964NOV 16, 2014 6:03 PM EST
By Mark Buchanan
Like many people, I’ve long wondered about the safety of genetically modified organisms. They’ve become so ubiquitous that they account for about 80 percent of the corn grown in the U.S., yet we know almost nothing about what damage might ensue if the transplanted genes spread through global ecosystems.
How can so many smart people, including many scientists, be so sure that there’s nothing to worry about? Judging from a new paper by several researchers from New York University, including “The Black Swan” author Nassim Taleb, they can’t and shouldn’t.
The researchers focus on the risk of extremely unlikely but potentially devastating events. They argue that there’s no easy way to decide whether such risks are worth taking — it all depends on the nature of the worst-case scenario. Their approach helps explain why some technologies, such as nuclear energy, should give no cause for alarm, while innovations such as GMOs merit extreme caution.
The researchers fully recognize that fear of bad outcomes can lead to paralysis. Any human action, including inaction, entails risk. That said, the downside risks of some actions may be so hard to predict — and so potentially bad — that it is better to be safe than sorry. The benefits, no matter how great, do not merit even a tiny chance of an irreversible, catastrophic outcome.
For most actions, there are identifiable limits on what can go wrong. Planning can reduce such risks to acceptable levels. When introducing a new medicine, for example, we can monitor the unintended effects and react if too many people fall ill or die. Taleb and his colleagues argue that nuclear power is a similar case: Awful as the sudden meltdown of a large reactor might be, physics strongly suggests that it is exceedingly unlikely to have global and catastrophic consequences.
Not all risks are so easily defined. In some cases, as Taleb explained in “The Black Swan,” experience and ordinary risk analysis are inadequate to understand the probability or scale of a devastating outcome. GMOs are an excellent example. Despite all precautions, genes from modified organisms inevitably invade natural populations, and from there have the potential to spread uncontrollably through the genetic ecosystem. There is no obvious mechanism to localize the damage.
Biologists still don’t understand how genes interact within a single organism, let alone how genes might spread among organisms in complex ecosystems. Only in the last 20 years have scientists realized how much bacteria rely on the so-called horizontal flow of genes — directly from one bacterium to another, without any reproduction taking place. This seems to be one of the most effective ways that antibiotic resistance spreads among different species. Similar horizontal exchange might be hugely important for plants and animals. No one yet knows.
In other words, scientists are being irresponsibly short-sighted if they judge the safety of GMOs based on the scattered experience of the past couple decades. It’s akin to how, ahead of the 2008 financial crisis, analysts looked at 20 years of rising house prices and assumed they would always go up. The honest approach would be to admit that we understand almost nothing about the safety of GMOs, except that whatever happens is pretty likely to spread.
Science is at its best when it acknowledges uncertainty and focuses on defining how much can be known. In the case of GMOs, we know far too little for our own good.
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