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Articles 1 - 8 of 8
Full-Text Articles in Biology
The Status Of Dwarfed Populations Of Short-Horned Lizards (Phrynosoma Hernandesi) And Great Plains Toads (Anaxyrus Cognatus) In The San Luis Valley, Colorado, Megan E. Lahti
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The San Luis Valley is a large valley formation in Colorado surrounded on either side by mountain ranges exceeding 4,267 m. Within the Valley, two of the 14 amphibian and reptile species are dwarfed: the short-horned lizard (Phrynosoma hernandesi) and the Great Plains toad (Anaxyrus cognatus). Since its initial reporting in 1968 and confirmation in 1981, no research further investigating this dwarfism has been conducted. I collected morphological measurements to determine the extent and patterns of dwarfism of both species. I then investigated the genetics of both species using mitochondrial DNA to determine whether they are …
Evolutionary History And Taxonomy Of The Cuscuta Umbellata Complex (Convolvulaceae): Evidence Of Extensive Hybridization From Discordant Nuclear And Plastid Phylogenies, Mihai Costea, Saša Stefanović
Evolutionary History And Taxonomy Of The Cuscuta Umbellata Complex (Convolvulaceae): Evidence Of Extensive Hybridization From Discordant Nuclear And Plastid Phylogenies, Mihai Costea, Saša Stefanović
Biology Faculty Publications
The Cuscuta umbellata complex is one of the 15 major clades recently circumscribed in C. subg. Grammica. Most of its members occur in North AMerican and the Caribbean (C. desmouliniana, C. lacerata, C. lacerata, C. leptantha, C. liliputana, C. odontolepsis, C. polyanthemos, C. tuberculata, C. umbellata), but three species (C. acuta, C. membranacea, C. umbellata) grow in South America, and one (C. hyalina) is found as a native species in India, Pakistan and Eastern to South Africa. Basic morphology, scanning electron microscopy and …
Assessing Traditional Morphology- And Chemistry-Based Species Circumspections In Lichenized Ascomycetes: Character Evolution And Molecular Species Delimitation In Common Western North American Lichens, Steven Leavitt
Theses and Dissertations
Accurate species delimitation has critical implications for ecological and conservation studies; and for understanding factors driving diversification. However, a growing body of evidence indicates that morphology-based species circumspection in lichenized ascomycetes often fails to accurately represent the number of fungal species. The use of molecular data in lichen systematics provides an important alternative to traditional morphological characters for identifying natural groups and assessing evolutionary histories in challenging lichen taxa. In this work, I examined two common lichen-forming genera in western North America, Rhizoplaca and Xanthoparmelia, as models for investigating character evolution, species delimitation in morphologically and chemically diverse species, …
Utilization Of Phylogenetic Systematics, Molecular Evolution, And Comparative Transcriptomics To Address Aspects Of Nematode And Bacterial Evolution, Scott M. Peat
Theses and Dissertations
Both insect parasitic/entomopathogenic nematodes and plant parasitic nematodes are of great economic importance. Insect parasitic/entomopathogenic nematodes provide an environmentally safe and effective method to control numerous insect pests worldwide. Alternatively, plant parasitic nematodes cause billions of dollars in crop loss worldwide. Because of these impacts, it is important to understand how these nematodes evolve, and, in the case of entomopathogenic nematodes, how their bacterial symbionts evolve. This dissertation contains six chapters. Chapter one is a review of DNA markers and their use in the phylogenetic systematics of entomopathogenic and insect-parasitic nematodes as well as a review of phylogenetic, co-phylogenetic, and …
Behavioural Display Systems Across Nine Anolis Lizard Species: Sexual Dimorphisms In Structure And Function, Michele A. Johnson, J. Wade
Behavioural Display Systems Across Nine Anolis Lizard Species: Sexual Dimorphisms In Structure And Function, Michele A. Johnson, J. Wade
Biology Faculty Research
Relationships between structure and function are a primary focus in biology, yet they are most often considered within individual species. Sexually dimorphic communication behaviours and the morphology of associated structures can vary widely, even among closely related species, and these traits provide an ideal opportunity to investigate the evolution of structure-function patterns. Using nine Anolis lizard species, we addressed a series of questions regarding sex differences in and the evolution of relationships between extension of the throat fan (dewlap) and morphology of the muscles and cartilage controlling it. The main results indicated that within species, males displayed the dewlap more …
Development Of Representative Species-Level Molecular Markers And Morphological Character Analysis Of Leucothoid Amphipods (Crustacea: Amphipoda), Kristine Nicolle White
Development Of Representative Species-Level Molecular Markers And Morphological Character Analysis Of Leucothoid Amphipods (Crustacea: Amphipoda), Kristine Nicolle White
Dissertations
Leucothoid amphipods were investigated using morphology and molecular rDNA gene sequence fragments. The morphological diagnostic characters for traditional taxonomy have been clarified, a molecular marker for representative species has been developed, and one of the current anamorph-leucomorph connections has been confirmed with molecular sequence data. Ultimately this study has combined traditional morphological and modern molecular methods to clarify the taxonomy and to propose a preliminary phylogeny of the Leucothoidae. Analysis of 18S rDNA gene fragments from 13 species in two genera supported the current morphological species designations and the separation of the family into two clades. Combined analysis of 18S …
The Contributions Of Evolutionary Divergence And Phenotypic Plasticity To Geographic Variation In The Western Fence Lizard, Sceloporus Occidentalis, Christine R. Buckley, Duncan J. Irschick, Stephen C. Adolph
The Contributions Of Evolutionary Divergence And Phenotypic Plasticity To Geographic Variation In The Western Fence Lizard, Sceloporus Occidentalis, Christine R. Buckley, Duncan J. Irschick, Stephen C. Adolph
Biology Department Faculty Publication Series
Local genetic adaptation and phenotypic plasticity are two mechanisms that can have marked effects on the morphology, performance, and behaviour of animals, producing geographic variation among populations. However, few studies have examined how these mechanisms interact during ontogeny to shape organismal phenotypes. We incubated eggs of the western fence lizard, Sceloporus occidentalis, from four populations (representing two latitudes and altitudes) in either a warm or cool environment in the laboratory. We then raised the hatchlings under common laboratory conditions, measured morphological and performance traits until 5 weeks of age, and compared juvenile morphology with that of field-caught adults from …
The Effect Of Activator Application On The Anatomy, Morphology, And Viability Of Lycopersicon Esculentum Mill. Pollen, İlkay Öztürk Çali, Feyza Candan
The Effect Of Activator Application On The Anatomy, Morphology, And Viability Of Lycopersicon Esculentum Mill. Pollen, İlkay Öztürk Çali, Feyza Candan
Turkish Journal of Biology
The present study examined the effect of ACT-2, a K-vitamin group activator intensively applied to tomato (Lycopersicon esculentum Mill.), on the anatomy, morphology, and viability of tomato pollen from plants grown under greenhouse conditions. The activator was applied to tomatoes at the recommended dosage (150 cc/100 L of tap water) and double the recommended dosage (300 cc/100 L of tap water). Pollen width and length, exine and intine layer thickness, pore width and length, and crevice width and length were measured using an ocular micrometer. Reductions were observed in all the measured parameters in all application groups, except for pollen …