The Concept of Certainty in Ecological Science

Go through any scientific paper and you’ll find it littered with uncertainty. Scientists qualify parameters, give standard errors, make way for random processes even when experiments have been planned to the finest detail. Even when we get the answers we want, we provide alternative explanations that fly in the face of the assumptions we’re trying to test. Honestly, sometimes it seems like we don’t really ‘know’ anything.

I’ve written about our reluctance to declare that we know things in science before, but here I want to try and answer a couple of questions. Why is uncertainty such a crucial part of science? How does this affect the non-scientific public’s perception of science? And does this relationship with knowledge need to change in the future?

The attitudes of scientists to knowledge are evident when you look at the word in other languages. In German, the word “Wissenschaftler” roughly translates to “knower”. Early scientific colleges were born from the church, an institution which historically, on a surface level at least, has had no problem talking in certainties. But how certain does one have to be in modern science to declare knowledge of something?

A couple of the more prominent statistical methods make use of confidence intervals – essentially a percentage qualification of how sure we are that we didn’t just happen across a result by chance. A good level in science has traditionally been 95%, but results that hover around the 96-97 mark don’t exactly inspire confidence. And whilst we like to write our methods sections so that any experiment is theoretically reproducible, the chances that someone will test our numbers out are slim, so in a lot of situations, if you’re searching for facts in scientific papers, all you have to go on is a percentage chance of something being true that someone else has dictated.

But whilst this may sound like a weakness of the discipline, I really believe it’s a strength. It means we can’t just rest on our laurels once an experiment is complete and has produced an interesting result. We have to work to collaborate with other researchers working on similar questions to build up a comprehensive knowledge base that increases our confidence in that result. It means that we’re constantly looking for pitfalls or new ways of thinking to challenge that result.

So why is this a problem?

Because it’s not something inherent in all strains of life, and most notably in some which are coming into direct conflict with science these days. In countries where reducing carbon emissions or habitat fragmentation aren’t compatible with furthering economic agendas, politicians and ecologists inevitably end up at loggerheads. And whilst ecologists should be loathe to talk in certainties of future events, most politicians don’t shy away from this. As Ian Winfield at the UK’s Centre of Hydrology and Ecology puts it;

The problem is if you come up with a scientific case against a political case, politicians tend to speak in absolutes about what will happen, which they can’t possibly know. Understanding economics is as difficult as understanding landscape ecology. You know the kind of ways that things have happened in the past but you’re still predicting for the future with a degree of uncertainty.

Our own cautiousness isn’t something that’s at the forefront of the public’s minds when science crops up. In popular media, science is often portrayed as a discipline full of answers (think any forensic science show ever) and miracles (think the whole of science fiction). Perhaps modern teaching of science has evolved, but my high school experience with science didn’t involve a lot of ‘maybe’ and ‘theoretically’, it concerned what science knew.

Environmental science, which ecology falls under, suffers from this moreso than other disciplines. Whilst many basic principles relating to chemistry, physics, or math are directly observable, basic ecological principles aren’t always. Take Liebig’s Law, which implies that a species’ distribution will be limited by the scarcest of the resources it depends on. This is hard to document in species, whether it’s because the resource fluctuates, their biology is a mystery to us, or simply because the species is hard to find. It’s one of the few ecological laws, and it’s still often difficult to demonstrate in a practical nature.

We can always count on xkcd to point out some of the flaws of our understanding of science (Image Credit: www.xkcd.com)

We can always count on xkcd to point out some of the flaws of our understanding of science (Image Credit: http://www.xkcd.com)

Ambiguity like this can be frustrating, especially if you’re looking for a practical solution to an ecology related problem and you have the false perception of ecology as a source for all your answers. If you’re looking for a solution for algal blooms in your local lake, an ecologically-friendly removal of local wolf populations, or want to know how to lower your farm’s soil acidity, you don’t want parameter estimates or scenario likelihoods, you want definite answers. The reluctance of science to speak in black and white can shake our faith in it, when we’ve been brought up thinking of it as a discipline unwavering in its surety.

Conversely, let’s look at the Theory of Evolution, something which scientists are as close to certain on as they can get. I talked about an ecological law earlier. The main difference between a law and a theory in science is a general lack of exceptions. Strange as it may seem, there are a few exceptions to the Theory of Evolution. So we call it a theory. But a fundamental misunderstanding of the not only the cautious nature, but the cautious language of science, leads people to doubt its notions.

Where to?

So what’s the solution? Do scientists start to combat those parties with political and economic interests contrary to ecological interests with our own bold statements of what will 100% happen if a certain course of action is taken? As much as it pains me to let the aforementioned parties barrel over scientists, I don’t think this attitude helps. It strikes me as disingenuous, and has the potential to further undercut science’s credibility in the future.

I believe that the cautious nature of science should be introduced to us at an earlier age, when it’s more likely to stick with us. More interactions between scientists and the public on non-planet-threatening issues is a good start as well. In an ideal world, we’d also be able to stop asking the people who run Hollywood to stop portraying scientists as eccentric geniuses, but that may be a bridge too far. But making people aware that scientists, particularly ecologists, dabble in likelihoods and not in absolutes, is a step in the right direction.

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