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  • UC Riverside
  • College of Natural and Agricultural Sciences

Leonard Nunney


Professor of Biology
Office: 3306 Spieth Hall
Phone (951) 827-5011


Ph.D., University of Nottingham, England 1977

My research is in population and evolutionary genetics, with an emphasis on the application of basic theory to practical problems.   Projects include:

  • The evolution of cancer suppression   This project arose from my interest in how selection acts at different levels of organization.  Cancer results from a conflict between individual cells and an individual organism and, if all else is equal, cancer risk increases as animals become larger and/or longer lived.  But big long-lived animals do not get more cancer (an observation I named Peto's paradox), due to adaptive change.  We use an evolutionary approach to understand how different organisms have adapted to minimize the occurrence of cancer.
  • Conservation genetics/genomics.   Current areas of emphasis: effective population size, inbreeding, adaptation in a changing environment, and the role of wildlife linkages in long-term conservation strategies.
  • Evolutionary genomics of the plant pathogenic bacterium Xylella fastidiosa.  The goal of this project is to successfully apply the methods of evolutionary genomics to understand and ultimately control this bacterium that causes serious disease in a wide range of agricultural crops, including Pierce's disease of grapevine.

I participate in three graduate programs:   Evolution, Ecology, and Organismal Biology (EEOB); Genetics, Genomics, and Bioinformatics (GGB); and Microbiology.   In addition, I participate in the Evolutionary Biology Joint-Doctoral Program with San Diego State University.  I am a member of UCR's Center for Conservation Biology, which promotes conservation research and participate in the UC Intercampus Research Program on Experimental Evolution (UCIRPEE)

I am the current Treasurer of the International Society for Evolution, Ecology, and Cancer (ISEEC), and an external faculty member of the Center for Evolution and Cancer at UCSF.

Publications ...

Profile in Google Scholar Citations

Some recent examples:

Evolution of Cancer Suppression

  • Nunney, L. 2016.  The multistage model of carcinogenesis, Peto's paradox, and evolution.  Int. J. Epidemiol. In Press.
  • Noble, R., Kaltz, O., Nunney L., Hochberg, M.E. 2016.  Overestimating the role of environment in cancers.  Cancer Prevention Research. In Press.
  • Nunney, L. and B. Muir. 2015.  Peto's paradox and the hallmarks of cancer:  constructing an evolutionary framework for understanding the incidence of cancer.  Phil. Trans. Roy. Soc. B 370: 2015161 (7pp).
  • Muir, B. and L. Nunney 2015.  The expression of tumor suppressors and proto-oncogenes in tissues susceptible to their hereditary cancers.  Brit. J. Cancer 113: 345-353.

Conservation Genetics

  • Nunney, L. 2016.  The effect of neighborhood size on effective population size in theory and in practice.  Heredity. In Press.
  • Nunney, L. 2016.  Adapting to a changing environment:   modeling the interaction of directional selection and plasticity.  J. Heredity. 107: 15-24
  • Enders, L.S. and L. Nunney. 2016.  Reduction in the cumulative effect of stress-induced inbreeding depression due to intra-generational purging in Drosophila melanogaster.  Heredity. 116: 304-313.
  • Enders, L.S. and L. Nunney. 2012.  Seasonal stress drives predictable changes in inbreeding depression in field-tested captive populations of Drosophila melanogaster.  Proc Roy Soc. B 279: 3756-3764

Evolutionary Genomics of Xylella

  • Almeida R.P.P. and L. Nunney. 2015.  How do plant diseases caused by Xylella fastidious emerge?   Plant Disease. 99:1457-1467
  • Nunney, L., B. Ortiz, S. Russell, R. R. Sanchez and R. Stouthamer. 2014.  The complex biogeography of the plant pathogen Xylella fastidious:  genetic evidence of introductions and subspecific introgression in Central America.  PLoS ONE 9: e112463 (8pp).
  • Nunney.L., E. L. Schuenzel, M. Scally, R. E. Bromley, and R. Stouthamer. 2014.  Large scale inter subspecific recombination in the plant pathogenic bacterium Xylella fastidious is associated with the host shift to mulberry.   Appl. Environ. Microbial. 80: 3025-3033.
  • Nunney, L., D. Hopkins, L. D. Morano, S. Russell, and R. Stouthamer. 2014.  Inter subspecific recombination in Xylella fastidious native to the United States:  infection of novel hosts associated with an unsuccessful invasion.  Appl. Environ. Microbial. 80:1159-1169.

Recent Teaching....

  • Biology 5C, Introduction to Evolution and Ecology
  • Biology 108, Introductory Population Genetics
  • Biology 110, Biology of Human Problems
  • Biology 119, Introduction to Genomics and Bioinformatics
  • Biology 214, Population Genetics