The debate over the use of genetically modified (GM) crops has been going on for a long time. Despite the controversy, GM crop production has grown rapidly since 1996, and GM crop varieties are now planted on 3.5% of the World’s total agricultural land (1). In an article published this week in PLOS Biology, Ottoline Leyser argues that this debate is distracting us from addressing the real challenges facing modern agriculture: global food security and environmental sustainability (2).
Leyser starts by discussing how GM is considered by many to be the epitome of all that’s bad in modern agriculture: the dominance of profit-driven multinational corporations, high-intensity monoculture farming and the accompanying use of large quantities of environmentally-damaging chemicals. As a plant scientist and nature-lover, I am also concerned about these farming practises. However, as Leyser points out, they have nothing to do with GM technology. It is a situation that was reached long before GM-crops were first grown commercially and is prevalent all over the world, including in the EU, where GM-crops have never been widely grown.
Many people are concerned about GM-technology because they say it is not “natural” for DNA from one species to be inserted into another. To start with, it is important to remember that very little is “natural” in 21st century living. We eat plants and animals that have been selectively-bred to the point that many bear little resemblance to their wild ancestors (click here for an illustration of maize and its wild ancestor teosinte). We use industrially-made chemicals to promote crop growth and fend off pests. We use computers, drive cars, and take medication made by genetically modified bacteria.
Secondly, humans were not the first species to take DNA from one species and insert it into another. Bacteria regularly acquire DNA that originated from other bacterial species, which is one of the reasons that antibiotic resistance can spread so quickly amongst bacterial populations. Many viruses, including HIV, insert DNA into their host’s genome to reproduce. Lab techniques for genetic modification of organisms often utilise these natural processes. For example, a common method for genetic modification of plants in the laboratory uses modified forms of Agrobacterium tumefaciens, which naturally inserts DNA into its plant hosts.
When deciding whether to grow a new crop variety, it is the trait, not the technology used to produce the trait that is more important. For example, herbicide-tolerant GM-crop varieties have come under criticism because studies have found that their use decreases the biodiversity of local wildlife. However, this has nothing to do with genetic modification of the variety. Instead, the studies demonstrate that more effective weed control, which can be achieved when using herbicide tolerant crop varieties, is bad for wildlife. Conventionally bred (non-GM) herbicide-tolerant crop varieties also make more effective weed control possible, so a study using these varieties would produce similar results.
Unfortunately, EU law regulates crop varieties by technology, not trait. So, while new GM crops have to pass through rigorous testing and trials before they can be grown commercially, conventionally-bred crop varieties with similar traits can be grown without much regulation or consideration to their impact on the environment.
Regardless of whether we grow GM crops or not, regulation of new crop varieties by trait could provide much better protection to the environment than the EU’s current framework. Since both sides of the GM debate want to make agriculture more environmentally friendly and sustainable, maybe it is something we could all agree on.
1) Open Knowledge. GM crops: Top ten facts and figures http://knowledge.allianz.com/environment/food_water/?500/gm-crops-facts-and-figures (retrieved 13/06/14)
2) Leyser, O. (2014) Moving beyond the GM Debate. PLOS Biology http://www.ploscollections.org/article/info:doi/10.1371/journal.pbio.1001887