#233 – James Smith on why he quit everything to work on a biothreat nobody had heard of
When James Smith first heard about mirror bacteria, he was sceptical. But within two weeks, he’d dropped everything to work on it full time, considering it the worst biothreat that he’d seen described. What convinced him?
Mirror bacteria would be constructed entirely from molecules that are the mirror images of their naturally occurring counterparts. This seemingly trivial difference creates a fundamental break in the tree of life. For billions of years, the mechanisms underlying immune systems and keeping natural populations of microorganisms in check have evolved to recognise threats by their molecular shape — like a hand fitting into a matching glove.
Mirror bacteria would upend that assumption, creating two enormous problems:
- Many critical immune pathways would likely fail to activate, creating risks of fatal infection across many species.
- Mirror bacteria could have substantial resistance to natural predators: for example, they would be essentially immune to the viruses that currently keep bacteria populations in check. That could help them spread and become irreversibly entrenched across diverse ecosystems.
Unlike ordinary pathogens, which are typically species-specific, mirror bacteria’s reversed molecular structure means they could potentially infect humans, livestock, wildlife, and plants simultaneously. The same fundamental problem — reversed molecular structure breaking immune recognition — could affect most immune systems across the tree of life. People, animals, and plants could be infected from any contaminated soil, dust, or species.
The discovery of these risks came as a surprise. The December 2024 Science paper that brought international attention to mirror life was coauthored by 38 leading scientists, including two Nobel Prize winners and several who had previously wanted to create mirror organisms.
James is now the director of the Mirror Biology Dialogues Fund, which supports conversations among scientists and other experts about how these risks might be addressed. Scientists tracking the field think that mirror bacteria might be feasible in 10–30 years, or possibly sooner. But scientists have already created substantial components of the cellular machinery needed for mirror life. We can regulate precursor technologies to mirror life before they become technically feasible — but only if we act before the research crosses critical thresholds. Once certain capabilities exist, we can’t undo that knowledge.
Addressing these risks could actually be very tractable: unlike other technologies where massive potential benefits accompany catastrophic risks, mirror life appears to offer minimal advantages beyond academic interest.
Nonetheless, James notes that fewer than 10 people currently work full-time on mirror life risks and governance. This is an extraordinary opportunity for researchers in biosecurity, synthetic biology, immunology, policy, and many other fields to help solve an entirely preventable catastrophe — James even believes the issue is on par with AI safety as a priority for some people, depending on their skill set.
The Mirror Biology Dialogues Fund is hiring, including for a deputy director and a role in operations. You can also express your interest for future roles and keep an eye on the MBDF jobs page for future openings.
This episode was recorded on November 5-6, 2025.
Video and audio editing: Dominic Armstrong, Milo McGuire, Luke Monsour, and Simon Monsour
Music: CORBIT
Camera operators: Jeremy Chevillotte and Alex Miles
Coordination, transcripts, and web: Katy Moore
A note from Rob Wiblin about infohazards
Some listeners have raised the concern that the information in this episode is an ‘infohazard’ — that is, information that’s dangerous to publicise and which we should avoid covering on the show.
It was no doubt a complex decision for the small group who originally identified the mirror bacteria threat to decide whether to go public with it. I know they debated it at length and shared it with other scientists only very gradually.
In the end, they decided it was a clear call to sound the alarm for reasons they briefly summarise in their technical report under ‘Rationale for Public Release’.
In short, scientists almost certainly would have noticed the same issues at a later time, and perhaps impulsively shared them with the world. But by that point, with biology progressing normally in the meantime, there would have been less of a technical buffer between current science and the actual development of mirror bacteria. The sooner we can implement a moratorium on new research that makes it easier to create them, the wider we can keep that buffer, and the safer we will be.
For us here at 80,000 Hours, the decision is more straightforward. The risk of mirror bacteria was published to widespread media coverage in December 2024, in The New York Times, Financial Times, CNN, The Guardian, and Le Monde, among many others. There are YouTube videos describing mirror bacteria with millions of views.
So it’s very far from a secret now.
The existence of this interview does little to change how salient mirror bacteria are on a global scale.
But thanks to our audience, we can make a big difference to whether MBDF and others can hire the dedicated staff they need to successfully close the technical path to actually developing mirror bacteria. That makes the interview a clear win in expectation, which is the view of experts in mirror bacteria who work on this problem full time.





