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  • UC Riverside
  • College of Natural and Agricultural Sciences

Nickolas M. Waser


Professor of Biology Emeritus


Ph.D., University of Arizona, 1977

Animal visitors such as bumble bees, solitary bees, and hummingbirds play a critical role in the sexual reproduction of many higher plants.  How do such pollinators choose flowers, and how does this translate into natural selection on discrete and quantitative traits such as flower color and shape or nectar production? What is the role of animal visitors in gene dispersal, and how does this influence spatial genetic structure of plant populations, the establishment of hybrid populations, and plant speciation? How do the "post-pollination" events beginning after dispersal of pollen and culminating in seed production modify the selection and gene flow caused by pollinators? From a community perspective, how are plant-pollinator interactions organized, how and why are they usually generalized, and what are the implications for resilience of food webs and conservation of endangered species? I am exploring these and related questions, mostly with plant-pollinator systems in the Rocky Mountains and southwestern deserts.

Dr. Waser participates in the Evolutionary Biology graduate group.

Some Representative Publications....

  • Waser, N. M. 1978. Interspecific pollen transfer and competition between co-occuring plant species. Oecologia 36:223-236.
  • Waser, N. M. and M. V. Price. 1983. Pollinator behaviour and natural selection for flower colour in Delphinium nelsonii. Nature 302:422-424.
  • Waser, N. M., L. Chittka, M. V. Price, N. Williams, and J. Ollerton. 1996. Generalization in pollination systems, and why it matters. Ecology 77:1043-1060.
  • Waser, N. and L. Chittka. 1998. Bedazzled by flowers. Nature 394:836-837.
  • Kearns, C. K., D. W. Inouye, and N. M. Waser. 1998. Endangered mutualisms: the conservation biology of plant-pollinator interactions. Annual Review of Ecology and Systematics 29:83-112.
  • Chittka, L., J. D. Thomson, and N. M. Waser. 1999. Flower constancy, insect psychology, and plant evolution. Naturwissenschaften 86:361-377.
  • Waser, N. M., M. V. Price, and R. G. Shaw. 2000. Outbreeding depression varies among cohorts of Ipomopsis aggregata planted in nature. Evolution 54:485-491.
  • Waser, N. M. 2001. Pollinator foraging and plant speciation: looking beyond the "ethological isolation" paradigm. In: Cognitive Ecology of Pollination, eds. L. Chittka and J. D. Thomson, Cambridge University Press, Cambridge UK.

Click here for a complete publication list.

Recent Teaching....

  • Biology 5C, Introduction to Population Biology
  • Biology 118/218, Field Course in Evolutionary Ecology
  • Biology 216, The Theory of Evolution
  • Biology 217, Graduate Population and Community Ecology