The Last Word On Nothing

Two weeks ago, I wrote about scientists who intentionally killed 80,000 feral goats on one of the islands in the Galápagos archipelago. The effort was in the name of biodiversity and conservation, sure, but was it right? The post spurred some fascinating questions and comments, particularly from Jason G. Goldman, who writes The Thoughtful Animal blog at the Scientific American Blog Network. I put Jason in touch with LWONian Michelle Nijhuis, who just wrote a feature for Scientific American about how conservationists decide which species to save. Below you’ll find their conversation.

Michelle: So what was your first reaction when you read Ginny’s post about the “Judas goat” and the extermination of feral goats in the Galápagos?

Jason: I thought it was actually a fairly clever method of addressing the problems caused by this invasive species. But what was in some ways more interesting to me was the comment made by one of Ginny’s co-travelers: “I really enjoyed the trip, but the one big downer for me was the extermination of the goats and the donkeys and their very anti-Darwin approach…” My assumption was that the phrase “anti-Darwin approach” was meant to suggest that this is a case of humans unfairly intervening in a situation, or “playing God.” But it strikes me as an extremely anthropocentric view of evolution and natural selection. Isn’t human behavior – whatever drives it – itself a selection pressure?

Michelle: That caught my attention, too. We as humans have applied selection pressure to the Galápagos by bringing the goats in, and now we’re applying – or releasing – a different sort of pressure by taking them away. I’m wondering about your perspective as a cognitive neuroscientist – when I read about an effort like this, my logical brain supports the effort to restore ecological processes and biodiversity – but my emotional reaction to the killing of so many goats is different than the reaction I’d have to killing a bunch of invasive cockroaches, or, say, getting rid of a flu virus. Do we feel more concerned about goats and other mammals partly because their brains are more similar to ours?

Jason: There’s probably something there. I’m not sure we necessarily feel more towards animals whose brains or minds are more similar to ours, but at the very least, I think goats are more charismatic than cockroaches or flu viruses. We humans have a thing for the cute and cuddly, for the furry or fuzzy. Though individual differences probably play an important role as well. Most of us tend to think of cockroaches as pests, but I imagine there are those who have come to view goats as pests as well.

Michelle: So when we make management decisions about invasive species – should we learn to live with them, should we kill them – we’re bringing a lot of conscious and unconscious biases to the table. What questions do you think we should ask when we’re trying to decide whether an invasive species is “good” or “bad” that would help us overcome those biases, or at least see them more clearly?

Jason: It’s such a tricky, complicated question. If the dinosaurs had not been wiped out, perhaps mammals would not have had the chance that they did to proliferate to the extent that they have. From an anthropocentric, selfish perspective, the extinction of the dinosaurs was perhaps a good thing. By analogy, from the perspective of some species, the removal of goats from the Galápagos would be a welcome intervention and for other species it might be catastrophic. And the consequences of those sorts of decisions could potentially not be obvious for a long time.

So one of the questions we might ask is whether we can reasonably infer the short-range consequences of a species management decision, but I think we also have to be generally aware that the long-range consequences are a great big unknown. Ecosystems exist across space, but also across time. Can we do better than deciding a priori that management decisions should be made from a particular perspective?

Michelle: Good points. We’re biased by our own interests – we naturally take the anthropocentric point of view – and also by our own lifespans, in a way – we can’t clearly conceive of, much less predict, the consequences of our actions hundreds of years from now. So where does that leave us? I recently wrote about how scientists and wildlife managers are starting to explicitly “triage” species protection – that is, they’re trying to make decisions about which species to save and which to ignore by considering things like cost of protection, evolutionary potential, ecological function or some combination of factors. Do you think those sorts of methods might help our anthropocentric, time-challenged brains make wiser decisions about invasive species?

Jason: My sense is that these sorts of decision-making methods are probably all we’ve got, assuming we wish to be proactive. If we’ve got the funding to address problems X or Y, but not W or Z, then at least it narrows our potential choices. The critical piece, I think, is in recognizing the biases that influence our decision-making and maintaining explicit awareness of them. Just as with any other cognitive or perceptual bias – these things are built into our minds, they’re fundamental to the way we think – making our biases explicit is probably all we can do, rather than attempting to overcome them.

Michelle: I agree. One of the professional environmentalists I interviewed for the triage story said, “We live in a world of unconscious triage” – his point was that we were making decisions through inaction whether we liked it or not, and that it was important to be more transparent. But I can understand why people would prefer not to make those decisions about saving species or killing invasives or both explicit – doing so requires us to acknowledge that we are “playing God” in the sense that we’re not only an evolutionary force but also that we hold the power of life and death over much of the rest of nature. At the same time, it forces us to acknowledge that we’re not all-powerful – we might be playing God, but we’re only playing. We can’t save everything or restore everything, so we have to make choices.

Jason: I understand the reluctance to engage with these sorts of questions, too. We’re being forced (or, maybe forcing ourselves) into an inherently uncomfortable position. I think it’s worth exploring what makes it uncomfortable.
We know from experiments in moral psychology that we’re motivated to act on behalf of the greater good – that is, we’ll act to save five people if it means not saving one person. In cases like this, we already accept as given that we can’t save everyone. For analogous problems in conservation – do we try to save grey wolves or rockhopper penguins – the challenge will be determining, as you said above, what counts as the “greater good.”

We also know that humans would prefer that negative things occur due to inaction rather than explicit action (we’re not okay with killing one person to save five people). In moral psychology and in philosophy, this is called the doctrine of double effect. The idea is that we find it more acceptable to cause harm when that harm is a foreseen side effect, or the “double” effect, of an action that will bring about a good result, but not when the harm is the means to the good result. To continue with the above example, we do not need to actively harm the rockhopper penguins to save the grey wolves. The extinction of one species would merely be a foreseen side effect of the fact that our limited resources necessarily requires that we pick and choose.

On the other hand, I think this nicely demonstrates the problem that people can have with eliminating invasive species, as with the Galápagos goats. The elimination of the goats is not merely a foreseen side effect of an action; it’s the action itself. This might be what makes these conservation management questions feel emotionally distinct from others. Perhaps, if nothing else, understanding where the hesitation and discomfort comes from is a useful first step in moving towards making these important decisions.

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Photo by maessive