"December 2001" / Bibliography: leaves 227-246. / iv, 246 leaves : ill. ; 30 cm / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Environmental Biology, 2002

Thesis (MSc)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: The present study aims to determine the phylogenetic relationships among the sand lizards, Pedioplanis. In addition, a single mitochondrial gene is used to investigate the geographic genetic structure of the widey distributed P. burchelli. With 11 species, Pedioplanis is the most speciose genus among the southern African genera of the family Lacertidae. All the species are restricted to the subcontinent with the exception of three (P. namaquensis, P. undata and P. benguellensis), which extend their range northwards into Angola. A total of 2200 nucleotide positions derived from two mitochondrial markers (ND2 and 16S rRNA) and one nuclear gene (RAG-1) are used to determine the phylogenetic relationships among ten of the eleven Pedioplanis species. The first well resolved gene tree for the genus, drawn from 100 individuals, is presented and this is largely congruent with a phylogeny derived from morphology. Contrary to some previous suggestions, Pedioplanis forms a monophyletic assemblage with Heliobolus and Nucras. The genus Pedioplanis is monophyletic with P. burchelli/P. laticeps forming a sister clade to all the remaining congeners. Two distinct geographic lineages can be identified within the widespread P. namaquensis; one occurs in Namibia, while the other occurs in South Africa. The “P. undata” species complex is monophyletic, but one of its constituent species, P. inornata, is paraphyletic. Relationships among the subspecies of P. lineoocellata are much more complex than previously documented. An isolated population previously assigned to P. l. pulchella is paraphyletic and sister to the three named subspecies. The phylogeny identifies two biogeographical groupings that probably diverged during the mid-Miocene. The development of the Benguella Current could have initiated isolation mechanisms associated with changes in habitat that could have generated barriers and played a role in the evolution of this group. At the lower taxonomic level, the mtDNA phylogeographic structure of the wide spread P. burchelli in South Africa reveal at least six distinct clades that are geographically partitioned. The first one is restricted to the eastern mountains along the Great Escarpment (GE). The next three are found along the Cape Fold Mountains (CFM): the north-west CFM, central CFM and eastern CFM. The fifth one shares samples from central CFM and GE. The last clade is restricted to the eastern central mountains of the GE. These six geographic groupings are genetically divergent from each other and they started separating in the early Pliocene period. Phylogeographic studies on other taxa in the region have found different levels of genetic structuring among or within taxa. The fact that P. burchelli is restricted to high altitude areas could have resulted in limited dispersal and consequently contributed to its geographic structure. However, the exact cause of the pattern obtained is not readily apparent. Habitat fragmentation in the past is probably one of the most influential factors shaping the genetic distribution of the species across South Africa. The inclusion of nuclear markers will shed more light on the evolutionary history of P. burchelli in South Africa. / AFRIKAANSE OPSOMMING: Die huidige studie stel ten doel om ‘n filogenie daar te stel vir die Sand akkedisse, Pedioplanis. ‘n Enkele mitochondriale geen is ook gebruik om die geografiese genetiese struktuur van die wydverspreide P. burchelli vas te stel. Met 11 spesies is Pedioplanis die mees spesieryke genus onder die suidelike Afrika genera wat aan die Lacertidae familie behoort. Al die spesies is beperk tot die subkontinent met die uitsondering van drie (P. namaquensis, P. undata en P. benguellensis), wat ‘n uitgebreide verspreiding het noordwaarts tot in Angola. ‘n Totaal van 2200 nukleotied posisies wat afkomstig is van twee mitochondriale merkers (ND2 en 16S rRNA) en een nukluêre geen (RAG-1) is gebruik om die filogenetiese verwantskappe tussen 10 van die 11 Pedioplanis spesies vas te stel. Die eerste goed geondersteunde geen boom vir die genus, gebasseer op 100 individue, is verkry en dit is meestal ooreenstemmend met ‘n filogenie gebasseer op morfologie. In teenstelling met sekere voorstelle van die verlede vorm Pedioplanis ‘n monofiletiese groep tesame met Heliobolus en Nucras. Die genus Pedioplanis is monofileties met P. burchelli/P. laticeps wat ‘n suster groep vorm van al die oorblywende lede van die genus. Twee herkenbare geografiese lyne kan geidentifiseer word in die wydverspreide P. namaquensis; een kom in Namibia voor, terwyl die ander een in Suid Afrika voorkom. Die “P. undata” spesies kompleks is monofileties, maar een van die spesies wat deel uitmaak van die groep, P. inornata, is parafileties. Verwantskappe tussen die subspesies van P. lineoocellata is meer kompleks as wat aanvanklik aanvaar is. ‘n Geisoleerde bevolkimg wat voorheen toegesê is aan P. l. pulchella is parafileties en verteenwoordig ‘n suster groep van die benaamde subspesies. Die filogenie identifiseer twee biogeografiese groeperings wat moontlik gedivergeer het gedurende die middel-Miocene. Die ontwikkeling van die Benguella stroom het dalk versperrings geinisiëer as gevolg van die gesamentlike veranderinge in habitat wat dalk ook ‘n rol gespeel het in die evolusie van die groep. Op die laer taksonomiese vlak het die mtDNA filogeografiese struktuur van die wydverspreide P. burchelli in Suid Afrika ten minste ses groepe aangetoon wat geografies van mekaar geskei is. Die eerste een is beperk tot die oostelike berge wat aan die Groot Eskarpement (GE) behoort. Die volgende drie word gevind in die Kaapse Vouberge (KVB): die noord-westelike KVB, sentrale KVB en oostelike KVB. Die vyfde een deel eksemplare van beide die GE en die KVB. Die laaste groep is beperk tot die oostelike en sentrale berge van die GE. Hierdie ses geografiese groepe is geneties geskei van mekaar en hulle het begin om apart te ontwikkel gedurende die vroë Pliocene periode. Ander filogeografiese studies in die area het verskillende vlakke van genetiese struktuur vertoon tussen en binne taksa. Die feit dat P. burchelli beperk is tot hoogliggende dele kon moontlik bygedrae het tot die geografiese struktuur. Die presiese oorsaak van die patroon wat verkry is, is nie ooglopend nie. Habitat fragmentasie in die verlede is moontlik een van die mees invloedrykste faktore wat die genetiese verspreiding van die spesie in Suid Afrika beinvloed het. Die insluiting van nukluêre merkers sal meer lig warp op die evolusionêre geskiedenis van P. burchelli in Suid Afrika.

Plantago ovata Forssk. (Plantaginaceae) is a winter annual species which, in North America, inhabits desert and Mediterranean habitats of the southwest United States, northwest Mexico and the Channel Islands of California and Mexico. In the eastern hemisphere P. ovata inhabits desert regions ranging from the Canary Islands, across northern Africa to western India. The wide disjunction between P. ovata in the western and eastern hemispheres poses an interesting question as to the origin and biogeography of the species. Previous authors have hypothesized that P. ovata was introduced to North America over the Bering land bridge, from Asia, during the Miocene, or introduced anthropogenically from Europe during the 18th century by Spanish settlers. In this study we examined sequence data from the chloroplast trnL-trnF, trnS-trnG and psbA-trnH regions, the nuclear ribosomal internal transcribed spacer (ITS) and a region 5' of the TCP region of a CYCLOIDEA gene. Using a molecular clock based on an ITS calibration within the Plantago genus, and a clock for plant chloroplast, we date a non-anthropogenic introduction event, from the Old World to North America, approximately 200,000-650,000 years ago. This is consistent with a Pleistocene origin, and does not support a Miocene origin of the disjunction. Based on a morphological survey of 552 specimens, from throughout the world range of P. ovata, we suggest the recognition of four subspecific taxa. Molecular phylogenetic analysis of chloroplast DNA and nuclear ribosomal DNA ITS sequences support this taxonomic treatment. Furthermore, phylogenetic sequences of the CYCLOIDEA gene support the morphological data. Both suggest the origin of North American P. ovata as a result of hybridization between Old World P. ovata varieties. This event provides further evidence that hybridization may serve as a predictor of invasiveness in plants. / Graduation date: 2005

Two of the most challenging goals of evolutionary biology are to reconstruct the evolutionary relationships among all extant species and to understand the process by which new species form. Accomplishing these goals will require accurate computational methods for reconstructing phylogenetic trees, general analytic models of speciation, and powerful statistical tools for studying the process of speciation in natural systems. In the first chapter, I study the effects of improper model assumption on estimates of phylogeny. Using DNA sequence data simulated under a variety of models of sequence evolution, I demonstrate that use of oversimplified models can result in erroneous phylogeny estimates. This result suggests that if the models currently utilized are oversimplified then current estimates of phylogeny may be inaccurate and more complex models need to be developed and employed. In the second and third chapters, I study one process thought to be important in completing the final stages of speciation: reinforcement. Using simulations of a hybrid zone, I show that the process of reinforcement can result in patterns other than reproductive character displacement. I also show that speciation by reinforcement is more likely when the genes involved in reproductive isolation are sex-linked. In the fourth chapter, I develop a statistical method of quantifying the degree of isolation between species undergoing divergence. Using genotype data obtained from natural hybrid zones, this novel method can be used to estimate the fitness of hybrids during different stages of their life cycle. This approach offers a new approach to empirical biologists studying extrinsic postzygotic isolation in natural systems.

The taxonomy and biogeography of the southern African pheasant shell fauna are poorly known. Thirty–one nominal taxa referable to Phasianelloidea have been described or recorded in this region, but no systematic revision of these has ever been undertaken. Morphological evidence suggests that 16 taxa represent valid species, 13 are synonyms and two represent incorrect identifications. DNA sequence data from mitochondrial COI and 16S markers are used to assess the validity of the described nominal southern African Tricolia species. Phylogenetic analyses recovered seven distinct clades. Tricolia adusta, T. elongata, T. formosa, T. kochii, T. saxatilis and T. neritina were recovered as distinct species. Tricolia africana and T. capensis are genetically indistinguishable. However, morphological characters of the shell are clearly diagnosable. This could be due to incomplete sorting (ancestral polymorphism) reflecting recent speciation with rapid morphological and ecological divergence co–incident with geographical separation. Similarly, there is little genetic differentiation between T. bicarinata, T. insignis and T. kraussi. In this case the similarity is also supported by morphological data as the three species are conchologically close with intergrading shell characters, and might even be one species exhibiting ecogeographic variation in shell form. Monophyly of the southern African Tricolia species is not supported as well as the relationship between these and the European Tricolia pullus. In the last chapter a molecular phylogeny based on sequence data from mtDNA (COI and 16S), nuclear (18S and 28S) and the combined data (COI, 16S, 18S and 28S) is presented for the Phasianelloidea. Bayesian inference analyses performed on the combined data support the monophyly of Tricolia sensu stricto, Eulithidium and Phasianella. Tricolia sensu lato is not monophyletic, as its southern Australian and Indo–West Pacific species do not cluster with its southern African and Eastern Atlantic representatives. The position of Hiloa and Gabrielona within the Phasianelloidea is unresolved. Phylogenetic reconstructions using bayesian inference support monophyly of the Phasianelloidea. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

Orientador: Shirlei Maira Recco Pimentel / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-14T11:03:41Z (GMT). No. of bitstreams: 1 Egito_GabrielToselliBarbosaTabosado_M.pdf: 537508 bytes, checksum: e9fd34e6de85068aa05990a955acff88 (MD5) Previous issue date: 2009 / Resumo: Dendropsophus minutus está amplamente distribuído ao Leste dos Andes, na América do Sul e possui uma grande diversidade acústica e morfológica, o que sugere que possa haver mais de uma espécie sob esse nome. Sua coloração dorsal pode ser classificada em dois padrões principais, hourglass e bivittata. No presente estudo, 14 parâmetros morfométricos e seqüências de DNA com 357 pares de bases do gene citocromo b mitocondrial foram analisados objetivando um melhor entendimento acerca da variação de D. minutus no Brasil. Tanto os resultados moleculares quanto os fenotípicos revelaram a presença de uma alta estruturação da diversidade dessa espécie, mostrando que a divergência entre populações é, geralmente, proporcional à distância geográfica, exceto no estado de São Paulo, sudeste do Brasil. Nessa região, a Serra do Mar está aparentemente agindo como uma barreira geográfica para o fluxo gênico, isolando duas linhagens. A primeira, formada pelas populações da Mata Atlântica, tem padrão hourglass de coloração dorsal. A segunda, do interior de São Paulo, assim como a população do Rio Grande do Sul, possui padrão bivittata de coloração dorsal. Esses resultados corroboram a hipótese de que o táxon D. minutus contém duas linhagens crípticas. Apesar disso, uma amostragem maior se faz necessária, bem como um melhor estudo de caracteres para defini-las como espécies ou não. / Abstract: In despite of its complex reproductive behavior, Dendropsophus minutus has a large distribution at East of Andes, South America and show high acoustic and morphologic diversity, suggesting that possibly more than one species may exist under this name. Its dorsum coloration has basically two main patterns, hourglass or bivittata. Here, 14 morphometric parameters and partial mitochondrial cytochrome b gene sequences (357 base pairs) were analyzed aiming to understand more about Brazilian D. minutus variation. Both molecular and morphologic results agree with a high structuration of this species diversity, showing population divergence generally proportional to their geographic distance, except in São Paulo State, southeastern Brazil. At this region, Serra do Mar high mountains are apparently acting as a barrier for dispersion, isolating two lineages. The first of them, formed by populations from Atlantic Rainforest domain, has an hourglass dorsum pattern, whereas the second, comprising inner São Paulo State populations gathered with D. minutus from Rio Grande do Sul (South Brazil), shows bivittata dorsum coloration pattern. These results corroborate the hypothesis that D. minutus could comprise more than one species, revealing two cryptic lineages. However, these lineages should not be defined as different species before sampling enlargement to the present study. / Mestrado / Biologia Celular / Mestre em Biologia Celular e Estrutural

Graduation date: 2004

Scarabaeid pests in South Africa and especially KwaZulu-Natal are characterised by a very long larval life cycle and short pupal and adult periods. However, it has nearly always been the adults of the species that have been identified, with very little attention paid to the larval identification of the species. This is unfortunate as it is nearly always the larval stage that is found to be associated with crop damage. Accurate identification of the species of these larvae is important for the management of scarabaeid pest species, as it unlocks the necessary information on the biology and ecology of many species, which allows the adaptation of control methods for different species. Inadequate keys for the taxonomy of larvae of these groups, as well as the lack of morphological taxonomists working on these groups have been identified as constraints. When a species is difficult to identify using traditional taxonomic methods, DNA diagnostic tools can be useful. Chapter 2 investigated the feasibility of identifying scarabaeid larvae using mitochondrial DNA data. Variation in the base pair sequence of the mitochondrial cytochrome c oxidase sub unit I (cox 1) gene was used. DNA sequences of cox 1 from scarabaeid larvae collected from sugarcane fields were compared with sequences from scarabaeid adults of known species in order to identify the species attacking sugarcane. Neighbour-joining and maximum parsimony analyses of 658 bp cox 1 sequences identified groups of larvae that linked to adult specimens. The major groupings delimited specimens belonging to the subfamilies Dynastinae, Melolonthinae and Rutelinae. Within-group sequence divergence ranged from 0 - 3.4 % and divergence between sister groups ranged from 2.6 - 25.1 %. The recorded divergence range within and between tribes was 0 - 21.3 % and 17.3 - 28.5% respectively. Similarly, the divergence range observed within and between genera was 0 - 19.2 % and 17.1 - 25.4% respectively. The maximum sequence divergence observed within subfamilies was 23.7 % and divergence between subfamilies ranged from 16.8 - 26.7 %. Examination of pairwise sequence divergence levels as well as node support allowed 68% of the unidentified larval specimens to be associated with identified adult specimens. Phylogenetic analysis matched identified adult mtDNA with unidentified larval mtDNA. This allowed the identification of those larvae through morphological characteristics unique to certain species. To create a field key to the subfamilies of Dynastinae, Melolonthinae and Rutelinae the most useful character distinguishing larvae of different species was the raster but additional morphological characteristics were included. These relationships between larval and adult scarabaeid specimens from sugarcane were examined using various phylogenetic tools. The data set included a total of 19 morphological characters as well as 166 partial cox 1 gene sequences. Maximum parsimony analyses were performed on morphological, molecular and combined data. The same morphological and molecular data sets were run both separately and as a combined analysis with MrBayes. In both types of analyses the morphological data performed poorly and crude groupings resulted, dividing taxa to tribe level only. Molecular data showed greater resolution than the morphological data and taxa were separated into groups equivalent to species and morphospecies designated in Chapter 2. A partition homogeneity test indicated that both data types could be combined. It is recommended that both morphological and molecular data be utilised in identification of scarabaeid sugarcane pests and that a character-based approach be implemented. Further molecular data from other genes should be included to test the accuracy of these results. The keys produced during this study will allow workers to focus on a single species biology, and subsequently allow an analysis of between species interactions, and within species control. These advances are a start to the improvement of knowledge of the species composition of scarabaeid larvae in sugarcane fields, thus making management and biological control of these pests a greater possibility. Further recommendations for future work are discussed in Chapter 5. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

Thesis (DPhil)--University of Stellenbosch, 2008. / ENGLISH ABSTRACT: Sub-Antarctic islands represent the only mid to high latitude terrestrial biomes in the Southern Hemisphere. These islands have various geological origins and histories, well-preserved terrestrial ecosystems and high levels of species endemism. In an attempt to understand the evolution and biogeography of terrestrial taxa in the South Polar Region, the first broad-scale molecular phylogeny was constructed for the unique terrestrial group, the ameronothroid mites (genus Halozetes (Oribatida)), collected from sub-Antarctic and Maritime Antarctic localities. Phylogenetic analyses based on a combined mitochondrial (cytochrome oxidase subunit I (COI)) and nuclear (histone-3 (H3)) sequence dataset indicated that the evolution of these mites were habitat specific (i.e. intertidal, supralittoral and terrestrial). Notwithstanding criticisms levelled against a molecular clock, the mites were evolutionary young (<10myo), contrary to their status as an ancient group predating Gondwana fragmentation. Biogeographic analyses indicated a complex pattern mainly sculpted by multiple independent dispersal events across the Antarctic Polar Frontal Zone similar to previous findings for other marine and terrestrial taxa. Also, the molecular phylogeny displayed considerable discourse with contemporary taxonomy suggesting the need for taxonomic revisions and reassessment of morphological characters. Sub-Antarctic Marion Island, the larger of the two islands comprising the Prince Edward Island archipelago (PEI), has experienced extensive glaciation and volcanism. To assess the impact of historical events (volcanism (including recent eruptions) and glaciation) and contemporary mechanisms (gene flow) on the genetic spatial distribution of species from Marion Island, two mite species namely Eupodes minutus (Prostigmata) and Halozetes fulvus (Oribatida) as well as a single plant species, Azorella selago (Apiaceae), were selected as model organisms. For independent phylogeographic analyses, mitochondrial sequence data (COI) were obtained for both mite species, while chloroplast sequence (trnH-psbA) and amplified fragment length polymorphism (AFLP) data were generated for the cushion plant, A. selago. Since A. selago is typified by two growth forms namely discrete cushions and continuous mats, it was essential to examine the growth dynamics prior to phylogeographic analyses. The sequence and fragment data indicated that both mite and plant species were significantly substructured across Marion Island. Manual comparisons indicated unique populations on the western (Kaalkoppie for H. fulvus, La Grange Kop for E. minutus and Mixed Pickle for A. selago), eastern (Bullard Beach for H. fulvus and Kildalkey Bay for E. minutus), northern (Middelman and Long Ridge for H. fulvus) and southern side (Grey Headed for H. fulvus and Watertunnel for A. selago) of the island. Importantly, the western side had unique localities for all species. Interestingly, based on the H. fulvus data, the western populations were relatively young, characterized by high migration rates, small effective (female) population sizes with no isolation-by-distance. The opposite scenario was found for the eastern populations. This spatial genetic structure described for species on Marion Island can be ascribed to both historical events and environmental conditions. These areas with their unique genetic composition are of special conservational concern; consequently this research will contribute to an active management plan for PEI, South Africa’s only Special Nature Reserve. / AFRIKAANSE OPSOMMING: Sub-Antarktiese eilande verteenwoordig die enigste terrestriële bioom in die middel tot hoër breedtegrades van die Suidelike Halfrond. Hierdie eilande besit ‘n verskeidenheid van geologiese oorspronge en geskiedenisse, goed-bewaarde terrestriële ekosisteme en hoë vlakke van endemisme. In ‘n poging om die evolusie en biogeografie van terrestriële taksa in die Suid Pool Area te verstaan, is die eerste grootskaalse molekulêre filogenie saamgestel vir ‘n unieke terrestriële groep, die ameronothoïed miete (genus Halozetes (Oribatida: Ameronothroidea)), vanaf menigte sub-Antarktiese en Maritime Antarktiese lokaliteite. Filogenetiese analises gebaseer op die saamgestelde mitochondriale (sitokroom oksidase subeenheid I (COI)) en nukluêre (histoon-3 (H3)) basispaarvolgordes het aangedui dat die evolusie van hierdie miete habitat spesifiek is (m.a.w inter-gety, supralitoraal en terrestrieël). Ongeag die kritiek teenoor ‘n molekulêre klok, is hierdie miete evolusionêr jonk (<10mjo), wat teenstrydig is met hulle status as ‘n antieke groep wat terugdateer voor Gondwana fragmentasie. Biogeografiese analises het ‘n komplekse patroon aangedui wat grotendeels gekarakteriseer word deur menigte onafhanklike verspreidingsgebeurtenisse bo-oor die Antarktiese Polêre Frontale Zone, wat ooreenstemmend is met vorige bevindinge vir ander mariene en terrestriële taksa. Die molekulêre filogenie het ook aansienlik verskil van die tradisionele taksonomie, dus is taksonomiese aanpassings en herklassifisering van morfologiese karakters noodsaaklik. Sub-Antarktiese Marion Eiland, die groter eiland van die Prins Edward eilandgroep (PEI), het uitermate glasiasie en vulkanisme ondervind. Om die impak van historiese gebeurtenisse (vulkanisme (insluitend onlangse uitbarstings) en glasiasie) en kontemporêre meganismes (geenvloei) op die genetiesgespasieërde verspreiding van spesies vanaf Marion Eiland te bepaal, was twee mietspesies naamlik Eupodes minutus (Prostigmata) en Halozetes fulvus (Oribatida) asook ‘n enkele plantspesie, Azorella selago (Apiaceae), gekies as model organismes. Vir onafhanklike filogeografiese analises, was die mitochondriale basispaarvolgorde (COI) vir beide mietspesies bepaal, terwyl chloroplast basispaarvolgorde (trnH-psbA) asook geamplifiseerde fragmentlengte polimorfisme (AFLP) data gegenereer was vir die kussingplant, A. selago. Aangesien A. selago gekenmerk word deur twee groeivorme, naamlik diskrete kussings en aaneenlopende matte, was dit noodsaaklik om eers die groeidinamika van die plant te ondersoek alvorens ‘n filogeografiese studie kon geskied. Die basispaarvolgordebepalings en fragmentdata het aangedui dat beide mietspesies sowel as die plantspesie betekenisvolle substruktuur vertoon regoor Marion Eiland. Informele vergelykings het unieke populasies aangedui op die westelike (Kaalkoppie vir H. fulvus, La Grange Kop vir E. minutus en Mixed Pickle vir A. selago), oostelike (Bullardstrand vir H. fulvus en Kildalkeybaai vir E. minutus), noordelike (Middelman en Long Ridge vir H. fulvus) en suidelike kant (Grey Headed vir H. fulvus en Watertunnel vir A. selago) van die eiland. Die westelike kant besit dus unieke lokaliteite vir al die spesies. Interressantheidhalwe het die H. fulvus data getoon dat die westelike populasies relatief jonk is en gekarakteriseer word deur hoë migrasiesyfers en klein effektiewe (vroulike) populasiegroottes met geen isolasie-oor-afstand nie. Die resultate vir die populasies aan die oostelike kant van die Marion Eiland was presies teenoorgesteld. Dié beskryfde substruktuur vir die spesies op Marion Eiland is afkomstig van beide historiese gebeurtenisse asook omgewingstoestande. Hierdie areas met hul unieke genetiese samestelling, is belangrik vir natuurbewaring. Hierdie navorsing sal bydra tot die bestuursriglyne van PEI, Suid Afrika se enigste Spesiale Natuurreservaat.

Low copy number anonymous nuclear loci were used to search for species markers in four species of Klamath Basin suckers. We sequenced 28 randomly chosen loci representing 10,421 bp; 21 loci were similar to sequences in GenBank. Eight fixed sequence differences were found among Klamath species. Locus 120 contained rare but diagnostic markers for Deltistes luxatus and for Catostomus rimiculus. Locus 4 also contained three rare but unique sites in Catostomus rimiculus. No sequence differences were found between Chasmistes brevirostris and Catostomus snyderi. Loci 4 and 120 exhibited allele frequency differences between Rogue River C. rimiculus and all Klamath Basin suckers. Genotype BB of locus 4 was a fixed diagnostic marker and genotype BB of locus 120 was a frequency dependent marker for Rogue C. rimiculus. Although Klamath suckers represent three genera, very limited variation was found among 10,431 base pairs. We examined phylogenetic patterns of five loci in eleven catostomid genera and 25 species to determine if the homogeneity in the Upper Klamath Basin was due to massive hybridization and introgression or to retention of ancestral sequences. Two loci with no similarity to GenBank sequences (non-coding loci) and three loci with substantial similarity to GenBank sequences (coding loci) gave similar results, providing support for various subfamilies and tribes, more support for eastern genera and little support for western genera. Each locus was a mosaic of species or population markers, sometimes providing discriminatory power for allopatric populations of a species, such as C. macrocheilus, while not discriminating other species. Upper Klamath Basin species were noteworthy in their lack of autapomorphies, but had similar numbers of derived informative sites as other catostomins. Upper Klamath Basin species consistently shared ancestral or equivocal informative sites either with moxostomatins or a variable group of western species and shared derived sites with other western species, especially C. occidentalis. The data suggest that Upper Klamath Basin species have retained a largely ancestral genome at these loci. Thus, the failure of this technique to uncover significant variation in Upper Klamath Basin species may be a reflection of their plesiomorphic genome at these loci and not necessarily hybridization. / Graduation date: 2004