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Full-Text Articles in Life Sciences
Genetic Diversity Correlates With Morphological Diversity Among Populations Of Achyrachaena Mollis, Rachel S. Bice
Genetic Diversity Correlates With Morphological Diversity Among Populations Of Achyrachaena Mollis, Rachel S. Bice
University Honors Theses
Biodiversity is important for ecosystem health and sustainability, especially in the current, rapidly changing climate. Understanding the underlying causes behind morphological variation will allow for more accurate predictions about how a population will respond to climate change, and potentially yield better natural resource management strategies. Achyrachaena mollis is an annual, self-fertilizing, range-limited, endemic species found in Northern California and Southern Oregon. This species depends primarily on wind seed dispersal for gene flow, making it a good study species in seed dispersal experiments. Additionally, A. mollis is more readily influenced by changes in its environment than a perennial due to its …
An Efficient Pipeline For Assaying Whole-Genome Plastid Variation For Population Genetics And Phylogeography, Brendan F. Kohrn
An Efficient Pipeline For Assaying Whole-Genome Plastid Variation For Population Genetics And Phylogeography, Brendan F. Kohrn
Dissertations and Theses
Tracking seed dispersal using traditional, direct measurement approaches is difficult and generally underestimates dispersal distances. Variation in chloroplast haplotypes (cpDNA) offers a way to trace past seed dispersal and to make inferences about factors contributing to present patterns of dispersal. Although cpDNA generally has low levels of intraspecific variation, this can be overcome by assaying the whole chloroplast genome. Whole-genome sequencing is more expensive, but resources can be conserved by pooling samples. Unfortunately, haplotype associations among SNPs are lost in pooled samples and treating SNP frequencies as independent estimates of variation provides biased estimates of genetic distance. I have developed …
Frequency-Dependent Seed Dispersal By Ants Of Two Deciduous Forest Herbs, Brent H. Smith, Catherine E. De Rivera, Cara Lin Bridgman, John J. Woid
Frequency-Dependent Seed Dispersal By Ants Of Two Deciduous Forest Herbs, Brent H. Smith, Catherine E. De Rivera, Cara Lin Bridgman, John J. Woid
Environmental Science and Management Faculty Publications and Presentations
Two co—occurring deciduous forest myrmecochores, Asarum canadense and Jeffersonia diphylla, release their seeds at approximately the same time, and therefore potentially compete for ants as dispersers. Within a single woodlot, we placed seeds of both species inside a dense Jeffersonia population away from Asarum plants, inside a dense Asarum population away from Jeffersonia plants, and in a site where plants of neither species occurred. No preference was exhibited by ants where natural populations were absent. Preference at the other two sites was frequency dependent: ants preferred seeds of the introduced species. Species preferred by ants have higher seed and …
Small Mammal Dissemination Of Dwarf Mistletoe Seeds, Daniel Eugene Lemons
Small Mammal Dissemination Of Dwarf Mistletoe Seeds, Daniel Eugene Lemons
Dissertations and Theses
No study has been done in the western United States concerning dispersal of dwarf mistletoe by mammals. At the outset of the study it was determined that the red squirrel, the yellow pine chipmunk (Eutamias amoenus), the northern flying squirrel, and the bushy-tailed wood rat (Neotaoma cinerea), were all potential vectors of seeds. The red squirrel was chosen as the main object of study because it is diurnal and is closely associated with ponderosa pine (Pinus ponderosa), a heavily infected species. The study was undertaken to determine whether small mammals play a significant role in transporting mistletoe seeds to uninfected …