The ‘Sagan standard’ devised by the famous astronomer and science communicator Carl Sagan that extraordinary claims should be supported by extraordinary evidence would be well applied to the current speculation on the origins of Covid-19. By diverting the focus away from the most likely wildlife-to-human transmission origin and instead sustaining the idea that Covid-19 entered the human population as a result of Chinese scientific ineptitude or even malice at the Wuhan Institute of Virology, we run the risk of not learning the important lessons we need to learn in order to prevent the next pandemic.

It may not be evident at first glance, but the global public health community almost perfectly predicted and prepared for the Covid-19 pandemic. The small detail that upset all the planning was that the pandemic agent wasn’t influenza, for which there is an elaborate surveillance and response network that allowed the world to react swiftly when H1N1 swine flu arose in Mexico City in 2009.

Instead, it was another of the very many zoonoses (diseases that jump from animals to humans) circulating in the environment that caught the world unprepared, even though there had been clear warnings from SARS (2002), Ebola (2013) and MERS (2015).

Zoonotic pathogens circulate all over the world and form a constant backdrop of diseases that are difficult to diagnose and treat. Australia has numerous well-known examples such as Ross River virus, Barmah Forest virus, Australian bat lyssavirus and Hendra virus. Zoonoses present a persistent health threat to those working in remote regions, in abattoirs and with wildlife.

The constant threat of zoonoses was recognised when the World Health Organization and the World Organisation for Animal Health led the creation of the OneHealth initiative in 2008 to increase surveillance and preparedness in the face of the growing threat.

Our current global pandemic wasn’t a surprise but instead was highly anticipated—for those working in the field of public health, it has been an article of faith at least since the turn of the century that a pandemic was inevitable and probably imminent. As evidence, I submit the lack of affront from the notoriously pernickety scientific community at the terrifying plot line of the 2011 movie Contagion.

With this background, you can see why scientists generally are frankly flummoxed that an alternate theory about the origins of Covid-19 that has little supporting evidence is getting any attention at all.

If we look at the main evidence proposed for the alternative origin theory—that the Wuhan Institute of Virology is nearby and works on coronavirus—it doesn’t stand up to much scrutiny. Southern China and Southeast Asia form a continuous globally recognised hotspot for the emergence of new diseases. Apart from the extensive and well-equipped Chinese Center for Disease Control and Prevention network in most of the country’s major cities, many other research institutes are dotted through the region, such as the US Naval Medical Research Unit-2 detachment in Phnom Penh, the Pasteur Institute’s nine Asia–Pacific research institutes and the Oxford Centre for Tropical Medicine and Global Health’s five. It would be difficult for a disease to arise in Asia without there being a research institute nearby almost certainly studying that pathogen. Putting researchers near disease hotspots is a sign of foresight and planning, not criminal intent.

That’s not to say that lab accidents don’t happen and that dangerous viruses don’t escape from containment. They most certainly do—and at a disturbing rate. But it’s worth repeating that so far there’s no evidence of this happening in Wuhan. And it’s worth observing that an independent panel of experts assembled by the WHO inspected the institute and declared it ‘extremely unlikely’.

There is still a huge dose of culpability on the head of the Chinese government. The now well-reported initial cover-up by local officials was the first and most critical in a chain of extraordinarily bad governance decisions made around the world, the rest of which were made much later and in spite of the availability of good scientific advice. It is hard to blame waves 2, 3 and 4 on anything but political incompetence.

My own experience working with scientists from Wuhan trying to publish data in the early months of the pandemic was one of openness and collaboration. But they found it extremely difficult to get their work published in international journals even though they were working hard to report their findings from inside the epicentre of an overwhelming public health crisis. Valuable experience and insight in the early days of the pandemic wasn’t available to scientists and clinicians around the world, not because of Chinese government cover-ups, but because few were listening.

Media reports that there are clues to the artificial origin of SARS-CoV-2 buried in the genome are not credible. The field of bioinformatics has exploded since the publication of the human genome over 20 years ago. Across the world, there are many thousands of these biological cryptologists with access to room-sized supercomputers who are expert at finding traces of evidence and who compulsively share everything they do (1.8 million submissions have been lodged so far on the GISAID Covid-19 database). For once, I think we can conclude that the absence of evidence is evidence of absence.

So trying to fit a conspiracy theory around the emergence of SARS-CoV-2 could be seen as a little like trying to blame cosmic rays for global warming. Cosmic rays become a plausible theory only if you’re willing ignore the more obvious gigatons of CO₂ and methane that humans pump into the atmosphere.

We could only guess at the attractions behind wanting to investigate a theory for which there is no evidence. For some it may be just another tool in the ongoing strategic competition between China and the Western liberal democracies. But it has the effect of drawing attention away from the core issues that need to be addressed to prevent another pandemic. If we can blame a lab accident (or even malice), then we don’t need to worry about addressing other, more difficult causes. It will give cover to those wanting to ignore the hard facts of human pressure on the environment, dangerous animal husbandry practices, and the abhorrent and cruel trade in wildlife into wet markets.

It also drags the spotlight away from the really crucial call for deep global cooperation and open data sharing launched by Helen Clark, the former prime minister of New Zealand who co-chaired the International Panel for Pandemic Preparedness and Response. To give the WHO the power to report without seeking approval from member governments and investigate outbreaks without notice will require a lot of international goodwill.

What could be a more likely consequence of giving fringe theories more oxygen than driving deeper wedges where there should be openness and cooperation?