Education
BA Carleton College, Biology, 1996
MS University of Arizona, Ecology and Evolutionary Biology, 2000
PhD University of Arizona, Ecology and Evolutionary Biology, 2004
David Hearn
Associate Professor
Areas of Expertise
Evolutionary, developmental, and ecological processes responsible for land plant diversity
Biography
My research focuses on understanding the evolutionary, developmental, and ecological processes responsible for land plant diversity. The analysis of character evolution using tools from molecular phylogenetics and molecular genetics forms the core of this research. In particular, fascination with plant form, plant morphogenesis, and plant development fuel these interests. Currently, I am examining the evolutionary and developmental mechanisms responsible for water storage tissue in stems and roots (i.e., plant succulence). Stem succulence provides a classic example of convergent evolution, as over thirty lineages have evolved stem succulence. I predicted that shared (homologous) developmental modules are switched on and off during evolution to account for multiple origins of succulent growth habits. My lab is undertaking phylogenetic, bioinformatic, anatomical, and molecular genetic analyses in Brassica, Arabidopsis, Vitaceae, and Passifloraceae to understand what aspects of succulence evolution and development are shared and which aspects differ among distantly related lineages. Such an understanding will contribute to a richer picture of mechanisms of anatomical patterning, and, in the process, gene regulatory mechanisms may be discovered that can generate storage-rooted and succulent-stemmed crops. Additional projects include the analysis of biological shape, biodiversity informatics, and computational approaches to characterize plants in an automated fashion. At its most general, my lab focuses on the patterns and processes of biological pattern formation and employs computational/bioinformatic, mathematical, field and lab experimental approaches.
Recent Publications
Allen, R. J.*, Brenner, E. P. *, VanOrsdel, C. E. *, Hobson, J. J. *, Hearn, D. J.+, and M. R. Hemm+. 2014. Conservation analysis of the CydX protein yields insights into small protein identification and evolution. BMC Genomics 15: 946 doi:10.1186/1471-2164-15-946. +=joint anchor authors.
Evans, M.+, Aubriot, X.+, Hearn, D. J., Lanciaux, M., Lavergne, S., Cruaud, C., Lowry, P. P. 2nd, and T. Haevermans. 2014. Insights on the evolution of plant succulence from a remarkable radiation in Madagascar (Euphorbia). Systematic Biology 63: 697-711. Cover photo. +=Joint first author.
Estes, A. M., Hearn, D. J., Snell-Rood, E. C., Feindler, M., Feeser, K.*, Abebe, T.*, Dunning Hotopp, J. C., and A. P. Moczek. 2013. Vertical transmission of a unique gut microbiome in the dung beetle Onthophagus taurus (Coleoptera: Scarabaeidae). PLoS ONE: DOI: 10.1371/journal.pone.0079061.
Hearn, D. J., Poulsen, T.*, and R. Spicer. 2013. The evolution of growth forms with expanded root and shoot parenchymatous storage is correlated across the eudicots. International Journal of Plant Sciences 174: 1049-1061.
Hearn, D. J. 2013. Dissection of evolutionary networks to assess their role in the evolution of robustness, function, and diversification. Evolution 67: 2273-2283.
Pignal, M., Yockteng, R., Hearn, D., and J.-N. Labat. 2013. Adenia barthelatii (Passifloraceae), a new endemic species of Mayotte and its phylogenetic status within the genus Adenia. Phytotaxa 99: DOI: http://dx.doi.org/10.11646/phytotaxa.99.1.3.
Estes, A. M., Hearn, D. J., Burrack, H. J., Rempoulakis, P., and E. A. Pierson. 2012. Prevalence of ‘Candidatus Erwinia dacicola’ in wild and laboratory olive fly populations and across developmental stages. Environmental Entomology 41: 265-274.
Evans, M. E., Hearn, D. J., K., Theiss, Cranston, K., Holsinger, K., and M. Donoghue. 2011. Extreme environments select for reproductive assurance: evidence from evening primroses (Oenothera). New Phytologist 191: 555-563.
Wang, D., Zhang, C., Hearn, D. J., Kang, I.-H., Punwani, J. A., Skaggs, M. I., Drews, G. N., Schumaker, K. S., and R. Yadegari. 2010. Identification of transcription-factor genes expressed in the Arabidopsis female gametophyte. BMC Plant Biology 10: 110. doi:10.1186/1471-2229-10-110
Estes, A. M., Hearn, D. J., Bronstein, J., and E. Pierson. 2009. The olive fly endosymbiont, "Candidatus Erwinia dacicola", switches from an intracellular to an extracellular existence during host insect development. Applied Environmental Microbiology 75: 7097-7106.
Hearn, D. J. 2009. Developmental patterns in anatomy are shared among separate evolutionary origins of stem succulent and storage root-bearing growth habits in Adenia (Passifloraceae). American Journal of Botany 51: 209-215.
Pryer, K. M., and D. J. Hearn. 2009. Evolution of leaf form in marsileaceous ferns: evidence for heterochrony. Evolution 63: 498-513.
Hearn, D. J. 2009. Shape analysis for the automated identification of plants from images of leaves. Taxon 58: 934-954.
Hearn, D. J. 2009. Descriptive anatomy and evolutionary patterns of anatomical diversification in Adenia (Passifloraceae). Aliso 27: 13-38.
Courses Taught
- Spring: BIOL 202 Intro to Ecology and Evolution