Studying and managing the risk of cross-fertilization between transgenic crops and wild relatives


  • P. Kareiva's general interests involve the application of ecological models to environmental problems, conservation biology, and basic theoretical ecology. C. Jacobi's research emphasizes the interplay of dispersal and habitat heterogeneity in determining population dynamics, as well as the use of ecological theory for the development of sustainable ecosystems. W. Morris is interested in using mechanistic models of insect behaviour and demography to better understand insect communities and plant-insect interactions.

Department of Zoology, University of Washington, Seattle, WA 91895, USA. Fax 206–543–3041


Drawing on field studies of pollen dispersal, we identify features of the hybridization process that need quantification. Our emphasis is on standardized measures, as opposed to the idiosyncratic and often anecdotal methods with which gene flow or out-crossing data are currently reported. In addition to proposing specific maximum likelihood approaches, we summarize some results to date from small-scale field trials that bear on the risks anticipated for large-scale commercialization. We conclude that absolute containment of recombinant pollen or genes is unlikely if physical isolation is the only containment strategy. Because we conclude that the escape of transgenic pollen is inevitable, we argue that the focus of risk analysis should be shifted towards the ‘invasiveness’ of transgenic plants and ‘mitigation’ of their impact on natural, as well as agricultural systems.