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GMOs in 2015

by Trevor Sorrells

The public understanding of genetically modified organisms (GMOs) remains lower than any other mainstream scientific concept (even lower than evolution and climate change). As a scientist, I chose to write about three events from the last year that have shaped the way I think about GMOs.    

In April, Chipotle announced that they would eliminate GMOs from their products. Although this announcement resulted in a lot of publicity for the company, it was at the expense of public knowledge. The company deliberately misrepresented the scientific consensus on GMOs (the consensus is that they are safe) and also continued to use GMOs, resulting in a class-action lawsuit. Just as oil companies used anti-intellectualism and pseudoscience to mislead Americans for years about climate change, the same is happening for GMOs.

In May, scientists published a surprising finding: that sweet potatoes are natural GMOs. The same technology that is used to make transgenic crops (a bacterium called Agrobacterium tumifaciens), was found naturally occurring in the genomes of all sweet potatoes, which are eaten by millions of people worldwide. This means that sweet potatoes have been making bacterial proteins since their domestication more than 8,000 years ago.

This finding is problematic for enthusiasts of labeling GMOs, and demonstrates that the definition of GMOs is nearly impossible to pin down. Would we label all sweet potatoes as GMOs even though they have been that way for thousands of years? The sweet potato has functional bacterial genes in its genome, whereas the Flavr Savr tomato simply makes less of a tomato gene. The diversity in actual biological mechanism of transgenes is nearly as broad as the diversity in mechanism of traditional breeding methods that rely on random mutations. Singling out GMOs for labeling demonstrates a misunderstanding of how food crops are developed for human consumption.

In November, the Food and Drug Administration approved the first GMO animal for human consumption, the AquAdvantage salmon. Created in 1989, the salmon was under regulatory evaluation for nearly 20 years. Scientists took a region of DNA from the ocean pout that turns on a growth gene from the Chinook salmon, and inserted it into the Atlantic salmon genome. The result is that the salmon grows faster than typical farmed salmon. These farmed salmon have already been bred using traditional breeding to alter their genetics to grow faster.

One common criticism of GMOs is that they combine genes from different organisms to create “frankenfoods” with unknown properties. This argument usually reflects a lack of understanding of basic biology and an attempt to brand GMOs as scary. In the case of the AquAdvantage salmon, the gene that was added was from a related species of salmon. This gene already exists in the Atlantic salmon; adding another copy simply makes more of it. As a scientist who studies how evolution alters the “amounts” of each gene that an organism makes, I can verify that this is common, and in simple examples involving a single gene, we understand how it works.

Another criticism often brought up is that the salmon could disrupt the ecology of wild salmon if they escape, either by interbreeding with them or competing with them for food. Again, evolution can easily alter the expression of these genes in the wild, and so if more of this growth hormone conferred a competitive advantage, it is likely the salmon would already have evolved this trait. It is much more likely that the AquAdvantage salmon would die because their life cycle is not adapted to the environment. Furthermore, the AquAdvantage are engineered to have three sets of chromosomes, so they are sterile and cannot interbreed with wild populations or reproduce at all.

Despite their potential to reduce world hunger, GMOs are often vilified for illogical reasons. It is the responsibility of the media and of scientists themselves to combat public ignorance of science.

Article originally published on Medium here

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