Parmly 320Organization for Tropical Studies (OTS): Tropical Biology, 1996
Graduate Degree: Ph.D., University of California, Davis, 2000
Monitoring populations of plants and animals is crucial for protecting endangered species, managing biological resources, and tracking the spread of invasive species. Yet, the design of population monitoring programs is often an afterthought, based more on tradition and expediency than on rational analysis. I am developing simulation models parameterized with data from a variety of species to determine optimal approaches to monitoring populations. I am also investigating the kinds and amounts of data needed to design an effective program for any given species.
Ecology and Evolution of Mountaintop Salamanders
Virginia is home to several endemic salamanders that are restricted to tiny ranges on one or several mountaintops. My lab is studying several of these species in order to determine their biogeographic origin and their likely response to climate change. With Sherando Salamanders, we are examining the structure of contact zones with the more common Red-Backed Salamander, and we are using morphology and mitochondrial DNA to look for evidence of interbreeding. With Peaks-of-Otter Salamanders, we are monitoring responses to logging and habitat disturbance in order to predict the long-term dynamics of the species.
Research and Publication Bias in Clinical Trial Reports
Throughout the biomedical research literature, clinical trials published with pharmaceutical industry support are more likely to reach positive conclusions about new products than are comparable trials conducted by academic or governmental institutions. However, few studies have done the necessary work to determine the reasons behind these discrepancies. For example, industry-supported trials might be less likely to be published, or they might be inherently biased, or they might just be of higher quality than non-industry trials. We are using standard meta-analytical techniques and some novel approaches to tease out the causes of bias in the clinical trials literature.
Statistics for Biology and Medicine (BIOL 301)
Clinical Trials (BIOL 395 - NEW CLASS FALL '09)
Animal Behavior (BIOL 243)
Field Herpetology (BIOL 242)
Marsh, D.M., Page, R.B., Hanlon, T.J., Corritone, R*., Little, E.E.*, Seifert, D.E.*, and Cabe, P.R. 2008. Effects of roads on patterns of genetic differentiation in red-backed salamanders, Plethodon cinereus. Conservation Genetics 9: 603-613.
Marsh, D.M, Page, R.B., Hanlon, T. J., Bareke, H.* Corritone, R.* Jetter, N.*, Beckman, N.G.*, Gardner, K.*, Seifert, D.E.*, and Cabe, P.R. 2007. Ecological and genetic evidence that low-order streams inhibit dispersal by red-backed salamanders (Plethodon cinereus). Canadian Journal of Zoology 85: 319-327.
Marsh, D.M. and Hanlon, T.J. 2007. Seeing what we want to see: confirmation bias in animal behavior research. Ethology 113: 1089-1098.
Cabe, P.R., Page, R.B., Hanlon, T.J., Aldrich, M.E.*, Connors, L., and D. M. Marsh. 2007. Fine-scale genetic population structure and gene flow in a terrestrial salamander living in continuous habitat. Heredity 98: 53-60.
Marsh, D.M. 2007. Edge effects of gated and ungated forest roads on terrestrial salamanders. Journal of Wildlife Management 71: 389-394.
Marsh, D. M., Milam. G. S.*, Gorham, N. P.*, and N. G. Beckman*. 2005. Forest roads as partial barriers to terrestrial salamander movement. Conservation Biology 19: 2004-2008.
Adams, V. M.*, Marsh, D. M., and J. S. Knox. 2005. Importance of the seed bank for population viability and population monitoring in a threatened wetland herb. Biological Conservation 124: 425-436.
Marsh, D. M. and Hanlon, T. J. 2004. Observer gender and observation bias in animal behaviour research: experimental tests with red-backed salamanders. Animal Behaviour 68:1425-1433.
Marsh, D. M., Thakur, K. A.*, Bulka, K. C.*, and L. B. Clarke*. 2004. Dispersal and colonization through open fields by a terrestrial woodland salamander. Ecology 85: 3396-3405.
Marsh, D. M. and Beckman, N. G.* 2004. Effects of forest roads on the abundance and activity of terrestrial salamanders in the Southern Appalachians. Ecological Applications 14:1882-1891.
American Society of Ichthyologists and Herpetologists
Ecological Society of America Homepage
Mountain Lake Biological Station
DAPTF Home Pages (Declining amphibian population task force
NBII - FrogWeb Home (an amphibian decline and deformity site)
