Are GMOs harmful to the environment?

Expert response from Dr. L. Curtis Hannah

Professor, University of Florida

Thursday, 30/03/2017 21:59

In addressing this question, one should realize that there are three federal agencies involved in regulating the commercial growth of GMO crops: the US Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS), the Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA). Hence potential environmental concerns of a new GMO crop are addressed by the EPA long before commercial growth is allowed.
 
The major GMO crops currently on the market contain genes conditioning resistance to the herbicide Round-Up and/or resistance to attack by certain insects. These genes have been good for the environment since less spraying is needed, hence reducing the carbon foot print of farming. In considering these genes though, it is important to note that plant breeders have historically described naturally-occurring genes for insect and herbicide resistance. Hence, while the particular herbicide and the particular insects addressed by these transgenes now on the market are unique, the concept of plant genes for resistance has a long history in plant improvement programs. Hence these new resistance genes are not novel.
 
As is the case in the use of any resistance gene, selection occurs in nature for genetic variants in the plant pest (insect or weed) that overcomes resistance. These variants, while rare in occurrence, quickly take over fields since they can grow and reproduce. This Darwinian evolution occurs whether the plant gene for resistance occurred naturally or was man-made. This has occurred with virtually all naturally-occurring genes and it has also happened with the transgenes for Round-Up resistance and resistance to the insects killed by the BT types of insecticidal proteins.