Thomas Whitham, PhD

Thomas Whitham, PhD
  • Professor, Ecology
  • College of Engineering, Forestry and Natural Sciences




Subject-matter expertise

  • Biodiversity
  • Community and ecosystem genetics
  • Community ecology
  • Conservation biology
  • Impact of climate change on communities


A pioneer in community and ecosystem genetics, Dr. Whitham’s research is primarily focused on the community-level understanding of the consequences of plant genetics and climate change on foundation plant species and their dependent communities.  Foundation species that serve as model study systems for this research include cottonwoods, pines and eucalypts.  For example, because different cottonwood genotypes support different communities of microbes, insects and understory plants, the impact of climate change on the genetic structure of these trees has community and ecosystem consequences. 

Dr. Whitham’s genes-to-ecosystem approach and his collaborative work with a team of researchers is featured in the 2012 award-winning eco-documentary, “A Thousand Invisible Cords: Connecting Genes to Ecosystems.”  This film describes the 30-year scientific journey to uncover how an entire ecosystem can be changed by one gene in one plant or animal. An understanding of which, Dr. Whitham and his team say, is important for decision makers who want to restore habitats, maintain biodiversity and reduce the negative effects of climate change.

Dr. Whitham’s research team works with the Bureau of Reclamation, the National Park Service, Arizona Game and Fish, Arizona Forestry, the Ogden Nature Center and the Utah Department of Natural Resources to establish long-term and large-scale restoration / scientific experiments that address fundamental issues of both basic and applied value. His studies are funded primarily by the National Science Foundation and the Bureau of Reclamation.

A Regents’ Professor in the Department of Biological Sciences at NAU, Dr. Whitham is also a Fellow of the American Association for the Advancement of Science and a Fellow of the Ecological Society of America.  He is the Executive Director of the Merriam-Powell Center for Environmental Research. In 2011, he received the prestigious Eminent Ecologist Award by the Ecological Society of America — the group’s highest honor — for his outstanding body of work.


  • Title: A community and ecosystem genetics approach to conservation biology and management.
    Authors: Whitham, T.G., C.A. Gehring, L.M. Evans, C.J. LeRoy, R.K. Bangert, J.A. Schweitzer, G.J. Allan, R.C. Barbour, D.G. Fischer, B.M. Potts, and J.K. Bailey.
    Publication date: 2010
    Published: Molecular Approaches in Natural Resource Conservation and Management (A. DeWoody, J. Bickham, C. Michler, K. Nichols, G. Rhodes and K. Woeste, eds.), pgs. 50-73, Cambridge University Press
  • Title: Extending genomics to natural communities and ecosystems.
    Authors: Whitham, T.G, S.P. DiFazio, J.A. Schweitzer, S.M. Shuster, G.J. Allan, J.K. Bailey, and S.A. Woolbright.
    Publication date: 2008
    Published: Science, Vol. 320, pgs. 492-495
  • Title: A framework for community and ecosystem genetics:  From genes to ecosystems
    Authors: Whitham, T.G, J.K. Bailey, J.A. Schweitzer, S.M. Shuster, R.K. Bangert, C.J. LeRoy, E. Lonsdorf, G.J. Allan, S.P. DiFazio, B.M. Potts, D.G. Fischer, C.A. Gehring, R.L. Lindroth, J.C. Marks, S.C. Hart, G.M. Wimp, and S.C. Wooley
    Publication date: 2006
    Published: NATURE REVIEWS GENETICS, Vol. 7, pgs. 510-523.

*For a more complete list of Dr. Whitham’s research, please visit:

Awards and recognitions

  • Fellow of the Ecological Society of America, 2012
  • American Association for the Advancement of Science Fellow, 2011
  • Eminent Ecologist Award presented by the Ecological Society of America – the highest award for a senior scientist, 2011
  • Biology Graduate Students Outstanding Teacher/Advisor Award, 2001
  • Appointed Regents’ Professor by the Arizona Board of Regents, 1995
  • Biology Graduate Students’ Outstanding Instructor Award, 1992-1993
  • George Mercer Award presented by the Ecological Society of America – the highest award for a junior scientist, 1980

Special groups and committees

  • Board of Directors of the Arboretum at Flagstaff
  • Chair, Advisory Board of EVOLTREE, European Union
  • Dept. of Interior, Importance of Conserving Hybrids Under the Endangered Species Act.
  • Editor for Ecology and Ecological Monographs
  • Executive Director of the Merriam-Powell Center for Environmental Research
  • Grand Canyon Trust, Science Advisory Committee
  • Numerous NSF Panels and Review Boards
  • USDA/APHIS (Animal Plant Health Inspection Service), on the Community and Ecosystem Consequences of Genetically Engineered Forest and Fruit Trees


  • B.S., Plant Pathology and Horticulture, Iowa State University, 1969
  • M.S., Zoology, Ohio State University, 1973
  • Ph.D., Biology, University of Utah, 1978

Web pages