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Michael Arnold

Blurred image of the arch used as background for stylistic purposes.
Distinguished Research Professor
Department Head
Ph.D. (1986) Australian National University
  • Visiting Professorship, National Center for Biological Sciences, Tata Institute of Fundamental Research – (Bengaluru, India)
  • Named a Distinguished Research Professor, University of Georgia
  • Fellow, American Association for the Advancement of Science
  • "Thousand Talents" Awardee (Chinese Academy of Sciences)
  • Visiting Professorship, Dipartimento di Biologia Vegetale, Università di Roma 'La Sapienza', Rome, Italy
  • Visiting Research Fellowship, Merton College, University of Oxford (Trinity Term 2007)
  • Visiting Professorship, Universitat Autònoma de Barcelona, Barcelona, Spain, 2005
  • Visiting Professorship, Universität Konstanz, Konstanz Germany, 2004
  • Creative Research Medal, University of Georgia, 1997
  • Distinguished Merit Award, Society for Louisiana Irises
  • Research Interests -
    • Members of Mike Arnold’s lab have tested evolutionary hypotheses in a wide array of organisms – including fungi, plants and animals.  In spite of the taxonomic diversity reflected in this work, there is a unifying theme.  This theme is well described by the title of a 1954 Evolution paper authored by the plant evolutionary biologists, Edgar Anderson and Ledyard Stebbins – “Hybridization as an Evolutionary Stimulus”.  Thus, our group has examined a range of phenomena associated with the process of gene exchange between organisms in nature.  The data collected have derived from analyses of population genetics, phylogenetics, reproductive biology, pollinator behavior, eco-physiology, molecular evolution and, most recently, linkage/QTL mapping of fitness traits.
Research Areas:
Research Interests:

Hybridization and evolution: process of gene exchange between organisms in nature; hybridization as an evolutionary stimulus.

Selected Publications:


  • Arnold, M.L. 2015. Divergence With Genetic Exchange. Oxford University Press. In press.
  • Arnold, M.L. 2009. Reticulate Evolution and Humans – Origins and Ecology. Oxford University Press.
  • Arnold, M.L. 2006. Evolution Through Genetic Exchange. Oxford University Press.
  • Arnold, M.L. 1997. Natural Hybridization and Evolution. Oxford Series in Ecology and Evolution, Oxford University Press.

Reseach papers, reviews and book chapters:

  • Arnold, M.L., A.N. Brothers, J.A.P. Hamlin, S.J. Taylor and N.H. Martin. 2015. Divergence-with-gene-flow – What humans and other mammals got up to. In press.
  • Hamlin, J.A.P. and M.L. Arnold. 2014. Determining population structure and hybridization for two Louisiana Iris species. Ecology and Evolution 4:743-755.
  • Arnold, M.L. 2014. Hybrid Speciation. In Oxford Bibliographies Online: Evolutionary Biology, J.B. Losos ed. Oxford University Press, New York.
  • Ballerini, E.S., K. Mockaitis and M.L. Arnold. 2013. Transcriptome sequencing and phylogenetic analysis of Type II MIKCC MADS-box and R2R3 MYB transcription factors in reproductive tissue from the non-grass monocot Iris fulva. Gene 531:337-346.
  • Brothers, A.N., J.G. Barb, E.S. Ballerini, D.W. Drury, S.J. Knapp and M.L. Arnold. 2013. The genetic architecture of floral traits in Iris hexagona and Iris fulva. Journal of Heredity 104:853-861.
  • Arnold, M.L., J.A.P. Hamlin, A.N. Brothers and E.S. Ballerini. 2012. Natural hybridization as a catalyst of rapid evolutionary change. Chapter 25, Pp. 256-265. In Rapidly evolving genes and genetic systems, R.S. Singh, J. Xu, and R.J. Kulathinal eds. Oxford University Press, Oxford.
  • Ballerini, E.S., A.N. Brothers, S. Tang, S.J. Knapp, A. Bouck, S.J. Taylor, M.L. Arnold and N.H. Martin. 2012. QTL mapping reveals the genetic architecture of loci affecting pre- and post-zygotic isolating barriers in Louisiana Iris. BMC Plant Biology 12:91.
  • Arnold, M.L., E.S. Ballerini and A.N. Brothers. 2012. Hybrid fitness, adaptation and evolutionary diversification: lessons learned from Louisiana Irises. Heredity 108: 159-166.
  • Dobson, M.C., S.J. Taylor, M.L. Arnold and N.H. Martin. 2011. Patterns of herbivory and fungal infection in experimental Louisiana Iris hybrids. Evolutionary Ecology Research 13: 543-552.
  • Liu, J., L. Yu, M.L. Arnold, C-H. Wu, S-F. Wu, X. Lu and Y-P. Zhang. 2011. Reticulate evolution: frequent introgressive hybridization of Chinese hares (genus Lepus) revealed by analyses of multiple mitochondrial and nuclear DNA sequences. BMC Evolutionary Biology 11: 223.
  • Arnold, M.L. (ed). 2010. Reticulate Evolution. Genes.
  • Arnold, M.L. and N.H. Martin. 2010. Hybrid fitness across time and habitats. Trends in Ecology and Evolution 25: 530-536.
  • Arnold, M.L., S. Tang, S.J. Knapp and N.H. Martin. 2010. Asymmetric introgressive hybridization among Louisiana Iris species. Genes 1: 9-22.
  • Tang, S., R.A. Okashah,  S.J. Knapp, M.L. Arnold and N.H. Martin. 2010. Reproductive isolation in Louisiana irises: Transmission ratio distortion. BMC Plant Biology 10: 48.
  • Taylor, S.J., M.L. Arnold and N.H. Martin. 2009. The genetic architecture of reproductive isolation in Louisiana Irises: Hybrid fitness in nature. Evolution 63: 2581-2594.
  • Zinner, D., M.L. Arnold and C. Roos. 2009. Is the new primate genus Rungwecebus a baboon? PLoS ONE 4: e4859.
  • Martin, N.H., Y. Sapir and M.L. Arnold. 2008. The genetic architecture of reproductive isolation in Louisiana Irises: Pollination syndromes and pollinator preferences. Evolution 62: 740-752.
  • Arnold, M.L. 2008. Reticulate Evolution and Humans – Origins and Ecology. Oxford University Press.
  • Cornman, R.S. and M.L. Arnold. 2007. Phylogeography of Iris missouriensis (Iridaceae) using transposon display. Molecular Ecology 16: 4585-4598.
  • Martin, N.H., A.C. Bouck and M.L. Arnold. 2006. Detecting adaptive trait introgression between Iris fulva and I. brevicaulis in highly selective field conditions. Genetics 172: 2481-2489.
  • Bouck, A.C., R. Peeler, M.L. Arnold and S.R. Wessler. 2005. Genetic mapping of species boundaries in Louisiana Irises using IRRE retrotransposon display markers. Genetics 171: 1289-1303.
  • Cornman, R.S., J.M. Burke, R.A. Wesselingh and M.L. Arnold. 2004. Contrasting genetic structure of adults and progeny in a Louisiana Iris hybrid population. Evolution 58: 2669-2681.
  • Johnston, J.A., L.A. Donovan and M.L. Arnold. 2004. Novel phenotypes among early generation hybrids of two Louisiana Iris species: Flooding experiments. Journal of Ecology 92: 967-976.
  • Kentner, E.K., M.L. Arnold and S.R. Wessler. 2003. Characterization of high copy number retrotransposons from the large genomes of the Louisiana Iris species and their use as molecular markers. Genetics 164: 685-697.
  • Burke, J.M., M.R. Bulger, R.A. Wesselingh and M.L. Arnold. 2000. Frequency and spatial patterning of clonal reproduction in Louisiana Iris hybrid populations. Evolution 54: 137-144.

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