Advances in genetic modification have been revolutionizing medical research for decades, helping humans gain a deeper understanding of the biological process, treat various diseases and forms of cancer, and develop a wide range of other modern vaccinations. When it comes to food and agriculture, however, genetic modification tends to elicit a nearly complete and opposite emotional reaction amongst the public; given the understandably profound and nearly unanimous connection human culture has to food, few people, if any, have no opinion on the subject. Yet at the same time, most consumers do not think twice about eating organic broccoli or if their dog sneaks a bite too.
It often comes as a surprise that, without the presence of mankind, neither broccoli nor the dog that consumed it would exist—in its loosest definition, the term genetically-modified organism can be applied to nearly every extant life form with which humans regularly interact. From artificial selection (selective breeding for desired traits) of the first domesticated animals and plants; to hybridization (forced mating of uniquely different cultivars and species) of the high-yield cereal varieties behind the Green Revolution; to current transgenic innovations (insertion of recombinant DNA and exogenous genes into organisms) behind the GMO revolution, human development can even be described as the process of optimizing our sources of food. As such, the recent development and proliferation of genetically-engineered crops—the more accurate title for crops consciously modified on a directly genetic level—is often clouded in confusion, fear, and a deeply instinctual reflex to protect our most hard-earned resource: food.
For better or for worse, we humans have, both consciously and unconsciously, been altering the world around us since our genesis. As a species, we have even engendered our own proposed epoch, the Anthropocene, a period when human activities began to significantly affect the earth’s ecosystem—starting at the first dog’s bark. Believed to have been selectively bred and domesticated (rendering an animal or plant dependent on humans or artificial environments for continued existence) in a search to better secure food, dogs (of the subspecies Canis lupus familiaris) first diverged from wolves roughly 30,000 years ago, so long ago in fact, that the first native peoples brought their dogs with them into the Americas.
In the continued search for our most prized resource, humans expanded their efforts to traditional livestock and plants. Although it is impossible to know precisely when and where agriculture first began, the first crops—cereals such as einkorn wheat—appear to have been domesticated in Mesopotamia between ten and twelve thousand years ago. Providing a rare yet visible glimpse into the motivation behind selective breeding (a term coined by Charles Darwin), wild and cultivated einkorn wheat differ in only one regard; the seed heads of the domesticated variety do not shatter and disperse as easily as wild einkorn, a mutation selected by humans that sacrifices natural seed dispersal for ease of harvest.
Selective breeding, also known as artificial selection, was not unique to a single culture or continent either. Millenia before Leif Erikson or Christopher Columbus first traveled to the Americas, for example, ancient civilizations in modern-day Mexico had domesticated corn from a nearly unrecognizable grass known as teosinte. Speaking to the power of artificial selection, when George W. Beadle of Cornell University first suggested the link, many scientists had trouble believing such a profound physical change could have occurred in only a few thousand years; in fact, rice was first considered to be more closely related to teosinte than to corn.
Corn, which now accounts for over 20 percent of human nutrition worldwide, was far from the only common foodstuff altered and domesticated by ancient cultures. In an even more extreme case of physical change between selectively bred crops, what we now know as broccoli, cauliflower, kale, kohlrabi, collard greens, and Brussels sprouts were all cultivated from the same species of wild mustard plant. Two of the world’s most popular fruit, oranges and bananas, were domesticated in antiquity as well, albeit through forms of hybridization.
Going a step further than simple selective breeding, hybridized crops are defined as the product of breeding two genetically distinct (often on a taxonomic level) crops or animals. Hybridization, however, was not as fully understood, at least in relation to artificial selection, until much later. Known primarily for his work with peas of the species Pisum sativum, Augustinian friar Gregor Mendel famously founded the modern field of genetics. Although farmers were long aware of many general principles behind successful hybridization, as evidenced by the existence of both oranges and bananas, Mendel established what are now known as the laws of Mendelian inheritance between 1856 and 1863, therein bringing an elucidating and statistical approach to humans’ understanding of heredity.
Within several decades, scientists and farmers were consistently experimenting with hybridized crops. By the 1940’s, Mendel’s discoveries helped jump start an agricultural revolution. Building off the work of Italian geneticist Nazareno Strampelli, the United States became one of the first countries to experience widespread adoption of field crop hybrids. Within 25 years of the record low reached during the Dust Bowl, wheat yields had already increased by nearly 250 percent. American Norman E. Borlaug even brought experimental hybrids to numerous developing countries over the course of the next few decades; in Mexico, for example, Borlaug was able to cross a drought-hardy, rust-resistant strain of wheat with a dwarf Japanese strain, producing a high-yield hybrid short enough to survive the wind and redirect that energy into the growth of its grains. Hybrid species of basic cereals were so successful, in fact, that Borlaug is often credited as having saved upwards of a billion lives during India’s Green Revolution. In combination with the advent of pesticides, among other modern farming practices, hybrid crops are largely responsible for feeding the billions of lives on earth today.
Hybridization, however, is not necessarily the epicurean panacea for which many had hoped. Although hybrids of genetically distinct animals or crops are often more genetically diverse than their parents, humans’ tendency to continuously graft or selectively breed the most commercially valuable varieties has contributed to populations of oftentimes genetically identical monocultures. With their defenses inhibited by their genetic similarity, for example, both oranges and bananas have seen devastating diseases spread like wildfire in the past few years, hamstringing production and stifling global supply.
And although widespread commercial hybridization has long had vocal critics—largely due to their susceptibility to disease as monoculture plants—nothing could compare to the global backlash that would come next with so-called GMOs.
It would be misguided to deny that genetic engineering (GE) represents only the latest innovation in our species’ innate desire to optimize our most vital resource, food; it would be equally misguided to believe that it poses no threat to our species’ welfare. Between 1972 and 1974, several breakthroughs in genetic engineering were made by a number of American scientists, such as Herbert Boyer and Stanley Cohen, who developed the toolbox of molecular scissors and glue by which they could extract one gene from bacterium, insert it into a completely different bacterium, and in doing so transfer the molecular mechanism of antibiotic resistance.
The underlying principles of these genetic tools are so fundamental to biological life that by next year scientists had already developed the first GE animals. The process was considered so potentially revolutionary, in fact, that the scientific field scrambled and called for a moratorium on genetic engineering development by organizing an industry-wide conference—later dubbed the Asilomar Conference on Recombinant DNA—to establish a set of framework and guidelines under which further progress should continue.
As powerful as the burgeoning technology was, the involved process was not cheap and in its infancy was prone to failure. To ensure the financial feasibility and promote a wider use of the technology, the United States Supreme Court ruled that scientists could patent GE bacteria in 1980. Thereafter, both the industry and the economy were highly incentivized to continue researching genetic engineering.
It was only two years later that the FDA approved market access for Humulin, a GE form of insulin that no longer required unreliable and potentially impure slaughtered cattle and pigs for production (100 percent of insulin in the US is now genetically-engineered, both porcine and bovine insulin was discontinued in the US in 2006). The same technology has become so ubiquitous, in fact, that recombinant DNA is used to produce nearly every modern vaccine.
The approval of the world’s first genetically-engineered plant fit for human consumption, however, would not come as quickly. Rather, it took the USDA five years of rigorous health and environmental testing before they approved Calgene’s Flavr Savr tomato in 1992. Finally brought to market in 1994, the Flavr Savr possessed genetically-engineered traits that kept it ripe and firm far longer than its unmodified relatives. Despite the innovation, the Flavr Savr did not last long; unfounded rumors (later confirmed by the UK House of Commons) that genetically-engineered crops had caused gut lesions in lab rats quickly eroded any chance of commercial success.
By the time Flavr Savr tomatoes were pulled from shelves, several other GE plants had already reached the market; however, the following wave of GE products were noticeably marketed towards farmers rather than direct consumers. Of note was the first crop engineered to produce a protein from the bacteria Bacillus thuringiensis: a variety called Bt corn which possesses the gene to produce such protein that then acts as a natural defense for the crop against various pests.
Perhaps the most notorious GE crops have been Monsanto’s Roundup Ready varieties, which are engineered to resist strong glyphosate herbicides that might otherwise kill them. Although Roundup Ready crops with sterile "terminator seeds" were never commercially marketed, Monsanto's attempted acquisition of a company which did produce such seeds instantly set off protests in countries such as India. Yet at the same time, Monsanto, among other companies, has also granted royalty-free licenses for GE crops such as Golden Rice—a variety of rice fortified with beta-carotene that is intended to mitigate the 1-2 million deaths caused by vitamin A deficiencies each year.
Until very recently, however, creating GE plants and animals was generally a very imprecise and labor intensive process. With the advent of CRISPR—an acronym for clustered regularly interspaced short palindromic repeats—scientists now possess a previously unparalleled precision in editing the genes of plants and animals. After only a suggestion from a mushroom farmer, for example, biologists at Penn State were able to successfully inactivate an oxidase gene which leads cut mushrooms to brown upon exposure to air. What’s more, given that CRISPR deletes already present genes rather than introducing new DNA from outside the organism, the USDA has already decided that CRISPR-edited genes do not fall under its regulation—calling into question whether these modified crops can or will be grouped together with other GE crops. Any commercial crops created using CRISPR, however, still appear to be years away.
Given the ubiquity of food labels which stress their GE or GMO-free ingredients, consumers might find it surprising that only 29 species of plants currently possess GE varieties. Moreover, the majority of these crops have not been approved in the majority of the only 28 countries which currently grow GE crops. Rather, GE crops are highly concentrated in a handful of countries; 13 of the 28 countries growing GE crops in 2015 grew 0.1 or less hectares of such crops, while the United States, Brazil, and Argentina alone accounted for 140 million hectares, or 75 percent, of global acreage. In the United States, genetically-engineered crops such as corn, soybeans, and cotton now account for roughly 92, 94, and 93% of total US plantings, respectively. Of note, however, is that plantings fell for the first time in history in 2015, from 448.5 to 444.0 million acres that year.
Although record low commodity prices have strongly contributed to this drop in acreage, a growing distaste for GE crops among the public remains the primary reason for such a saturated market. In 2015, a Pew Research poll found that nearly 60 percent of US adults viewed genetically-modified food as unsafe (compared to 88 percent of American Association for the Advancement of Science members who consider them generally safe), while over 90 percent of US adults were in favor of mandatory labeling.
Consumers are generally opposed to GE crops for ecological, economic, or health reasons, and often a combination of the three. For one, genetically-modified plants and animals, if released into the wild, may outcompete their unmodified peers. Pests and diseases have also already displayed an ability to adapt to crops’ genetically-modified defenses; it only took pink bollworms seven years to become resistant to Bt cotton in India (some federal agencies, such as the US Environmental Protection Agency, require farmers to plant a given percent of area surrounding GE crops with non-GE seeds in order to mitigate these risks). Beyond simple pest resistance, there may also be other ecological issues, such as yet unproven theories which indicate Bt corn as a potential contributor to colony collapse disorder in beehives.
Given the recent clamor, President Obama signed bill S. 764 on July 29th of 2016, which included requirements for the labeling of products made with GE ingredients. Yet despite what would appear to be a hard-earned success for food-labeling advocates, many within the movement are up in arms about the federal law which now supersedes Vermont’s recently passed state law; as opposed to the latter legislation, the federal law allows for companies to disclose GMO ingredients through QR codes or 1-800 numbers rather than a clear and uniform label, an obvious extra step for concerned consumers. Regardless of the bill’s intended effects—for which the USDA now has two years to implement—it appears as though public opinion may have already reached a critical mass. In 2016 alone, multinational food processors and producers such as ConAgra, Kellogg’s, Mars, General Mills, and Campbell’s all pledged to begin labeling products that contain GE ingredients.
To completely absolve ourselves of these innovations, however, may engender comparatively, if not equally, dire outcomes. To borrow from above, both oranges and bananas have seen devastating diseases spread like wildfire in the past few years due to their selectively-bred genetic uniformity, among other causes unrelated to genetic engineering. While ensuring diversity among crops should always be a priority, to do so successfully can take decades for some organisms and is highly limited by sexual incompatibility. Furthermore, as climate change becomes increasingly common, GE crops have been cited for their higher yields despite lower chemical use.
Selective breeding has given our species agriculture, civilization, and even our best friend, while hybridization has given us highly efficient crops that have saved billions of lives. Few, if any, would argue that there are no risks associated with genetically-modified organisms, especially with a growing number of genetically-modified plants and animals making their way into our complex and often opaque supply chains. Increased visibility and clear regulatory oversight, therefore, are paramount. Furthermore, educated consumers should always be able to discern and decide whether they wish to consume genetically-modified foods for themselves, regardless of reason.
That is not to say, however, that potential risks should preclude or stifle technological innovation. With an expected nine billion people on earth within the next few decades, such innovation will be both decisive and necessary in feeding our ballooning population. If history is to serve as an example, agricultural innovation and the development of mankind are inextricably linked; as recently as India’s Green Revolution in the 1960’s, the discernable application of these innovations has saved millions, if not billions, of lives. Yet to give a sense of how polarized the issue has become, over a hundred Nobel laureates recently signed a June 2016 letter compelling the environmental NGO Greenpeace to abandon its campaign against GMOs such as Golden Rice on both scientific and humanitarian grounds.
Even if the magnitude of yield increases is debatable, genetically-engineered crops have time and again been proven safe both for human consumption and the environment—most recently in May of 2016 by the independent National Academies of Sciences, Engineering and Medicine. Although the frontier of science has always been met with generally understandable skepticism, human necessity has ultimately dictated the course of our future. With that in mind, a sensible approach to the burgeoning GMO industry appears most fruitful.