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Full-Text Articles in Life Sciences

A Genomic Investigation Of Divergence Between Tuna Species, Pavel V. Dimens Aug 2022

A Genomic Investigation Of Divergence Between Tuna Species, Pavel V. Dimens

Dissertations

Effective management and conservation of marine pelagic fishes is heavily dependent on a robust understanding of their population structure, their evolutionary history, and the delineation of appropriate management units. The Yellowfin tuna (Thunnus albacares) and the Blackfin tuna (Thunnus atlanticus) are two exploited epipelagic marine species with overlapping ranges in the tropical and sub-tropical Atlantic Ocean. This work analyzed genome-wide genetic variation of both species in the Atlantic basin to investigate the occurrence of population subdivision and adaptive variation. A de novo assembly of the Blackfin tuna genome was generated using Illumina paired-end sequencing data and …


Reassessment Of Species Boundaries And Phylogenetic Relationships In The Desmodium Ciliare Complex (Fabaceae) Using Morphological And Dna Data, Joshua Wilkinson May 2022

Reassessment Of Species Boundaries And Phylogenetic Relationships In The Desmodium Ciliare Complex (Fabaceae) Using Morphological And Dna Data, Joshua Wilkinson

Master's Theses

Desmodium (Beggar's ticks) is a generally weedy genus of approximately 280 species in the angiosperm family Fabaceae (Subfamily Papilionoideae, Tribe Desmodieae) characterized by indehiscent loments constricted into segments. Within the Southeastern U.S., the Desmodium ciliare group is one of two Desmodium species complexes that have been historically difficult, with much argument about the limits of species and the role of hybridization. There are three commonly recognized species within the D. ciliare group, D. ciliare (Muhl. ex Willd.) DC., Desmodium marilandicum (L.) DC., and D. obtusum (Muhl. ex Willd.) DC., with two supposed hybrids in addition to the …


Effects Of Tectonics And Large Scale Climatic Changes On The Evolutionary History Of Hyalomma Ticks, Arthur F. Sands, Dmitry A. Apanaskevich, Sonja Matthee, Ivan G. Horak, Alan Harrison, Shahid Karim, Mohammad K. Mohammad, Kosta Y. Mumcuoglu, Rupika S. Rajakaruna, Maria M. Santos-Silva, Joshua Kamani, Conrad A. Matthee Sep 2017

Effects Of Tectonics And Large Scale Climatic Changes On The Evolutionary History Of Hyalomma Ticks, Arthur F. Sands, Dmitry A. Apanaskevich, Sonja Matthee, Ivan G. Horak, Alan Harrison, Shahid Karim, Mohammad K. Mohammad, Kosta Y. Mumcuoglu, Rupika S. Rajakaruna, Maria M. Santos-Silva, Joshua Kamani, Conrad A. Matthee

Faculty Publications

Hyalomma Koch, 1844 are ixodid ticks that infest mammals, birds and reptiles, to which 27 recognized species occur across the Afrotropical, Palearctic and Oriental regions. Despite their medical and veterinary importance, the evolutionary history of the group is enigmatic. To investigate various taxonomic hypotheses based on morphology, and also some of the mechanisms involved in the diversification of the genus, we sequenced and analysed data derived from two mtDNA fragments, three nuclear DNA genes and 47 morphological characters. Bayesian and Parsimony analyses based on the combined data (2242 characters for 84 taxa) provided maximum resolution and strongly supported the monophyly …


Species Delimitation And Phylogenetic Relationships Of The Wild Yams (Dioscorea) Native To Eastern North America, Tori A. Collins May 2015

Species Delimitation And Phylogenetic Relationships Of The Wild Yams (Dioscorea) Native To Eastern North America, Tori A. Collins

Honors Theses

Most taxonomic treatments currently recognize two to three species of native yams in eastern North America: Dioscorea villosa, D. floridana, and sometimes D. quaternata, a segregate of D. villosa. Earlier authors (e.g., J. K. Small) had recognized as many as five species (with D. hirticaulis and D. glauca also as segregates of D. villosa). Key morphological features in distinguishing these putative species are rhizome morphology (long and cord-like vs. thick and contorted), number of first leaves (1–3 vs. 4–7), and habitat (sandy, rocky, swampy). Unfortunately, these critical features are rarely collected and preserved on herbarium …


Using Manipulative Models To Develop Tree-Thinking, Donaven C. Mclaurin May 2013

Using Manipulative Models To Develop Tree-Thinking, Donaven C. Mclaurin

Honors Theses

It is well known that students often struggle with tree-thinking, a core aspect of evolutionary education. Scientists consider phylogenetic trees multidimensional hypotheses of evolutionary relationships. However, student view textbook diagrams as static, two-dimensional images. Physical manipulatives have been used to facilitate learning science content in areas such as genetics, but these instructional tools have not yet been tested in tree-thinking. In order to circumvent students’ tree-thinking struggles, I investigated the use of manipulative, three-dimensional tree models in an introductory biology course designed for non-science majors (n=163). Specifically my research questions included: What are the differences in tree-thinking learning gains when …