Standard Article

Genetically Modified Organisms

Natural Resources and Agriculture

  1. Joe N. Perry

Published Online: 15 JAN 2013

DOI: 10.1002/9780470057339.vnn030

Encyclopedia of Environmetrics

Encyclopedia of Environmetrics

How to Cite

Perry, J. N. 2013. Genetically Modified Organisms. Encyclopedia of Environmetrics. 3.

Author Information

  1. Rothamsted Research, Hertfordshire, UK

Publication History

  1. Published Online: 15 JAN 2013


Genetically modified organisms (GMOs) are those in which the genetic material (the DNA) has been altered in a way that does not occur naturally. In all countries, the release of GMOs into the environment is regulated and a risk assessment is required. GMOs have many medical applications, but this article focuses on agricultural and ecological uses. The principle of the comparative approach is explained and various statistical issues arising from it are discussed. These include the need for an equivalence or noninferiority test in addition to the traditional difference test; the need for power analysis; consumer and producer risk, false positives and false negatives; multiple testing and sample surveys. The importance of meta-analyses, mathematical modeling, and uncertainty analysis is stressed. The issue of estimation for events that are deemed risks but which have never been observed is considered. Two case studies provide further background reading. The article finishes with some challenges for estimating the environmental impact of future GMOs.


  • genetically modified organism;
  • GM plants;
  • GM animals;
  • risk assessment;
  • power;
  • equivalence;
  • hazard;
  • exposure;
  • uncertainty;
  • biotechnology