Today, a whole bunch of things came together that made me think again about weeds – and more generally about what constitutes an “undesirable.” In a press release from the University of Arizona, I read this:
The recent field of invasion biology faces a new challenge as 19 eminent ecologists issue a call to “end the bias against non-native species” in the journal Nature.
The group is questioning the automatic (and politically correct) assumption that native species are inherently more valuable and “good” than non-native ones. It turns out that plants and critters brought in by accident in luggage or on purpose to eradicate a pest sometimes thrive so well in their new habitats that they crowd out the oldies. This causes consternation and a call to wipe out the newcomers, to put back the clock, to return nature to its “pristine” state. But as endless examples have shown, once these space invaders have gotten established, there is no going back. Just look at the cane toads in Australia, the zebra mussels in the Great Lakes and the Kudzu vine or Tamarisk in the Eastern US. Like it or not, they’re here to stay.
Reading that paragraph over, it struck me that this isn’t just a problem with plants and animals. Here in Switzerland many people exhibit exactly this same bias against other, “invading” human populations. They don’t look right, smell right, eat the right things. They’re crowding us out of our jobs! They don’t share our ideas about what’s important! I think it’s actually a very human tendency – resistance to change. We often assume that how things were is automatically superior to how things are, particularly when newcomers are involved.
But it’s certainly a selective resistance. As the press release mentioned, native species often do just as much, if not more damage than invaders. Nobody would mind at all if the bark beetles died out, gobbled up by, say, ladybugs from Outer Mongolia. I doubt anyone would fuss if the Anopheles Mosquito kicked up its heels and disappeared off the face of the Earth. Our outrage seems to be proportionally related to the cuteness of the local species and the ickiness of the invading one. Even our word choice screams bias — we employ the adjectives “invasive” and “non-native” much more frequently than “opportunistic” or “exotic” (this last is often used to refer to non-native plants sold in nurseries, however, which can be classified as attractive and thus are okay).
In a remarkable coincidence, I came across an article in the New York Times about a cute little hamster living in the Alsace region of France that’s having a hard time surviving because the farmers have stopped planting alfalfa and are putting in corn or selling off their land for housing developments. These guys wake up after a winter of hibernation and there’s nothing to eat! There are only about 800 of them left in Alsace, although they’re apparently thriving in Eastern Europe and in no danger of extinction. The EU is planning to slap the French with up to $25 million in fines if they don’t take measures to get the numbers up.
Meanwhile, in Switzerland, the two wolves that are permitted to live in the Alps are under close scrutiny. They’d better behave themselves, because if they so much as show a whisker near a herd of sheep the hue and cry goes up and the guns come out. Livelihoods are at stake! This native species was eradicated ages ago long before anyone had written a thesis on “invasive species,” and nobody really wants them back, because the newcomers (people, sheep and cattle) aren’t interested in living in a balanced predator-prey ecosystem. The only predator here is the cheesemaker, the butcher and, eventually, the bank. (That’s Switzerland for you!) I guess their cuteness factor just doesn’t make the cut.
All this underscores a problem I’ve had with conservation biology (and now the new field, “Invasion Biology”) for a long time — that we’ve made the mistake of taking ourselves out of the equation. This is both mathematically and philosophically irresponsible. We don’t exist in parallel to nature, where one kind of reasoning applies to us, and another to the rest of the natural world. Our species is just another species, deeply interwoven with all the others, altering things irreversibly all the time, just like they are.
I read today that every human parent passes 30 mutations on to his/her children. Like the rest of the natural world, we are in a state of constant adaptation. Nothing stays the same! We’re not going to stop traveling, so invaders will continue to invade. It doesn’t look like we’re going to stop heating up the planet, either, so habitats are going to change, making room for even more invaders. We’re invading each other, they’re invading us, we’re invading them — it’s a war zone out there! So once again, I say, carpe diem, take a good look at what’s around you and savor it right now. It might be covered with Kudzu next week.
Come to think of it, isn’t there an argument that life on Earth originated from stuff that hitched a ride on a meteorite? Maybe the whole shebang we call “life” is one big massive accidental invasion. God is up there saying “now look what happened, I had a perfectly decent planet and now it’s crawling with vermin…”