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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Population Genetics, Karyology, and Morphology of Certain Species of the Peromyscus Truei Group

Hart, Billy Joe 05 1900 (has links)
The systematic relationship of two species of the Peromyscus truei group (P. truei and P. difficilis) was analysed through the application of starch gel electrophoresis, numerical taxonomy, and chromosomal techiques. Of 20 loci examined, 11 were monomorphic in all populations, two exhibited variation in only two populations, and seven loci were polymorphic in two or more populations. The mean number of polymorphic loci per population was 0.186, the mean number of polymorphic loci per individual was 0.024, and the proportion of loci heterozygous per individual was 2.4%. Chromosomal forms of P. truei, P. t. gentilis (FN 54) and P. t. truei (FN 62), and P. difficilis, P. d. petricola (FN 56) and P. d. nasutus (FN 58), were consistent for their karyotypes throughout their geographic ranges. No chromosomal hybrids were detected. Numerical analysis of morphological characters and similarity values based on allelic frequencies utilizing Roger's coefficient (S) demonstrated a distinct seperation of karyotypic forms of P. truei (S = 0.902) and P. difficilis (S = 0.924) and were below the mean value of S for conspecifics (S = 0.950). All data indicates that each chromosomal form of the P. truei group examined represents four distinct species. The oldest available name for chromosomal forms of P. true with a fundamental number of 62 is Peromyscus truei Shufeldt (1885) and the oldest available name for chromosomal forms with a fundamental number of 54 is Peromyscus gratus Merriam (1898). The oldest available name for chromosomal forms of P. difficils with a fundamental number of 58 is PeromYSCus nasutus Allen (1891) and the oldest available name for chromosomal forms with a fundamental number of 56 is Peromyscus difficilis Allen (1891).
2

Habitat associations of the long-nosed potoroo (potoroos tridactylus) at multiple spatial scales

Norton, Melinda A. January 2009 (has links)
Thesis (M.Sc. (Res.))--University of Wollongong, 2009. / Typescript. Includes bibliographical references: leaf 147-159.
3

Phylogenetic systematics of Scrapter (Hymenoptera: Anthophila: Colletidae).

Davies, Gregory Bernard Peter. January 2006 (has links)
Scrapter Lepeletier de Saint-Fargeau & Audinet-Serville, 1828 (Hymenoptera: Aculeatea: Anthophila: Colletidae) is a genus of solitary bees largely endemic to southern Africa. This dissertation investigated the phylogenetic systematics of the genus. Eleven new species of Scrapter are described, principally from the Succulent Karoo biome of South Africa, bringing the total number of species in the genus to 42. An updated dichotomous key to facilitate identification is provided. The previously unknown females of S. albifumus Eardley and S. amplispinatus Eardley are also described. The genus is recorded from outside southern Africa for the first time with the collection of S. nitidus (Friese) in Kenya. This constitutes a significant range extension of the genus. The taxonomic status of five species described by Cockerell in 1944, and subsequently overlooked, is addressed. They are all found to be synonyms of other Scrapter species, except one, which is found to be a Ctenoplectrina species (Apidae: Apinae: Ctenoplectrini). The new synonymies are: S. subincertus Cockerell = S. niger Lepeletier de Saint-Fargeau & Audinet-Serville; S. brunneipennis Cockerell = S. niger Lepeletier de Saint-Fargeau & Audinet-Serville; S. merescens Cockerell = S. leonis Cockerell; S. sinophilus Cockerell = S. algoensis (Friese). Scrapter ugandica Cockerell becomes Ctenoplectrina ugandica (Cockerell) as a new combination. Investigation of selected morphological features (e.g. postmentum, facial fovea, galea) revealed much diversity in Scrapter. The monophyly of Scrapter is not supported by unambiguous apomorphies, but is defensible by the congruence of various qualitative characters (e.g. premental fovea, T2 fovea, hindleg and sternal scopa in [females], two submarginal cells). A cladistic analysis using 25 morphological characters recovered numerous most parsimonious trees under both equal- and successive-weighting. To aid in resolution, several taxa known from only one sex or from very limited material, and with many unknown states, were deleted from the matrix. Analysis using this reduced matrix under equal- and successive-weighting resulted in better resolution, although with low consistency index values. Several subclades were common to both cladograms, and likely represent monophyla. The low consistency indices and general lack of unique synapomorphies upholding these subclades, however, dictated against making any classificatory re-arrangements. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.
4

Systematics of Bonatea (Orchidaceae) : species boundaries and phylogeny.

Ponsie, Mariaan E. January 2006 (has links)
Bonatea Willd. (Orchidaceae: Habernariinae) is a small genus confined to the African continent and Arabia. Phylogenetic and morphometric analyses were undertaken in order to evaluate phylogenetic relationships and species delimitations within Bonatea. In the phylogenetic analyses, little congruence was found between ITS and matK molecular data, while morphological results were largely congruent with those of the ITS region. There is little sequence variation within and between Bonatea species, which could indicate a recent and rapid radiation. The generic characters for Bonatea were reevaluated. Bonatea is closely related to Habenaria but differs in having a galeate middle rostellum lobe that is clearly separated from the vertical anther thecae. By contrast, species of Habenaria have short anthers that are slightly arcuate and flank the rostellum. Morphometric analyses were used to determine taxon boundaries within the Bonatea speciosa and Bonatea cassidea complexes, respectively. Principle component and cluster analyses of morphological variation support the recognition of Bonatea antennifera Rolfe, Bonatea boltonii (Harv.) Bolus and Bonatea speciosa (L.f.) Willd. as distinct species. Morphological evidence supports the inclusion of Bonatea porrecta (Bolus) Summerh. and Bonatea volkensiana (Kraenzl.) Rolfe in the B. speciosa c1ade and this is corroborated by molecular data for the former. Clinal variation in petal lobe dimensions and colour across the distribution range of Bonatea cassidea Sond. encompasses the taxon Bonatea saundersiae (Harv.) T.Durand & Schinz, which is reduced to synonymy. Bonatea saundersioides (Kraenzl. & Schltr.) Cortesi, the sister species to B. cassidea, also exhibits colour variation in its petals. A revision of Bonatea is presented recognizing 14 species. Bonatea eminii (Kraenzl.) Rolfe was excluded due to insufficient information. Full descriptions are provided with diagnostic characters and distributional maps. Bonatea bracteata G.McDonald & McMurtry and Bonatea tentaculifera Summerh. are removed from Bonatea based on their rostellum structure which is inconsistent with the revised generic concept. Bonatea bracteata was transferred as Habenaria transvaalensis Schltr. and B. tentaculifera was renamed Habenaria bonateoides M.Ponsie, as the specific epithet is currently occupied within Habenaria. / Thesis (M.Sc.)-University of KwaZulu-Natal, 2006.

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