Crop to wild gene flow: Does more sophisticated research provide better risk assessment?

Research into introgression, the permanent incorporation of alleles of one species into another, is flourishing and gives new insights into evolution and speciation. The possible transfer of transgenes from crop species to wild relatives is of major concern for regulators. Applicants that want to introduce a genetically modified (GM) crop on the European market need to indicate the likelihood of introgression and its anticipated effects in an Environmental Risk Analysis (ERA). The European Food Safety Association (EFSA) and competent authorities of different countries evaluate the ERA. Predicting which crop alleles will or will not be permanently incorporated into wild populations requires, apart from information on seed production of hybrids, information on how these crop alleles are associated with fitness. Advances in genetics open new avenues to address this question in more detail. We argue, however, that, even with the best techniques, predicting introgression from crop to wild species will always have a considerable margin of uncertainty. One must therefore be prudent to demand more detailed research for the ERA, especially since the possible harm of transgenes in natural populations remains so poorly defined by regulators. ⺠Genes can sometimes flow from genetically modified crops to wild plants. ⺠The probability can be predicted from seed production of hybrids and backcrosses. ⺠Nevertheless predictions about introgression remain uncertain. ⺠One should be reluctant to ask too much detail in Environmental Risk Assessment. ⺠Instead possible harm should have a more central place.