UT Tyler

Biology Research

Placyk Lab Research


Research conducted in the Placyk lab has four main foci: 1) molecular ecology, 2) the effect of nature and nurture on phenotypic traits, 3) chemical ecology, and 4) conservation biology. While most of our past work has been done with reptiles and amphibians, we are interested in graduate students and collaborators working on ANY organism with an emphasis on one of the lab's four foci.

1) Molecular ecology

Placyk lab molecular ecology research conducted to date has primarily focused on hybridization, population genetics, and the phylogenetics and systematics of reptiles and amphibians. Specifically, the lab is interested in the evolutionary history of organisms in terms of their phylogeography and the conservation of threatened and endangered species. The phylogeographic data is used to understand how animals have adjusted to past climate change and can help to better understand the possible effects of global warming on species distributions. We also use data collected in our lab to assist conservationists and various government agencies in the management of species of conservation concern. Such data permits the best decisions for reintroductions, relocations, and breeding programs. Current and past projects include work with box turtles (Terrapene sp.), the Texas horned lizard (Phrynosoma cornutum), the common gartersnake (Thamnophis sirtalis), Butler's gartersnake (T. butleri), the plains gartersnake (T. radix), California tiger salamanders (Ambystoma californiense), map turtles (Graptemys sp.) and southern flying squirrels (Glaucomys volans).


The Placyk molecular ecology lab at the University of Texas at Tyler is fully equipped with brand new state-of-the-art molecular genetics equipment. The lab is capable of carrying out work with AFLPs, SNPs, microsats, allozymes, mtDNA sequences, nuclear sequences, and other markers.

Call for Tissue Samples -- We are always interested in tissue samples from the Texas horned lizard and any species or subspecies of Terrapene, Thamnophis, Nerodia, and Storeria. These can come from anywhere in the range of these groups. If you are interested in assisting with tissue sample collection, let us know and we will send you a tissue sample collection kit.

Representative molecular ecology publications from the Placyk lab:

Placyk, J. S., Jr., B. M. Fitzpatrick, G. S. Casper, R. L. Small, R. G. Reynolds, D. W. A. Noble, R. J. Brooks, and G. M. Burghardt. In press. Hybridization between two gartersnake species (Thamnophis) of conservation concern: A threat or an important natural interaction? Conservation Genetics.

Fitzpatrick, B. M., J. S. Placyk, Jr., M. L. Niemiller, G. S. Casper, and G. M. Burghardt. 2008. Distinctiveness in the face of gene flow: hybridization between specialist and generalist gartersnakes. Molecular Ecology 17:4107-4117 .

Placyk, J. S., Jr., G. M. Burghardt, R. L. Small, R. B. King, G. S. Casper, and J. W. Robinson. 2007. Post-glacial recolonization of Michigan by the common gartersnake (Thamnophis sirtalis) inferred from mtDNA sequences. Molecular Phylogenetics and Evolution 43:452-467.


2) The effect of nature and nurture on phenotypic traits

The Placyk lab is interested in how both genetics and environment influence morphological, behavioral, and life-history traits. Most phenotypic characteristics are the result of a combination between underlying genetics and environmental influences and our research attempts to tease the influence of those two variables apart. We are also interested in how genes and environment interact, phenotypic plasticity, and norms of reaction/reaction norms. Most work in this area has focused on traits related to selection pressures associated with prey (e.g., foraging behavior, head morphology) and predators (e.g., antipredator behavior, antipredator-related morphology) and on reproductive life-history traits (e.g., neonate characteristics, litter characteristics, size at maturity), but we are also interested in how environmental contaminants influence phenotypic traits, especially behavior.


Representative nature and nurture publications from the Placyk lab:

Placyk, J. S., Jr. In press. The role of innate and environmental influences in shaping antipredator behavior of mainland and insular gartersnakes (Thamnophis sirtalis). Journal of Ethology

Placyk, J. S., Jr., and G. M. Burghardt. 2011. Evolutionary persistence of chemically elicited ophiophagous antipredator responses in gartersnakes, Thamnophis sirtalis. Journal of Comparative Psychology 125:134-142.

Placyk, J. S., Jr. 2006. Historical processes, evolutionary change, and phenotypic plasticity: Geographic variation in behavior morphology, and life-history traits of common gartersnake, Thamnophis sirtalis, populations. Ph.D. dissertation. University of Tennessee, Knoxville.

3) Chemical ecology

The Placyk lab is founded on its early chemical ecology roots and research in this area continues to this day. Most work in this area has focused on the role of the vomeronasal system in mediating various behaviors, but research examining the roles of gustation, olfaction, and vision are also carried out. Specifically, we are interested in how animals use their chemical senses and other special senses to detect and avoid predators, find and identify mates and other conspecifics, distinguish between conspecifics and heterospecifics, and detect and consume prey.


Above illustration by Dr. David Kirshner

Representative chemical ecology and other special senses publications from the Placyk lab:

Martin, B. T., D. D. Goodding, N. B. Ford, and J. S. Placyk, Jr.In press. Sensory mediation of foraging behavior in the western lesser siren (Siren intermedia nettingi). Journal of Herpetology.

Placyk, J. S., Jr. 2002. The effect of predatory and nonpredatory snake cues on the foraging behavior of the zigzag salamander (Plethodon dorsalis). Southeastern Biologist 49:144-145.

Placyk, J. S., Jr. and B. M. Graves. 2002. Prey detection by vomeronasal chemoreception in a plethodontid salamander. Journal of Chemical Ecology 28:1017-1036.

Placyk, J. S., Jr. and B. M. Graves. 2001. A new technique for observing redback salamanders, Plethodon cinereus, in the absence of visual stimuli. Herpetological Review 32:94-95.

Placyk, J. S., Jr. and B. M. Graves. 2001. Foraging behavior of the red-backed salamander (Plethodon cinereus) under various lighting conditions. Journal of Herpetology 35:521-524.

Placyk, J. S., Jr. 2000. Sensory mediation of foraging behavior in Plethodon cinereus, the redback salamander. M.S. Thesis. Northern Michigan University.


4) Conservation biology

The Placyk lab is interested and involved in a variety of conservation biology projects and questions, and all members of the lab that study reptiles and amphibians are members of Partners in Amphibian and Reptile Conservation (PARC). While much of our conservation work is tackled in our molecular ecology lab, we are also involved in traditional ecological, behavioral, morphological, and natural history-oriented conservation projects. Active research in the area of conservation biology include studies with the North American box turtles (Terrapene sp.), Texas horned lizard (Phrynosoma cornutum), Butler's gartersnake (Thamnophis butleri ), the Sabine map turtle (Graptemys ouachitensis sabinensis).

Representative conservation biology publications from the Placyk lab:

Cantrell, J. L., Placyk, J. S., Jr., L. R. Williams, J. C. McCumber, and D. W. Pogue. In press. Vegetation composition influences avian species distributions in the post oak savannah ecoregion of northeast Texas. Texas Journal of Science.

Placyk, J. S., Jr. and B. A. Harrington. 2004. Prey abundance and habit use by migratory shorebirds at coastal stopover sites in Connecticut. Journal of Field Ornithology 75:223-231.


Miscellaneous Publications:

Placyk, J. S., Jr. and L. Torretti. In press. Detection and discrimination of visual stimuli by the orb-weaver spider Cyclosa conica (Araneidae). Texas Journal of Science.

Sanders, S., J. Coleman, and J. S. Placyk, Jr. 2010. Graptemys ouachitensis sabinensis. Coloration. Herpetological Review 41:214.

Placyk, J. S., Jr. and G. M. Burghardt. 2005. Geographic variation in the frequency of scarring and tail stubs in eastern gartersnakes (Thamnophis s. sirtalis) from Michigan, USA. Amphibia-Reptilia 26:353-358.

Placyk, J. S., Jr. 2004. Herpetological research at the Department of Ecology & Evolutionary Biology at the University of Tennessee. Tennessee Herpetological Society Newsletter 2:5-6.

Placyk, J. S., Jr. 2003. Funding opportunities for students researching amphibians and reptiles. Tennessee Herpetological Society Newsletter 1:3-4.

Placyk, J. S., Jr. and J. C. Gillingham. 2002. Biogeography of the herpetofauna of the Beaver Archipealgo: A synthesis and reevaluation. Bulletin of the Chicago Herpetological Society 37:210-215.

Placyk, J. S., Jr., M. J. Seider, and J. C. Gillingham. 2002. New herpetological records for High and Hog Islands of the Beaver Archipelago, Charlevoix County, Michigan. Herpetological Review 33:230.

Placyk, J. S., Jr. and B. M. Graves. 2001. Plethodon cinereus. Site Attachment. Herpetological Review 32:246.

Placyk, J. S., Jr., L. Torretti, and B. M. Graves. 2000. Plethodon cinereus. Intraspecific Aggregation. Herpetological Review 31:167.

Current graduate students:

Katie Chamberlain

Katie Chamberlain graduated from Iowa State University in the Spring of 2009 with a B.S. in Animal Ecology. Her previous research focused on the population ecology of Mourning Doves and occurrence of West Nile Virus across a land-use gradient. Katie’s interests are broad, including avian ecology and evolution, life-history traits, and conservation. In the Placyk lab, Katie is studying the effect of the pesticide atrazine on the behavior and life-history traits of Marcy's checkered gartersnake (Thamnophis m. marcianus). Contact Katie



Bradley Martin

Bradley Martin graduated from the University of Texas at Tyler in the Fall of 2009 with a B.S. in Biology. Bradley started as an undergraduate in the lab studying the conservation genetics of box turtles (Terrapene sp.). As a graduate student, he is taking this research to the next level in a rangewide overview of the molecular phylogenetics of the Terrapene genus. Bradley is also interested in examining the population genetics of box turtles to aid in their conservation. Contact Bradley

If you are interested in joining the lab as a graduate student, please contact us.

Past Graduate Students

Jamie Cantrell - currently pursuing her Ph.D. in the Department of Zoology at Southern Illinois University Carbondale

Sheri Sanders - currently pursuing her Ph.D. in the Department of Biological Sciences at the University of Notre Dame

Current and Past Undergraduates

Isaac Hemby - Ribbonsnake phylogenetics - current
Sadie Hillis - Ribbonsnake phylogenetics - current
James Boulger - Gartersnake phylogenetics and population genetics - current Katy Ereman - Gartersnake phylogenetics and population genetics - past Juan Galvan - Gartersnake phylogenetics - Bradley Martin - Box turtle conservation genetics - past Matt Moseley - Ribbonsnake life-history traits - past Elwyn Welch - Map turtle phylogenetics and ecology - past

If you are interested in joining the lab as an undergraduate, please contact Dr. Placyk.

Pertinent Links

UT Tyler