What is genetic modification/genetically modified organisms (GMOs)?

Genetic modification is an alteration in the DNA sequence or the genes of any organism (including animals, plants, and bacteria).  All organisms have genetic material, either DNA (deoxyribonucleic acid) or RNA (ribonucleic acid).  DNA and RNA are made up of repeating structures called nucleotides, and DNA and RNA make up genes.  These genes “code” for different traits, which can be physical, behavioral, etc.  Genetic modification changes that DNA in some way to produce a desired trait.  They do this in a few ways; one way uses a “gene gun,” which inserts a gene into a sequence.  Another uses viruses that are created to go into a cell and inject genetically modified DNA instead of their viral RNA.

What is the controversy?

While genetic modification has been used widely in bacteria and even some animals for laboratory experiments, the controversy comes from the use of GMO’s in agriculture.  For example, the common complaint is against Monsanto, a large corporation who patented “RoundUp,” an herbicide that is meant as a weedkiller.  Then, they modified and sold plants that were RoundUp-resistant and made a lot of money off of it, which many people find problematic.

There are a few other problems that people have with GMO’s.  Natural writes, “In sum, genetic engineering artificially combines genes from different species and forcibly inserts them into unknown and random locations on the host genome. The procedure, which disrupts the precise orchestration of thousands of genes that has evolved over millennia in the normal plant’s genome, is highly mutagenic. (We now know that genes, like nutrients, do not work singly, but as part of highly integrated networks.) Plus it introduces bacterial genes for drug resistance along with strong promoters to express the foreign proteins at high levels in all parts of the plant.”

What does science say?

Genetically modification is actually not a new concept.  Humans have been altering the DNA sequence of plants and animals through selective breeding for thousands of years.  Selective breeding is when people identify a certain trait that is desirable, and then they breed other individuals in that species with the individual that possesses that trait, in order to spread that trait to the rest of the population.  The end result is similar to genetic modification: humans change the proportions of traits in a population.

Natural seems to use a lot of rhetoric in their post, such as genes are being “forcibly inserted.”  When genetic modification is done correctly, and it has been done correctly, the results are exactly what we want to see.  It can be problematic when genetic modification is not done correctly, but when it is, the results are incredibly beneficial.  For example, vitamin A deficiency in some developing countries is a huge problem.  Therefore, using genetic modification, scientists developed golden rice, which is rice that has been modified to include beta-carotene.  This gives the golden rice more vitamin A to combat these nutritional problems.  Another example is biofuels; sorghum can be modified to weaken the cells wells to make it easier to break down for biofuels, which makes biofuels even more efficient.  Finally, some of the most widely known benefits of GMO’s are benefits to agriculture.  Because genes for insecticide and pesticides are inserted into genes, it reduces the use of pesticides on the outside, which can seep into the soil and cause problems with surface runoff.  GMO’s have a similar benefit with fertilizer and water; if we can genetically modify plants to be drought-resistant or to need less fertilizer, we can solve many pressing global issues.

Common Misconceptions

(1) Round-Up is toxic and can harm humans.  Round-Up is a chemical called glyphosate, which is a polar substance.  This means that the molecule has areas of positive charge and areas of negative charge.  However, when toxic chemicals build up (or bioaccumulate) in our bodies, they do so in fatty cells, which are very nonpolar.  When it comes to polarity, like dissolves like, so glyphosate would not bioaccumulate in these fatty cells due to polarity.  Therefore, it is, for the most part, simply excreted through urine and therefore does not harm humans.

Obviously, ingesting chemicals can be harmful, but this is more an issue with the use of fertilizers and pesticides in general, rather than an issue with genetically modified organisms.  Many argue that our diversity, key species, and the soil is harmed by herbicides or pesticides, but this is not because of GMO’s, but a wider problem.

(2) Joining plant genes with genes from organisms is not natural.  This may be true, this would never happen in nature.  However, the genetic makeup of DNA is exactly the same between these domains (a nucleotide guanine in one is the same as a guanine in the other).  Additionally, it is important to remember that these genetic materials are still related, just very distantly.  Since all organisms are derived from one common ancestor, plant and bacterial genetics are related.

It is important to keep in mind that genetic modification CAN be harmful if done incorrectly.  However, when done carefully and by experts, it can be a powerful tool for preserving our environment, reducing our destruction of ecosystems, and helping us feed a growing world population.

Please feel free to ask questions in the comments and I will try to do some research and answer them!



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