OUR PEOPLE
Learn about Faculty Research Interests Below
The Biology Faculty have active programs and research labs where students can gain firsthand experiences and work on independant projects. Click on faculty names to find contact and other information:
Dr. Rachel Collins, (she/her), Thornill Professor of Biology
Contact
Webpage
- B.S., North Carolina State University
- M.S., Miami University
- Ph.D., University of Pittsburgh
As a community ecologist, I am interested in how organisms in forests interact with each other and with the environment to affect ecosystem function (e.g., species diversity, productivity, invasibility, and other dynamics). I am especially interested in species diversity. Many factors contribute to the number of species in an area and the number of species in an area impact ecosystem functions. You may have noticed that there seems to be some circularity in my description. Although in academic writing, one might try to avoid circular arguments, understanding this circular nature of species diversity is key to understanding natural systems. And it is this interplay of the causes and consequences of species diversity that I am most interested in exploring in my research lab and classes.
Dr. Brooks Crozier, (he/him), Professor of Biology
Contact
Hear Dr. Brooks on his research interests via Academic Minute
- B.S., Roanoke College
- M.S., Virginia Polytechnic Institute and State University
- Ph.D., Virginia Polytechnic Institute and State University
My research interests have concentrated on the tracking of fecal bacteria in surface water (Microbial source tracking, MST). Until recently, we have been unable to identify the animal-source of surface water fecal contamination. Standard filtration methods can be used to obtain fecal coliform (E. coli) and fecal enterococci counts of water samples. However, cattle commonly frequent waterways as do waterfowl, deer and other animals capable of shedding pathogenic bacteria and viruses into the water. Therefore, the source of this contamination cannot be determined by traditional microbiological methods alone.
Quantitative PCR (qPCR) has become the benchmark tool to predict the source of contamination. Most recently my students and I have been using qPCR to detect human and cattle fecal contamination, and we have detected the presence of an elusive aquatic salamander, the hellbender, comparing their location to fecal markers. We are also excited about developing novel detection methods using Next Generation Sequencing (NGS) in order to detect the source of fecal contamination across entire watersheds in more of a “community” aspect, yielding significantly more information. My training is also as a mycologist, and so I have students interested in fungal projects largely surrounding the highly desired but cryptic fungus Morchella that produces morels.
Dr. Christopher S. Lassiter, (he/him), Professor of Biology
Contact
Website
Hear Dr. Lassiter on his research interests via Academic Minute
- B.S., Furman University
- Ph.D., Duke University
My research interests lie in the field of developmental biology. The mechanisms by which a single cell can give rise to a complex organism have always amazed me. Cells must differentiate and signal to each other, turning on vast networks of genes while coordinating growth, shape, and function. Much research has been done on small range signaling molecules during development. During my graduate work, I became interested in molecules that signal over longer ranges: hormones.
My work has focused on the estrogen signaling pathway. Estrogen is an important molecule in the developing embryo and in the adult vertebrate. This small molecule signals in many tissues of the body, including reproductive tissues, adipose, brain, bone, and heart. Estrogen signals by binding to estrogen receptors. My work has involved characterizing the estrogen receptors along with aromatase, the gene that codes for estrogen synthesis. The expression pattern of aromatase in the embryonic brain and its control by steroid hormones is well conserved among vertebrates. The pleiotropic effects of estrogen in the developing brain could affect neural architecture resulting in morphological and behavioral effects well into adulthood.
My lab also explores developmental toxicology of endocrine disrupting compounds that can affect vertebrate development by altering the estrogen and androgen signals in developing embryos. We study how these compounds affect a variety of organs including the developing jaw and heart. Recent projects in the lab are using CRISPR to create zebrafish models of human disease and investigating estrogenic pollution levels in the Roanoke River.
Dr. DorothyBelle (DB) Poli, (she/her), Professor of Biology
Contact
- B.S., University of Pittsburgh
- Ph.D., University of Maryland
I enjoy exploring how a physiological process evolved into the process that is taught in textbooks. For example, my Ph.D. dissertation looked at the role of polar auxin transport on the development of the sporophyte body axis. Future experiments would continue the classification of polar auxin transport in sporophytes, but more importantly, I want to explore polar auxin transport across gametophytic structures since the current literature is not normalized, contains many gaps, and therefore, evolutionary generalizations cannot be drawn.
The movement of plants from the water to the land created the need for plants to become larger and more erect in order to compete for light. This transition resulted in the evolution of vascular tissue, stomata, guard cells, and the cuticle. My goal is to examine these features across the extant plants to begin to fill in the evolutionary relationships between the physical changes and the physiological processes.
My research goal is to use these projects as a training platform for undergraduates who are interested in research or who desire preparation for their graduate studies. Both of these projects have the capacity to offer a broad research experience for undergraduates, including exposure to morphology, anatomy, molecular biology, bioinformatics, biochemistry, evolution, and physiology. Also, these projects have aspects that will require collaboration with other scientists, and this experience is one that many undergraduates do not get in traditional research internships and interactions. Developing research projects that ask broad questions gives an undergraduate a research experience that teaches them scientific theory and critical thinking while they learn the basics of the scientific material. These projects are broad enough to allow a student to take them in directions that drive their interests as well as mine.
Dr. Steven Powers, (he/him), Associate Professor of Biology
Contact
Research webpage
- B.S., Georgetown College
- M.S., Eastern Kentucky University
- Ph.D., University of Alabama
My primary research interest is the evolution of stream fishes of the southeastern United States and the ecological and historical variables that have influenced and continue to influence them. Not only are fishes inherently interesting due to their high level of diversity, range of evolutionary novelties, and varied ecologies, they are also excellent model organisms for investigating evolutionary processes. For many fishes, confinement to small streams and low dispersal capability provide a natural setting for investigating modes of speciation and biogeographic patterns. Dramatic sexual dimorphism present in several groups of fishes also indicates that sexual selection has played a major role in their evolution. Furthermore, the physical pressures of living in stream habitats have influenced the evolution of stream fishes and the communities to which they belong.
My research has studied and continues to study evolution, biogeography, systematics, ecology, and conservation of freshwater fishes of the southeastern United States. To address such a wide variety of topics, I have employed many techniques, including assessments of genetic differentiation, molecular and morphological phylogenetic systematics, quantifying stream habitat and community structure, forming and testing biogeographic hypotheses, and quantifying life history characteristics.
One of the strengths of my research program is a strong working knowledge of my study organisms, the communities to which they belong, and streams of the southeastern United States. By working in similar systems, with similar species, I gain a more solid foundation from which to build hypotheses about the processes influencing the evolution of my study organisms. These hypotheses can then be tested and modified by continual addition of data and further analyses. By developing more refinded hypotheses of evolutionary patterns, I am able to develop more refined hypotheses of evolutionary processes. This leads to reciprocal illumination of evolutionary questions and forms a cornerstone of my research program.
Dr. Leonard D. Pysh, (he/him), Professor of Biology
Contact
- A.B., Wabash College
- Ph.D., University of California, San Diego
The general aim of my research conducted with students is to understand how the shapes of cells are determined. Cell shape is an important aspect of cell function (because form determines function in biological systems), yet little is known about how cell shape is determined in any organism. The fact that cell shape is remarkably consistent from generation to generation suggests that the process has genetic and molecular components. We use a combination of molecular, genetic, and cellular approaches to identify the molecules that play a role in determining the shapes of cells in the roots of the model plant Arabidopsis thaliana, with the expectation that the molecules and principles we identify in this plant will be more broadly applicable to all plants.
Dr. Marilee A. Ramesh, (she/her), Professor of Biology
Contact
- B.S., University of Wisconsin-Stevens Point
- Ph.D., Indiana University
An underlying feature of the biological sciences is the assumption that all life has evolved from a single ancestor. The diversity of life we see all around us is even more amazing when we consider that each organism is in some way related to the others. Resolving those relationships has been a major focus of evolutionary biology.
I am interested in studying the origins and evolution of the process of meiosis. Meiosis is a specialized form of cell division that produces reproductive cells, such as eggs and sperm in mammals, megaspores and pollen in most plants and spores in fungi. Meiosis is absent in bacteria. It is a process that occurs only in eukaryotic organisms (animals, plants, fungi and protists), but it is not known whether meiosis occurs in all eukaryotes. When meiosis first originated and how it has evolved throughout the eukaryotic lineage are two largely unanswered questions. Much of what we know about meiosis is limited to studies using animal, plant or fungal model systems. However, protists are by far the most informative group in which to study the evolution of this process among eukaryotes. Protists represent not only the greatest number of species but also exhibit the greatest variation among the four major groups of eukaryotes. However, until recently, these single-celled eukaryotes have been difficult to work with as laboratory model systems.
Recent technological advances in the area of genomics and bioinformatics have enabled us to begin unraveling the mysteries of protist meiosis. The genomes of many protists, particularly those species that are the causative agents of diseases such as malaria, sleeping sickness, and intestinal discomforts are currently being sequenced. Strategies much like those used to sequence the human genome are being applied to these organisms. In my research laboratory, we make use of the data collected from these sequencing projects by searching or "mining" them for the specific meiotic genes we are interested in studying.
Questions I am interested in are i) whether a species has all the genetic information necessary to perform meiosis, and if so, ii) are these genes expressed, iii) are the gene products functional and iv) how have these proteins changed throughout the course of eukaryotic evolution. Projects in my lab involve a combination of computational analysis and the application of molecular biology techniques to study elements of the genome of certain protists. In connection with this, I am interested in culturing local protist species and including them in these analyses.