By: Priscilla Hayes
Am I being superstitious or karmic to believe that every time we casually and callously bring about the extinction of a creature or plant, we are moving ourselves towards our own extinction year by year? I have in my mind a chart from the wonderful Ray Archuleta (if you don’t know him, everyone should). Ray is a soil scientist with the USDA Natural Resources Conservation Service who has a schematic (see below) of interconnected organisms in healthy soil. As the schematic shows, each organism is crucial to the survival of the rest. When something we humans do kills one kind of organism, it often leads to collapse of another species, and so on. Soil health is lost, and the whole network begins to collapse.
So too, with extinctions—I believe that Earth’s ecological network will begin to collapse. We humans cannot believe ourselves immune, since we, too, are one of Earth’s organisms that is supported by many others. And we are supported by not just the animals we keep as livestock and the plants we grow in neat farm rows. Could we live if we wiped out all species except those we utilize to create food, clothing, shelter, and the other “things” of our lives? I fear that we will wake up one day to a catastrophic collapse in systems that seems like it happened overnight, but really, is the sum of all the extinctions we have left in our wake.
It could be happening some places already. It turns out that Guam, the island where I spent my senior year of high school, could be the place where something like this gets played out first.
Since the loss of the flying-fox, Guam has experienced a cascade of extinctions, brought about by the introduction of the brown tree snake (Boiga irregularis). As a result its forests are now largely silent, the island having lost many of its pollinators and fruit dispersers. The fate of Guam’s ecology in the wake of such destruction should be of much interest to biologists, as many regions may come to resemble it in future.
This quote, from a wonderful book called A Gap in Nature: Discovering the World’s Extinct Animals, seems carefully worded to me, leaving the horror of extinctions on an island scale to the imagination of the reader. The book was a four-year project of Tim Flannery and Peter Schouten, who together, examined written and museum specimen evidence for hundreds of extinct or possibly extinct animals, and then chose 123 of them for which the evidence was sufficient to create a life-size portrait of the animal in its known native habitat before extinction.
The paintings are stunning, even reproduced and less than full-size within the book. The stories of extinction are stunning too, partly in their similarity. When the first humans would arrive at an island that had never seen humans, the creatures there were curious about this new life—to their peril, since humans would bludgeon or stab the curious creatures easily. When only a few remained, people eager to add to their collections of stuffed zoological curiosities consistently shot the last of the species. Or, cats, rats, foxes and snakes that humans brought with them, whether by chance or on purpose, generally made sure that any survivors disappeared.
So, what would life in the future look like for Guam, with its ecology wiped out? We can keep the island humans on life support by importing all the food they need. Even when I lived on Guam, many of the necessities like milk were imported—there weren’t any cows, and no real farming, that I could discern. So, we drank a reconstituted milk called Milkman, and lots of Hawaiian Punch, which I thought was sort of ironic at the time. But what if the plants just start vanishing, along with the pollinators? Or at least the native ones? How much ecological life support can we sustain? Will Guam be able to show us how fragile the “web of life” is, and our own need for diversity of species?
It could be that I am also influenced by my childhood love for science fiction. In the famous short story, A Sound of Thunder, by Ray Bradbury, humans invent a time-travel system that allows wealthy humans to travel back and see the dinosaurs and other ancient creatures. In order that time not be changed, the traveler must remain on an elevated walkway. One traveler leaves the walkway for long enough to kill a butterfly. On his return to the present, the man discovers that a Nazi-like society has taken over the world, just from the changes cascading down from that one death. How much more must the death of a whole species of individuals change the world?
Ray Archuleta is a “soil health” advocate for the United States Department of Agriculture Natural Resources Conservation Service. Read about him at http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/health/?cid=stelprdb1049238
For a detailed and comprehensive website on what soil health is, and who are the organisms that live in soil and ultimately support life on Earth, see http://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/health/
My favorite part of this website is on the soil food web, at http://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/soils/health/biology/?cid=nrcs142p2_053868