Life Sciences Commons^™

Biogeography Of Special Metabolites Produced By Ant-Associated Bacteria, Katherine Hansen

Scripps Senior Theses

There is an urgent and growing need for novel antibiotics with the growing prevalence of antibiotic-resistant pathogens. Ecologically-guided discovery is a strategy that focuses on how and where specially evolved metabolites such as antibiotics are used in nature. This strategy reveals unique active molecules with potential for human use. An unexplored niche with great potential for antibiotic discovery exists with Southwestern fungus-farming Trachymyrmex ants and their Actinobacteria symbionts. In exchange for nutrients from the ant, the ants’ bacterial symbiont produces antifungal molecules that protect the ants’ fungal cultivar from invasion by pathogenic microorganisms. They also produce antibacterial molecules to protect …

Environmental Controls On The Spatial Distribution Of Greenfin Darters And Biodiversity In The Blue Ridge Mountains, Dri Tattersfield

CMC Senior Theses

Disproportionate concentrations of biodiversity in mountains worldwide suggest linkages between geologic processes and biodiversity that are not yet well understood. The Tennessee River Basin in the Blue Ridge Mountains of the southeastern U.S. is a global hotspot for freshwater fish biodiversity. To investigate drivers of biodiversity in the Tennessee River Basin, and explore links to geologic processes, I study the Greenfin Darter (Nothonotus chlorobranchius), a small fish endemic to the upper Tennessee River Basin. I use generalized linear models (GLMs) to evaluate the influence of topography, lithology, climate and land use on the distribution of the Greenfin Darter, …

Systematics, Biogeography And Leaf Anatomy And Architecture Of Bursera Subgen. Bursera (Burseraceae) In The Greater Antilles And The Bahamas, María Cristina Martínez-Habibe

CGU Theses & Dissertations

This dissertation presents a comprehensive study on the origin and evolutionary relationships of the species of Bursera in Cuba, Hispaniola, Jamaica and the Bahamas. The goals of the first chapter were to test monophyly of the group, revisit a recent transfer of two species of Bursera to Commiphora, and place recently discovered mainland species using the reconstructed phylogenies. Additionally, divergence estimations using fossils were used as independent tests of several hypotheses regarding the arrival of the modern biota to the Greater Antilles and Bahamas (GAB). I conclude that all endemic taxonomic entities of the genus in this region belong …

Vascular Plants Of The High Sierra San Pedro Mártir, Baja California, Mexico: An Annotated Checklist, Robert F. Thorne, Reid V. Moran, Richard A. Minnich

Aliso: A Journal of Systematic and Floristic Botany

The Sierra San Pedro Mártir (SSPM) is the highest mountain range in Baja California, Mexico, the summit of Picacho del Diablo peak attaining 3095 meters. An annotated checklist describes the vascular flora of the SSPM high country, defined here as above 1800 m. It comprises almost 500 species in 251 genera and 78 families. The high country is dominated by coniferous forest species known from montane California and Arizona whose southern ranges terminate in the SSPM. The annotated checklist identifies 453 species in 236 genera as indigenous, of which 23 species and one variety are endemic to the SSPM. Over …

Jane: A New Tool For The Cophylogeny Reconstruction Problem, Chris Conow, Daniel Fielder '11, Yaniv J. Ovadia '10, Ran Libeskind-Hadas

All HMC Faculty Publications and Research

Background

This paper describes the theory and implementation of a new software tool, called Jane, for the study of historical associations. This problem arises in parasitology (associations of hosts and parasites), molecular systematics (associations of orderings and genes), and biogeography (associations of regions and orderings). The underlying problem is that of reconciling pairs of trees subject to biologically plausible events and costs associated with these events. Existing software tools for this problem have strengths and limitations, and the new Jane tool described here provides functionality that complements existing tools.

Results

The Jane software tool uses a polynomial time dynamic …

Classification And Biogeography Of Panicoideae (Poaceae) In The New World, Fernando O. Zuloaga, Osvaldo Morrone, Gerrit Davidse, Susan J. Pennington

Aliso: A Journal of Systematic and Floristic Botany

Panicoideae (Poaceae) in the New World comprise 107 genera (86 native) and 1357 species (1248 native). As circumscribed herein, Panicoideae include eight tribes: Andropogoneae, Arundinelleae, Centotheceae, Gynerieae, Isachneae, Paniceae, Steyermarkochloeae, and Thysanolaeneae. The two major tribes are Andropogoneae with 230 species (16.95% of all New World panicoids), and Paniceae with 1082 species (79.73%). Andropogoneae are divided into nine subtribes (Andropogoninae, Anthistiriinae, Coicinae, Germainiinae, Ischaeminae, Rottboelliinae, Saccharinae, Sorghinae, and Tripsacinae), while Paniceae are divided into seven subtribes (Arthropogoninae, Cenchrinae, Digitariinae, Melinidinae, Panicinae, Paspalinae, and Setariinae). Brazil is the center of diversity of New World panicoids with 741 species (54.6% of all …

Classification And Biogeography Of New World Grasses: Chloridoideae, Paul M. Peterson, J. Travis Columbus, Susan J. Pennington

Aliso: A Journal of Systematic and Floristic Botany

Subfamily Chloridoideae (Poaceae) in the New World includes 72 genera (61 native, 11 introduced), 678 species (607 native), and, including intraspecific taxa, 817 total taxa. The five largest genera are Muhlenbergia (147 species), Eragrostis (111), Sporobolus (76), Bouteloua (57), and Chloris (35). Three tribes are recognized in this study: Cynodonteae, Eragrostideae, and Zoysieae, with ten, three, and two subtribes, respectively. Cynodonteae, the largest tribe, comprise 58 genera and 451 species (67% of all New World chloridoids), including 25 genera (98 species, 22% of all New World Cynodonteae) with unknown affinities (incertae sedis). In Mexico, the USA, and Canada there are …

Classification And Biogeography Of New World Grasses: Anomochlooideae, Pharoideae, Ehrhartoideae, And Bambusoideae, Emmet J. Judziewicz, Lynn G. Clark

Aliso: A Journal of Systematic and Floristic Botany

Molecular data support Anomochlooideae and Pharoideae as the two most basal extant clades within Poaceae. Anomochlooideae are endemic to the New World and have two tribes and two genera including the widespread Streptochaeteae (3–4 spp.) and the critically endangered Anomochloeae (1 sp.) of coastal Bahia, Brazil. Pharoideae are pantropical with one tribe, three genera, and 14 species; all eight species of Pharus occur only in the New World. Bambusoideae and Ehrhartoideae are sister groups and together form a clade sister to Pooideae, although support for this set of relationships is low. Ehrhartoideae are a worldwide subfamily represented in the New …

Phylogeny And Biogeography Of Endemic Festuca (Poaceae) From New Zealand Based On Nuclear (Its) And Chloroplast (Trnl–Trnf) Nucleotide Sequences, Kelvin M. Lloyd, Angela M. Hunter, David A. Orlovich, Suzanne J. Draffin, Alan V. Stewart, William G. Lee

Aliso: A Journal of Systematic and Floristic Botany

We investigated the phylogenetic relationships of the endemic New Zealand (NZ) species of Festuca (Poaceae, Pooideae) by assessing sequence variation from the nuclear internal transcribed spacers (ITS) and a chloroplast intergenic spacer (trnL–trnF) and by measuring DNA content using flow cytometry. The ITS and trnL–trnF data sets were congruent in showing that the NZ species of Festuca have two origins. One group, containing F. coxii, F. luciarum, F. multinodis, and F. ultramafica, is closely related to Festuca sect. Aulaxyper. The other group includes a clade of five endemic …

Vascular Plants Of The Whipple Mountains, Sarah J. De Groot

Aliso: A Journal of Systematic and Floristic Botany

The Sonoran and Mojave deserts meet just north of the Whipple Mountains, which are situated in southeast San Bernardino County, California, along the Colorado River and adjacent to Arizona. Vegetation from the Pleistocene to the present was inferred from previously published packrat midden data and the current floristic composition. Climate data suggest that summer rainfall is a factor underlying the vegetational differences between the western and eastern portions of the Sonoran desert. Plant collections in the area yielded primarily California Sonoran plants, but also several Mojave and Arizona Sonoran plants. A fair number of the Arizona Sonoran plants collected were …

Phylogenetic Analyses And Biogeography Of Trilliaceae, Susan B. Farmer

Aliso: A Journal of Systematic and Floristic Botany

Trilliaceae are plants of North Temperate forests with a holarctic distribution and a high degree of endemism. Molecular phylogenetic analyses are presented in order to examine the tribal, generic, and species-level classification of the family. These molecular studies, and earlier morphological studies, support the placement of the genus Pseudotrillium as basal in the family and sister to the tribes Trillieae and Parideae, which are monophyletic sister groups. Trillidium (Trillium) govanianum provides an unresolved problem: morphologically it is included within Parideae, but molecular data place it within Trillium as sister to T. undulatum. Within tribe Trillieae, clades are …

The Evolutionary And Biogeographic Origin And Diversification Of The Tropical Monocot Order Zingiberales, W. John Kress, Chelsea D. Specht

Aliso: A Journal of Systematic and Floristic Botany

Zingiberales are a primarily tropical lineage of monocots. The current pantropical distribution of the order suggests an historical Gondwanan distribution, however the evolutionary history of the group has never been analyzed in a temporal context to test if the order is old enough to attribute its current distribution to vicariance mediated by the break-up of the supercontinent. Based on a phylogeny derived from morphological and molecular characters, we develop a hypothesis for the spatial and temporal evolution of Zingiberales using Dispersal-Vicariance Analysis (DIVA) combined with a local molecular clock technique that enables the simultaneous analysis of multiple gene loci with …

Missing Links Between Disjunct Populations Of Androcymbium (Colchicaceae) In Africa Using Chloroplast Dna Noncoding Sequences, Alberto Del Hoyo, Joan Pedrola-Monfort

Aliso: A Journal of Systematic and Floristic Botany

With the objective of clarifying some aspects of the biogeography, phylogeny, and taxonomy of the genus Androcymbium, we sequenced three chloroplastic DNA noncoding regions (trnL intron, trnL-trnF IGS, and trnY-trnD IGS). These data were analyzed with maximum parsimony and the ancestral areas methods following Bremer. Results show that Androcymbium is not monophyletic and that the origin of its distribution and speciation is situated in western South Africa. Later, it dispersed to North Africa, going first to eastern South Africa. Androcymbium austrocapense and A. roseum allow us to phylogenetically connect the species of …

Gondwanan Origin Of Major Monocot Groups Inferred From Dispersal-Vicariance Analysis, Kåre Bremer, Thomas Janssen

Aliso: A Journal of Systematic and Floristic Botany

Historical biogeography of major monocot groups was investigated by biogeographical analysis of a dated phylogeny including 79 of the 81 monocot families using the Angiosperm Phylogeny Group II (APG II) classification. Five major areas were used to describe the family distributions: Eurasia, North America, South America, Africa including Madagascar, and Australasia including New Guinea, New Caledonia, and New Zealand. In order to investigate the possible correspondence with continental breakup, the tree with its terminal distributions was fitted to the geological area cladogram ((Eurasia, North America), (Africa, (South America, Australasia)) and to alternative area cladograms using the TreeFitter program. The results …

Yuccas (Agavaceae) Of The International Four Corners: Southwestern Usa And Northwestern Mexico, Lee W. Lenz, Michael A. Hanson

Aliso: A Journal of Systematic and Floristic Botany

Yuccas (Yucca, Agavaceae) are an easily recognizable constituent of the vegetation of the International Four Corners; an area made up of portions of Arizona, New Mexico, Sonora and Chihuahua. We recognize three species as native to the region, Yucca baccata, Y. elata and Y. madrensis, together with interspecific hybrids, and document for the first time naturally occurring intersectional hybridization between baccate-fruited (sect. Yucca) and capsular-fruited (sect. Chaenocarpa) species. We examine the reproductive barriers to hybridization operating within the genus, i.e., spatial, temporal and ethological, and we consider circumstances that may have been responsible for the production and …

Morphological Stasis Abd Molecular Divergence In The Intercontinental Disjunct Genus Datisca (Datiscaceae), Aaron Liston, Loren H. Rieseberg, Thomas S. Elias

Aliso: A Journal of Systematic and Floristic Botany

The genus Datisca comprises two species and has an intercontinentally disjunct distribution: D. cannabina is native to southwest and central Asia, whereas D. glomerata is distributed from northern California to northern Baja California. In 1975, Axelrod proposed a geohistorical scenario to account for such "Madrean-Tethyan links," suggesting that these disjunctions resulted from migration across the mid-Atlantic from the Paleogene up to the Neogene, approximately 23 to 65 m.y.a. The two species are quite similar in most phenotypic traits which have been studied to date. The major difference between the two involves their breeding system: D. cannabina is dioecious while D. …