According to PZ Myers,associate professor of biology at the University of Minnesota Morris, the GMO rat study published more than a year ago in Food and Chemical Toxicology by Gilles-Éric Séralini was terrible and sloppy, with gaping deficiencies that somehow slipped past peer review. Scientists were appalled by its shoddy methodology. There are many problems with the paper, including the fact that the strain of test rats used in the study are bred to have high instances of random tumor growth. The authors also did not include statistical tests showing that the differences in mortality rates between the experimental groups and the control group were statistically significant.
It was rather peculiar that the paper reported only on mortality. They were studying the appearance of cancer, so a more relevant and direct measure would have been to assess by the appearance of tumors of a particular size, and then to humanely euthanize severely affected animals. This study had them languish in a cage until they died and could be scored. There was no description of the cancers in the control group! They did seem to have a number of rats with huge, grossly disfiguring tumors that were handy for photo ops, though.
Read the full, original story here: Belated retraction of Seralini’s bad anti-GMO paper