In a move being described as unprecedented in recent history, the highly respected scientific journal Nature has said that it should not have published a controversial article last year about the discovery of genetically engineered corn growing in Mexico. The journal’s editors concluded that the article, which was welcomed by opponents of genetic modification, did not present sufficient evidence to back its two important claims: first, that genetically altered corn had contaminated natural strains in Mexico’s southern valley, the international center for corn diversity; and second, that genes spliced into corn plants were unstable, a finding that appeared to challenge basic assumptions about agricultural biotechnology. The authors say they stand by the first finding and believe the second is also on the money, although they concede they might have misinterpreted some of the data in the latter case. Advocates of biotechnology, however, point to the Nature retraction as the triumph of science over ideology.