The first time I heard the phrase “GMO” was at a rally, and I had to ask my 9th-grade science teacher what it meant. That was before ballot initiatives demanding GMO labelling and beforeNon-GMO Projectlogos became familiar on food labels.
从那时起,人们对转基因生物的认识急剧增加。这是一个使人们两极分化的问题,并导致强烈的情绪,有时会压倒逻辑和科学数据。我朋友四岁的孩子会告诉你转基因食物不好吃。
But what are GMOs actually? Why are they so bad?
The Science of GMOs
GMO stands for Genetically Modified Organism, and it refers to any plant or animal that has had foreign DNA inserted into its genome.
That’s all I knew about GMOs until college when a very annoyed professor explained the process in more detail. She was tired of people talking about GMOs without understanding the science of the process.
Plant Breeding – “Natural” Genetic Change
To be clear, humans have been altering the genetic make-up of plant and animal populations for hundreds of thousands of years, through selective breeding, but genetic engineering is not the same at all.
Breeding makes use of genetic mutations that occur naturally and randomly in plants. Breeders encourage a particular mutation, like larger fruit, by crossing plants which display the desired trait. However, plant breeders have to wait for a desired trait to occur in one plant before they can select for it. That is the reason that, despite decades of breeding, there areno truly black roses. That particular pigmentation simply does not exist to be selected for.
By contrast, true genetic engineering essentiallycausesthe desired mutation, by inserting it into the gene sequence. However, even genetic engineering cannot produce justanyresult. The effectiveness and versatility is limited by the scientific process.
Modern Genetic Engineering and Modification
Let’s review basic cellular biology first. All our cellular activity is carried out by enzymes—short chains of amino acids. Enzymes control the activity, called “expression,” of our DNA. Every cell in our body, or in a plant, contains a full strand of DNA in the cellular nucleus. But only part of that DNA is being used in each cell. That’s why blood cells are different than brain cells and so on. Enzymes make that possible by “folding” and “unfolding” DNA, so that only the necessary parts are “readable” in any particular cell. Enzymes also cut and duplicate DNA when necessary, which makes them the natural tools for working with DNA.
Scientists and bioengineers useenzymes to slice a particular section of DNAout of one organism. Then there are a number of ways to get it into another organism. It can be done mechanically throughmicroinjection, but more commonly, scientists use a virus or bacteria as a carrier.
Viruses and bacteria are ideal vectors for carrying new DNA into an organism, because their method of reproduction naturally includes DNA transfers. Because they reproduce assexually, they need a different way to get genetic variety in their populations. So viruses and bacteria swap “packets” of genes calledplasmids. Plasmid transfers introduce genetic diversity to a population of bacteria or viruses.
Researchers working on developing GM crops use the natural ability of those simple organisms to transfer short strands of DNA into embryonic seeds. Once inserted, the DNA becomes seamlessly incorporated into the rest of the host plant’s DNA. When the plant reproduces, it carries the new DNA in its seeds.
For more information on the science of GMOs, check out this video from popular internet science geek, Hank Green. He presents a balanced and upbeat overview of the science and background of GMOS.
DNA is naturally flexible and adaptive. The diverse biological history of Earth tells us that, loud and clear. There is nothing unprecedented about DNA mutating, swapping, breaking, recombining or changing in any way. However, having a human hand in the process makes many people uncomfortable.
The History of GMOs
基因工程的研究在20世纪70年代开始生产转基因食品,但第一个转基因食品直到1992年才进入杂货店。The first GM food available, a tomato variety calledFlavr Savr,aroused suspicion and distrust from the public. It was a commercial failure. Two years later, in 1994, the FDA approved Monsanto’s Roundup-Ready corn, and the age of GMOs was born.
The active ingredient in Roundup is a chemical herbicide calledglyphosate, which kills most plants, including corn, and is toxic to other organisms. Bioengineers at Monsanto used DNA from a bacteria that is resistant to glyphosate and added it to the genome of their field corn. Roundup-Ready corn crops can be sprayed with glyphosate to kill weeds without harming the desirable crop.
Roundup-Ready crops have become king in conventional fields around the world.88% of America’s largest crop, corn, is Roundup-Ready, as is 93% of soy planted in the US.孟山都(Monsanto)是转基因研究的领军企业,也是抗草甘膦玉米的开发商,这并非巧合。
Who is Monsanto?
如果我们谈论转基因生物,我们就必须谈论孟山都。孟山都(Monsanto)这个名字已经与转基因作物紧密地交织在一起,以至于有时这两个名字被互换使用。然而,把这两个词组合在一起,充其量是误导。Monsanto is first and foremost a chemical manufacturer and in their long history haveproduced chemicals for a variety of industrial purposes, including Agent Orange and DDT. Currently they are a major producer of pesticides like Roundup and other agricultural chemicals, and they have become a leading researcher in agricultural biotechnology.
Monsanto’s corporate practices have made them a target of hatred and fear from the public. But they are not the only company which produces GM seeds—Syngenta and DowDupontare Monsanto’s major competitors. Nor are they the only company with a track record of environmental destruction.
Monsanto has suffered ahistory of PR crises, but the biggest began in 1998 when the companysued a Canadian canola farmerfor having patented seed on his property without paying. He claimed that he had not planted the seed, but it had blown onto his farm.
Monsanto won the case in the courts, but lost it decisively in the court of public opinion. Despite the public backlash, they have gone on to sue more farmers who save their patented seed, or have their fields contaminated.
Ultimately, the public hatred for Monsanto is linked to more than just their exploitive corporate practices and environmental abuses. It comes from fear for our health, our families, our planet, and our food. Monsanto is a visible and unpopular target.
Concerns about GMOs
Only a handful of GM crops are approved to be grown in the US, but those include some of the most common additives to processed foods, like corn, soy, canola, potatoes, and sugar beets, which is used to produce refined sugar. Unlike the ill-fated Flavr Savr tomato, most GMOs do not arrive directly on our plates, but are part of the production of the food we eat. Non-organic meat animals have eaten GM corn and soy all their lives. Corn syrup and fructose in processed foods and sodas are made from GM corn and sugar beets. Potato chips, french fries, and donuts have likely been fried in oil from GM soy or canola. As GMOs become more common in food we eat every day, we increasingly wonder: is GM food safe to eat and safe to grow?
关注#1:转基因食品会伤害我们的身体吗?
We all want to eat food that is safe and nourishing. How do GMOs affect our bodies and our health? Some opponents of GMOs point to a2012 studywhich linked GMO consumption to reproductive problems in rats, but that study hassince been retracted. There is no reliable evidence that GM foods have any impact on your body.
Of course, other factors are involved too. The power of our own perceptions is not to be underestimated. When I worry that a food is not good for my body, I don’t feel good after eating it, regardless of the actual nutritional content of the food.
And finally, since USDA organic standards forbid the use of GM seeds, all GMOs are conventional crops, sprayed with conventional pesticides and fertilizer. So if you are trying to avoid food that has been treated with pesticides, for personal or environmental reasons, you will also be avoiding GMOs.
Concern #2: Do GMO Foods Increase Pesticide Use?
Most GM crops fall into two broad categories: herbicide tolerant and Bt. Herbicide tolerant GMOs are like Roundup-Ready. They are designed to be immune to pesticides that kill other weeds. Bt, on the other hand, hasa gene sequence from the bacteriaBacillus thuringiensis. Bt produces a protein toxic to a number of worms and insects that attack crops, including the European Corn Borer.
Since the invention of Bt corn and cotton, advocates claim that GMOs lead to using fewer pesticides, butstudies show the opposite. Fields growing Bt crops do in fact use fewer herbicides, but the benefits are outweighed by the increased use of the other category of GMOs. GM crops like Roundup-Ready corn, soy and canola lead to an increase, not a decrease, in pesticide use.
Also, selection pressure from frequent use of Roundup has produced a new generation ofglyphosate-resistant weeds. In response, conventional farmers mix more than one type of herbicide, but this backfires. It leads to weed populations withresistance to multiple chemical poisons. Clearly, this is a serious environmental concern. Using pesticides is also ahealth and justice issue for farm workers, who have to spray them.
Benefits of GMOs
Despite these problems, which are serious and frightening, there are some benefits coming from genetically modified food. It’s not just for-profit corporations producing GM seeds. Many institutions including universities around the world develop and produce GM crops.
Benefit #1: GMOs May Prevent Starvation
研究人员希望转基因种子可以拯救生命。Intensive research at Oxford以及其他地方的转基因水稻项目的目标是生产能够忍受极端干旱的转基因水稻。Other researchers are developing GM seeds that areresistant to funguses and diseasesthat devastate crops. In a world with a growing population and an increasingly unstable climate, GMOs could possibly prevent massive starvation.
Benefit #2: GMOs May Help Farmers Stay Profitable
在离家更近的地方,许多传统农民从种植转基因作物中获得了经济上的好处。Genetic modification hasincreased yieldsin commodity crops like corn, soy and cotton. In our industrial food system it is easy to forget that although most farms are massive (the average farm size today according to the USDAis 1105 acres) nearly all of those farms—96%—are owned and operated by a single family. Many of those families are struggling to make ends meet.The USDA estimatesthat 69.3% of all farms have a profit margin of less than 10%.
农场是一个复杂而具有挑战性的系统,涉及劳动力、机械化和农药使用之间的权衡。转基因作物是农民保护他们的利润空间的另一个工具。与农民可以选择的其他选择一样,转基因作物也涉及到在利益和缺陷之间进行权衡的挑战。
GMOs: No Easy Answers
转基因食品的问题是复杂和两极分化的。基因改造是一种在不确定的未来有望减少饥饿的工具,但它已被企业利用牟利。没有证据表明转基因生物会伤害人体,但它们可能会对环境产生负面影响。
This spring, my partner and I wanted to plant a trial of heirloom corn to seed-save. Since corn is wind-pollinated, it needsa buffer of around half a mileto prevent cross-contamination, if you want to save the seeds. We visited our neighbors and offered to give them the seed we were growing to plant instead of the varieties they normally grew, so we could have a clean crop. Most people were happy to, but one neighbor, not to put too fine a point on it, refused. He had been planting Roundup-Ready corn for two decades, and wasn’t about to change for a couple of kids like us. He liked how he grew corn (read: with pesticides) and wasn’t about to start (weeding) new crops. GMOs were part of a lifestyle for him. Sadly, my partner and I shelved the corn breeding project.
There are no easy answers. Personally, I am excited about the possibility of GMOs helping prevent famine in the event of disease and drought. I want to see that research better funded and to see the findings implemented. However, in my daily life I mostly choose to avoid eating foods containing GM ingredients because of the many other problems with the industrial food system, including pesticide use, abuse of workers, and lack of transparency.
对转基因生物的恐惧和焦虑是更复杂问题的一部分。我们生活在一个迅速巩固和日益不透明的粮食体系中。我们对保护自己和家人免受肥胖、癌症等各种问题的伤害感到无助,而这些问题都与我们的食物有关。我们不信任大公司,却发现自己越来越被大公司包围。我们感到无人问津和不安全。转基因生物是这个故事的一部分,但只是一部分。作为消费者和园丁,我们可以自我教育,做出明智的选择,了解什么对我们的身体和家庭最好。我们可以与我们的朋友和当地的立法者分享我们的新知识。我们可以为环保局、美国农业部和第三方监管机构提供资金支持。我们可以提出反对垄断和公司权力的立法,并发起运动。 We can insist on being heard.
Rick Hessleinsays
There are more problems with GMO/Transgenic organisms/crops than just the excessive use of pesticides/herbicides. Transgenic produced food supplement L-tryptophan was proven to be responsible for hundreds of human deaths and thousands of serious illnesses which also illustrated the very complex nature of making the connection to to the GMO culprit. Thus our FDA / USDA exempting GMO foods from required testing through politically corrupt channels of persuasion is highly suspect. Further, the scientists and studies that have found concerns have been attacked and vilified rather than researched.
There is no question that disease and illnesses are rising extremely and that the biggest culprit is likely industrial food, How much harm from the GMO technology is a big question! And that’s the problem…we do know, however, that working with natural systems and employing true sustainable agricultural systems, such as organic methods, can improve human AND environmental health now and into the future!!