Lucina floridana is an intertidal clam that contains intracellular, sulfur-oxidizing
symbiotic bacteria in its gills. These bacteria are chemolithoautotrophic, using the energy
from the oxidation of reduced sulfur compounds to power carbon fixation. Although
sulfide is an energy-rich compound, it is also toxic to aerobic metabolism and autooxidizes
in the...
Animal signaling systems frequently utilize multiple traits to produce and transmit a signal. These system elements may span multiple levels of organization. Functional integration of these traits may be expected to generate concordance in evolutionary pattern among system elements, such that evolutionary change in one system component is correlated with...
The respiratory and metabolic biology of dinosaurs is poorly, if at all, reflected in the fossil record. By comparing anatomical features of modern taxa that are functionally linked to specific biology with the remains of theropod dinosaurs (Archosauria: Theropoda) and early birds, we may reasonably infer the physiology of long...
The remodeling of the central nervous system (CNS) during metamorphosis in Drosophila melanogaster is a prime model system in which to study the genetic control of the sexual dimorphisms in the abdominal ganglion of the CNS. I have been using a P[tau-lacZ] enhancer trap line, 4.078, to label a segmentally...
Population genetic structure is widespread in many organisms and can be found at small spatial scales. Fine-scale differentiation is the result of ecological and evolutionary processes working together to produce an overall pattern, but the relative importance of these factors in population differentiation is poorly understood. The goals of my...
Climate change is predicted to affect ecosystems, including systems already stressed by human impacts. One ecosystem that is already highly impacted by human land use is the cold headwater stream system of the Pacific Northwest. One method of assessing the function of an ecosystem is by using an indicator species....
How complex traits evolve continues to be a major focus of evolutionary
investigation. A current topic of debate is the hypothesis that the phenotypic
integration of complex traits gives rise to evolutionary constraints. I studied two color
traits in the common garter snake, Thamnophis sirtalis, that show a high level...
Chemoreception is one of the dominant sensory modalities for many species of salamanders (reviewed in Chapter 2). At least seven of the ten currently recognized salamander families are known to respond to some sort of chemical cue. These responses are as varied as delaying hatching, seeking refuge, or initiating aggressive...
An ancient pheromonal signal is found in aquatic courting salamandrids and terrestrial courting plethodontids, two highly divergent salamander families. In the aquatic courting salamandrids Cynops pyrrhogaster and C. ensicauda, the decapeptide sodefrin is cleaved from a larger 189 amino acid Sodefrin Precursor Factor (SPF) protein and released from a gland...