Response to Wilkinson & Tepfer's "Fitness and beyond: preparing for the arrival of GM crops with ecologically important novel characters".

Mike Wilkinson and Mark Tepfer’s commentary (Wilkinson and Tepfer, 2009) is a very welcomed contribution towards more realism in environmental risk assessment (ERA). I share most of their views regarding the next generation of GM crops with ecologically important novel characters. Looking at the past GM crops with herbicide tolerance and insect resistance traits, one must confess that environmental impacts reported so far are – if at all – small compared to other consequences of human activities (e.g. global climatic change or increased salinization of cropland). However, the quantification of ‘fitness’ is not an easy task, as this term clearly depends on the environmental context (e.g. the novel plant in the receiving environment). I know colleagues who recommend measuring ‘plant performance’ instead of ‘fitness’. Then the impact of novel genetically modified characters on the establishment and spread in the context of the receiving environment is a key point. Two considerations will strengthen the regulatory preparation for novel characters: (1) assessing the ecological phenotype and (2) definition of ‘weediness’.