Genetic manipulation of the food supply has been like that of a pyromaniac having found a box of matches. No human attempts at altering Nature have ever gone without unexpected consequences.
Pesticides, and even synthetic fertilizers, are excellent examples. Chemists did not anticipate the biological and environmental damage that they had brewed and set loose. It took decades to discover their folly.
In the US, 33% of all drugs approved by the FDA are later found unsafe. Commercial and public service chemists are unable to establish safety for chemical compounds explicitly and extensively tested for their health effects.
In creating genetically modified organisms, geneticists have been proceeding with much less surety in their foundation of comprehension than those chemists did.
To date, all genetic modifications have been to introduce a single gene package into an organism. Geneticists know next-to-nothing about the functional interrelationships between genes, or even the dynamics within a single gene complex. What is being discovered is that genes have intricate, unexpected relationships.
Even more damning is that geneticists understand little about genomes, period. Genetic modification efforts to manipulate insect pests have failed.
Small genetic variations within species can seriously impact the effectiveness of attempts using genetic technology. ~ American biologist Michael Wade
Due appreciation of the importance of epigenetics – intricate changes in the employment of genes – is recent and remains a crucial variable outside geneticists’ control.
All mechanisms are interrelated. Epigenetics are responsible for a considerable part of the phenotype of complex organisms. ~ American molecular biologist Gary Felsenfeld
Moreover, geneticists do not know how microbiomes work with host cells, and how those interactions affect the host genome. Healthy microbiomes are essential to the lives of macroscopic animals. Artificial genetic modifications necessarily involve setting off dynamics with unknown consequences.
It is known that gene editing is a stress which may cause cells to reject the injected mutagens. As CRISPR is derived from bacteria, immune systems may attack gene edits as foreign agents.
Accurate gene editing is problematic. Edits may target the wrong sites. Even if properly placed, a gene edit can affect DNA in a distant location via unknown interactions. CRISPR can cause large chunks of the chromosome to rearrange itself.
CRISPR editing works more efficiently in cancer cells than normal cells, which rightly resist the interference. Geneticists have yet to discover that gene editing incites cancer in animals, but such a finding would be unsurprising given its disruption.
That genetic manipulation would somehow be exempt from negative environmental side effects is unimaginable. That does not matter. Proceeding with speculative ventures is a sine qua non of human behavior – economists celebrate risk-taking exuberance as entrepreneurship. The point is that profiteers simply don’t care about anything but profiteering – genetics may be complex, but commercial motivation is quite simple. As the touted technological edge in industrialized agriculture, GMOs benefit the promoting chemical companies and food producers rather than consumers, who pay whatever the costs turn out to be.
Herbicide-resistant GM strains have engendered excessive use of herbicides – a known peril over an unknown peril. Evolutionary reaction by the weeds under threat ensures that the war will only escalate.
Strong selection pressure exists for the evolution of glyphosate-resistant weeds because management tactics vary so little between crops. ~ US National Research Council
Conversely, Bt GMO has facilitated using fewer pesticides. Less spraying has allowed arthropod predators to survive, thus affording natural pest control that otherwise would not be available. Meanwhile, consumers eat the toxins geneticists build into the food crops.