We’ve all seen them: aphids, dandelions, cockroaches, rats, bread molds, racoons, pigeons and many others. We’ve seen these unique and resilient organisms deemed pests by so many. These creatures are often considered objects to be exterminated or controlled, and for good reason. They harbor disease, they eat what isn’t theirs (according to us, at least) and they can ruin a perfectly ordered garden. I’ll submit that before we go and try rounding up all of these living things and giving them the same treatment as the western black rhinoceros or the American bison, we take a step back and consider a few things.
Thinking like an ecologist (or a child), it becomes abundantly clear that all of these organisms eat and are eaten by others. The removal of any significant proportion of any of their populations would have a tremendous impact on the surrounding trophic levels, otherwise known as participants in food webs, otherwise known as things that eat other things.
For instance, many people are fearful of spiders, but if we were to dramatically thin out their numbers in a short enough time frame, the results would be unpleasant to say the least. The spider’s primary prey, winged arthropods (bugs), would have considerably fewer predators and their populations would soon run rampant in areas where spiders were the predominant form of population control. Without spiders, we could literally be knee-deep in insects within a few years. Moreover, some bird species whose diets may depend heavily on spiders would experience a food scarcity and have no other option but to find new sustenance or die. The resulting behavior of the birds could result in increased competition with other animals, causing a cascade of other struggles for food and further straining a damaged ecosystem. The overabundance of winged arthropods could result in overgrazing of plant matter — or whatever items these flying bugs primarily eat — and could ruin the ecosystem for everybody.
Needless to say, removing a member of an ecosystem could have dire consequences.
It is also important to consider that evolution is a very opportunistic tinkerer and natural selection is a relentless mechanism. Any unoccupied niche in an environment is asking for something to step in and take advantage of the situation. Cockroaches are successful because they’re resilient to so many would-be fatal living conditions. They don’t need to eat much or count calories and they reproduce very quickly in spaces that many overlook. They can also survive pretty much everything except a direct nuclear strike. They can even have their heads cut off and continue to reproduce. Even if we did successfully engineer a system to wipe them out, something else would assume the then-empty role in a more tenacious way than we could imagine.
These garden-variety pests as we like to call them don’t exist the way they do simply to be an inconvenience to us. They’re playing the game of life, and winning. Despite all of the things we do to make non-human/non-human-cultivated life a non-factor — urbanization, proper sanitation, removing the lion’s share of loose food scraps, carpet-bombing crops with insecticides, habitat destruction and the many other things that make humans an inopportune species to share a planet with — these organisms are not only skating by, they’re thriving.
I’m not saying we should rapidly embrace the aphids, cockroaches, spiders and rats of the world. It’s often advantageous for us to remove them from our immediate vicinity for hygiene reasons. But it is important to consider that these organisms are participants in a system so prevalent, so natural that it’s very easy to lose sight of.
The classical mantras of manifest destiny, exploration and conquering the unknown have been synonymous with progress and advancement. But in reality, we humans are participants in a system that extends far beyond our own needs. The tune of mastering the environment should be changed to one of finding a way of successfully coexisting.
ALAN LIN tries to be a conscientious planet-mate. He can be reached at science@theaggie.org.
