This week’s post is a discussion about the need for and safety of genetically engineered crops. If you’ve not been following this debate in the news, questions in bold are common sentiments agricultural scientists face from the public. The arguments and opinions stated here are my own but are based on reproducible science and facts. Due to the breadth of supporting research, I will not link to many sources; however, if you have more questions, would like to have a conversation, or would like more information, please don’t hesitate to let me know and I will happily discuss it further or direct you to peer reviewed, non-biased, scientific studies.
‘Why do we need genetically engineered crops?’
This is a question that agricultural scientists hear pretty regularly from people with concerns about genetic engineering. ‘Why do we need transgenic corn or soybeans?’ ‘We’ve successfully grown traditional varieties for all this time, why should we change anything and risk unforeseen challenges?’ ‘Why aren’t scientists working to improve the systems we already have?’ That’s where most scientists will stop you, because that’s exactly what genetic engineering aims to do.
Since the beginning of agriculture, farmers have aimed to get more food from fewer inputs. These goals helped to form the agricultural science fields as they are today, where researchers try to identify the optimum levels of inputs to get the highest yield and quality from their production systems, like fertilizers, water, organic matter, tillage, pesticides, and in controlled environments, temperature, light, and CO2. The advancements being made in crop biotechnology don’t seek to eliminate these advancements, but to further optimize, refine, and reduce the inputs needed for production.
‘Why can’t we continue to optimize traditional production inputs and continue making improvements as was done in the past?’ We can and we will continue to optimize these inputs, however, as we improve our practices the gains to be made from better use of fertilizers, for example, is less and less every year. In developed countries like the US, this level of improvement will do, for now. But farmers in developing countries without sufficient access to water for their crops, let alone the most advanced fertilizer mixtures and pesticide formulations, need more immediate and accessible solutions.
There are 7 billion people on this Earth. Among these people 1 in 9 is undernourished, meaning they don’t have enough food, let alone enough food with high nutrient quality. ‘But developing countries have a surplus of food. We throw perfectly good food away. What we need is a way to redistribute the food supply’ Sure, that could help, but do you think that will happen soon enough to save the life of a child in rural Africa? The logistics required to ‘redistribute’ food wealth isn’t the only factor. What about the governments and economies of the countries with a food surplus? How do you propose American farmers would be compensated if the food they produced was sent to these starving nations? Would it even make it to the people who need it most? What about the people in our own country who go hungry every day? Look at our current political atmosphere. This issue certainly isn’t on the mind of our politicians now, and it won’t be anytime soon. The solution lies in giving farmers in developing countries access to agricultural technology, including GE crops, which will allow them to produce higher quality food with fewer inputs and reduced losses to pests and environmental stresses. This is believed by many to be an important step toward reducing poverty and improving the health of people in developing communities, which can, in turn, lead to improved education and equality, especially for girls, and ultimately a higher standard of living and slower population growth, which are all huge topics on their own, but are each linked to the power of positive change that improved agricultural practices, including GE crops, can have.
‘So what makes you think genetically engineered crops will solve anything?’ We don’t just think GE crops will improve agricultural practices, we know they will. As mentioned in previous posts, transgenic crop plants have been studied for nearly 50 years. The benefits of this technology have been proven across several crop species and against a significant span of limiting growth factors. No supporter of GE crops believes that this technology will solve all of our production problems or that it can be used without regard to optimizing other production practices. What we are saying, is that this technology allows us to overcome the plateau in food production that we have presently reached. This technology will help to produce more food on our existing arable land with reduced environmental impacts, allowing us to feed the starving people of today, and those of the future who will be a part of our rapidly growing population, which is predicted to reach 9.7 billion by 2050. That’s only 34 years from now.
‘Why don’t we just use new cultivars from traditional breeding?’ Plant breeders are working hard to address the major problems we have in crop production. They have and are still making great strides toward higher yielding and quality crops with reduced environmental impact; however, some of these challenges are difficult to address quickly and effectively through traditional breeding. For example, suppose you are a wheat breeder trying to combine 4 desirable traits into one cultivar. You have 4 plants that each have one of these traits, so you design a series of crosses to try to obtain offspring that have all four. Not only will this take a long time and a lot of plants, there is no guarantee that once you have a plant with 2 of the traits, you will be successful in adding the others. This is due to gene linkages and interactions within the plant genome and the environment that are out of a breeder’s control. Alternatively, you found the trait you want in another plant species but you cannot successfully cross it with your crop plant without complications. Genetic engineering is technology that breeders can add to their toolbox to quickly and reliably introduce a single gene or a set of genes into their breeding program, bringing better and more reliable cultivars to growers. By saving time in this manner, we will be better able to respond to changing environments and new pest threats to our food supply through targeted breeding efforts.
‘Even if they do improve production, how do we know that genetically engineered crops are safe to the environment and our health?’ The last few Cultivate Curiosity posts have focused on DNA, natural variation, and transgenic technology. You’ll remember that genetically engineered crops are generated by altering a single gene within the entire organism’s DNA and that due to the specificity of transcription of these genes from DNA into proteins, certain genes are only expressed in certain tissues. Why is this relevant to safety? Well first of all, in some GE crops, the altered gene is only expressed in certain tissues of the plant, often tissues that are not consumed by humans. Therefore, you never eat the proteins that result from the altered gene. Secondly, if the genes are expressed in the plant tissues that we use as food, the resulting proteins are not toxic to humans. They are often compounds that are found in nature elsewhere, and they are designed to act within the plant with such specificity that they only target pest species, for example. Therefore, unless you are a caterpillar, virus, nematode, beetle, etc., absolutely nothing is going to happen to you. Also, you consume such small quantities of these compounds that they couldn’t truly have an effect on you anyway.
‘So what about the environment and non-target organisms? Don’t GE crops hurt bees?’ No, GE crops don’t hurt bees because bees are not crop pests. What does hurt bees are pesticides. The large amounts of pesticides used on our crops, especially insecticides, are not nearly as species specific as GE crops. An insecticide will kill any insect, not just pest species. Therefore, they kill bees and other beneficial insects that are present within and near crop fields. GE crops have the ability to reduce and sometimes eliminate the need for pesticides because they make their own. This goes back to the concept of reducing inputs and improving practices. Some propose that this reduction in pesticide use can be solved by organic practices. On some farms, it does; however, pesticide use is permitted in organic production, the limitation is only on what these pesticides are made of. Organic rarely means pesticide-free. This topic will get its own post soon, but it is so often presented as an alternative to GE crops that it warranted mentioning here.
‘What about herbicide resistant weeds? Isn’t that caused by using Roundup Ready crops?’ The natural variation post from a couple of weeks ago talked about the natural evolution of species in response to a selection pressure, where individuals strong enough to withstand a selection force survive to reproduce and pass on their specific traits. This is what is happening when any pest develops resistance to a pesticide. In this case, weed plants that survive herbicide applications live and reproduce. Over time the herbicide is no longer effective. This happens not only with Round-up Ready crops that can protect themselves from specific herbicides but in all cases where herbicides are applied. This issue has been known by scientists long before the introduction of Roundup Ready crops and is being addressed through herbicide rotation programs, where herbicides with different modes-of-action (or how they work to kill a weed) are used to prevent resistant weeds from evolving. When used properly, this technique is very effective. The second thing to note is that the use of herbicide-resistant crop plants (like Roundup Ready crops) does not necessarily mean increased use of herbicides on these fields. Farmers don’t want to use pesticides if they don’t have to. They are expensive and require time and labor to apply, therefore farmers will use as little herbicide as they can without having losses to their crops. Herbicide-resistant crop plants allow farmers to get better herbicide coverage and less crop damage from the applications that they do make, so when the herbicides work better, they don’t need to use as much of them. More successful weed control permits reduced tillage practices, which are more sustainable because they lessen soil erosion, improve soil health, protect micro-ecosystems, and reduce fuel needs for equipment.
There’s a lot more to the story of GE crops than most media discussion leads you to believe. When formulating your own opinions on GE crops, be sure to consider all aspects: how and why they have been developed, how they work, who they can help, and when used correctly how they can contribute to solving some of the biggest food security challenges of today and the future.