This thesis concerns the molecular phylogenetics of three tribes of the family Bovidae, the Antilopini, Neotragini, and Tragelaphini. None of these tribes have been studied extensively with molecular techniques. The tribe Antilopini is one of the most speciose tribes (it includes 6 genera with 20 species) and the classification of several species of the genus Gazella is not clear. The tribe Neotragini is thought to be paraphyletic. Mitochondrial sequences of the cytochrome c oxidase ill and cytochrome b genes totalling 1083 base pairs have been determined for 52 taxa and used to determine phylogenetic relationships using cladistic and distance methods. Karyological analysis identified polymorphisms in several species (especially in Gazella saudiya and G. subgutturosa). Karyotypes of G. dorcas pelzelni and an XXY karyotype of a G. dorcas individual are shown for the first time. The main conclusions are that the Antilopini and the Tragelaphini are monophyletic and that the tribe Neotragini is paraphyletic. There is a lack of phylogenetic resolution between tribes which is probably due to the rapid radiation of the different tribes about 20 million years ago. The genus Taurotragus in the tribe Tragelaphini is shown to be paraphyletic and it would be appropriate to incorporate these taxa in the genus Tragelaphus. The genus Gazella could be paraphyletic, due to the position of Antilope cervicapra, in which case the genus needs to be split into two genera or renamed as Antilope. It is also argued that the use of the subgenus Trachelocele should be discontinued and that its only species, G. subgutturosa should be included in the subgenus Gazella. G. rufifrons and G. thomsonii may be more appropriately considered as conspecific. Cytogenetic and sequence data reveal that the herd of G. saudiya in Al Areen Wildlife Park is hybridised with G. bennettii and it is argued that it is important to identify unhybridised G. saudiya in other collections, since this species is on the brink of extinction. This case study demonstrates the need to genetically screen individuals which are part of a captive breeding program, especially if they are intended for reintroduction into the wild.

Although pollinator-driven selection is known to generate pigmentation variation in plants, the contribution of abiotic factors in the evolution of pigmentation is still poorly understood. This is largely due to a lack of research on pigmentation variation in wind-pollinated (anemophilous) plants, where the confounding effect of pollinators can be excluded. Here, I study pigmentation variation in Carex, the world’s largest anemophilous genus. Using 456 North American species, I use phylogenetic comparative methods to test (1) whether darker inflorescence parts are correlated with short growing seasons and (2) whether inflorescence pigmentation has affected the diversification dynamics of Carex throughout time. I also examine UV irradiance and precipitation at both the interspecific and intraspecific (four wide-ranging species, >100 accessions each) levels, factors previously associated with floral darkness at high altitude and latitude. At the inter- and intraspecific level, darker inflorescence parts are associated with short growing seasons, as seen in arctic and alpine regions. Additionally, dark pigmentation is associated with stronger UV irradiance and higher precipitation in the intraspecific dataset. Finally, despite the adaptive importance of pigmentation in arctic and alpine regions, it has not contributed to the diversification dynamics of Carex. The results suggest that climatic conditions can promote pigmentation variation in anemophilous plants, and are most consistent with the hypothesis that dark inflorescence parts accelerate reproductive development by absorbing solar energy. Finally, despite the adaptive importance of pigmentation in arctic and alpine regions, it has not contributed to the diversification dynamics of Carex.

No description available.

One of the few remaining mysteries in mammalian phylogeny is the issue of Chiropteran phylogeny. In order to further investigate the diphyletic hypothesis that states that Megachiroptera evolved from primate-like gliders and that Microchiroptera evolved from insectivores, the cholinergic, catecholaminergic, serotonergic and orexinergic systems were analyzed in, not only five insectivores (Crocidura cyanea, Crocidura olivieri, Sylvisorex ollula, Paraechinus aethiopicus and Atelerix frontalis) and three prosimian primates (Galagoides demidoff, Perodicticus potto and Lemur catta), but in species from other orders of interest including the Afrotheria (Potamogale velox, Amblysomus hottentotus and Petrodromus tetradactylus), Lagomorpha (Lepus capensis) and Scandentia (Tupaia belangeri). Brains of the mammals were coronally sectioned and immunohistochemically stained with antibodies against cholineacetyltransferase, tyrosine hydroxylase, serotonin and orexin-A. The presence or absence of 93 nuclei within these neuromodulatory systems was entered into modern cladistics software for analysis of the 13 studied species, as well as an additional 40 previously studied mammals. The majority of nuclei revealed in the current study were similar among the species investigated and to mammals generally, but certain differences in the nuclear complement highlighted potential phylogenetic interrelationships. The Afrotherian, A. hottentotus, presented unusual cholinergic interneurons in the cerebral cortex, hippocampus, olfactory bulb and amygdala, and exhibited an unusual foreshortening of the brain, such that a major mesencephalic flexure in the brainstem was evident. The Afrotherian, P. tetradactylus, lacked the catecholaminergic A15d nucleus as in a previously studied member of Macroscelididae. The three Insectivoran shrews lacked the cholinergic parabigeminal and Edinger-Westphal nuclei, had a mediodorsal arch of the cholinergic laterodorsal tegmental nucleus, lacked the catecholaminergic A4 and A15d nuclei and presented an incipient ventral division of the substantia nigra which is identical to previously studied Microchiroptera. All three prosimians presented a central compact division of catecholaminergic locus coeruleus (A6c) surrounded by a shell of less densely packed (A6d) tyrosine hydroxylase immunopositive neurons. This combination of compact and diffuse divisions of the locus coeruleus complex is only found in primates and Megachiropterans of all the mammalian species studied to date. T. belangeri of the Scandentia contained ChAT+ neurons within the nucleus of the trapezoid body as well as the superior olivary nuclear complex, which has not been described in any mammal studied to date. L. capensis of the Lagomorpha presented vi the rodent specific rostral dorsal midline medullary nucleus (C3), while T. belangeri was lacking both the ventral and dorsal divisions of the anterior hypothalamic group (A15v and A15d), and both species were lacking the primate/Megachiropteran specific compact portion of the locus coeruleus. Our neuroanatomical analysis suggests a phylogenetic relationship between the Soricidae (shrews) and the Microchiropterans, supports the phylogenetic grouping of primates with Megachiropterans, confirms previous molecular evidence of the relationship between lagomorphs and rodents within the super-order Glires, and suggests that primates are phylogenetically closer to Megachiroptera than to any members of the Euarchontoglires. The cladistic analysis confirmed the neuroanatomical analysis with the most parsimonious tree placing Megachiroptera into the Euarchontoglires as a sister group to primates and the Microchiroptera next to Soricidae within the Laurasiatheria.

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Montagnea arenaria [Hymenogastrales, Basidiomycota] , adapted to desert and xeric habitats, is morphologically and phenotypically variable. Species have been described on the basis of macromorphology and spore shape and size. This study was initiated to investigate populations of M. arenaria from Namibia in Africa and the Southwestern United States. It was hypothesized that biological species would exist in the widely separated populations. Spores from single sporocarps were germinated, single spore isolates were obtained and selfed to obtain mating types. On transfer, clamp connections were not maintained and mating patterns could not be achieved. Nuclear staining revealed multinuclei in the hyphae of both single spore isolates and compatible crosses. Spores were stained and found to have either 1 or 2 nuclei, but only four sterigmate basidia were observed. Limited partial compatibility was achieved and in some cases clamp connections formed within and between crosses from the two continents. Genomic DNA was extracted from old herbarium specimens. The ITS1, 5.8S, and ITS4 regions of nuclear ribosomal DNA were amplified and sequenced directly. Phylogenetic analysis using PAUP was performed. The hypothesis that Montagnea would form different biological species based on continental separation was rejected. In fact, the complex of isolates from widely varying locations not only had partial compatibility, but the variation in ITS sequences among widely distributed collections was relatively low. Lastly, no correlation between sporocarp size and gene flow among specimens from a wide variety of habitats was found. It appears that M. arenaria is a single, highly variable, widely distributed species. / Master of Science