Dr. Daniel A. Hahn

Professor and Associate Department Chair
Evolutionary Physiology

Dan Hahn specializes in ecological and evolutionary physiology. His scientific work focuses on rapid adaptation, phenotypic plasticity, and seasonal biology of insects both from basic research and applied agricultural perspectives. Our lab is particularly interested in understanding the fundamental mechanisms underlying hardiness to environmental stress, predicting winners and losers in the face of climate change, and improving environmentally friendly methods for insect pest control including biological control and phytosanitary treatments for commodities.

• Research

  Seasonal Adaptation: The changing of the seasons is a common stressor for ectotherms, including beneficial and damaging insects. Thus insects have evolved many adaptations to mitigate seasonal stress and to synchronize their lifecycles with favourable times. As global climates change, the timing of the onset and end of winter relative to growing seasons is changing and predictions call for greater climatic variability at the seasonal shoulders. Both of these factors can strongly affect ectotherm populations. As a product of climate change, some damaging insects are projected to increase their ranges, population sizes, and number of generations per year while some beneficial insects are at greater risk for extinction. We study the physiological and genetic mechanisms of adaptation in seasonal dormancy (diapause) and seasonal stress tolerance with an eye to predicting potential winners and losers in the context of climate change. 

  Adaptive Radiation in Insect-Host Relationships: Phytophagous insects represent a large slice of animal diversity and host-plant specialization has been shown to increase diversification. Most work on host-plant specialization focuses on host plant chemistry, specifically nutrition and defences, but seasonal synchrony between insect herbivores and their host plants is also a critical dimension of diversification. We study how the physiological and genetic mechanisms underlying life history timing may interact with host-plant feeding and host-choice in phytophagous insects to facilitate or constrain diversification of insect herbivores.

  Applications to Pest Management: We are interested in using our knowledge about the physiological and genetic mechanisms of stress hardiness and seasonal biology to improve biologically based, environmentally friendly methods of pest management. We are particularly interested in: 1) improving the performance of sterile males in the sterile insect technique, 2) improving non-pesticidal post-harvest phytosanitary treatments for commodities, 3) improving the rearing of biological control agents including enhancing storage and shelf-life to suppor the biological control industry, and 4) applying knowledge of seasonal biology to improve the selection and performance of biological control agents in the field.

• Teaching

  Graduate Insect Physiology:

  The over-arching learning goal for this course is for students to achieve a level of knowledge and a deep enough understanding of selected insect physiological systems for the student to recognize opportunities to extend this learning to improve their own current or future work, from basic perspectives in physiological ecology & evolution to practical applications in pest management. This course is not designed to be a brief survey of insect physiological systems; we will not cover everything in the textbook. Instead, my goal is for you to learn enough about select physiological systems so that you are comfortable in your ability to learn about any physiological system on your own in the future.

Contact

PO Box 110620
Steinmetz Hall (Bldg #970)
1881 Natural Area Drive
Gainesville, FL 32611-0620
(352) 273-3968
dahahn@ufl.edu

• Education
  • Postdoctoral Studies, Insect Physiology & Molecular Biology, Ohio State University 2003-2005
  • Ph.D., Insect Science, University of Arizona, 2003
  • B.S., Biological Sciences, Florida State University, 1996
• Google Scholar Publications
  • Google Scholar Publications
• Selected Publications

  Seasonal Adaptation:

  Gerken, A.R., Eller, O.C., Hahn, D.A., and Morgan T.J. 2015. Constraints, independence, and evolution of thermal plasticity; probing the genetic architecture of long and short-term thermal acclimation. PNAS. 112: 4399-4404.

  Williams, C.M., M. Watanabe, M. Guarracino, M.B. Ferraro, A.S. Edison, T.J. Morgan, A. Boroujerdi, and D.A. Hahn. 2014. Cold adaptation shapes the robustness of metabolic networks in Drosophila melanogaster. Evolution. 68:3505-3523.

  Clemmensen, S.F., and D.A. Hahn. 2015. Dormancy cues alter insect temperature-size relationships. Oecologia. 177: 113-121.

  Hahn, D.A., and D.L. Denlinger. 2011. Energetics of Diapause. Annual Review of Entomology. 56:103-121.

  Adaptive Radiation in Insect-Host Relationships:

  Ragland, G.J. Almaskaar, K., Vertacnick, K.L. Gough, H.M., Feder, J.L., Hahn, D.A., and Schwarz D. 2015. Differences in performance and transcriptome-wide gene expression associated with Rhagoletis (Diptera: Tephritidae) larvae feeding in alternative host fruit environments. Molecular Ecology. 24: 2759-2776.

  Wadsworth, C. B., W. A. Woods, D. A. Hahn, and E. B. Dopman. 2013. One phase of the dormancy developmental pathway is critical for the evolution of insect seasonality. Journal of Evolutionary Biology 26:2359-2368.

  Ragland, G.J., S.B. Sim, S. Goudarzi, J.L. Feder, and D.A. Hahn. 2012. Environmental interactions during host race formation: host fruit environment moderates a seasonal shift in phenology in host races of Rhagoletis pomonella. Functional Ecology, 26:921-931.

  Applications to Pest Management:

  Lopez-Martinez, G., J.E. Carpenter, S.D. Hight, and D.A. Hahn. 2014. Low-oxygen atmospheric treatment improves the performance of irradiation-sterilized male cactus moths used in SIT. Journal of Economic Entomology. 107:185-197.

  Knutson, A., A. Mukherjee, D.A. Hahn, and K.M. Heinz. 2014. Biological control of giant salvinia (Salvinia molesta) in a temperate region: cold tolerance and low temperature oviposition of Cyrtobagous salviniae. BioControl. 59:781-790.

  Lopez-Martinez, G., and D.A. Hahn. 2012 Short-term anoxic conditioning hormesis boosts antioxidant defenses, lowers oxidative damage following irradiation, and enhances male sexual performance in the Caribbean fruit fly, Anastrepha suspensa. Journal of Experimental Biology, 215:2150-2161.

  Other Projects in Life-History Physiology: Folks in our lab have broad interests and most of our work is collaborative in nature, so we love to bring our expertise to bear in helping other answer important questions in their research programs.

  Hatle, J. D., J. W. Kellenberger, E. Viray, A. M. Smith, and D. A. Hahn. 2013. Life-extending ovariectomy in grasshoppers increases somatic storage, but dietary restriction with an equivalent feeding rate does not. Experimental Gerontology 48:966-972.

  Visser, B., D. Roelofs, D.A. Hahn, P.E.A. Teal, M. Janine and J. Ellers. 2012. Understanding the molecular mechanisms of evolutionary trait loss: Lacking lipid synthesis in parasitoids. Genome Biology and Evolution, 4:752-762.

  Judd, E.B., M. Drewery, F.J. Wessels, D.A. Hahn, and J.D. Hatle. 2011. Ovariectomy in grasshoppers increases somatic storage, but proportional allocation of ingested nutrients to somatic tissues is unchanged. Aging Cell. 10:972-979.