This post is only 90% true. Among these ten items, one was deliberately made-up. Each items includes links to sources, so you can easily check if they are true. Can you find the fake item? (More information about the series here.)
- Insect-resistant, genetically-modified maize have been cultivated in Spain and Portugal for more than twenty years. A 2019 study analyzed the environmental effects: aside from the obvious decrease in pesticide pollution and water savings, there was a measurable drop in greenhouse-gas emissions. This is because diesel-powered tractors were no longer needed to spray the insecticides. The downside of insect-resistant GMOs is that new pests will eventually emerge after a few decades, just like they do with chemical pesticides. Biotechnology could also have an impact on climate change in a more direct manner – for example, engineering the gut microbiota of cows to minimize the production of methane by cattle, or genetically modifying poplars for wood production so they no longer release isoprene, a pollutant that increases the air concentration of ozone and methane.
- You might think that millions of years of evolution would have fully optimized photosynthesis, but it is not quite the case. Many crops are much less efficient than what would be possible in theory. Multiple genetic strategies are possible to increase the yield of crops, for example to increase their carbohydrate production. In soybeans, rice and wheat, the process of photorespiration diverts part of the energy obtained from photosynthesis. Using tobacco plants as a model, researchers were able to increase biomass by more than 20% in field trials, just by optimizing the expression levels of various photosynthetic components.
- Improving the nutritional qualities of crops through genetic modification is also promising, especially in third-world countries were malnutrition is rampant. The “golden rice”, a variant of rice with a high level of vitamin A was developed more than fifteen years ago. So far, it has not been widely adopted (in part due to efforts from Greenpeace to undermine it). More recently, by enhancing cassava with an iron transporter and the iron-storage protein ferritin, it was possible to increase the plant’s iron and zinc content by about ten-fold.
- Even without genetic modification, the fruits and vegetables we eat are very different from what is found in nature, owing to centuries of breeding. This is visible in still-life paintings from the Renaissance where fruits are on display. If you are wondering what vegetables looked like in their natural, not-genetically-modified forms, here are pictures of wild-type bananas, wild-type corn, and wild-type carrots1This last links points to a website called World Carrot Museum, with the tagline “discover the power of carrots”. That might not be an academic source, but I am sure we can trust them for all our carrot questions..
- Since humans started agriculture thousands of years ago, the selection of plants by breeding has completely changed our food habits. This, in turn, put an evolutionary selection pressure on humans themselves. The textbook example is lactase persistence, when the domestication of cows gave a great advantage to humans who could digest cow milk. Now, according to some research, modern humans have evolved some kind of dependency to selected plants. That is, if all the domesticated plants were to suddenly go back to their wild state, most humans would have trouble finding food they can digest.
- Starting in the 1950s, exposing crops to radiation became a popular way to generate new mutant varieties. The typical “gamma garden” design involves a circular field with a Cobalt-60 gamma ray source in the middle. This way, seeds are exposed to a gradient of radioactivity – the plants near the center usually die, the peripheral plants are unaltered, and interesting things can happen in the intermediate range. Needless to say, gamma rays produce mutations all over the genome, and large chromosomal rearrangements are frequently observed. Despite being much messier than genetic modification techniques like CRISPR, plants obtained through “atomic gardening” are not legally considered GMOs. They may even be accepted in organic food.
- There are no Terminator seeds. The legend goes that some greedy GMO company sold seeds that would turn sterile after the first generation, so that farmers could not sow them and would have to buy it again from the company every year. The underlying technology does exist, but it was never used in any commercialized product. That being said, farmers buying new seeds every year is nothing new (and not restricted to GMOs): for decades they have relied on hybrids from inbred plants, which have desirable properties but can be sowed only once since their offspring would be too heterogeneous.
- Local production has become an important criterion for consumers. Somehow, people are starting to realize there might be something wrong about shipping fruits and vegetables from the other side of the planet. In general, the more local, the greener. But there is a loophole: not all places are equally fertile. According to a study from 2020, only one third of the world population could sustainably feed on food produced in a radius of 100 km. In some cases, outsourcing food production to more fertile grounds could allow to spare land (i.e. growing forests), which is a good way to sequester GHG. In fact, a recent paper advocated for combining high-yield farming in some spots with land-sparing in other spots, as the optimal strategy for environment-friendly agriculture.
- According to large surveys of representative samples in the USA, France and Germany, extreme opponents of genetically modified foods know the least but think they know the most (this is one of the best titles for a scientific article).
- Like cellphones, micro-wave ovens and every other new technology, GMOs have been accused of causing cancer2For some reason, it’s always cancer. I have never met anybody who feared GMOs would cause pica or Capgras syndrome, although that would be pretty funny.. And technically speaking, yes, they do – but just as much as regular food. Carcinogenic substances can be found in small amounts in all kinds of food, e.g. in red meat, cereals, apple juice3In most cases, the amount is negligibly small. The only association that I would take seriously is red meat.… In fact, it is even possible to engineer plants so that they protect against cancer, like this broccoli.
Could you find the false item? If you have doubts, feel free to discuss about it in the comment section.