Life Sciences Commons^™

The Evolution Of Floral Symmetry Across The Plant Order Lamiales, Jinshun Zhong

Dissertations

Bilaterally symmetrical corollas have evolved independently numerous times from radially symmetrical ancestors and are thought to represent adaptation to specific pollinators. However, evolutionary losses of bilateral symmetry have occurred sporadically in different lineages. CYC2-like and RAD-like are genes needed for the normal development of bilateral symmetry in snapdragon corollas. However, exactly how changes in the floral symmetry patterning genes correlate with the origin and loss of floral bilateral remains poorly known. To address this question, a densely sampled phylogeny of CYC2-like genes across the order Lamiales was inferred and calibrated. The expression patterns of these genes in early diverging and …

Failed Species, Innominate Forms, And The Vain Search For Species Limits: Cryptic Diversity In Dusky Salamanders (Desmognathus) Of Eastern Tennessee, Stephen G. Tilley, Joseph Bernardo, Laura A. Katz, Lizmarie López, J. Devon Roll, Renáe L. Eriksen, Justin Kratovil, Noëlle K.J. Bittner, Keith A. Crandall

Biological Sciences: Faculty Publications

Cytochrome B sequences and allozymes reveal complex patterns of molecular variation in dusky salamander (Desmognathus) populations in eastern Tennessee. One group of allozymically distinctive populations, which we refer to as the Sinking Creek form (SCF), combines morphological attributes of Desmognathus fuscus with cytB sequences characteristic of Desmognathus carolinensis. This form is abruptly replaced by D. fuscus just north of Johnson City, TN with no evidence of either sympatry or gene exchange. To the south, allozymic markers indicate a broad zone of admixture with populations characterized by distinct cytB sequences and that may or may not be ultimately referable to Desmognathus …

Intraspecific Relationships In Paracalanus Quasimodo [Calinoideae] And Temora Turbinata [Calinoideae] Along The Southeastern Coast Of The United States, Richard Y. Chang

FIU Electronic Theses and Dissertations

Paracalanus quasimodo and Temora turbinata are two calanoid copepods prominent in the planktonic communities of the southeastern United States. Despite their prominence, the species and population level structure of these copepods is yet unexplored. The phylogeographic, temporal and phylogenetic structure of P. quasimodo and T. turbinata are examined in my study. Samples were collected from ten sites along the Gulf of Mexico and Florida peninsular coasts. Three sites were sampled quarterly for two years. Individuals were screened for unique ITS-1 sequences with denaturing gradient gel electrophoresis. Unique variants were sequenced at the nuclear ITS-1 and mitochondrial COI loci. Sampling sites …

Fossil Trachemys (Testudines: Emydidae) From The Late Hemphillian Of Eastern Tennessee And Its Implications For The Evolution Of The Emydidae, Steven E. Jasinski

Electronic Theses and Dissertations

Trachemys (Testudines: Emydidae) represents one of the most well-known turtles today. The evolution of Trachemys, while being heavily documented with various fossil representatives, is not well understood. Numerous fossils from the Gray Fossil Site in northeastern Tennessee are helping to elucidate the taxon’s evolution. The fossil Trachemys at the Gray Fossil Site represent a new species. A review of previously named Trachemys taxa reveals that a huge majority of them are not valid or have been previously misinterpreted. A phylogenetic analysis preformed on modern emydids and supposed fossil representatives of those genera also shows the evolution of a portion …

Diversification And Coexistence In The Madagascar Olive (Noronhia, Oleaceae), Cynthia Hong-Wa

Dissertations

The long-isolated island of Madagascar provides a suitable setting for studying species diversification, with most groups of organisms there both radiating and showing a high level of endemism. Noronhia is one of these groups and represents the most successful radiation of the olive family (Oleaceae) in Madagascar, with ca. 80 species. In this study, using plastid and nuclear DNA sequences obtained from a comprehensive sampling both within Noronhia and the family, I show that Noronhia, together with Indian Ocean species of Chionanthus, form a monophyletic clade sister to African Chionanthus. The diversification of Noronhia followed a likely Cenozoic dispersal from …

Reconstruction Of Family-Level Phylogenetic Relationships Within Demospongiae (Porifera) Using Nuclear Encoded Housekeeping Genes, Malcolm S. Hill, April Hill, Jose Lopez, Kevin J. Peterson

Dartmouth Scholarship

Background: Demosponges are challenging for phylogenetic systematics because of their plastic and relatively simple morphologies and many deep divergences between major clades. To improve understanding of the phylogenetic relationships within Demospongiae, we sequenced and analyzed seven nuclear housekeeping genes involved in a variety of cellular functions from a diverse group of sponges.

Methodology/Principal Findings: We generated data from each of the four sponge classes (i.e., Calcarea, Demospongiae, Hexactinellida, and Homoscleromorpha), but focused on family-level relationships within demosponges. With data for 21 newly sampled families, our Maximum Likelihood and Bayesian-based approaches recovered previously phylogenetically defined taxa: Keratosap, Myxospongiaep, Spongillidap, Haploscleromorphap (the …

Sinularia Leptoclados (Ehrenberg, 1834) (Cnidaria: Octocorallia) Re-Examined, Catherine S. Mcfadden, Leen P. Van Ofwegen, Yehuda Benayahu

All HMC Faculty Publications and Research

Sinularia leptoclados (Ehrenberg, 1834) is re-described. Sinularia leptoclados var. gonatodes Kolonko, 1926 is synonymized with S. maxima Verseveldt, 1977. Two new species of Sinularia with digitiform lobules, leptoclados-type surface clubs and unbranched interior spindles, are described. An updated maximum likelihood tree of Sinularia species with leptoclados-type clubs (clade 5C) based on two mitochondrial genes (mtMutS, COI) and a nuclear gene (28S rDNA) is presented.

The Phylogenetics Of Tachinidae (Insecta: Diptera) With An Emphasis On Subfamily Structure, Daniel J. Davis

Browse all Theses and Dissertations

The parasitoid flies of the Tachinidae family are an important and diverse (>10,000 species) lineage of insects. However, tachinids are not well studied partially due to their confusing classification and taxonomy. DNA sequences were obtained from twenty tribal representatives of Tachinidae, along with eight outgroups in order to phylogenetically reconstruct the superfamilial, subfamilial and tribal relationships of Tachinidae. Seven gene regions of six genes (18S, 28S, COI, CAD, Ef1a, and TPI) were sequenced for each taxon (6214 bp total). Both maximum likelihood and Bayesian methods were used to infer phylogenies. The Sarcophagidae and Oestridae were usually reconstructed as monophyletic. …

Reductive Evolution And The Loss Of Pdc/Pas Domains From The Genus Staphylococcus, Neethu Shah, Rosmarie Gaupp, Hideaki Moriyama, Kent M. Eskridge, Etsuko N. Moriyama, Greg A. Somerville

School of Biological Sciences: Faculty Publications

Background: The Per-Arnt-Sim (PAS) domain represents a ubiquitous structural fold that is involved in bacterial sensing and adaptation systems, including several virulence related functions. Although PAS domains and the subclass of PhoQ-DcuS-CitA (PDC) domains have a common structure, there is limited amino acid sequence similarity. To gain greater insight into the evolution of PDC/PAS domains present in the bacterial kingdom and staphylococci in specific, the PDC/PAS domains from the genomic sequences of 48 bacteria, representing 5 phyla, were identified using the sensitive search method based on HMM-to-HMM comparisons (HHblits).

Results: A total of 1,007 PAS domains and 686 …

The Tick Genus Amblyomma In Africa: Phylogeny And Mutilocus Dna Barcoding, Omobolanle Kushimo

Electronic Theses and Dissertations

The tick genus Amblyomma includes approximately 130 species, 28 of which are found on the African continent and/ or in Madagascar. In order to understand the evolutionary phylogeography of the genus, it is necessary to gain a better understanding of the relationships between African taxa. Therefore, the main goals of this work were to, (1) reconstruct the phylogenetic relationships of the African Amblyomma available to us and (2) test markers for their usefulness as barcoding tools to link unknown immature specimens to their corresponding adults. The mitochondrial gene markers used in this study (12SrDNA and COI) did not resolve the …

Phylotastic! Making Tree-Of-Life Knowledge Accessible, Reusable And Convenient, Arlin Stoltzfus, Hilmar Lapp, Helena Deus, Brian Sidlauskas, Christian M. Zmasek, Gaurav Vaidya, Enrico Pontelli, Karen Cranston, Rutger Vos, Campbell O. Webb, Luke J. Harmon, Megan Pirrung, Brian O'Meara, Matthew W. Pennell, Siavash Mirarab, Michael S. Rosenburg, James P. Balhoff, Holly M. Bik, Tracy A. Heath, Peter E. Midford, Joseph W. Brown, Emily Jane Mctavish, Jeet Sukumaran, Mark Westneat, Michael E. Alfaro, Aaron Steele, Greg Jordan

Tracy Heath