The thing with engineered foods is that they are based on the DNA of the organism. A new gene is inserted into the plant's genome. Often, there is an antibiotic resistance gene inserted for selection, which is usually not removed. Monsanto probably won't reinvent this wheel, which is a possible point of argumentation on the part of the anti-GMO folks. However, it's not the gene that is the problem. It's just DNA and it won't survive digestion. It's the protein that the gene is responsible for that poses the issue. That also will not survive digestion in our stomachs.
For the bugs that eat the particular GMO, say GMO corn and corn borers, it attacks a receptor in their stomachs and kills them. If an insect doesn't eat that GMO, it won't be affected, and if it doesn't have that particular receptor, it won't be affected.
Organic growers often use the SAME exact compound to kill pests, except they apply it topically and every time the stuff wears off the leaves, they must reapply, which can involve overspray and more of the compound ending up in the water supply.
In the scenario of the GMO, we are the bioremediators, and we can do this because of the enzymes we have in our stomachs which break down the chemical bonds of DNA and proteins.
In the case of the tomato, these were modified to extend shelf life. In the beginning, the added gene was already native to the tomato, it's just a second copy, inserted in reverse to block the production of ethylene, which causes fruit ripening. Other efforts included truncated versions of the genes that interfered with ethylene production. Monsanto's version eventually started using an exogenous gene, which blocks ethylene production by breaking down its precursor.
The point is that often, these changes are targeted to the altered organism or its predator. They do not produce changes in humans, and cannot survive digestion, thereby making them safe for consumption.
My own concerns stem from the effects on the environment and genetic crossing over. As for the direct environmental impact, I have more concerns with Organics than GMO because of the overspray or overdusting, onto other plants, with different insects. GMOs involve no overspray or overdusting, so they will only affect the target insect.
GMOs carry the possibility of creating a genetic cross or spreading pollen. However, we've noticed that over time, when left alone, the wild type plants tend to take over, and the modified plants somehow die out. There is no real induced evolution. I'm sure there can be some residual plants, but they will eventually be crowded out by the wild type. I'm not sure how this happens, except that it may be along the lines of what Ernst Mayr called the "balance theory" or, termed by I.M. Lerner, "genetic homeostasis."
I'm sure you've read about the rats that grew humongous tumors while eating GMOs and the Monarchs which were affected by corn pollen, and these studies were published. However, there were problems with these studies. In the case of the rats, these rats were engineered to grow tumors. So it wouldn't have mattered if they were fed organics or GMOs, they would have developed grotesque tumors, so this study was pulled by Nature.
As for the monarch butterfly, you can read more about it here. Put on your logic hat and see if you're able to find holes.
I have a different concern, which is not for the monarch butterflies, but for corn borers and other targeted insects. What happens to their populations? Are there regions where they are able to live and feed without losing vast numbers of their population? If not, how does their place in the circle of life affect other species, such as birds, that may feed on them?
I think this is of greater concern with GMOs than the fates of monarchs, which are maximally affected over a period of only two weeks, and depending on the gusts of wind, blowing pollen onto and off of milkweed leaves.
Well, what about RoundUp Ready crops? RoundUp (glyphosate) interrupts a synthetic pathway for amino acids, which is present only in plants and microbes. RoundUp Ready plants have a backup of the enzyme which is blocked by glyphosate, which does not bind to glyphosate. For humans, we still need to wash our fruits and veggies well to clean off many things, including glyphosate and its accompanying chemicals. Read the MSDS for Roundup. Again, the compounds within the plant cells are broken down mechanically, by chewing and by our digestive enzymes.
Once again, we wonder how glyphosate affects the environment around and the water supply. I think there is still research being done, regarding its effects on mammals, as well.
I hope you will find that paying a dollar or so more for your organics isn't really offering you much of a benefit. In fact, while there are downsides to GMOs, one of the first GMOs was Golden Rice, a humanitarian effort, if there ever was one. Other crops are engineered to offer greater supplemental coverage, dietarily. GMOs have led to drug production via bioreactors through E. coli and yeast. Crops are being made that can withstand high salinity soils and drought. Genetic modifications are keeping our favorite and life-sustaining crops from total extinction. Read about the Hawaiian papaya. Let's keep in mind the role of GMOs in fighting hunger.
If you want to support organic growers, choose local and small farmers who are concerned with their impact on the environment. As for GMOs, we need to answer our questions and we need to protect the environment. But, let's not throw the baby out with the bathwater.
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