Matching Items (1,847)
Filtering by
- Creators: Debussy, Claude, 1862-1918
Description
As an evolutionary force, hybridization outcomes include introgression, admixture, speciation, and reproductive isolation. While hybridization has been studied in several primates, the marmoset genus Callithrix is an important, but little studied example of Neotropical hybridization. Varying degrees of reproductive isolation exist between Callithrix species, and hybridization occurs at species borders or regions containing introduced and native species. Interbreeding between Callithrix species carries important implications for biodiversity and genetic integrity within the genus. However, species origins and levels of genetic admixture in marmoset hybrid zones are generally unknown, and few population genetic studies of individual Callithrix species exist. Using the mitochondrial control region and 44 microsatellite markers, this work explored the genetic diversity and species origins of two C. penicillata and C. jacchus hybrid zones, as well as genetic diversity and divergence in the parental species. Both marker types showed that C. penicillata is more genetically diverse than C. jacchus. Based on mtDNA, C. jacchus seems to have experienced a past population expansion and C. penicillata evolved under constant population size. The data revealed the existence of a previously undocumented natural hybrid zone along the São Francisco River in NE Brazil and confirmed species origins of an anthropogenic zone in Rio de Janeiro state. The data also showed much lower levels of admixture and genetic diversity within the natural hybrid zone than in the anthropogenic zone. Further, the data suggested that the São Francisco River is an important geographic barrier to gene flow in the natural hybrid zone. On the other hand, admixture patterns within the anthropogenic hybrid zone suggested collapse of reproductive barriers, and the formation of a hybrid marmoset swarm. Thus, this work suggested different evolutionary dynamics in anthropogenic vs. natural animal hybrid zones. Restriction Associated DNA sequencing (RADseq) identified a large number of single nucleotide polymorphisms within C. jacchus and C. penicillata genomes. These preliminary data were used to measure intraspecific genomic diversity and interspecific divergence. In the future, RADseq will be used to study genus-wide diversity of Callithrix species, examine past and present marmoset demographic history, and applied to the evolutionary study of marmoset hybridization.
ContributorsMalukiewicz, Joanna (Author) / Stone, Anne C. (Thesis advisor) / Nash, Leanne (Committee member) / Rosenberg, Michael (Committee member) / Hedrick, Phil (Committee member) / Ruiz-Miranda, Carlo (Committee member) / Arizona State University (Publisher)
Created2013
Description
Malaria is a vector-borne parasitic disease affecting tropical and subtropical regions. Regardless control efforts, malaria incidence is still incredible high with 219 million clinical cases and an estimated 660,000 related deaths (WHO, 2012). In this project, different population genetic approaches were explored to characterize parasite populations. The goal was to create a framework that considered temporal and spatial changes of Plasmodium populations in malaria surveillance. This is critical in a vector borne disease in areas of low transmission where there is not accurate information of when and where a patient was infected. In this study, fragment analysis data and single nucleotide polymorphism (SNPs) from South American samples were used to characterize Plasmodium population structure, patterns of migration and gene flow, and discuss approaches to differentiate reinfection vs. recrudescence cases in clinical trials. A Bayesian approach was also applied to analyze the Plasmodium population history by inferring genealogies using microsatellites data. Specifically, fluctuations in the parasite population and the age of different parasite lineages were evaluated through time in order to relate them with the malaria control plan in force. These studies are important to understand the turnover or persistence of "clones" circulating in a specific area through time and consider them in drug efficacy studies. Moreover, this methodology is useful for assessing changes in malaria transmission and for more efficiently manage resources to deploy control measures in locations that act as parasite "sources" for other regions. Overall, these results stress the importance of monitoring malaria demographic changes when assessing the success of elimination programs in areas of low transmission.
ContributorsChenet, Stella M (Author) / Escalante, Ananias A (Thesis advisor) / Clark-Curtiss, Josephine (Committee member) / Rosenberg, Michael (Committee member) / Taylor, Jesse E (Committee member) / Arizona State University (Publisher)
Created2014
Description
A phylogenetic revision of the broad-nosed weevil genera Minyomerus Horn, 1876, and Piscatopus Sleeper, 1960 (Entiminae: Tanymecini) is presented. These genera are distributed throughout western North America, from Canada to Mexico and Baja California, primarily in arid and desert habitats, and feed on shrubs such as creosote (Larrea tridentata (DC.) Coville: Zygophyllaceae) and several Asteraceae. Piscatopus was considered monotypic, comprised solely of P. griseus Sleeper, 1960, whereas Minyomerus formerly was comprised of seven species: M. innocuus Horn, 1876 (designated as the type species for Minyomerus in Pierce, 1913), M. caseyi (Sharp, 1891), M. conicollis Green, 1920, M. constrictus (Casey, 1888), M. languidus Horn, 1876, M. laticeps (Casey, 1888), M. microps (Say, 1831). This revision includes comprehensive redescriptions of the previously described species in these genera and descriptions of ten new species: M. imberbus sp. nov., M. caponei sp. nov., M. reburrus sp. nov., M. cracens sp. nov., M. trisetosus sp. nov., M. puticulatus sp. nov., M. bulbifrons sp. nov., M. politus sp. nov., M. gravivultus sp. nov., and M. rutellirostris sp. nov. A cladistic analysis using 46 morphological characters of 22 terminal taxa (5 outgroup, 17 ingroup) was carried out in WinClada and yielded a single most-parsimonious cladogram (length = 82, consistency index = 65, retention index = 82). The monophyly of Minyomerus is supported by the preferred cladogram. The results of the cladistic analysis place Piscatopus griseus within the genus Minyomerus as sister to M. rutellirostris. Therefore, Piscatopus is demoted to a junior synonym of Minyomerus and its sole member P. griseus, is moved to Minyomerus as M. griseus (Sleeper), new combination. Additionally, the species M. innocuus Horn, 1876 is demoted to a junior synonym of M. microps (Say, 1831), based on the principle of priority, and M. microps is elevated to the rank of type for the genus. The species M. languidus, M. microps, and M. trisetosus are putatively considered parthenogenetic, and lack male specimens over a broad range of sampling events. The diversity in exterior and genitalic morphology, range of host plants, overlapping species distributions, and geographic extent suggests an origin during the Miocene (~15 mya).
ContributorsJansen, Michael Andrew (Author) / Franz, Nico M (Thesis advisor) / Wojciechowski, Martin (Committee member) / Rosenberg, Michael (Committee member) / Arizona State University (Publisher)
Created2014
Description
Rhodoferax antarcticus strain ANT.BR, a purple nonsulfur bacterium isolated from a microbial mat in Ross Island, Antarctica, is the first described anoxygenic phototrophic bacterium that is adapted to cold habitats and is the first beta-proteobacterium to undergo complete genome sequencing. R. antarcticus has unique absorption spectra and there are no obvious intracytoplasmic membranes in cells grown phototrophically, even under low light intensity. Analysis of the finished genome sequence reveals a single chromosome (3,809,266 bp) and a large plasmid (198,615 bp) that together harbor 4,262 putative genes. The genome contains two types of Rubiscos, Form IAq and Form II, which are known to exhibit quite different kinetic properties in other bacteria. The presence of multiple Rubisco forms could give R. antarcticus high metabolic flexibility in diverse environments. Annotation of the complete genome sequence along with previous experimental results predict the presence of structural genes for three types of light-harvesting (LH) complexes, LH I (B875), LH II (B800/850), and LH III (B800/820). There is evidence that expression of genes for the LH II complex might be inhibited when R. antarcticus is under low temperature and/or low light intensity. These interesting condition-dependent light-harvesting apparatuses and the control of their expression are very valuable for the further understanding of photosynthesis in cold environments. Finally, R. antarcticus exhibits a highly motile lifestyle. The genome content and organization of all putative polar flagella genes are characterized and discussed.
ContributorsZhao, Tingting, M.S (Author) / Touchman, Jeffrey (Thesis advisor) / Rosenberg, Michael (Committee member) / Redding, Kevin (Committee member) / Stout, Valerie (Committee member) / Arizona State University (Publisher)
Created2011
Description
Collaborative learning is a common teaching strategy in classrooms across age groups and content areas. It is important to measure and understand the cognitive process involved during collaboration to improve teaching methods involving interactive activities. This research attempted to answer the question: why do students learn more in collaborative settings? Using three measurement tools, 142 participants from seven different biology courses at a community college and at a university were tested before and after collaborating about the biological process of natural selection. Three factors were analyzed to measure their effect on learning at the individual level and the group level. The three factors were: difference in prior knowledge, sex and religious beliefs. Gender and religious beliefs both had a significant effect on post-test scores.
ContributorsTouchman, Stephanie (Author) / Baker, Dale (Thesis advisor) / Rosenberg, Michael (Committee member) / Ganesh, Tirupalavanam G. (Committee member) / Arizona State University (Publisher)
Created2012
ContributorsDebussy, Claude, 1862-1918 (Composer)
ContributorsDebussy, Claude, 1862-1918 (Composer)
ContributorsDebussy, Claude, 1862-1918 (Composer)
ContributorsDebussy, Claude, 1862-1918 (Composer)
ContributorsDebussy, Claude, 1862-1918 (Composer)