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Full-Text Articles in Life Sciences
Role Of Eukaryotic Sel-1 Like Repeat Containing Genes In Helicobacter Pylori Evolution And Pathogenesis., Kalyani Putty
Role Of Eukaryotic Sel-1 Like Repeat Containing Genes In Helicobacter Pylori Evolution And Pathogenesis., Kalyani Putty
Electronic Theses and Dissertations
Background: Helicobacter pylori (Hp) establishes life-long gastric infection in billions of humans, and is often responsible for diseases such as peptic ulcer and gastric cancer. Cumulative actions of genetic drift and natural selection over several millennia sculpted the present Hp population structure, which is characterized by extreme genetic diversity and striking geographic clustering of genotypes. Natural selection is more commonly imprinted in DNA sequences of Hp proteins that interact with host components; however, in most instances biological relevance of selection during Hp infection remains unknown. Here, I attempted to elucidate the consequence of natural selection in two different contexts: (1) …
Historical Biogeography Of Velvet Ants (Hymenoptera: Mutillidae) In The North American Deserts And Arid Lands, Joseph S. Wilson
Historical Biogeography Of Velvet Ants (Hymenoptera: Mutillidae) In The North American Deserts And Arid Lands, Joseph S. Wilson
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
For centuries, scientists have been intrigued by the high amount of biodiversity that is found in the deserts of North America. Recently, several studies have investigated the causes of the high diversity found in desert-dwelling mammals, reptiles, and amphibians. These studies have found that many of these organisms seem to have diversified in response to the same historical events. Little work has been done, however, on diverse desert-dwelling insect groups. In this dissertation, I investigate the patterns of genetic diversity in four groups of nocturnal wasps called velvet ants. I compare the patterns of genetic diversity to the historical events …
Biogeography And Diversification In The Neotropics: Testing Macroevolutionary Hypotheses Using Molecular Phylogenetic Data, Juan Manuel Daza Rojas
Biogeography And Diversification In The Neotropics: Testing Macroevolutionary Hypotheses Using Molecular Phylogenetic Data, Juan Manuel Daza Rojas
Electronic Theses and Dissertations
Lineage diversification in the Neotropics is an interesting topic in evolutionary biology and one of the least understood. The complexity of the region precludes generalizations regarding the historical and evolutionary processes responsible for the observed high diversity. Here, I use molecular data to infer evolutionary relationships and test hypotheses of current taxonomy, species boundaries, speciation and biogeographic history in several lineages of Neotropical snakes. I comprehensively sampled a widely distributed Neotropical colubrid snake and Middle American pitvipers and combined my data with published sequences. Within the colubrid genus Leptodeira, mitochondrial and nuclear markers revealed a phylogeograhic structure that disagrees with …
Investigating Instructors' Conceptions Of Evolution Through The Development Of The Classroom Test Of Evolutionary Reasoning, Patricia Eileen Palko
Investigating Instructors' Conceptions Of Evolution Through The Development Of The Classroom Test Of Evolutionary Reasoning, Patricia Eileen Palko
Electronic Theses and Dissertations
In order to assess the evolutionary understanding of high school biology teachers, an instrument entitled the Classroom Test of Evolutionary Reasoning (CTER) was developed. Content, response process, relations to another variable (the Conceptual Inventory of Natural Selection, or CINS), and internal structure evidence were compiled. The second version of the CTER was found to have adequate reliability and validity estimates to allow it to continue to be used as a measurement tool for an understanding of evolution. When assessing a sample of teachers (n = 724), the mean score was 6.35 out of a possible 13 points. The sample was …