through the Lower Carboniferous. Rather, local environmental stresses are the major architects of bryozoan colony morphology.
2
ergezer, mehmet. "OPPOSITIONAL BIOGEOGRAPHY-BASED OPTIMIZATION". Cleveland State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=csu1392301939.
Testo completo
3
Alvarado, Barrantes Ricardo. "Statistical models in biogeography". Doctoral thesis, Università degli studi di Padova, 2013. http://hdl.handle.net/11577/3423067.
Testo completoAbstract (sommario):
We concentrate on the statistical methods used in Biogeography for modelling the spatial distribution of bird species. Due to the difficulty of specifying a joint multivariate spatial covariance structure in environmental processes, we factor such a joint distribution into a series of conditional models linked together in a hierarchical framework. We have a process that corresponds to an unobservable map with the actual information about a bird species, and the data correspond to the observations that are connected to that process. Markov chain Monte Carlo (MCMC) simulation approaches are used for models involving multiple levels incorporating dependence structures. We use a Bayesian algorithm for drawing samples from the posterior distribution in order to obtain estimates of the parameters and reconstruct the true map based on data. We present different methods to overcome the problem of calculating the distribution of the Markov random field that is used in the MCMC algorithm. During the analysis it is desirable to delete some of the predictors from the model and only use a subset of covariates in the estimation procedure. We use the method by Kuo & Mallick (1998) (KM) for variable selection and combine it with multiple independent chains which successfully improves the mixing behaviour. In simulation studies we show the better performance of the pseudolikelihood over other likelihood approximation methods, and the good performance of the KM method with this type of data. We illustrate the application of the methods with the complete analysis of the spatial distribution of two bird species (Sturnella magna and Anas rubripes) based on a real data set. We show the advantages of using the hidden structure and the spatial interaction parameter in the spatial hidden Markov model over other simpler models, like the ordinary logistic model or the autologistic model without observation errors.Ci concentriamo sui metodi statistici utilizzati in Biogeografia per modellare la distribuzione spaziale delle specie di uccelli. A causa della difficoltà nello specificare una struttura multivariata congiunta della covarianza spaziale nei processi ambientali, fattorizziamo tale distribuzione congiunta in una serie di modelli condizionati connessi asieme in un modello gerarchico. Abbiamo un processo che corrisponde ad una mappa non osservabile con le informazioni effettive su una specie di uccelli, ed i dati corrispondono alle osservazioni che sono collegate a tale processo. Vengono utilizzati gli approcci di simulazione Markov chain Monte Carlo (MCMC) per i modelli a più livelli che incorporano strutture di dipendenza. Usiamo un algoritmo Bayesiano per estrarre campioni dalla distribuzione a posteriori al fine di ottenere stime dei parametri e ricostruire la vera immagine basata sui dati. Presentiamo diversi metodi per superare il problema del calcolo della distribuzione del campo aleatorio markoviano che viene utilizzato nell’ algoritmo MCMC. Durante l’analisi, è opportuno eliminare alcuni predittori dal modello e utilizzare solo un sottoinsieme di covariate nella procedura di stima. Usiamo il metodo di Kuo & Mallick (1998) (KM) per la selezione delle variabili che, combinato all’uso dei più catene independenti, incrementa con successo il mixing delle catene. Negli studi di simulazione, presentiamo le migliori prestazioni della pseudo-verosimiglianza rispetto agli altri metodi di approssimazione e le buone prestazioni del metodo KM per queso tipo di dati. Illustriamo l’applicazione dei metodi con l’analisi completa della distribuzione spaziale di due specie di uccelli (Sturnella magna e Anas rubripes), basandoci su di un insieme di dati reale. Dimostriamo i vantaggi nell’uso della struttura latente e del parametro di interazione spaziale nel modello spaziale markoviano latente rispetto agli altri modelli più semplici, come l’ordinario modello logistico o il modello autologistico senza errori di osservazione.
4
Herbert, Jane. "Systematics and biogeography of Myricaceae". Thesis, University of St Andrews, 2005. http://hdl.handle.net/10023/2687.
Testo completoAbstract (sommario):
Two molecular phylogenetic studies were undertaken to examine relationships within Myricaceae. Analyses of DNA sequences of the plastid rbcL gene, trnL-Fregion and nuclear ITS region showed the family to be monophyletic. In all analyses Canacomyrica, a monotypic genus endemic to New Caledonian that bears several distinctive features such as staminodes in the female flowers, fell into a well- supported clade sister to the rest of Myricaceae. Phylogenetic analyses of ITS and trnL-F sequence data, representing all genera and subgeneric groups, were undertaken using maximum parsimony and Bayesian methods. The following relationships were strongly supported: (Canacomyrica (Comptonia (Myrica, Morella))). The clade containing all species formerly considered to comprise Myrica s.l. was split into two strongly supported clades corresponding to Myrica s.s. and Morella; this finding strengthens the argument for recognition of these as separate genera. Within Morella, two clades corresponded to previously recognized subgenera. Molecular dating analyses were performed using Penalized Likelihood. Close correlations between lineage-specific diversification and major orogenic or climatic events were inferred. This study suggests that much of the diversity in Morella arose during the Neogene and seed-dispersal by birds has been a significant factor in determining the modem distribution. A study of the conservation status of Canacomyrica was conducted using field observations and data from herbarium specimens. This species was found to occur in just eleven fragmented localities: six outside protected areas and three threatened by mining or bush fires. IUCN Red List status of Endangered was recommended. The morphology and ecology of Canacomyrica was studied to enhance knowledge of this poorly known species and provide comparative data for use in a study of the morphology of the entire family. A new classification scheme with keys was presented including, for the first time, Canacomyrica. New combinations in Morella were recommended.
5
Gelang, Magnus. "Babblers, Biogeography and Bayesian Reasoning". Doctoral thesis, Stockholms universitet, Zoologiska institutionen, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-71321.
Testo completoAbstract (sommario):
In this thesis, I try to proceed one step further towards an understanding of the biogeographic processes forming the distribution patterns of organisms that we see today. Babblers and warblers are diverse groups of passerines that are phylogenetically intermixed with other groups in the superfamily Sylvioidea. First, the gross phylogeny of the babblers and associated groups was estimated. Five major lineages of a well-supported monophyletic babbler radiation were recovered, and we proposed a new classification at family and subfamily level. Further, the genus Pnoepyga was excluded from Timaliidae, and we proposed the new family Pnoepygidae fam. nov. Second, the systematic position was investigated for the Albertine Rift taxon Hemitesia neumanni, which was found to be nested within the almost entirely Asian family Cettidae, and possible biogeographical scenarios were discussed. We concluded that the most plausible explanation involved late Miocene vicariance in combination with local extinctions. Third, the historical biogeography of a Leiothrichinae subclade, the Turdoides babblers and allies, was inferred. We concluded that the Middle East region probably played an important role in the early history of this clade, followed by local extinctions in this region. Fourth, a Bayesian method to reconstruct the historical biogeography under an event-based model was proposed, where the total biogeographic histories are sampled from its posterior probability distribution using Markov chains. In conclusion, I believe that, especially with more sophisticated methods available, we will see an increasing number of studies inferring biogeographic histories that lead to distribution patterns built up by a combination of dispersals and vicariance, but where these distributions have been extensively reshaped, or litterally demolished, by local extinctions. Therefore, my answer to the frequently asked question dispersal or vicariance? is both, but not the least: extinctions.At the time of the doctoral defence the following papers were unpublished and had a status as follows; Papers 3 and 4: Manuscripts
6
McGuire, Avery Faye. "Phylogeny and biogeography of Erica /". Electronic thesis, 2003. http://etd.wfu.edu/theses/available/etd-12162003-111147/.
Testo completo
7
Proud, Roland Hudson. "A biogeography of the mesopelagic community". Thesis, University of St Andrews, 2016. http://hdl.handle.net/10023/12025.
Testo completoAbstract (sommario):
There are a large number of research vessels and fishing vessels equipped with echosounders plying the world ocean, making continual observations of the ocean interior. Developing data collation programmes (e.g. Integrated Marine Observing System) and automated, repeatable analyses techniques enable the upper c. 1,200 meters of the world ocean to be sampled routinely, and for their characteristic deep scattering layers (DSLs) to be compared. Deep scattering layers are comprised of zooplankton (e.g. euphausiids) and fish, particularly myctophids or lantern fish, and comprise the majority of sub-surface biomass. Here we present, by the analysis of a global acoustic dataset, a mesopelagic biogeography of the sea. This was accomplished by (i) the collation and processing of a global active acoustic dataset, (ii) the development of a standardised and automated method of sound scattering layer (SSL) extraction and description, (iii) the derivation of the environmental drivers of DSL depth and biomass, (iv) the definition of a mesopelagic biogeography based on the drivers of DSL metrics and (v) the prediction, using output from the NEMO-MEDUSA-2.0 coupled model, of how the metrics and biogeography may change by 2100. Key findings include, the development of the Sound Scattering Layer Extraction Method (SSLEM) the inference that primary production, water temperature and wind stress are key drivers in DSL depth and biomass and that mesopelagic fish biomass may increase by 2100. Such an increase is a result of increased trophic efficiency from the shallowing of DSLs and rising water temperatures, suggesting, that as the climate warms the ocean is becoming more efficient. The biophysical relationships and biogeography derived here, serve to improve our understanding of mesopelagic mid-trophic level dynamics in open-ocean ecosystems. This will aid both fisheries and conservation management, which now adopt more holistic approaches when monitoring and evaluating ecosystem health and stability.
8
Goldberg, Emma Elizabeth. "Macroevolutionary and coevolutionary models in biogeography". Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2007. http://wwwlib.umi.com/cr/ucsd/fullcit?p3255000.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--University of California, San Diego, 2007.Title from first page of PDF file (viewed May 8, 2007). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
9
Smith, Fraser D. M. "Case studies in biogeography and extinction". Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334231.
Testo completo
10
Rosser, N. S. "Speciation and biogeography of heliconiine butterflies". Thesis, University College London (University of London), 2013. http://discovery.ucl.ac.uk/1386054/.
Testo completoAbstract (sommario):
In this thesis I investigate the speciation and biogeography of neotropical heliconiine butterflies (Lepidoptera: Nymphalidae: Heliconiina). In Chapter 2, I present a large database of locality records for heliconiine species and subspecies, and use these data to test evolutionary and biogeographic hypotheses for their diversification. I find evidence that geographical gradients in species richness are driven at least in part by variation in speciation and/or extinction rates, rather than via evolutionary age or niche conservatism alone. The eastern Andes are characterised by high species richness and short phylogenetic branch lengths, suggesting that new species frequently arise there. Conversely, the Amazon basin is notable for high intra-specific phenotypic diversity. In Chapter 3, I use the geographic data to estimate the frequency of sympatric speciation in heliconiines. I find that the patterns of range overlap observed in heliconiines are consistent with sympatric speciation. However, parapatric speciation followed by a tendency for daughter species to expand rapidly into one another’s ranges presents a plausible alternative explanation. I also present evidence that shifts in mimetic wing colour patterns and host plants are associated with speciation in heliconiines, suggesting that ecological adaptation may be important in triggering speciation events. In Chapter 4, I test the prediction that hybrid zones between Andean and Amazonian races of Heliconius should be moving towards the Andes. I find the position of the hybrid zones to be unchanged from 1986 – 2011, and located on a band of peak rainfall at the edge of the Andes. This suggests that rainfall peaks act as "sinks" for dispersal in butterflies and stabilise the hybrid zones on this low fitness region. The results oppose the Pleistocene Refugium theory, which predicts that centres of ranges, rather than contact zones at the edges, should be centred on current rainfall peaks.
11
Benfield, John Nettleton. "The systematics and biogeography of Araucariaceae". Thesis, University of Reading, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294513.
Testo completo
12
Valles, Carlos Mariano Alvez. "Biogeography and conservation of Amazon palms". Universidade Federal de Juiz de Fora (UFJF), 2017. https://repositorio.ufjf.br/jspui/handle/ufjf/6607.
Testo completoAbstract (sommario):
Submitted by Renata Lopes (renatasil82@gmail.com) on 2018-03-27T19:45:32Z
No. of bitstreams: 1
carlosmarianoalvesvalles.pdf: 5972976 bytes, checksum: 908806a8077c5751983d6b9690d566cd (MD5)Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-04-09T19:22:27Z (GMT) No. of bitstreams: 1 carlosmarianoalvesvalles.pdf: 5972976 bytes, checksum: 908806a8077c5751983d6b9690d566cd (MD5)
Made available in DSpace on 2018-04-09T19:22:27Z (GMT). No. of bitstreams: 1 carlosmarianoalvesvalles.pdf: 5972976 bytes, checksum: 908806a8077c5751983d6b9690d566cd (MD5) Previous issue date: 2018-02-22
-
Palms are abundant in tropical forests and are recognized as effective bioindicators of hot climates. Moreover, play an important ecological and economic role for local populations. Though palms remain relatively well-conserved, they are under increasing pressure from deforestation. Therefore, endemicity is important for the delimitation of conservation areas. The purposes of the study is 1) to synthesize available information in the literature on species diversity, ecological aspects, use and conservation of Amazon palms (Chapter 1); to analyse palms species richness patterns relative to the latitudinal gradient, sample efforts, and deforestation in the Amazon region (Chapter 2); to compare richness and floristic similarities patterns among the Amazonian sub-regions (Chapter 2); to detect endemic areas for palms in the Amazon region (Chapter 3); and to determine whether the species that define these endemic areas are protected within conservation units (Chapter 3). Records of occurrences were extracted from the Global Biodiversity Information Facility (GBIF). The final dataset consisted of 17,310 records, for 177 species of Amazonian palms. The areas with the greatest richness were in the western, central and northeastern Amazon, principally at latitudes 0–5ºS. Most palms species grow in different habitats, but the highest species richness are found in terra firme forest. Palms are widely used with different category of use according to the regions and species, principally are used for human consumption, elaboration of utensils and tools, and construction of houses. Highest rates of deforestation (>2000 km2) were found in the southern and eastern brazilian Amazon, which coincide with low species richness and gaps in records. Similarity analysis resulted in two groups of sub-regions: the first included the Amazon s.s., Andes and Guiana, and the other group included the Plateau and Gurupi sub-region. The combination of PAE and NDM-VNDM analyses resulted in eight endemic palm areas in western Amazon shared with Andean sub-region. Of the species that define the endemic areas, five are threatened with extinction in one of three IUCN categories (EN, VU, NT), and they are not protected in any conservation units. In conclusion, the western Amazon, besides having high palm richness, also has palm endemic areas, especially, near the Andean sub-region and the Peruvian Amazon, and areas with low species richness, especially those areas with data deficiency, need to be further researched for a better knowledge of their diversity and richness patterns.
13
Guillet, Alfredo. "Biogeography and ecology of African waterbirds". Doctoral thesis, University of Cape Town, 1986. http://hdl.handle.net/11427/21812.
Testo completoAbstract (sommario):
Bibliography: pages 192-208.Patterns of distribution and diversity for African waterbirds are investigated at the continental, sub-continental, ecosystem and species levels. The focal species is the Great White Pelican Pelecanus onocrotalus, one of South Africa's 'Red Data' bird species. The 'focal' ecosystem is Rondevlei Bird Sanctuary (34°'04'S, 18°30'E), one of the few conserved areas in Africa set aside especially for waterbirds. Biogeographically, waterbirds partition Africa much more coarsely (into 8 vs 18 avifaunal zones) than do non-aquatic birds. Waterbird species diversity (number of species) and endemism are higher outside the tropics, and exhibit longitudinal gradients, with higher diversity in the east. Non-aquatic bird diversity is higher in the tropics and varies latitudinally. Spatia-temporal variation in habitat availability and quality are the primary factors which control waterbird distribution, and the dynamic nature of waterbird dispersion is an adaptation to dramatically fluctuating habitats. About 69% o£ the variance in African waterbird species diversity can be explained in terms of present-day environmental variation. Part of the unexplained variance is attributed to the effects of historical factors, with areas of unexpectedly high species possibly acting as refugia during dry climatic phases.
14
Sang, Tao. "Phylogeny and Biogeography of Paeonia (Paeoniaceae) /". The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487928649988039.
Testo completo
15
Laumann, Katie May. "Sturgeon (Acipenseridae) phylogeny, biogeography, & ontogeny". W&M ScholarWorks, 2016. https://scholarworks.wm.edu/etd/1539616731.
Testo completoAbstract (sommario):
Thought of as "ancient" fishes, 25 broadly recognized extant sturgeon species are classified in four genera (Acipenser, Huso, Pseudoscaphirhynchus, and Scaphirhynchus). Molecular and morphological analyses have led to broad but conflicting changes to sturgeon phylogeny. For example, the position of Scaphirhynchus among other sturgeons had been contentious, and various sets of sturgeon species have been proposed to make up the subfamily Husinae. Here, a molecular phylogeny of sturgeons, based on the full mitogenome, is presented. In this phylogeny, Scaphirhynchus is recovered with strong support as basal to the other sturgeons. Huso huso is recovered as basal within a clade containing P. kaufmanni and several species of Acipenser, and is proposed as a new, monotypic subfamily Husinae. This phylogeny is used to examine phylogenetic signal in individual genes and in gene families. The protein coding genes as a unit, and individually, along with 16s rRNA, show phylogenetic signal most similar to that of the full mitogenome. The phylogeny, along with evolutionary relationships of pinnipeds and lampreys, provides the basis for the exploration of sturgeon biogeography. Relationships among geographic areas inhabited by sturgeons are found, finding two sets of related areas- a Pacific area group and an Atlantic group. Relationships of areas within and between these groups reflect area relationships proposed by previous biogeographic and geologic studies. Phylogenetic signal is tested amongst ontogenetic characters, and is recovered in the timing at which larval sturgeon teeth are completely resorbed, indicating that the timing of ontogenetic milestones can carry signal. The phylogeny is used to remove confounding signal from, and investigate correlations among, behavioral and morphological ontogenetic characters. Correlation is found between one pair of characters.
16
Kiel, Steffen. "Taxonomy and biogeography of late Cretaceous gastropoda". [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=964103850.
Testo completo
17
Rogers, Stephanie F. "The Biogeography of the Strait of Florida". NSUWorks, 2008. http://nsuworks.nova.edu/occ_stuetd/107.
Testo completoAbstract (sommario):
The Strait of Florida is a crescent – shaped channel, 180 km long that separates Florida from the Bahama Platform and Cuba and connects the Gulf of Mexico with the Atlantic Ocean. The Strait was investigated by four major dredging and trawling efforts: the U.S. Coast and Geodetic Survey Steamer Blake in the 1870s; the U.S. Fish Commission Steamer Albatross in the 1880’s; the Woods Hole Oceanographic Institute’s R/V Atlantis in 1938 and 1939, and the University of Miami’s R/V Gerda and Pillsbury from 1962 to 1971. This study uses multivariate statistics to analyze qualitative published and museum records of dredged and trawled material to determine patterns of benthic fish and invertebrate distributions in the Strait of Florida and to recognize possible assemblages and associations among these organisms. Distributional information was correlated with mean bottom hydrodynamic and physicochemical data (water velocity, salinity and temperature) and depth to develop hypotheses about environmental controls of distributional patterns. Results reveal definite zonation patterns among selected invertebrate species in the Strait of Florida.
18
Edwards, Danielle L. "Biogeography and speciation of southwestern Australian frogs". University of Western Australia. School of Animal Biology, 2007. http://theses.library.uwa.edu.au/adt-WU2008.0058.
Testo completoAbstract (sommario):
[Truncated abstract] Southwestern Australia is a global biodiversity hotspot. The region contains a high number of endemic species, ranging from Gondwanan relicts to more recently evolved plant and animal species. Biogeographic models developed primarily for plants suggest a prominent role of Quaternary climatic fluctuations in the rampant speciation of endemic plants. Those models were not based on explicit spatial analysis of genetic structure, did not estimate divergence dates and may be a poor predictor of patterns in endemic vertebrates. Myobatrachid frogs have featured heavily in the limited investigations of the biogeography of the regions fauna. Myobatrachid frogs are diverse in southwestern Australia, and while we know they have speciated in situ, we know little about the temporal and spatial patterning of speciation events. In order to gain insight into the biogeographic history and potential speciation patterns of Myobatrachid frogs in the southwest I conducted a comparative phylogeography of four frog species spanning three life history strategies. I aimed to: 1) assess the biogeographic history of individual species, 2) determine where patterns of regional diversity exist using a comparative framework, 3) determine whether congruent patterns across species enable the development of explicit biogeographic hypotheses for frogs, and 4) compare patterns of diversity in plants with the models I developed for frogs. I conducted fine-scale intraspecific phylogeographies on four species. ... Geocrinia leai: deep divergences, coincident with late Miocene arid onset, divide this species into western and southeast coastal lineages, with a third only found within the Shannon-Gardner River catchments. Phylogeographic history within each lineage has been shaped by climatic fluctuations from the Pliocene through to the present. Arenophryne shows the first evidence of geological activity in speciation of a Shark Bay endemic. Divergence patterns between the High Rainfall and Southeast Coastal Provinces within C. georgiana are consistent with patterns between Litoria moorei and L. cyclorhynchus and plant biogeographic regions. Subdivision between drainage systems along the southern coast (in M. nichollsi, G. leai and the G. rosea species complex) reflect the relative importance of distinct catchments as refuges during arid maxima, similarly the northern Darling Escarpment is identified as a potential refugium (C. georgiana and G. leai). Divergences in Myobatrachid frogs are far older than those inferred for plants with the late Miocene apparently an important time for speciation of southwestern frogs. Speciation of Myobatrachids broadly relates to the onset of aridity in Australia in the late Miocene, with the exception of earlier/contemporaneous geological activity in Arenophryne. The origins of subsequent intraspecific phylogeographic structure are coincident with subsequent climatic fluctuations and correlated landscape evolution. Divergence within frogs in the forest system may be far older than the Pleistocene models developed for plants because of the heavy reliance on wet systems by relictual frog species persisting in the southwestern corner of Australia.
19
Kaiser, Hinrich. "Systematics and biogeography of eastern Caribbean frogs". Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41632.
Testo completoAbstract (sommario):
This study examines the systematics and biogeography of frogs in the Eastern Caribbean, a biogeographical province consisting of the Lesser Antilles, Trinidad, and Tobago. A comprehensive collection of specimens was subjected to an analysis incorporating morphometric, osteological, and biochemical approaches. An investigation of $ alpha$-level taxonomy revealed the presence of four additional taxa: Colostethus chalcopis sp. nov. on Martinique, Eleutherodactylus amplinympha sp. nov. on Dominica, E. euphronides comb. nov. on Grenada, and E. shrevei comb. nov. on St. Vincent. Based on species distributions and detailed analyses of the largely congruent data sets, Eastern Caribbean frogs can be grouped into two major categories, those originating with South American stock and those of Greater Antillean ancestry. A South American origin is obvious for species which have no congeneric relatives in the Greater Antilles, e.g. C. chalcopis, Leptodactylus fallax, L. wagneri. Among the Eleutherodactylus species, northern Eastern Caribbean taxa form a monophyletic group within the E. auriculatus species group; the topology of relationships is ((E. barlagnei, E. pinchoni) ((E. amplinympha, E. martinicensis) E. johnstonei)). The southern Eastern Caribbean species may or may not form a monophyletic group, but E. euphronides and E. shrevei are sister taxa. The topology for these species is (E. urichi (E. terraebolivaris (E. euphronides, E. shrevei))). Thus, the Eastern Caribbean forms a biogeographic link between the large South American and Greater Antillean radiations of Eleutherodactylus; Eleutherodactylus is the only truly circum-Caribbean frog genus. Furthermore, historical evidence shows that the patchy, Caribbean-wide distribution of E. johnstonei is the direct result of accidental introduction mitigated by humans during the past three centuries.
20
Seears, Heidi. "Biogeography and phylogenetics of the planktonic foraminifera". Thesis, University of Nottingham, 2011. http://eprints.nottingham.ac.uk/11879/.
Testo completoAbstract (sommario):
The planktonic foraminifera are a highly abundant and diverse group of marine pelagic protists that are ubiquitously distributed throughout the worlds’ oceans. These unicellular eukaryotes are encased in a calcareous (CaCO3) shell or ‘test’, the morphology of which is used to identify individual ‘morphospecies’. The foraminifera have an exceptional fossil record, spanning over 180 million years, and as microfossils provide a highly successful paleoproxy for dating sedimentary rocks and archiving past climate. Molecular studies, using the small subunit (SSU) ribosomal (r) RNA gene are used here to investigate the biogeographical distributions and phylogenetic relationships of the planktonic foraminifera. Biogeographical surveys of two markedly different areas of the global ocean, the tropical Arabian Sea, and the transitional/sub-polar North Atlantic Ocean, revealed significant genotypic variation within the planktonic foraminifera, with some genetic types being sequenced here for the first time. The foraminiferal genotypes displayed non-random geographical distributions, suggestive of distinct ecologies, giving insight into the possible mechanisms of diversification in these marine organisms. The ecological segregation of genetically divergent but morphologically cryptic genetic types could, however, have serious repercussions on their use as paleoproxies of past climate change. Phylogenetic analyses of the foraminifera based firstly on a partial ~1,000 bp terminal 3´ fragment of the SSU rRNA gene, and secondly on the ~3,000 bp almost complete gene supported the hypothesis of the polyphyletic origins of the planktonic foraminifera, which appear to be derived from up to 5 separate benthic ancestral lineages. The almost complete gene is sequenced here in the planktonic taxa for the first time, though amplification was problematic. In a first step to addressing a pressing need for new genetic markers to support data gained from the SSU rRNA gene, a culture system was established for the benthic foraminifera, in order to provide a reliable source of DNA for EST library construction or full genome sequencing. Finally, to overcome difficulties associated with the PCR amplification of the foraminifera, a new lysis buffer and DNA extraction procedure was developed. A highly successful buffer was created, allowing high quality DNA to be extracted from foraminiferal specimens, whilst leaving the delicate calcitic shell intact for morphological reference.
21
James, Phillip. "Towards the biogeography of British soil microorganisms". Thesis, University of Newcastle Upon Tyne, 2013. http://hdl.handle.net/10443/1840.
Testo completoAbstract (sommario):
Soils are complex and highly variable ecosystems within which a multitude of diverse microbial populations can be found. Here the effects of co-correlating environmental variables and spatial separation upon the diversity and community structure of two microbial kingdoms is investigated using several molecular based community assessment methods. Using an optimised nucleic acid extraction procedure, suitable for landscape scale surveys of microbial biogeography, large scale bacterial and fungal targeted terminal restriction fragment length polymorphism (t-RFLP) analysis was undertaken on soils collected as part of the Countryside Survey 2007 to show that populations of both kingdoms are structured, in part, by variability in environmental and edaphic conditions as well as spatial separation. In the case of soil bacteria, pH was identified as the most important environmental variable, although computed models suggest that many other environmental variables also play strong roles. Fungal systems have weaker relationships with environmental variability and stronger spatial relationships, although dominant plant species and soil pH were shown to significantly affect community structure. However, comparing results generated from different genes with different taxonomic resolutions hinders accurate comparisons between divergent microbial kingdoms. Pyrosequencing analysis was undertaken on 15 geographically isolated soil samples forming a natural pH gradient to address the changes in bacterial and fungal populations at great sequencing depth and at taxonomic resolutions closer to the species level. Again, in both cases, members of these kingdoms responded to differences in soil pH and the above ground plant community. A number of bacterial and fungal taxa were found to be responsible for the changes in community structure and diversity noted in the t-RFLP based experiments and are proposed as candidates for indicators of soil pH. In summary soil bacterial and fungal populations are structured according to complex laws relating to co-correlating environmental and spatial variables. This leads to the hypothesis that microbial communities are structured in similar ways to terrestrial macro organisms, and thus ecological theories derived from observations of larger animals may be investigated within the microbial world.
22
Nitz, Barbara. "Integrative systematics and biogeography of Limax (Gastropoda:Stylommatophora)". Diss., Ludwig-Maximilians-Universität München, 2013. http://nbn-resolving.de/urn:nbn:de:bvb:19-175895.
Testo completo
23
Tun-Garrido, Juan. "Biogeography and cladistic relationships of Psittacanthus (Loranthaceae)". Thesis, University of Reading, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437141.
Testo completo
24
Thompson, Peter N. "The biogeography and systematics of Coriaria (Coriariaceae)". Thesis, University of Leicester, 1996. http://hdl.handle.net/2381/35358.
Testo completoAbstract (sommario):
The family Coriariaceae contains the single genus Coriaria. Seemingly isolated from all other families and genera the genus has a unique disjunct distribution covering five separate areas in the northern and southern hemispheres. Possible explanations for this distribution have been explored by studying evolutionary relationships, using cladistic analysis, breeding systems, taxonomy and the fossil record. Characters used in the cladistic analysis have been both phenotypic (morphological, anatomical, phytochemical and cytological) and molecular (sequences of the tRNALeu1 intron of the chloroplast genome). The genus is seen to be probably monophyletic and composed of two monophyletic groups, one in the northern hemisphere and one in the southern. The ancestral taxon was most likely the immediate ancestor of C. terminalis which, while occurring in the Himalayas, is closely related to the southern hemisphere group. From this evidence it is inferred that the genus is ancient with its origin on the Indian plate in the early Cretaceous with the ancestor being rafted to its present position during the break-up of Gondwanaland. The S. and C. American species, C. microphylla, appears to be ancestral to the southern hemisphere group from the molecular evidence, although it is embedded within the southern clade on the basis of phenotypic characters. It is inferred that it arrived in its present position through spread around the Australasian - Antarctic - S. American block of Gondwanaland. The species, C. ruscifolia, is shown to be identical in New Zealand and Chile with identical tRNALeu1 intron sequences. A recent separation into these two areas by dispersal mechanisms would account for this trans-Pacific distribution. New Zealand itself is seen to be a secondary centre of diversity. A formal taxonomic revision has been made in which the original 16 species have been reduced to 13.
25
Bystriakova, Nadia. "The ecology and biogeography of tree ferns". Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612141.
Testo completo
26
Chatterjee, Helen Jane. "Phylogeny and biogeography of gibbons, genus Hylobates". Thesis, University College London (University of London), 2001. http://discovery.ucl.ac.uk/48140/.
Testo completo
27
Hackel, Jan. "Molecular biogeography of grasses and tropical grasslands". Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30222.
Testo completoAbstract (sommario):
Les graminées (Poaceae) sont une très grande famille cosmopolite de plantes. Dans la thèse présentée ici, j'ai utilisé des méthodes moléculaires pour analyser leur histoire biogéographique. Le premier chapitre s'intéresse aux déterminants de la dispersion dans la sous-tribu tempérée Loliinae. La distance apparaît comme le facteur dominant. Le deuxième chapitre présente une analyse des origines des graminées de Madagascar. Les résultats montrent deux grandes radiations in situ de graminées C3 et une immigration répétée de graminées C4, soutenant l'existence de savanes malgaches avant la présence humaine. Le troisième chapitre résout la position d'une lignée C3 d'Asie à l'aide de la phylogénomique, avec des implications pour l'évolution de la photosynthèse C4 et des savanes tropicales. Le quatrième chapitre présente une méthode de méta-barcoding pour l'analyse des communautés d'endophytes fongiques associées aux graminées à Madagascar, démontrant des limitations méthodologiquesGrasses (Poaceae) are a large, cosmopolitan plant family. In this dissertation, I used molecular methods to study their biogeographic history. The first chapter focuses on determinants of lineage dispersal in the temperate subtribe Loliinae, with distance found to be the dominant factor. The second chapter analyses the origins of Madagascar's grass flora. Two large in situ radiations of C3 grasses were found while C4 grasses immigrated more frequently and support the pre-human presence of grasslands in Madagascar. The third chapter resolves relationships of an Asian C3 lineage using phylogenomic methods, with implications for C4 photosynthesis evolution and the assembly of tropical grasslands. The fourth and final chapter developed a metabarcoding method for the analysis of fungal endophyte communities associated to grasses in Madagascar, with results highlighting methodological limitations
28
De, Klerk Helen Margaret. "Biogeography and conservation of terrestrial afrotropical birds". Doctoral thesis, University of Cape Town, 1999. http://hdl.handle.net/11427/17318.
Testo completoAbstract (sommario):
Includes bibliography.This study aimed to describe patterns of distribution in terrestrial Afrotropical birds, to investigate the causes of these patterns, and examine how aspects of distributional patterns may be used to prioritize local regions for conservation attention. Presence-only data were gathered and digitized at one-degree square scale for 1686 terrestrial bird species that breed on or regularly visit sub-Saharan Africa as non-breeding migrants. Biogeographical analysis of the 1437 species that are globally restricted to sub-Saharan Africa (Afrotropical endemics) revealed a suite of geographical areas that have a homogenous and characteristic avifaunal composition, termed avifaunal zones. The approach used in this study ensured representativeness in the resultant biogeographical classification scheme, which was not biased towards avifaunas that are species rich or that contain many narrow endemics, and further included avifaunas that consisted of few, but taxonomically and ecologically distinct species (e.g. the Namib Province). Analysis of zonal boundaries exhibiting high levels of turnover, defined specifically as species replacement, were distinguished from zonal boundaries that are characterised by species richness gradients. For instance, the northern forest-savanna boundary between the Guineo-Congolian and Northern Savanna Subregions was shown to consist of a sharp ecotone between forest and savanna, whereas the boundary between the Northern Savanna and Northern Arid Subregions was shown to be dominated by species drop-outs. This shows that whereas the Northern Savanna Subregion represents a unique avifauna that is distinct from that of the Guineo-Congolian Subregion, the Northern Arid Subregion is merely a depauparate subset of the Northern Savanna avifauna. Patterns of species richness and narrow endemism where shown to differ between species groups that exhibit different life history characteristics (e.g. residents vs. migrants) and distributional characteristics Atrotropical endemics vs. nonendemics). Differences can probably be attributed to island biogeography and aerography theory.
29
Shah, Arpit. "DISTRIBUTED BIOGEOGRAPHY BASED OPTIMIZATION FOR MOBILE ROBOTS". Cleveland State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=csu1335969537.
Testo completo
30
Reed, Andrew J. "Biogeography of West Nile Virus in Ohio". Bowling Green State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1609806272985721.
Testo completo
31
Santos, Ana Margarida Coelho dos. "Ecology and biogeography of island parasitoid faunas". Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/5759.
Testo completoAbstract (sommario):
Islands constitute natural laboratories for the study of evolutionary and ecological processes due to their discrete and isolated nature. Island biotas tend to be species–poor and disharmonic compared to the mainland; typically, interspecific competition is low, and entire groups of predators, parasitoids or pathogens are absent from their biotas, so the ecological space is often not fully saturated. Consequently, species from island assemblages often use a wider range of resources than their counterparts from the source mainland. Here, I investigate whether island parasitoid communities have proportionally more generalist species than their source mainland, and which factors determine island community structure. These questions were approached using data on the distribution of Ichneumonoidea (Hymenoptera) species worldwide and with data from a survey conducted in the Macaronesian region. Prior to the global analyses, I assessed whether islands and archipelagos follow the same species–area relationship, and identified which islands have comparable inventories. Globally, islands have proportionally more idiobionts (i.e. generalists) than continental areas. However, there is a latitudinal gradient in the level of generalism of island parasitoid faunas that correlates with some environmental factors and island characteristics; the species pool is the most important determinant of island community structure, together with temperature (for braconids) or biogeographical region (for ichneumonids). Host and parasitoid larvae collected in different islands of the Macaronesian region and adjacent mainland were assigned to Molecular Operational Taxonomic Units using a protocol based on host dissection and DNA barcoding. At this scale, mainland faunas have proportionally more koinobiont species and island communities have a greater proportion of idiobionts. Although overall parasitism rates were similar between islands and mainland, islands had higher idiobiont parasitism rates than expected by chance. In summary, results from this thesis indicate that indeed island parasitoid faunas are biased towards generalist species.
32
Simaika, John P. "Conservation biogeography of South African dragonflies (Odonata)". Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/1711.
Testo completo
33
Kodandaramaiah, Ullasa. "The dispersal-vicariance pendulum and butterfly biogeography /". Stockholm : Department of zoology, Stockholm university, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-29505.
Testo completoAbstract (sommario):
Diss. (sammanfattning) Stockholm : Stockholms universitet, 2009.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: In press. Paper 5: In press. Härtill 5 uppsatser.
34
Schuman, Irina. "The Molecular Diversity and Biogeography of Tardigrades". Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-143134.
Testo completoAbstract (sommario):
Tardigrades can handle extreme conditions such as heat, cold and drought, thanks to a process called cryptobiosis which can be found in a limited amount of taxa on Earth. More knowledge about such animals may help us to understand the potential and limitations of life both on Earth and possibly in space. Such knowledge may also help develop novel, useful applications for the society, such as better storage of sensitive medicine. However, our knowledge about tardigrades is limited. We know little about their distribution and diversity, especially in Sweden, and above all in northern Sweden. The aim of this study was threefold; i) to explore the biogeography of the tardigrades based on molecular data; ii) to screen for tardigrades in Umeå by examining moss samples from different locations; and iii) to explore some of the associates of tardigrades in moss (such as bacteria and micro- and meiofauna). The biogeography was explored by collecting all published ribosomal gene sequences (the small subunit 18S rRNA) from the Silva gene database. These sequences were used for plotting the locations from which these gene sequences had been retrieved on a world map and the correlation between gene sequence, country and biotope was examined. The tardigrade groups most sequenced are Macrobiotus, Ramazottius and Echiniscus, and the milieu most studied seems to be different types of soil. Other investigated isolation sources are drinking water, cryconite and church walls. However, much remains to be further explored. For example, the world map showed that the only molecular data on Swedish tardigrades have been retrieved from Öland. In the lab, tardigrades were found in some of the moss samples, together with other micro- and meiofauna. Three groups of bacteria (Betaproteobacteria, Gammaproteobacteria and Firmicutes) could be identified in one of the investigated mosses. These results suggest that tardigrades live in a diverse environment with different types of organisms both on the microbial as well as on the micro-meio-fauna level.
35
Portillo, José Thales da Motta. "Biogeography and ecophylogenetics of atlantic forest snakes /". São José do Rio Preto, 2019. http://hdl.handle.net/11449/181614.
Testo completoAbstract (sommario):
Orientador: Ricardo Jannini SawayaBanca: Marcio Roberto Costa Martins
Banca: Laura Rodrigues Vieira de Alencar
Banca: Fernando Rodrigues da Silva
Banca: Cristiano de Campos Nogueira
Resumo: A Mata Atlântica da América do sul é um mosaico de diferentes fitofisionomias, relacionadas a pressões seletivas correspondentes a fatores ecológicos e evolutivos distintos, os quais regulam a distribuição da biodiversidade entre os habitats. Exploramos, neste trabalho, como a diversidade de serpentes é distribuída ao longo do gradiente latitudinal da Mata Atlântica. Primeiro analisamos a associação entre a riqueza em espécies e a diversidade filogenética de serpentes com tempo para especiação e extensão geográfica ao longo do gradiente latitudinal. Nós também exploramos as amplitudes de nicho climático destas serpentes. E, finalmente, decompusemos a composição filogenética de ilhas costeiras do sudeste da Mata Atlântica no intuito de entender como área e distância com o continente poderia afetar diferentes componentes da diversidade de serpentes. Encontramos que área é o principal fator relacionado com riqueza em espécies, independentemente do tempo para especiação. Observamos a maior riqueza em espécies em linhagens mais recentes nas zonas serranas do sudeste. Amplitudes de nicho climático, associadas à precipitação, mostraram conservação filogenética, afetando a distribuição dos clados mais recentes. Em nosso exemplo de ilhas, mostramos que distintos fatores ecológicos podem afetar riqueza em espécies e diversidade filogenética diferentemente. Desta maneira, fatores idiossincráticos poderiam gerar diferentes respostas em diferentes linhagens ao longo do gradiente...
Abstract: The Atlantic Forest of South America is a mosaic of different vegetation physiognomies corresponding to distinct evolutionary and ecological factors that drive biodiversity distribution. One of these factors is climatic variation. We explored herein how snake diversity, (measured as species richness and phylogenetic diversity) is distributed along the Atlantic Forest latitudinal gradient, taking area and time-for-speciation into account. We first analyzed the association of species richness and phylogenetic diversity with time-forspeciation and geographical extent along the latitudinal gradient. We also explored climatic niche breadths. And finally, we decomposed the phylogenetic composition across coastal islands in southeastern Atlantic Forest, to understand how island area and distance from the mainland drive different components of snake diversity. We found that area is a major driver of species richness, regardless of time-for-speciation. We observed higher species richness of more recent lineages in southeastern mountain ranges. Climatic niche breadths associated to precipitation showed phylogenetic conservatism, affecting the distribution of more recent clades. In our island case study, we show that distinct ecological factors can drive species richness and phylogenetic diversity differently. In this way, idiosyncratic factors generate different responses in different lineages across environmental gradients. We hope to shed some light on ecological and historical ...
Doutor
36
Jensen, Paul Robert. "Marine actinomycete diversity, biogeography, and secondary metabolite production". Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2006. http://wwwlib.umi.com/cr/ucsd/fullcit?p3204582.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--University of California, San Diego, 2006.Title from first page of PDF file (viewed April 4, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
37
Glaeser, Jens. "In situ Metabolism and Biogeography of Phototrophic Consortia". Diss., lmu, 2004. http://nbn-resolving.de/urn:nbn:de:bvb:19-19707.
Testo completo
38
Sebastian, Patrizia. "Phylogenetics and biogeography of two clades of Cucurbitaceae". Diss., lmu, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-146298.
Testo completo
39
Sawada, Michael Charles. "Late quaternary paleoclimates and biogeography of North America". Thesis, University of Ottawa (Canada), 2001. http://hdl.handle.net/10393/9031.
Testo completoAbstract (sommario):
Pollen, spores, and dinoflagellate cysts are used with the modern analog technique (MAT) to provide paleoclimate reconstructions for terrestrial and marine environments in northeastern North America. Multivariate analysis of marine and nearby terrestrial pollen sequences from Hudson Bay, Labrador and the St. Lawrence, differentiate tundra, boreal and deciduous forest assemblages in time and space. These three regions had differing climate histories with respect to deglaciation and air mass boundaries. Prior to 6000 14C yr BP, cooler temperatures reconstructed along the Labrador margins agree with climate simulations indicating a persistent anticyclone over the Quebec-Labrador ice sheet. A late Holocene cooling at forest-tundra sites suggests a recent southern movement in the mean position of the polar front. The degree to which those critical thresholds of dissimilarity, that are used to identify non-analog pollen assemblages, are due to limitations of the modern pollen database or critical decisions within the MAT are explored by means of stochastic simulation, spatial statistics and graphical techniques. Critical thresholds of SQD, as derived by the expected value under randomization, become greater as the number of taxa in the pollen set increases. Larger pollen sets, with continentally infrequent but regionally abundant taxa, better distinguish between continental vegetation zones. Global and local spatial autocorrelation within climate anomalies indicate where the modern sample network induces biases in the climate reconstruction using the MAT. The spatial scale of terrestrial climate or vegetation reconstructions from pollen in lake-sediments is investigated through the study of pollen source area in southern Quebec. Despite the different regional vegetation, estimated pollen source areas and relevant pollen productivity for Pinus, Picea, Abies, Fagus, Quercus and Tsuga are consistent with studies from Michigan, Wisconsin and Sweden. These estimates are robust with respect to various plant abundance distance-weighting schemes and imply that the same inferences can be made regarding plant abundance from pollen throughout a lake-derived fossil pollen sequence. Stochastic simulations illustrate that the definition of relevant pollen source area requires consistent within-site vegetation heterogeneity within a network of pollen sites. Underutilized proxy-climate data from wetland taxa are demonstrated to contain climate signals at the continental scale and have the potential to further our climatic and biogeographic picture of North America over the past 21,000 years. Pollen and spores from modern wetland taxa conform to their geographic ranges and allow interpretations of their past range changes. The climatic tolerances that govern their geographic distributions are used to interpret past range changes in climatic terns. Sphagnum spore distributions suggest major peatland developments after 9 ka and 5 ka. Sphagnum, Potamogeton, Isoetes, Myriophyllum Typha/Sparganium, and Menyanthes trifoliata were in Alaska during the last glacial maximum (LGM) and moved into the ice-free corridor by 13 ka. Since the LGM, four migration routes for aquatic taxa are identified in response to the climate changes of the late Quaternary.
40
Bouchard, Giselle. "Freshwater diatom biogeography of the Canadian Arctic Archipelago". Thesis, University of Ottawa (Canada), 2004. http://hdl.handle.net/10393/26589.
Testo completoAbstract (sommario):
The biogeography of diatoms in 62 lakes across the Canadian Arctic Archipelago was studied. A total of 326 taxa was found, with up to 85 and as low as 8 taxa identified in any one lake. Rarefaction-estimated richness correlated with lake size. Although diatom assemblages showed regional patterns, between-lake variability in any region was high, indicating that local factors are important in determining the assemblages. Newly delineated genera showed interpretable geographic patterns and could be related to environmental factors, suggesting that this more natural grouping may enhance our understanding of diatom ecology. Some taxa showed southern and regionally limited distributions. Many taxa prefer colder temperatures while others were more influenced by lake water parameters. Assemblages with zero or low abundance of fragilaroid taxa tended to occur in larger lakes with higher silica. These lakes had more diverse assemblages including Gomphonema, Encyonema , and Encyonopsis taxa, suggesting a possible relationship between non-fragilaroid taxa and lake size and silica. Geographic, physical, and chemical factors are needed to explain diatom distributions in the Arctic.
41
Jennings, John T. "Systematics and biogeography of hyptiogastrine wasps (Hymenoptera: Gasteruptiidae)". Title page, contents and summary only, 1999. http://web4.library.adelaide.edu.au/theses/09PH/09phj543.pdf.
Testo completoAbstract (sommario):
Copies of six of the author's previously published articles in pocket inside back cover. Bibliography: leaves 188-208. This study has investigated the phylogenetic relationships among genera and species of hyptiogastrine wasps, examined whether the current distribution of taxa can be explained by vicariance events, and revised the taxonomy of species. (summary)
42
Wang, Rui. "Osteology, phylogeny and biogeography of Parioglossus (Perciformes: Gobioidei)". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ63243.pdf.
Testo completo
43
Wells, Alice. "The systematics and biogeography of Australian hydroptilidae (Trichoptera) /". Title page, contents and abstract only, 1986. http://web4.library.adelaide.edu.au/theses/09PH/09phw453.pdf.
Testo completo
44
Squire, Gareth. "The biogeography of the Indo-West Pacific echinoids". Thesis, Queen Mary, University of London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391824.
Testo completo
45
Quinn, Rachel. "The biogeography of rare species and their conservation". Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311471.
Testo completo
46
Sanders, Kate L. "Cryptic speciation and biogeography in Indomalayan pitvipers (Trimeresurus)". Thesis, Bangor University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402664.
Testo completo
47
Hughes, Alice Catherine. "The conservation and biogeography of Southeast Asian bats". Thesis, University of Bristol, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.541648.
Testo completo
48
Holstein, Norbert. "Evolution, biogeography, and monographic treatment of Coccinia (Cucurbitaceae)". Diss., Ludwig-Maximilians-Universität München, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-178656.
Testo completo
49
Parsons, Michael Jonathan. "The autecology and biogeography of New Guinea butterflies". Thesis, University of London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243801.
Testo completo
50
Kenicer, Gregory J. "Systematics and biogeography of Lathyrus L. (Leguminosae, Papilionoideae)". Thesis, University of Edinburgh, 2007. http://hdl.handle.net/1842/15150.
Testo completoAbstract (sommario):
The phylogenetic position of Lathyrus relative to the rest of tribe Fabeae was estimated based on sequence data from the chloroplast matK region. This study included 24 species of Lathyrus (including 19 newly sequenced). A clade containing Lathyrus, Pisum and Vavilovia is strongly supported as monophyletic. The results support the existing morphologically based hypothesis that Pisum and Vavilovia are sister genera. To study relationships within Lathyrus, accessions representing 53 of its species were sequenced for the internal transcribed spacers and 5.8S-coding region of nuclear ribosomal DNA (ITS), and the chloroplast trnL-F and trnS-G regions. Within Lathyrus, the majority of the sections are centred on the Mediterranean region, which appears to be the area of origin for the genus. Sections Orobus, Aphaca, and Pratensis form a northern Eurasian-New World clade. Within this clade, the North American and eastern Eurasian species, including both Holarctic species (L. palustris and L. japonicus), form a transberingian clade of relatively recent origin and diversification. In each phylogenetic analysis, the predominantly South American Notolathyrus group is resolved as monophyletic and unrelated to the transberingian clade. This finding refutes the traditional view that the South American species of Lathyrus are derived from the extant North American-East Asian lineage. The South American lineage may be derived from long-distance dispersals directly from Eurasia. This provides support for long-standing morphologically based hypotheses that sect. Notolathyrus is a natural grouping. A synoptic revision provides the first taxonomic treatment to cover all members of sect. Notolathyrus. The treatment recognises 26 species endemic to South America, plus a subspecies of L. pusillus extending to the southeastern USA. One species (L. bolivianus Kenicer) is described as new.