Potato bugs, weeds, and harmful bacteria. They all have something in common: Human efforts to kill them have only made them stronger.
The Colorado potato beetle, the scourge of potato plants everywhere, was once dealt with by hand picking them off plants. Yet as acreage increased, removing these pests by hand became inefficient. Early “chemical” treatments were generally earth-friendly and included a fine sprinkling of wood ash or soap applied to the plants. These were somewhat effective to discourage the bugs but did not kill many of them. They were primarily a deterrent. Harsher chemicals were produced that killed most, at least at first. But the bugs that were “resistant” went on to thrive. New pesticides replaced the old with the same results. The bugs that survived rapidly adapted. This is species evolution driven inadvertently by artificial selection. Today, the pesticides used commercially to control potato beetles are so powerful they cannot be purchased in a typical garden center. Given enough time, the bugs will adapt to these as well. The pesticide is non-selective in that it kills beneficial insects as well as harmful ones.
Around 1970, a new “miracle” product hit the agricultural market that promised to kill weeds and not the crop; at the time specifically commercially grown corn. Roundup (active ingredient is glyphosate), manufactured by Monsanto, became the most widely used herbicide ever invented. While it is banned in many countries, it is a mainstay of American agribusiness. But today’s Roundup is not exactly the same as in 1970. It is considerably stronger. Monsanto had to increase its strength because the weeds adapted. Most weeds died, but the few that were genetically predisposed to survive went on to reproduce. Today there are weeds that have evolved a nearly complete immunity to Roundup.
Agribusiness faced a problem. The potency of Roundup had to be increased so severely that it killed or stunted the plants it was supposed to help. Enter here genetically modified crops. Corn (and several other crops) was genetically engineered (genetic material from two or more organisms combined in one plant) so the plants could withstand the higher doses of Roundup.
Because of Roundup’s increased potency and widespread use, recent studies have shown up to a ten-fold increase in Roundup residue in Americans in the last 20 years. It has been listed by the World Health Organization as a probable cause of some types of cancer, liver disease, and other ailments. Thus the ban in European countries. Roundup is also sprayed directly on crops (wheat, potatoes, and others) to kill the foliage to make them more “harvest ready.”
When penicillin was first introduced, it was considered a miracle drug. Before its discovery, bacterial infections were one of the leading causes of death and suffering. Penicillin and its offspring have in fact saved countless lives and relieved a great deal of suffering throughout the world. The importance of antibiotics for fighting bacterial infections cannot be overstated. But the same evolutionary process that led to superbugs and superweeds has also led to antibiotic-resistant bacteria. Those bacteria that survive an antibiotic treatment have a slight genetic difference that makes them resistant. Those without the resistance die out, but the resistant individuals become increasingly immune to antibiotic treatments. Researchers have generally been able to stay one step ahead of adaptive harmful bacteria, but there are now some bacteria that antibiotics cannot kill. Researchers are fearful that, at some point, there may be no new antibiotic breakthroughs to keep pace with the evolving bacteria. Relatively new diseases, like tick borne Lyme disease, would be devastating without antibiotics.
Long term, on the order of decades rather than a few years, other methods other than chemicals will have to be discovered to keep our food source and us healthy. We cannot permanently outrun the evolutionary tendencies that have been around for billions of years.
Email Terry Mejdrich at firstname.lastname@example.org.