With broad interests in systematics and biogeography, emphasizing ichthyology, I have a number of ongoing research projects that span freshwater and marine environments. My current investigations are in spatial and temporal diversity of Neotropical freshwater and marine taxa utilizing independent morphological and molecular markers. One area of research is in the phylogeography and diversity of Neotropical freshwater fishes. I am simultaneously examining the biogeographic history of three genera of fishes (Characidae: Astyanax, Bramochrax and Hyphessobrycon) in lower Central America while undertaking a morphological revision of this fishes’ taxonomy and systematics. The complex, but well described, geological history of the Central American isthmian region affords an opportunity to hypothesize and test mechanisms of vicariance and dispersal in these fishes across a dynamic landscape. A second area of emphasis is to explore the phylogenetic histories of putatively monophyletic faunal assemblages that are distributed across the eastern Pacific /eastern Atlantic marine biogeographic track in an effort to test common biogeographic scenarios. And finally, alpha-taxaonomic descriptions are underway for additional species of New World halfbeak fishes (Hemiramphidae).

Current research addresses the patterns and controls of nitrogen (N) cycling dynamics in forest ecosystems with a primary focus on: i.) the role of fine roots in the N cycle, and ii.) the effects of prescribed burning on the loss, retention, and replacement of N in forest ecosystems. The primary goal of this research program is to gain an improved, mechanistic understanding of N cycling dynamics and controls on forest productivity which is critical to more accurately assess and predict the impact of management regimes (e.g., prescribed burning, site preparation, and harvesting) and anthropogenic disturbances (e.g., global warming, acid rain, and stratospheric ozone depletion) on the composition, structure, and function of forest ecosystems.

Physiology of the cornea.

Conservation genetics of fish species that are endemic to the Tallapoosa watershed in western Georgia. Specifically, the genetic structure of the Tallappoosa darter (Etheostoma tallapoosae) and the Tallapoosa shiner (Cyprinella gibbsi) populations is being determined. The aim of this research is to understand the geographic distribution of genetic diversity of these rare (though not yet endangered) species so that informed decisions can be made about conservation efforts. The population numbers of these species are low because of habitat degradation caused by impoundment, channelization, and excessive sediment deposition due to human population growth and increased land development.

Current research involves collaborating with the nursing department to study the effects of stress on the immune response. This research also involves an interest in the role of nutrition on the immune response. The primary goal of this research program is to gain an improved understanding of the effects of stress and diet on the body’s ability to fight infection. Past research interest included HIV DNA vaccination.

My primary research is in phylogenetic evolution and systematics, in which the goals are to reconstruct the evolutionary history (phylogeny) of a group of organisms and to find out how the organisms and their characteristics have originated and changed over time. The plants that I concentrate on are in the families Asteraceae (the sunflower family) and Rosaceae (the rose family).

My research centers around extracellular growth factors and how these growth factors may influence the growth of the lining of the intestines. A normal person living to age 70 will replace the lining of their intestines on the average of 5000-12000 times in their lifetime, depending on which part of the intestine is being discussed. Growth factors from inside our bodies as well as those derived from our environment (our diet, smoking, produced by bacteria etc.). Currently, we have several areas of investigation: 1) We are investigating the role nicotine has in regulating intestinal growth and repair to determine whether nicotine may predispose the intestines to the development of cancer, 2) We are investigating the influence of hormones related to glucose metabolism to determine if these hormones may influence the intestines in diabetic patients. 3) We are investigating the relationship of polyamines (produced by humans and bacteria) and how this family of compounds may influence growth and repair of the intestinal lining during periods of ischemia (lack of oxygen). The research involves cell culture work done at West Georgia and whole animal work performed in conjunction with Mercer University School of Medicine.

Insect pest resistance and ecology of stream invertebrates.

Dr. Quertermus has been involved in research projects which cover the fields of behavioral analysis, fisheries investigations, and environmental consulting, He has conducted studies on the behavior of freshwater fishes, including habitat selection and home range analysis of cichlids and centrarchids, social behavior of cichlids, and parasite burden effects on feeding behavior of centrarchids. Dr. Quertermus has conducted fisheries investigations such as the distribution of fishes in western Georgia streams, population trends of largemouth bass in Georgia reservoirs, growth rate studies, and the quality of freshwater sport fishing in Georgia. Dr. Quertermus' current research and environmental consulting interests include the study of trends in sport fishing quality and population dynamics of black basses in Georgia reservoirs using data form sport fishing tournaments, lake and pond ecology and management, and wetlands delineation.

Biochemistry of lens proteins.

Aquatic Ecology and Conservation: this research is focused around the biological integrity of streams in West Georgia and the impact of continued growth and development on the biodiversity of fishes.

Placoid Scale Morphology: this research is looking at the relationship between the morphological variability in placoid scales of Squaliforme sharks and function.

My laboratory has had a long-standing interest in how cells move and change shape. Cells that swim by beating flagella or cilia are interesting but I study cells that crawl or contract. These are complex movements that require coordination of events in all parts of the cell. Much of our current work revolves around the cytoskeletal protein, actin, and proteins that interact with actin. We use microscopy and molecular biology as tools to dissect the fundamental mechanisms by which actin contributes to the movement of cell. Our work is relevant to the mechanisms of muscle development and cellular transformation (cancer).