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Full-Text Articles in Ecology and Evolutionary Biology

Chromosome Number Evolution, Phylogeography, And The Effects Of Climate Change On Species Distributions In Polyploid Plant Systems, Courtney H. Babin Aug 2022

Chromosome Number Evolution, Phylogeography, And The Effects Of Climate Change On Species Distributions In Polyploid Plant Systems, Courtney H. Babin

University of New Orleans Theses and Dissertations

Polyploidy, a term used to describe organisms with cells having more than two paired sets of chromosomes, is a significant driver of diversification among land plants. Over a century of research has advanced our understanding of polyploidization in some taxa, but polyploid organisms remain understudied. In this dissertation, I investigate chromosome number evolution, phylogeographic structure, genetic differentiation, and the effects of climate change on ploidy level distribution using polyploid plant systems. In the first chapter, I inferred a molecular phylogeny of Allium, an economically important genus that includes cultivated crops and ornamentals, to investigate evolutionary transitions in chromosome number …


Genetic Diversity In An Invasive Clonal Plant? A Historical And Contemporary Perspective, Elliot D. Weidow Aug 2018

Genetic Diversity In An Invasive Clonal Plant? A Historical And Contemporary Perspective, Elliot D. Weidow

University of New Orleans Theses and Dissertations

Introduced populations of Eichhornia crassipes (Pontederiaceae) possess extremely low levels of genetic diversity due to severe bottleneck events and clonal reproduction. While populations elsewhere have been well studied, North American populations of E. crassipes remain understudied. We used Amplified Fragment Length Polymorphism markers to assess genetic diversity and population structure in North American E. crassipes populations. Patterns of diversity over the past fifty years were analyzed using herbarium specimens. Furthermore, we sampled populations across the Gulf Coast of the United States throughout a year to determine contemporary genetic diversity and assess potential seasonal effects. Genetic diversity was found to be …


Size-Dependent Patterns Of Reproductive Investment In The North American Invasive Plant Species Triadica Sebifera (L.) Small (Euphorbiaceae), Courtney H. Babin May 2017

Size-Dependent Patterns Of Reproductive Investment In The North American Invasive Plant Species Triadica Sebifera (L.) Small (Euphorbiaceae), Courtney H. Babin

University of New Orleans Theses and Dissertations

Knowledge of sex allocation trade-offs with tree growth in insect-pollinated woody plants is limited, particularly in invasive plants. This study examined patterns of growth and reproductive investment in a North American invasive plant species, Triadica sebifera, I hypothesized that the energy limitations of smaller trees may result in the production of more male reproductive structures that are energetically less costly. Diameter at breast height was a significant predictor of seed and catkin mass and regression can describe these relationships across sites. Seed and catkin mass were positively correlated across sites. The relationship between the seed mass:catkin mass ratio and …