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John Nason

John Nason

  • Professor Emeritus
I am an evolutionary biologist who employs ecological and genetic approaches to infer evolutionary process. A unifying theme in my research is the use of molecular data to investigate of the factors influencing gene flow (or lack thereof) and their impacts on the structuring of genetic variation in plants and associated insects over a broad range of temporal and spatial scales. This theme is exemplified in most of the research projects underway in my lab.

Contact Info

317 Bessey
2200 Osborn Dr.


  • Ph.D., Botany/Plant Genetics, University of California, Riverside
  • B. S., Biology, University of California, Davis

More Information

As described on our Projects page, research in my lab has focused on a number of topics in ecology and evolution. Currently, our primary research focuses on local- and landscape-scale variation in species interactions in a highly coevolved fig-fig wasp system comprised of the Sonoran Desert rock fig (Ficus petiolaris) and species-specific fig wasp mutualists (Pegoscapus pollinator) and antagonists (diverse non-pollinating genera). Specifically we are investigating geographic variation in mutualism "fitness" (seed and pollinator production) and how it is influenced by host population size, flowering phenology, and interactions with non-pollinating fig wasps, whose larvae parasitize fig fruit. Our analysis of this system employs extensive field work to quantify mutualism fitness, the costs of parasitism, and fig phenology, as well as SNP genotyping to estimate fig population sizes. Integrated analyses of these data will enable use to identify the mechanisms responsible for the exceptional geographic variation in mutualism fitness observed in the F. petiolaris system.

Area of Expertise: 

  • Evolutionary Biology
  • Population Genetics
  • Plant-Insect Interactions