Inferences regarding the biology of extinct taxa are often founded primarily
on cladistically-based phylogenetic hypotheses. However, these inferences are
frequently inconsistent with the morphology and physiology of modern animals. I
suggest that reference to the biology of modern animals might be a more
appropriate tool to aid in the reconstruction...
The giant hairy desert scorpion, Hadrurus arizonensis, is a long-lived species
of North American scorpion that is presented here as an important model for research
in mating systems evolution and sexual selection. Many behaviors found in this
species were undocumented and are described here for the first time. This thesis...
The acute phase response (APR) includes an early response of the innate immune
system to an inflammatory agent. Acute phase proteins (APP) are produced at
increased rates in the liver during this response. The APR has been well
characterized in mammals, but it is unclear to what degree teleosts mount...
Predator-prey interactions have historically been studied to explain patterns of organization observed in populations and communities. They have also been important in understanding the evolution of antipredator responses in prey and counterstrategies in predators. Despite the breadth of knowledge that exists for heterospecific interactions, relatively few studies have investigated the...
Pheromones are chemical cues produced by organisms that affect the behavior and/or physiology of conspecifics. The orchestration of reproductive behaviors in many animals depends on the expression of sex pheromones. In insects, intraspecific variation in sex pheromone expression is commonly observed and often influences social interactions between individuals. To what...
Intracellular symbioses between cnidarians and dinoflagellates from the genus Symbiodinium are widespread throughout the marine environment. These associations are ecologically significant, especially in tropical waters where symbiotic interactions between corals and Symbiodinium culminate in the formation of limestone reefs. This thesis focuses on cellular and molecular aspects of the symbiosis,...
My dissertation focuses on the factors that influence variation in female reproductive success in plethodontid salamanders and in toads. Variation in reproductive success fuels evolutionary change. Although, females often have been overlooked in studies of reproductive success due to perceived lower levels of variation when compared to variation in male...
The neurohypophysial peptide system is involved in modulating a
variety of physiological, neurological, and behavioral responses in
vertebrates. The principal forms of these peptides in non-mammalian
tetrapods are vasotocin (VT) and mesotocin (MT). The studies described
in this thesis used pharmacological, molecular, and biochemical
techniques, along with phylogenetic analyses, to...
In nature, animals survive threats by responding physiologically and behaviorally in ways that are appropriate to the situation. Which responses are appropriate depend on the animals' surroundings and current physiological and behavioral state. This dissertation investigated the neuroendocrine mechanisms that control context-dependent behavioral responses to stress by focusing on the...
In the past decade, declines in amphibian populations have captured scientific and popular interest. The causes of the declines are likely to be complex and involve interactions between several environmental stressors. Using multifactorial experiments, I investigated the combined effects of several anthropogenic stressors on developing amphibians in Oregon, USA. In...
This is a neuroanatomical and ethological study of the pectines, the primary
chemosensory organs of scorpions (Arachnida: Scorpiones). The pectines are
paired, ventromedial appendages that brush the substrate as the scorpion walks.
This comb-like organ consists of a supportive spine and an array of teeth. Each
tooth supports hundreds of...
Evaluating the relative influences of positive and negative interactions in shaping communities is a major topic in modern ecology. Facilitative interactions between basal species are important in habitats with intense predation pressure or severe abiotic stresses. However, few studies address the potential for positive interactions between trophic levels to influence...
Ultraviolet-B radiation (UV-B) has been suggested as a factor contributing to global amphibian population declines. While ambient UV-B levels damage the eggs and embryos of some amphibian species, few studies have addressed how UV-B affects other life history stages or sublethal responses. My dissertation focuses on (1) investigations of sublethal...
This dissertation focuses on science relevant to the design and implementation of marine reserves. The chapters explore a range of topics related to among-site variation in population, community, and ecosystem dynamics. My results demonstrate the value and feasibility of integrating this knowledge into more comprehensive conservation and management approaches. While...
The benefits of reproduction are clear, but there are also costs. Much is known about the costs of reproduction in females, but only recently have male costs been investigated in any depth. These costs of reproduction may be minimized by appropriately modifying behavior, but there has been little research on...
Biological introductions may considerably alter the composition and community dynamics of invaded areas thereby changing many ecosystem processes including productivity, decomposition, nutrient cycling and hydrology. The effects on native species may be obscured by a lack of information on distribution and abundance patterns. The Japanese eelgrass, Zostera japonica, was introduced...