Classroom Resources: Identity Crisis

By Douglas Fox
April-June 2008 / Vol. 9 No. 2

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Discussion Questions

  1. The term “hybrid vigor” is often used in relation to domesticated plants and animals. What does this term mean? Does this phenomenon have a role to play in conservation as well?
  2. How does the U.S. Endangered Species Act treat the issue of hybrids and hybridization? Do you agree or disagree with this treatment?
  3. The red wolf debate is often cited as an example of the potential negative and diluting effects of hybridization. And yet hybridization between Florida panthers and the Texas sub-species of panthers has been credited with the recent recovery of the panther in Florida http://www.sciencedaily.com/releases/2005/08/050821232913.htm. What is responsible for these different interpretations?

Websites for Further Information

Hybridization and Conservation in the News

Peer-reviewed Literature (in addition to the citations listed in the article)

  • Campton, D.E, L.R. Kaeding. 2005. Westslope Cutthroat Trout, Hybridization, and the U.S. Endangered Species Act. Conservation Biology 2005 19: 1323-1325.
  • Levin, D.A., J. Francisco-Ortega, R.K. Jansen. 1996. Hybridization and the Extinction of Rare Plant Species. Conservation Biology 10: 10-16.
  • R.J. Fredrickson, P.W. Hedrick. 2006. Dynamics of Hybridization and Introgression in Red Wolves and Coyotes. Conservation Biology 20:4 1272-1283.
  • Reich, D.E., R.K. Wayne, and D.B. Goldstein. 1999. Genetic evidence for a recent origin by hybridization of red wolves. Molecular Ecology 8: 139 – 144.
  • Salzburger, W., S. Baric, C. Sturmbauer. 2002. Speciation via introgressive hybridization in East African cichlids? Mol Ecol. 11: 619-25.
  • Wilson, P.J., S. Grewal, I.D. Lawford, J.N.M. Heal, A.G. Granacki, D. Pennock, J.B. Theberge, M.T. Theberge, D.R. Voigt, W. Waddell, R.E.Chambers, P.C. Paquet, G. Goulet, D. Cluff, and B.N. White. 2000. DNA profiles of the eastern Canadian wolf and the red wolf provide evidence for a common evolutionary history independent of the gray wolf. Canadian Journal of Zoology 78: 2156 – 2166.

Key Concepts

  • Hybridization
  • Introgression
  • Endangered species
  • Environmental change