Washington, DC
August 18, 2003

Gene flow common, but genetically modified (GM) crops raise new concerns about age-old phenomena

Gene flow is not unique to genetically modified crops (GM), but the possible spread of transgenic DNA to wild and domesticated relatives raises a new set of issues for scientists and policymakers to consider, according to a new issue brief released today by the Pew Initiative on Food and Biotechnology.

The brief, titled "Have Transgenes, Will Travel: Issues Raised by Gene Flow From Genetically Engineered Crops," summarizes the ecological and economic concerns experts mention when considering what could happen if novel traits from transgenic crops spread to other populations. It was developed as an accessible introduction to the issues for non-scientists and draws heavily on articles and interviews with leading plant researchers. Highlights include:

* A primary ecological concern is that transgenic plants will breed with wild relatives and confer a trait not otherwise found in nature to the resulting plant, thereby altering the gene pool for that crop and (potentially) threatening biodiversity.

* Economists have pointed out that specialty markets (such as organic crops) could be harmed economically if genetic material from transgenic plants were to spread and mix with a crop intended to exclude transgenic materials.

* Despite the theoretical concerns presented by gene flow, it is unclear if the spread of DNA from transgenic crops is an ecological help or a hinderance. Depending on the type of trait passed on, the general fitness of a plant could increase or decrease as a result of acquiring that trait.

* Concerns about gene flow from transgenic plants could be addressed by technologies currently under development that, if applied, could render GM crops sterile and unable to breed.

Gene flow is not peculiar to transgenic plants. It happens any time one plant breeds with a related species, thus passing along their combined genes to offspring. Some argue that gene flow from GM plants raises unique concerns and deserves special attention because GM plants have the capacity to spread novel traits into surrounding crops and ecosystems via pollen or seed.  Others, however, have argued that gene flow has happened since the beginning of time, can be thoughtfully controlled and is not a sufficient reason to stop the adoption of a powerful technology like genetic engineering.

"Gene flow is a natural process, but the introduction of biotechnology has brought new attention to the process and raised both economic and ecological issues," said Michael Rodemeyer, executive director of the Pew Initiative on Food and Biotechnology. "As new transgenic crops are tested and grown, preventing unwanted gene flow to other crops will present technical and regulatory challenges as well as possible economic conflict. We also need a better understanding of transgenic gene flow into wild plant populations if we are to frame appropriate policies. This brief is intended to help explain to policymakers and the public what is known and not known about transgenic gene flow."

The brief can be viewed at http://pewagbiotech.org/resources/issuebriefs/geneflow.pdf

The Pew Initiative on Food and Biotechnology is a nonprofit, nonpartisan research project whose goal is to inform the public and policymakers on issues about genetically modified food and agricultural biotechnology, including its importance, as well as concerns about it and its regulation. It is funded by a grant from The Pew Charitable Trusts to the University of Richmond.