Transgenes in Mexican maize: Desirability or inevitability?

For several years, there has been uncertainty about the presence of transgenes in maize landraces in the state of Oaxaca, Mexico. The first report of their presence in this region was that of Quist and Chapela (1, 2), who based their results on samples obtained in 2000; these findings were later called into doubt because of the methodology used. However, further studies by the Mexican government confirmed the presence of transgenes in Oaxaca in 2000 and 2001 (3, 4, †). Most recently, Ortiz-Garcia et al. (5), in an outstanding analysis, failed to find evidence for the presence of transgenes in the same area in 2003 and 2004. Presumably, their frequency had diminished greatly over the course of 2–3 years, and the genes may even have disappeared. It will be of scientific interest to monitor the presence and frequency of such genes in the future.

What, however, is the social significance of these results in the region concerned and in the broader context of the growing use of transgenic crops in agriculture throughout the world? Approximately one-eighth of the world's cropland is planted in transgenic crops, with nearly 10 million farmers involved in their cultivation, and the proportion of such crops is growing rapidly. Does this growth represent a threat to maize in its center of origin, to Mexico, or to the world? I offer the following comments as a member of the Commission for Environmental …