The Great GMO Debate

Depending on who you ask, GMOs are going to kill all of us slowly, turn us into bizarre Frankenstein monsters, or end world hunger.  However, amid all the hullabaloo, what actually is a GMO, how are they made, and why does everyone care about them?

GMO stands for “Genetically Modified Organism”, which is a remarkably vague name. Natural selection results in genetic modification, as does cross-breeding of plants, and selective breeding of animals for preferred genetics. So, what GMO actually means is an organism whose genetics were modified in a lab using molecular biology techniques as opposed to good old cross-breeding or selective breeding. This actually is more precise and therefore less disruptive to the crop’s DNA (1).

But doesn’t this mean that scientists are sticking fish genes in fruit or something? Not exactly. There are only 30 approved GMO crops worldwide. Of these, most are modified to be tolerant to herbicides or resistant to pests. A few are engineered to be drought resistant, and a couple have had their genes tweaked so they’ll ripen more slowly. Even fewer GMOs are approved in the U.S. The genes behind this often come from insects or bacteria–which may seem unnatural, until you realize that a good chunk of bacterial–and our–genomes come from viruses. The same goes for plants. So there’s already a lot of cross-kingdom gene swapping going on.

So what are the potential benefits of GMOs

  • Reduce world hunger by enabling crop growth in drought-prone areas
  • Reduce pesticide use: For example: this tweet-– “Great discussion at @FoodAgLiteracy on how GM eggplant reduced pesticide use 75-90% in Bangladesh. #FoodAg2018 @ucdavis”
    • This is important because developing economies may overuse pesticides, causing neurological damage to the farmers. For instance, in Afghanistan, where many farmers are illiterate, farmers “guesstimate” the pesticide dilutions and develop severe neurological conditions at a young age (as observed by my adviser).

Potential downsides:

  • GMO crops can’t always naturally propagate, so farmers have to buy new seed each year (however, GMO crops may have a higher yield to offset that).
  • Potential negative health consequences over the longterm????
    • This has not been shown over multiple studies of multiple GMOs in animals (2)
  • High use of GM crops with insect resistance (such as bt corn) can select for resistance in the insects (3).
  • Use of Roundup-resistance crops has lead to the development of roundup-tolerant weeds, leading to heavier application of roundup to counteract these weeds.
  • Many foods are labeled as “non-GMO” even if there aren’t any GMO versions available. This is similar to labeling of strawberries as “gluten free”
  • A number of states have instituted labeling for GMOs, caving to pressure from health advocates/anti-GMO advocate

 

Further reading:

(1) Genetically modified organisms: http://www.bt.ucsd.edu/gmo.html

(2) Harvard roundup of the research on whether GMO’s are harmful.  http://sitn.hms.harvard.edu/flash/2015/will-gmos-hurt-my-body/

(3) Pesticide resistance: http://www.bt.ucsd.edu/gmo.html 

https://well.blogs.nytimes.com/2015/06/08/fears-not-facts-support-gmo-free-food/

 

 

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