Nature has been radically modifying living things for billions of years. Natural descent with modification is responsible for a huge chunk of our dazzling biosphere, a tiny portion of which is shown above and well worth watching! But a Genetically Modified Organism, or GMO, is usually defined as any critter whose genetic material has been intentionally altered using genetic engineering techniques recently developed by humans. GMOs are by no means limited to plants. Similar techniques have been used on everything from microbes to fish and future applications may soon be developed for other creatures. Whether or not we have the methods to do what amounts to highly delicate nano-surgery on all sorts of creatures is another matter, and whether or not we have the wisdom to manage it safely is part of what concerns us today.
One of the first genetically modified organisms that found a critical commercial use was not a plant or a seed and it wasn't created by Monsanto or in secret U.S, bioweapons labs. It was a bacterium, and that genetic change made way back in the mid-1970s would dramatically improve countless lives and come to define a new technology. More on this and genetic modification in general, below the big orange fold.
Humans have recently learned to alter some some genomes in the last few millennia, but nature has been doing it since life first arose in a long lost primeval ocean or scalding pool brimming with toxic carbon compounds billions of years ago. It's called descent with modification, aka evolution, officially defined as a "change in the frequency of alleles—versions of genes—in a population over time." There are two main ways nature introduces novel genes into an individual organism that are of interest here: mutation and viral transfer.
The structure of the DNA double helix. The atoms in the structure are color-coded by element and the detailed structure of two base pairs are shown in the bottom right.
Mutation happens when one or more of the units that makes up a gene, which we'll call a base pair for now, is changed or deleted. Astute readers will recognise transfer as a subset of mutation. It happens when another organism like a virus—or in a wider context a sex cell—picks up some base pairs, particularly from another species, and later transfers those base pairs into another genome. Deleting or adding just a single base pair can cause an
enormous change. But most of these natural mutations are moot; they cause no change at all in the form or function of the organism. A biologist would say they change
genotype but not
phenotype, or in biology-lingo, they're not
expressed.
Most of the mutations expressed in the phenotype disrupt function, and can wound the organism mortally, or at least put it at a disadvantage. But every now and then a new gene arises that confers an advantage in mortality or fertility on the lucky recipient. Natural selection then favors that new genetic sequence, it can become widespread in the population over subsequent generations, and voila, evolution marches on!
Evolution conserves what works. Over billions of years encompassing trillions of generations, these changes added up and simple bacteria became a more complex organized collective of microorganisms. Some joined with others inside a single membrane, each adopting specialized roles. The video below provides a rare glimpse into the intricate workings of one such super-cell. This transition from simple to complex microbes took longer in years, and many times longer in generations, than the transition from tiny worm-like animals half a billion years ago to human beings today.
Not long after our species first appeared over 100,000 years ago, anatomically modern humans, probably unconsciously at first, began selecting for plants and animals they liked the most. After artificial selection replaced old-fashioned natural selection, the form and function of those desired plants and animals deemed useful to people exploded. Within just a few thousand years, dozens of plants and animals had been so modified by humans that some of our ancestors could stop hunting and gathering, and could settle down into the first city-states subsisting on farming and ranching. The rest is literally history.
It's only been in the last few decades that we hit on an even faster, albeit more controversial, method for modifying living things: direct genetic engineering. It's a science in its infancy. Some of the early creators of GMOs include ConAgra and Monsanto, but their products are already included in everything from cereal to chocolate.
But a gene is made of DNA, a structure so tiny and so delicate that it cannot even be seen with traditional microscopes, let alone operated on with clamps and scalpels. The only way to insert or remove genes at that microscopic level was to use existing chemical tools that snip apart or zip together pieces of genetic material. Which brings us back to the tiny organism that kicked this essay off.
In the 1970s, scientists working with the bacteria E. coli were able to take advantage of a feature called a plasmid. A plasmid can be crudely thought of as the "CD drive" to the bacterium's genomic "hard drive." If scientists could tease a foreign gene into the plasmid, it might be "downloaded" into the organism's central genome and go on to be expressed. After much trial and error, a micro-biologist named Herbert Boyer was able to snip out the gene for human insulin and zip it into a plasmid, where it was transported into the E. coli's chromosomes and began producing insulin.
The only other source of insulin for many years, outside of a human corpse, came from animals. It worked okay for the majority of diabetics, but animal insulin sometimes came with residual proteins and microbes that could cause fatal allergic reactions or infections in some users. A diabetic who can't use insulin will, sooner or later, face a lingering, painful death. The advent of cheap, safe, human insulin grown inside sterile bacteria cultured under highly controlled conditions has saved countless lives and untold misery. And it created a whole new industry: biotechnology.
Today those genetic engineering techniques have been greatly refined. And that's where the controversy comes in. Genetic engineering raises concerns about the practices and safety of engineered food products. While so far there is little in the way of peer-reviewed studies showing any danger unique to the process, introducing new genes into organisms is not without potential risks. Evolution has produced a dazzling array of magnificent creatures, but it has also produced plenty of deadly ones—rabies and leprosy for example. It's possible we could inadvertently create something dangerous to ourselves or our critical agricultural industries.
A related concern is that regulatory oversight of gene engineering has lagged behind technology and in some cases stalled altogether under conservative influence. The latter is ironic as some of the nuttiest objections to genetic engineering come not from health-conscious progressives, but from willfully ignorant conservatives who conflate or confuse inserting any human gene into a non-human species with the production of mutant human-animal hybrids .... Maybe some people have been watching too many late night sci-fi movies.
This natural caution over GMOs is needlessly exacerbated by the usual corporate stubbornness, led by a consortium of food companies lobbying tooth-and-nail against labeling GMO products. If these companies wanted to polish up their tarnished reputations and alleviate some of those concerns, they would voluntarily, indeed proudly, advertise the source of their product. Resisting such a simple, commonsense measure does nothing but fuel the worst fears of those most concerned.
That's unfortunate. History has taught us that technology genies, once liberated, are rarely squeezed back into the bottle. And with potential for risk comes great
promise: Just as artificial selection kick-started civilization, feeds an ever-more crowded planet, and now adorns our dinner tables with a rich diversity of food items our ancestors would drool over, genetic engineering has the potential to take us to the next level. Ideally, that would mean higher yields with safer chemical pesticides and fertilizers for an endlessly growing global population and new, tasty, and more nutritional hybrid strains. One day we might even learn to produce the fruit, vegetable, or meat alone, without the rest of the organism, reducing toxic chemical runoff from giant factory farms, and ending the horrible practice of raising animals by the thousands in tiny, filthy cages.
How this will play out, and what genetic engineering will eventually offer humanity, good or bad, remains to be seen. It's certainly a topic worthy of discussion here. And if we truly want a productive exchange, we heartily encourage all members to exercise the utmost respect for one another in comments below. Never forget that ultimately, the other side has way more money and all the influence and spin it can buy. But if we remain united, we have the numbers to beat them, and unlike our dwindling opposition, our numerical advantage grows stronger with every passing year.