Associate Director of Academic Affairs - School of Integrative Biology
B.Sc., 1982, University of Guelph, Ontario, Canada
Ph.D., 1988, University of Alberta, Canada
Postdoctoral positions: University of Michigan and Indiana University
General Education Biology
Plant Systematics (IB 335)
Systematics and evolution of flowering plants, with emphasis on the family Apiaceae; chloroplast genome structural evolution
Despite multidisciplinary studies using non-molecular characters, historical relationships among and within many families of flowering plants remain unclear. Reconstruction of phylogenies from molecular data is now routine in systematics and continues to provide valuable insight into evolutionary processes and relationships. We are using the record of molecular change contained within the chloroplast and nuclear genomes to trace evolutionary histories and elucidate patterns of phenotypic character evolution in the Apiaceae (or Umbelliferae), a plant family of much ecological, economical, and pharmaceutical interest. Current research is focused on the perennial, endemic umbellifers of western North America, such as Cymopterus and its allies, with the goals of clarifying generic- and species-level boundaries and revising the classification of the group.
Unique structural rearrangements of the chloroplast genome are useful as systematic characters, in part because their rarity suggests phylogenetic stability. Of additional research interest is the detection, characterization, and phylogenetic circumscription of these structural mutations.
Downie, S. R. and R. K. Jansen. 2015. A comparative analysis of whole plastid genomes from the Apiales: expansions and contraction of the inverted repeat, mitochondrial to plastid transfer of DNA, and identification of highly divergent noncoding regions. Systematic Botany 40: 336-351.
Liu, J., L. Shi, J. Han, G. Li, H. Lu, J. Hou, X. Zhou, F. Meng, and S. R. Downie. 2014. Identification of species in the angiosperm family Apiaceae using DNA barcodes. Molecular Ecology Resources 14: 1231-1238.
Wang, Z.-X., S. R. Downie, J.-B. Tan, C.-Y. Liao, Y. Yu, and X.-J. He. 2014. Molecular phylogenetics of Pimpinella and allied genera (Apiaceae), with emphasis on Chinese native species, inferred from nrDNA ITS and cpDNA intron sequence data. Nordic Journal of Botany 32: 642-657.
George, E. E., D. H. Mansfield, J. F. Smith, R. L. Hartman, S. R. Downie, and C. E. Hinchliff. 2014. Phylogenetic analysis reveals multiple cases of morphological parallelism and taxonomic polyphyly in Lomatium (Apiaceae). Systematic Botany 39: 662-675.
Spalik, K., Banasiak, M. A. E. Feist, and S. R. Downie. 2014. Recurrent short-distance dispersal explains wide distributions of hydrophytic umbellifers (Apiaceae tribe Oenantheae). Journal of Biogeography 41: 1559-1571.
Liao, C.-Y., S. R. Downie, Q. Li, Y. Yu, X.-J. He, and B. Zhou. 2013. New insights into the phylogeny of Angelica and its allies (Apiaceae) with emphasis on East Asian species, inferred from nrDNA, cpDNA, and morphological evidence. Systematic Botany 38: 266-281.
Banasiak, L., M. Piwczynski, T. Ulinski, S. R. Downie, M. F. Watson, B. Shakya, and K. Spalik. 2013. Dispersal patterns in space and time: a case study of Apiaceae subfamily Apioideae. Journal of Biogeography 40: 1324-1335.
Ming, R., R. VanBuren, Y. Liu, M. Yang, Y. Han, L.-T. Li, Q. Zhang, M.-J. Kim, M. C. Schatz, M. Campbell, J. Li, J. E. Bowers, H. Tang, E. Lyons, A. A. Ferguson, G. Narzisi, D. R. Nelson, C. E. Blaby-Haas, A. R. Gschwend, Y. Jiao, J. P. Der, F. Zeng, J. Han, X. J. Min, K. A. Hudson, R. Singh, A. K. Grennan, S. J. Karpowicz, J. R. Watling, K. Ito, S. A. Robinson, M. E. Hudson, Q. Yu, T. C. Mockler, A. Carroll, Y. Zheng, R. Sunkar, R. Jia, N. Chen, J. Arro, C. M. Wai, E. Wafula, A. Spence, Y. Han, L. Xu, J. Zhang, R. Peery, M. J. Haus, W. Xiong, J. A. Walsh, J. Wu, M.-L. Wang, Y. J. Zhu, R. E. Paull, A. B. Britt, C. Du, S. R. Downie, M. A. Schuler, T. P. Michael, S. P. Long, D. R. Ort, J. W. Schopf, D. R. Gang, N. Jiang, M. Yandell, C. W. dePamphilis, S. S. Merchant, A. H. Paterson, B. B. Buchanan, S. Li, and J. Shen-Miller. 2013. Genome of the long-living sacred lotus (Nelumbo nucifera Gaertn.). Genome Biology 14:R41.
Brullo, C., S. Brullo, S. R. Downie, C. A. Danderson, and G. G. del Galdo. 2013. Siculosciadium, a new monotypic genus of Apiaceae from Sicily. Annals of the Missouri Botanical Garden 99: 1-18.