We give ourselves altogether too much credit in our dealings with other species. Even the power over nature that domestication supposedly represents is overstated. It takes two to perform that particular dance, after all, and plenty of plants and animals have elected to sit it out. Try as they might, people have never been able to domesticate the oak tree, whose highly nutritious acorns remain far too bitter for humans to eat. Evidently the oak has such a satisfactory arrangement with the squirrel—which obligingly forgets where it has buried every fourth acorn or so (admittedly, the estimate is Beatrix Potter’s)—that the tree has never needed to enter into any kind of formal arrangement with us.I don’t like this metaphor; mostly because it embodies all the wrong instincts about how we should think of the environment. The bargain isn't equal. For one thing the selection pressure the plants exerts on man is not nearly as large as the pressure man exerts on the plant. Further, man’s long lifespan ensures that we respond to that pressure far slower than any domesticated plant (which ussually can yield a new generation each year). Representing domestication as a co-equal partnership is unspeak of the silliest kind.
If I had to propose my own metaphor I would say that domestication is something like a business arrangement: an exploitive one. After all, the apple and the potato didn’t choose to join us on our travels: we forced them to. We cleared fields of unsavory potatoes, replacing them with ones we could more efficiently exploit. And the second we found a more flavorful exploitable potato plant, we uproot our existing business partner and replanted again. Sure, we assist the plant in reproducing – but even Walmart pays it's employees enough to live. That doesn't mean they're getting a fair deal.
Of course, my metaphor has problems too. But it’s just as valid as Pollan’s. The reason I bother is to show that both metaphors make the same mistake: both assign independent moral worth to a plant.
I want to be clear. I’m not saying we have no moral obligation to preserve plants and animals. I’m just saying that those moral obligations are not inherient obligations. For example, we have a moral obligation to leave our children a livable world. Because of that we are obliged to preserve the world’s oceans and wildlife. But we certainly don’t *owe* the rainbow trout a place to live. If we decide that maintaining rainbow trout are beneficial to our long-term interests than we keep them, if not, too bad for rainbow trout.
The reason I take this position is because I think the concept of inherent moral worth of plant (and animal) species is just unworkable. We might take great lengths to prevent the native plants of Hawaii from being killed off by non-native species, but even those native species got there by invading the island and destroying the plants that came before. Similarly the cane toad might be annoying today but if – over the course of millions of years - it were to diverge into hundred of separate species found only in Australia, I think we’d rethink our current policy of trying to kill them off.
Now, I assume this is going to set off all kinds of bells and whistles in the heads of some of you. “But Tom! If the decision to preserve wildlife is based only on what it’s worth to people, won’t people make shortsighted decisions?” Why yes. Yes, they might. But the solution to that problem is to get people to make not make short-sighted decisions, not to pretend that god will get mad at us if we let Imperata cylindrical die out. Trying to fix bad judgment calls by inventing procedural grounds upon which to push your favored outcome is not a good way to ensure logical conclusions.
Update: Removing possibly over-the-top reference to slavery.