Leptosporangiate ferns, with more than 9000 extant species, are truly exceptional among the non-flowering lineages of vascular plants. However, this rather remarkable diversity was not simply a consequence of being able ...
<p>One of the major goals of evolutionary biology is understanding the process of species formation. There is particular interest in how selection can favor species formation through the process of reinforcement. When ...
All life is organized hierarchically. Lower levels, such as cells and zooids, are
nested within higher levels, such as multicellular organisms and colonial animals. The
process by which a higher-level unit forms from the ...
<p>Edaphic factors--those pertaining to the substrate or soil--are thought to play an important role in the diversification of flowering plants. Although edaphic factors are widely interpreted as causal agents in plant ...
<p>Evolution can be studied at many levels, from phenotypic to molecular, and from a variety of disciplines. An integrative approach can help provide a more complete understanding of the complexities of evolutionary change. ...
<p>Bryophytes, by their haploid dominant life cycle, possess several unique qualities ideal for study of mating patterns. In particular, the possibility of intragametophytic selfing in some species, and the vegetative ...
<p>Understanding the mechanisms that underlie the formation of, and innovation in biochemical pathways is an important goal in evolutionary biology. The following work addresses the problem of biochemical pathway evolution ...
<p>Evolutionary dynamics can be notoriously complex and difficult to analyze. In this dissertation I describe a population genetic regime where the dynamics are simple enough to allow a relatively complete and elegant ...
<p>Scallops, a family of swimming bivalve mollusks, have dozens of eyes arrayed along the edges of their valves. Relatively little is known about the form and function of these unusual eyes. To learn more about them, we ...
<p>Although evolution results from differential reproduction and survival at the level of the individual, most research in evolutionary genetics is concerned with comparisons made at the level of divergent populations or ...
Epithelial-mesenchymal transitions (EMTs) are fundamental and indispensable
to embryonic morphogenesis throughout the animal kingdom. At the onset of
gastrulation in the sea urchin embryo, micromere-derived primary ...
<p>Many factors, including gene networks, developmental processes, and the environment mediate the link between the activity of genes and complex phenotypes in higher organisms. While genetic variants are the raw material ...
<p>Biodiversity is generated by the process of speciation. Because biological species are defined as populations that are unable to exchange genes with one another, the study of the evolution of reproductive isolation ...
<p>Lichens are symbioses between a fungus and a photosynthesizing partner such as a green alga or a cyanobacterium. Unlike mycorrhizal or rhizobial symbioses, the lichen symbiosis is not well understood either morphologically ...
<p>The Zero Force Evolutionary Law predicts an increase in complexity at all levels of biological hierarchy unless there are constraints or selective forces opposing that increase. I present the first test of this universal ...
<p>In this project I expand the current model of hierarchical transition to include transition by individuation in addition to transition by integration and I apply my model of transition by individuation to the evolution ...
<p>Because species respond individually to climate change, understanding community assembly requires examination of multiple species from a diversity of forest niches. I present the post-glacial phylogeographic history of ...
Microtubules, dynamic structures that make up the cellular cytoskeleton, are essential for cellular transport, motility, division, and structural stability. Accordingly, their dynamics must be tightly regulated. One such ...
<p>The evolution of selfing from outcrossing is one of the most frequent mating system transitions in angiosperms. Plants that are highly selfing typically exhibit a suite of morphological traits termed a "selfing syndrome," ...
<p>Dendrite shape is a defining component of neuronal function. Yet, the mechanisms specifying diverse dendritic morphologies, and the extent to which their functioning depends on these morphologies, remain unclear. Here, ...