Mother Nature is not ‘the ultimate bioterrorist’

Despite the menacing track record of emerging pathogens, “Mother Nature is the world’s worst bioterrorist,” a long-overused catchphrase of scientists and public health professionals, is in urgent need of retirement.

Born in the maelstrom of Sept. 11, 2001, and the anthrax attacks that followed, the saying was meant to warn against fixating on bioterrorism while neglecting the risks posed by naturally emerging pathogens. This warning proved prescient. In the next several years, the all-consuming “war on terror” waged by the U.S. would fuel a tenfold boost in biodefense spending, and the focus on bioterrorism would be so strong that, when SARS hit the world stage in 2003, the editorial board of the journal Nature felt the need to remind its audience that the pandemic was not just a “fire drill” for a terrorist attack, but also a trial run for a future pandemic.

Sobriety and disillusionment around the war on terror started to set in toward the middle of the decade. In concert with this transition in public opinion, the meaning of the popular refrain “world’s worst bioterrorist” subtly shifted: Instead of admonishing people to pay due attention to naturally emerging pathogens, the phrase was increasingly used to downplay or dismiss the real — and growing — risks posed by bioterrorism and other human-engineered biological threats.

This new usage was on prominent display during the last decade’s debates over controversial “gain-of-function” avian influenza experiments, in which scientists sought to study the emergence potential of this deadly virus by artificially enhancing its transmissibility between mammals. Proponents of the unusually risky research suggested that, since “nature is the real bioterrorist,” the experiments’ disputed benefits outweighed their potential harms. As Samuel Stanley, chair of the National Science Advisory Board for Biosecurity, affirmed in 2017, “I believe nature is the ultimate bioterrorist and we need to do all we can to stay one step ahead.”

More recently, some leading biotechnologists have expressed similar sentiments. For example, while Twist Bioscience CEO Emily Leproust has written at length about how gene synthesis companies like Twist can better guard against the misuse of their technology by malevolent or reckless actors, she has also invoked the “ultimate bioterrorist” meme to downplay such risks. In a recently published interview, she noted, “I am concerned with the risks. There is potential for massive loss of life. But the risk isn’t from some postdoc or high schooler. The largest risk is from nature. … Nature is the greatest bioterrorist. The biggest losses of life have been from nature.”

Taken together, these examples show that this meme no longer serves us well. It is undoubtedly a mistake to underestimate the threats from natural pathogens. At the same time, it is equally unwise to wield this 19-year-old expression like a magic wand, intending to briskly banish concerns about people causing harm with biology. We can’t afford to blind ourselves or others to the uncomfortable truth that, with each passing day, humans grow more capable of outdoing nature and harnessing biotechnology to cause harm on a staggering scale, by either cruelty or carelessness.

Nature has no interests, motives, or political goals. To the extent it can be said to “want” anything, it is to perpetually enhance populations’ differential reproductive success, which only rarely aligns with causing greater harm to humans. Notably, the trillions of bacteria living in the average human’s colon appear to have adapted toward a peaceful and often mutually beneficial coexistence with their host. And even deadly pathogens may theoretically evolve toward making humans less sick if doing so opens up more opportunities for transmission between hosts.

The process of natural selection, for all its power, is highly constrained in its ability to generate “superbugs” possessing a diabolical suite of traits. Like human bioengineers, natural selection must work around stubborn physiological trade-offs between traits, such as genome replication rate and mutation rate. But natural selection is also handicapped by near-sightedness, driving improvements in traits that enhance a population’s fitness in its current environment with no attention to maintaining or improving traits that enhance fitness in other environments.

If creating an especially deadly pathogen were like winning a soccer match against a formidable opponent, natural selection would be competing with all the cunning of an especially persistent horde of 5-year-olds, glued to the ball and only ever capable of playing offense, defense, or goalie at any one time.

By contrast, modern biologists are gaining the ability to see the whole field, develop an intuition about where the ball will be next, and play multiple positions simultaneously. Through a combination of rational design, directed evolution, breeding, and brute force trial and error, they can increasingly engineer organisms that excel in multiple desired functions at once, such as the ability to grow quickly in a massive industrial fermenter while churning out commercially valuable biomolecules. This growing capability promises tremendous benefits for agriculture, industry, and human health, but its potential application to the creation of pathogens poses serious concerns.

It is worth emphasizing that trained biologists — let alone terrorists — still have difficulty one-upping natural selection’s creative output. Our understanding of biology is very much in its infancy. Yet our knowledge and capabilities are maturing rapidly, as evidenced by Twist’s prolific gene synthesis capabilities, along with recent feats in predicting protein structure, gene editing, and genome assembly. We are much closer to this exciting but frightening horizon today than we were in 2001, and this trend will likely persist.

It’s also worth noting that, when it comes to weapons-grade biotechnology, states likely pose a greater risk than non-state terrorists. States have vastly more resources to support the development of biological weapons, and about 23 are known or suspected to have maintained biological weapons programs in the 20th century. Some programs, like North Korea’s, likely persist to this day. As countries jockey for advantage, state biological weapons programs remain an ever-present danger, despite the treaties and export controls designed to rein them in. Covid-19, which has exposed countries’ vulnerability to biological threats, has done little to mitigate this danger.

Accidental releases pose an additional source of anthropogenic biorisk. Thanks to the U.S. government’s monitoring program, we know that dozens of agents and toxins with the potential to pose a severe threat to public health and agriculture are reported accidentally lost or released from U.S. labs every year. We also know that accidental releases around the world have already caused significant harm. Such risks increase as biotechnology expands across the world and gains in strength.

Biotechnology, with all its promise and peril, is moving fast. It’s irresponsible of us to shrug off current and emerging biotechnological threats by reciting “Nature is the ultimate bioterrorist” like some article of faith. As with global warming, the cost of willful ignorance and inaction is high — and increasing.

Our health security requires that we engage cautiously but honestly with the full spectrum of evolving biological risks, striving toward solutions with open eyes and moral courage.

Chris Bakerlee is a Ph.D. candidate studying evolutionary genetics at Harvard University and a fellow in the Council on Strategic Risks’s Fellowship for Ending Bioweapons Programs.