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THE GMO DEBATE: Traditional Crop Breeding and GMOs: Are They Mutually Exclusive?

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Although not an expert, I am impressed to add my views to the GMO debate after the court in Nigeria recently dismissed a case brought by somegroups against the introduction of Genetically Modified Seeds into the Agriculture Sector. What exactly are the issues with GMOs? I will refer to a few articles that have discussed this issue and also express my two pence

Traditional Crop Breeding and GMOs

Breeders identify certain traits and conduct research to see if they will be stay dominant in subsequent generations. They had and have in the process identified certain traits such as disease resistance when other similar crops were infected; bigger cobs and grains as compared to others, larger tubers; bigger fruits or seedless fruits etc. and bred to see if these traits will be carried to the next generation.

“The human race has been selectively breeding crops, thus altering plants’ genomes, for millennia. Ordinary wheat has long been strictly a human-engineered plant; it could not exist outside of farms, because its seeds do not scatter. For some 60 years scientists have been using “mutagenic” techniques to scramble the DNA of plants with radiation and chemicals, creating strains of wheat, rice, peanuts and pears that have become agricultural mainstays. The practice has inspired little objection from scientists or the public and has caused no known health problems” (David Freeman)

The difference is that selective breeding or mutagenic techniques tend to result in large swaths of genes being swapped or altered. GM technology, in contrast, enables scientists to insert into a plant’s genome a single gene (or a few of them) from another species of plant or even from a bacterium, virus or animal. Supporters argue that this precision makes the technology much less likely to produce surprises. Most plant molecular biologists also say that in the highly unlikely case that an unexpected health threat emerged from a new GM plant, scientists would quickly identify and eliminate it. “We know where the gene goes and can measure the activity of every single gene around it,” Goldberg says. “We can show exactly which changes occur and which don’t.”

Explanation by David Freedman

Genetically Modified and Genetically Engineered – What’s the difference?

Genetically engineered and genetically modified are often used interchangeably when referring to varieties of crops developed by means other than traditional breeding. Genetic modification refers to a range of methods (such as selection, hybridization, and induced mutation) used to alter the genetic composition of domesticated plants and animals to achieve a desired result. Genetic engineering is one type of genetic modification that involves the intentional introduction of a targeted change in a plant, animal, or microbial gene sequence to achieve a specific result.

There is a scientific consensus that currently available food derived from GM crops poses no greater risk to human health than conventional food,but that each GM food needs to be tested on a case-by-case basis before introduction.Nonetheless, members of the public are much less likely than scientists to perceive GM foods as safe.The legal and regulatory status of GM foods varies by country, with some nations banning or restricting them, and others permitting them with widely differing degrees of regulation (Wikipedia)

BENEFITS AND WORRIES

The bulk of the science on GM safety points in one direction. Take it from David Zilberman, a U.C. Berkeley agricultural and environmental economist and one of the few researchers considered credible by both agricultural chemical companies and their critics. He argues that the benefits of GM crops greatly outweigh the health risks, which so far remain theoretical. The use of GM crops “has lowered the price of food,” Zilberman says. “It has increased farmer safety by allowing them to use less pesticide. It has raised the output of corn, cotton and soy by 20 to 30 percent, allowing some people to survive who would not have without it. If it were more widely adopted around the world, the price [of food] would go lower, and fewer people would die of hunger.” (David Freedman)

In the future, Zilberman says, those advantages will become all the more significant. The United Nations Food and Agriculture Organization estimates that the world will have to grow 70 percent more food by 2050 just to keep up with population growth. Climate change will make much of the world’s arable land more difficult to farm. GM crops, Zilberman says, could produce higher yields, grow in dry and salty land, withstand high and low temperatures, and tolerate insects, disease and herbicides.

And although it might seem creepy to add virus DNA to a plant, doing so is, in fact, no big deal, proponents say. Viruses have been inserting their DNA into the genomes of crops, as well as humans and all other organisms, for millions of years. They often deliver the genes of other species while they are at it, which is why our own genome is loaded with genetic sequences that originated in viruses and nonhuman species. “When GM critics say that genes don’t cross the species barrier in nature, that’s just simple ignorance,” says Alan McHughen, a plant molecular geneticist at U.C. Riverside. Pea aphids contain fungi genes. Triticale is a century-plus-old hybrid of wheat and rye found in some flours and breakfast cereals. Wheat itself, for that matter, is a cross-species hybrid. “Mother Nature does it all the time, and so do conventional plant breeders,”.

Could eating plants with altered genes allow new DNA to work its way into our own? It is possible but hugely improbable. Scientists have never found genetic material that could survive a trip through the human gut and make it into cells. Besides, we are routinely exposed to—and even consume—the viruses and bacteria whose genes end up in GM foods. The bacterium Bacillus thuringiensis, for example, which produces proteins fatal to insects, is sometimes enlisted as a natural pesticide in organic farming. “We’ve been eating this stuff for thousands of years,” Goldberg says.

In any case, proponents say, people have consumed as many as trillions of meals containing genetically modified ingredients over the past few decades. Not a single verified case of illness has ever been attributed to the genetic alterations. Mark Lynas, a prominent anti-GM activist who in 2013 publicly switched to strongly supporting the technology, has pointed out that every single news-making food disaster on record has been attributed to non-GM crops, such as the Escherichia coli–infected organic bean sprouts that killed 53 people in Europe in 2011. (David Freedman)

Most scientists would say that almost all the food we eat has been “genetically modified” by man and that genetic modification includes not only conventional breeding, but simple selections man has made over millennia. Carrots were not orange until the 1700’s and tomatoes used to be the size of marbles. Corn used to have very small ears and kernels with hard seed coats and low digestibility. (See picture below from NSF).

NSF (Keith Edmisten)

Genetically modified food would include almost all the food we eat. Several different way plant genomes are altered “conventionally” and via genetic engineering are described here. Genetic engineering is the direct manipulation of an organism’s genome using biotechnology. Although many people think this means moving genes from one species to another, that is not always the case. There are several biotechnological methods of manipulating genes. Sometime this is done by actually moving genes within a species or from a closely related species. This resulting organism is referred to as cisgenic.

Gene editing is another method of manipulating DNA. There are several techniques available for gene editing including zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and the clustered regularly interspersed short palindromic repeats (CRISPR)/Cas systems. Gene editing may involve deletion, insertion, silencing or repression. The resulting organism from gene editing is called subgenic. The type of genetic engineering that the public is most likely familiar with is transgenic. This is where a gene is moved from one non-closely related species to another. Cisgenic changes to DNA would also be possible through conventional breeding, while transgenic changes to DNA are not possible via conventional breeding. (Keith Edmisten)

Both GMOs and GE foods have several advantages in strengthening the global food supply, including pest and disease resistance, herbicide tolerance, drought tolerance, cold tolerance and higher crop yields. The nutrition of certain foods can also be boosted, as in the case of golden rice, which has been genetically engineered to include more beta carotene (vitamin A); this offers more nutrition to populations who face a higher prevalence of malnutrition.

According to the FDA, GMOs and GE foods meet the same safety standards as foods from non-engineered crops and have been evaluated for toxicity, allergenicity and long-term safety; as of now, there are no GMO or GE foods on the market that do not meet these standards. Still, some critics argue that GMOs and GE foods have contributed to the increasing prevalence of allergies and that there may be human health risks that we don’t yet know about. Others suggest that there are hazards to the environment and its ecosystem: The use of GMOs and GE foods may cause unintended harm to other organisms; gene transfer to an unintended species may occur, unintentionally modifying that species genome; and pesticide resistance may develop.

Conclusion

Mutations occur spontaneously in nature without human intervention and identifying these changes has been the basis for conventional crop breeding. I remember conducting a study in 1987 on the colors of maize as my first degree research project. It was interesting to find purple seeds and red seeds in white maize cobs and taking them to a second generation to see if these colors will be dominant, also crossbreeding various colors to see what will happen in the next generation. This hasbeen the basis of conventional crop breeding.

Nigeria is the largest producer of yam tuber in the world, however, yield is 11 tons per hectare whereas Mali a neighboring country and Japan record yields of 22 tons per hectare. The difference comes from technology. In Nigeria yams are planted using yam setts from harvested tubers which still carry diseases and limitations from the parent stock. In Japan and Mali yams are planted using vines produced through biotechnology (hydroponics and aeroponics). They are disease free, higher yielding with better starch content. IITA and BiocropsNigeria (a private based biotechnology company) based in Abuja Nigeria are spearheading the transition using biotechnology to produce vines for yam production which should transform the yam value chain and make them to be more acceptable for export.

My Two Pence

  • Does GMO change maize, tomato, yam etc. from being what they are? Was any of the nutrients in these crops lost due to genetic modification? The only available answer for now is NO!
  • With the world population on the increase and challenges of food shortages; Are new technologies not the solution to rapidly produce food? The only answer available for now is YES! – The US Military uses Hydroponics and Aeroponics to produce food for their men in war zones to optimise the little space available and also to save cost of logistics of importing food into war zones for its officers. (Diamantis& Kotler)

There are people who are afraid of the effect of genetic modifications in the future. I think these fears are unfoundedbut have been hyped by Hollywood science fiction movies where plants become monsters and start attacking people. These are fictions and money making scams. Genetic modification in crops are as old as mankind, technology has only helped to speed up the process as against conventional breeding that takes years of research and confirmation.

I think activists should stop crying wolf where there is none and come up with better solutions if they have one. We have a hungry world to feed!!!

REFERENCES

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