Genetic Engineering – Definition, History, Benefits and Risks

Categories Science


Advances in genetic engineering have revolutionized medicine for decades; helping us to better understand biological processes, improve disease diagnosis, treat several diseases and conditions, and develop a wide range of vaccines.

When it comes to food and agriculture, however, the development of genetic engineering and proliferation of Genetically Modified Organisms (GMOs), is often clouded in confusion, fear, and an instinctual reflex to protect our food. This is probably because of a lack of clear understanding of GMOs and the inability to separate fact from myth.

Proponents see the potential benefits of genetic engineering traversing sectors like agriculture, health, industry and environment. They are convinced that GMOs can provide food to the 800 million food-insecure people around the globe. They believe that GMOs can mitigate most of the challenges faced by developing countries, which are manifested through increasing population, food shortages, declining nutritional levels, inadequate health care, environmental degradation, and declining industrial development.  They argue that the increased yields of genetically modified crops, animals and other organisms can boost incomes and living standards.

In agriculture, proponents see genetic engineering  helping to improve the understanding of diseases, improving the diagnosis and treatment of diseases, improving resistance to herbicides/insects/diseases, improving crop and animal varieties and yields, developing new uses for agricultural products, facilitating early maturation and improving food and feed nutritional value. They also see other potential benefits in agriculture, including reduced labor and capital inputs, improved environmental protection and strengthened rural economies.

Opponents, however, have concerns pertaining to genetic engineering, which they perceive to impact on the physical environment; human and animal health; values and norms; the ownership and control of and access to genetic resources; the livelihood, economic and social future of the poor; and, intellectual property rights.

At the moment, about twenty nine species of plants and quite a few animal species possess genetically engineered varieties. But majority of these varieties have not been approved for marketing in the majority of the approximately twenty eight countries which currently grow genetically engineered crops.

This article is the first of a series of four that discuss genetic engineering. It aims at shedding more light on what GMOs are, the history behind their development, what proponents consider as their benefits, and what opponents view as their potential risks.


A genetically modified or engineered organism (GMO) is any plant, animal, or microorganism whose genetic make-up (otherwise called DNA) has been manipulated by scientists to give the plant, animal or organism a characteristic that it does not normally or naturally have.

Genetic engineering is a painstaking step-by-step process whose main objective is to introduce useful or beneficial genes or traits into the plant, animal or organism. It involves identification of genes of interest, isolation of these genes, transformation, regeneration, verification, performance-testing and finally safety or risk assessments.

The manipulation of biological systems, living organisms or their components, by means such as genetic engineering, to develop useful agricultural, industrial, environmental, or medical technologies and products intended to improve the quality of human life is called modern biotechnology.

The term “modern biotechnology” is used to distinguish recent, research based activities from traditional fermentation technologies such as bread, cheese or beer making, and animal and plant breeding, which were the first examples of biotechnology.


Humans have been biotechnologists for thousands of years. Many years before the advent of modern biotechnology, farmers developed improved species of plants and animals by cross-pollination or cross-breeding. They did this by artificially selecting seed from plants or domestic animals that flourished best. As each generation of crops or animals passed, their traits became more pronounced in their offspring, resulting in bigger, more plentiful production. This process is otherwise called selectively breeding for desired traits. Entrepreneurs of those ages also created beer using yeast.

Selective breeding, also called artificial selection, was closely followed by hybridization, which is forced mating of uniquely or genetically different crops or animals (some of us may remember the grafting of orange and lemon plants). Hybridization helped to jump-start an agricultural revolution where scientists and farmers were constantly experimenting with hybridized crops. It was the technology which produced the higher-yield hybrid seeds which were behind the Green Revolution of the 1970s and 1980s.

Corn, rice, broccoli, cauliflower, kale, kohlrabi, collard greens, oranges, peas, bananas and Brussels sprouts were all altered through selective breeding, and sometimes hybridization, and domesticated.

Hybridization did not, however, provide the solution which many had hoped for. Although hybrids of genetically distinct animals or crops were often more genetically diverse than their parents, humans’ tendency to continuously graft or selectively breed the most commercially valuable varieties contributed to populations of oftentimes genetically identical monocultures which were more susceptible to diseases because their defenses were inhibited by their genetic similarity.

The advent of genetic engineering (GE) represented the latest innovation in human’s desire to optimize our health and sources of food. Genetic engineering is not entirely different from selective breeding, except for obtaining desired results through genetic manipulation by scientists instead of breeding.

By 1975, scientists had already developed the first genetically engineered animal. In 1982, the Food and Drug Administration (FDA) of the Unites States (US) approved market access for a genetically engineered form of insulin that no longer required unreliable and potentially impure slaughtered cattle and pigs for production. Today, genetic engineering is used to produce nearly every modern vaccine.

Then in 1994, FDA approved the marketing of the first genetically-engineered plant fit for human consumption, the Flavr Savr tomato, whereby scientists had altered and spliced the DNA of a tomato with fish DNA to give it a longer shelf-life and make it last longer without being frozen.

What followed after 1995 was the GMO revolution where land cultivated with GMOs had increased to over 222 million acres, fifty-five percent of these acres represented in the US.

Benefits of GMOs, as perceived by the proponents

Genetic engineering has created more robust plants and animals which may have the impact of enhancing food security and poverty alleviation, and reducing food prices.

Some plants and animals have been genetically engineered to be drought-tolerant, meaning that they will do well even in areas with scarce water resources.

Others have been genetically engineered to be pest-resistant; examples being the GM corn, soy, and cotton plants where a gene from a bacterium, Bacillus thuringiesis (Bt), has been introduced. The effect is that these plants produce an insecticidal protein or toxin which is harmful to pests but not to human beings. Crops that produce this toxin require fewer applications of pesticides, such as the weed killer Roundup, which may help to protect the environment.

Genetic modification has also produced plants and animals that are disease-resistant, whereby a gene from certain viruses are introduced into the DNA of plants or animals, which, in turn, become resistant to the virus, almost like vaccinating the animal or plant.

Some plants have been genetically engineered to become herbicide-resistant; in which case a gene is introduced into them which provides the crops with the ability to resist herbicides that might otherwise kill them. That means that the farmers can use some herbicides to kill weeds without harming the crops.

Some crops have been genetically engineered to possess minerals and vitamins, or healthful oils like Omega-3, through a process called bio-fortification; an example being Golden Rice, which is a variety of rice fortified with beta-carotene. The intention is to mitigate the human deaths that are caused by vitamin A deficiency. Fortification of staple foods would ensure that people receive the important nutrients they need, which would solve most problems that arise from malnutrition.

Some crops, like peanuts, have also been genetically engineered to reduce the level of allergens in them and provide protection for people who portray allergenic reactions.

Genetic engineering has produced micro-organisms that are used for environmental management such as waste recycling; including the use of bioreactors in manufacturing, micro-organisms to degrade oil slicks or organic waste

Genetically engineered bacteria are today used to produce human drugs, hormones, and monoclonal antibodies to identify antigens.

Potential risks and concerns, as perceived by the opponents

Since genetically engineered plants, animals and micro-organisms have only been around for about twenty four years, the following ecological, economic, or health concerns remain relating to their use, especially because research on their long-term effects on the human body, and on the ecology is still deemed insufficient:

Are GMOs safe to eat? Critics are concerned that by mixing genes from totally unrelated species, genetic engineering introduces proteins that aren’t natural to the original plant or animal, which may cause new, unpredictable toxicity and allergic reactions in the human body. Each of their studies, however, has been rebutted by the global scientific community.

The numerous studies carried out so far by independent researchers indicate that there is no evidence showing that genetically engineered crops and animals are substantially different from their unmodified counterparts and, therefore, they are safe to eat.

According to the World Health Organization (WHO), “GM foods currently available on the international market have passed safety assessments and are not likely to present risks, including allergic effects, for human health.” WHO, however, emphasizes that continued research, vigilance and assessment for safety is necessary to understand the long-term effects of these genetically altered foods.

Do GMOs have a negative effect on the environment and ecosystem? When it comes to genetically engineered plants, animals and other organisms (GMOs) and the environment, the issues of concern include: the capability of the GMO to escape and potentially introduce the engineered genes into wild populations; the persistence of the gene after the GMO has been harvested; the susceptibility of non-target organisms (e.g. insects which are non-pests) to the gene product; the stability of the gene; the reduction in the spectrum of other plants including loss of biodiversity; and, increased use of chemicals in agriculture.

Environmentalists are concerned that genetically engineered crops can harm non-target species such as birds, insects, amphibians, marine ecosystems, soil organisms and pollinators like bees and butterflies, thereby reducing bio-diversity and polluting water resources. They are concerned that, since some crops are engineered to be “herbicide tolerant”, it increases herbicide use. Overuse of herbicides has deleterious effects on non-target species, in addition to resulting in “super-weeds,” resistant to the herbicide, which in turn causes farmers to use even more herbicides. Not only does this create environmental harm, but also results in the genetically engineered foods containing higher levels of residues of herbicides. The GM plants may even pass on their herbicide-tolerant genes on to weeds.

Another concern by environmentalists is introducing what are essentially “super-crops” into the environment. They are worried that a GM crop is essentially just like an invasive species, which, through cross-pollination, seed drift and accidental reproduction in the wild, can run rampant throughout the environment, showing up on lands where farmers never planted them. The result is that the gene pool becomes contaminated and it becomes harder to find organic, naturally-occurring non-GM crops; even after creating buffer zones to segregate GM and non-GM plants as recommended by scientists.

Is Government regulation of GMOs inadequate? The safety and risk assessment process is a critical issue to the consumer. Government regulatory agencies evaluate, through a comparative analysis, food from genetically modified plants or animals to ensure that it is not any different from that derived from their non-genetically modified counterparts; that it carries the same risks and benefits; and, that it’s healthy for consumption. They investigate the functional consequences of the genetic modification, both intended and unintended, and perform toxicological, allergy and exposure assessments.

But critics still contend that the oversight by Government regulatory agencies worldwide is lax; that regulatory bodies ignore health and environmental risks of GMOs before the release of a GMO product into the market and that regulations and safety assessments are superficial. This is one of the reasons why stakeholders demand for labeling of GMOs.

My References

  1. What are GMOs and How Did They Get Here?
  2. The Great GMO Debate

Other articles in this series

  1. Genetic Engineering – The Great GMO Debate
  2. Genetic Engineering – Recent Advances; the Promise of Tomorrow
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