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Full-Text Articles in Ecology and Evolutionary Biology
Phylogeographic History Of The Leaf-Eared Mouse, Phyllotis Xanthopygus Complex, Tabitha R. Mcfarland
Phylogeographic History Of The Leaf-Eared Mouse, Phyllotis Xanthopygus Complex, Tabitha R. Mcfarland
Biology ETDs
Museum collections provide essential biodiversity sampling needed to understand the species limits, phylogeny, and biogeographic history of mammals, all key features of the foundation for comparative analyses in ecology and evolution. We add to this framework a diverse assemblage of species of leaf-eared mice (genus Phyllotis) in South America and then focus on the Phyllotis xanthopygus complex by combining available mitochondrial sequence (cytochrome b; cytb) data (351 GenBank samples) with 52 newly sequenced museum samples from the northern extent of this complex’s range (51 from Bolivia and 1 from northern Chile) to reconstruct evolutionary relationships using maximum …
Dynamics Of Avian Elevational Ranges Reveal Hidden Evolutionary Forces, Chauncey Gadek
Dynamics Of Avian Elevational Ranges Reveal Hidden Evolutionary Forces, Chauncey Gadek
Biology ETDs
The distribution of life across the Andes mountains reflects historical elevational-range contraction and expansion. Whereas contraction implies specialization, expansion requires overcoming hidden barriers. Three eco-evolutionary phenomena may drive patterns in rates of elevational range evolution: (1) The Dobzhansky-MacArthur Phenomenon (DMP) predicts lower rates of upward expansion with harsher physical conditions, while downward expansion increases with lower diversity; (2) the evolutionary tendency toward specialization predicts contraction increases when ranges are broad; and (3) natural selection for respiratory performance could suppress expansion across mid-elevations due to gene-environment mismatch. We modeled elevational range shifts of Neotropical landbirds. Contrary to the DMP, upward expansion …
Mixing It Up: The Impact Of Episodic Introgression On The Evolution Of High-Latitude Mesocarnivores, Jocelyn P. Colella
Mixing It Up: The Impact Of Episodic Introgression On The Evolution Of High-Latitude Mesocarnivores, Jocelyn P. Colella
Biology ETDs
At high latitudes, climatic oscillations have triggered repeated episodes of organismal divergence by geographically isolating populations. For terrestrial species, extended isolation in glacial refugia – ice-free regions that enable terrestrial species persistence through glacial maxima – is hypothesized to stimulate allopatric divergence. Alternatively, upon glacial recession, divergent populations expanded from independent glacial refugia and often contacted other diverging populations. In the absence of reproductive isolating mechanisms, this biogeographic process may trigger hybridization and ultimately, gene flow between divergent taxa. My dissertation research aims to understand how these episodic periods of isolation and contact have impacted the evolution of high latitude …
Immunology Of The Gray Short-Tailed Opossum During Pregnancy And Prenatal Development, Victoria L. Hansen
Immunology Of The Gray Short-Tailed Opossum During Pregnancy And Prenatal Development, Victoria L. Hansen
Biology ETDs
Vertebrate species that bear live young have overcome the evolutionary challenge of maintaining both a functional adaptive immune system and viviparous life cycle. In normal pregnancy, viviparous mothers are able sustain and nourish a fetus that is genetically half non-self without mounting an immunological attack. In 1953 Sir Peter Medawar brought attention to the “enigma of the fetal graft” and immunologists have been puzzling out the intricacies of fetal tolerance ever since. Although viviparity has evolved in all jawed vertebrate lineages aside from Aves, the vast majority of reproductive immunology research has been limited to eutherian mammals. There are insights …