One of the Big Questions about SARS-CoV-2, the virus that causes COVID-19, has for a while been about its origins. Most viruses that cause disease in humans have long, fascinating origin stories, with jumps from animal to animal until they finally make it into people and start killing them.

But COVID-19, goes the theory, must be lab-grown - either from an intentional lab leak or a mistake of epic proportions - there's simply too much circumstantial evidence to ignore! This idea doesn't really make sense. There's no special reason to believe that COVID-19 must have been grown in a lab.

Sure, there's political reasons that we might think the Chinese government is untrustworthy, but that's a slim basis for a theory. As humans, when we are given two possibilities, we assume that they are somewhat equivalent in likelihood, so when you hear "lab leak or natural origin" it's not unreasonable to assume that those two things are about as likely as one another, even though that makes no sense whatsoever.

We know from decades of evidence that new diseases jump from animals to humans all the time. There are literally dozens of cases in the last few decades alone where an entirely new disease has transferred from a non-human host to people.

This has even happened twice in recent memory with coronaviruses similar to SARS-CoV-2, which gives you some idea of just how unsurprising it is when a novel pathogen of likely animal origin is identified.

All of this is why scientists say that the "default assumption" is that the virus emerged naturally - it happens literally all the time.

And yet, headlines are currently screaming that scientists have "proved" that COVID-19 was bioengineered in a lab despite this being no more likely than in July 2020. What's going on?

The science

The paper that all the headlines are based on appears to be a perspective piece written by three authors that will soon appear in the journal Quarterly Review of Biophysics Discovery. This is a new journal that was launched in August 2020, which means that while it's connected to a fairly prestigious journal it's quite hard to say much about the publication itself.

And the paper clearly makes some quite controversial claims - the authors are quoted as saying that they have found "unique fingerprints" in the virus that could only have been created in a lab.

Moreover, the paper claims that China has deliberately destroyed data that could prove this hypothesis, which is a pretty wild claim to see published in a peer-reviewed academic piece.

Except, it's not published exactly. Usually, when you hear a story about coronavirus science, there is a scientific paper to read.

In this day and age, that paper may not be peer-reviewed - preprint servers have become the method of choice for a lot of urgent publications these days - but you could at least analyze the science that the headlines are based on.

In this case, however, we can't read the research yet because it hasn't been either published in a scientific journal or put up on a preprint server. Indeed, according to the Daily Mail who first broke the story, the research won't appear for at least a few more days - as of writing this, it isn't up on the journal's home site.

However, in the Daily Mail piece, there is an interesting quote- the authors say that they have had this data "for a year", but were ignored by academics and major journals. They also say that this new paper is essentially the same as their earlier work, but expands on their initial ideas. And, thanks to the sleuthing of Dr. David Gorski, we can see the original paper in all its glory.

The original paper. What glory, such wow. (Minerva)The original paper. (Minerva)

Now, this initial paper isn't present on a preprint server or academic publication - instead, it is currently hosted on the right-wing Norwegian newsletter Minerva, as part of a longer article in which the authors blame "foul play and political considerations" for the fact that they were rejected from both Science and Nature*.

All of this is extremely strange, and not what you'd expect from robust science, but you can't just reject evidence because it's hosted on right-wing Norwegian newsletters, or at least you probably shouldn't.

So what does this initial paper say?

Logic and evidence

The first point to note about this paper is that it is really bizarre. The authors claim that their argument provides sufficient evidence to "reverse the burden of proof", which just isn't how logic works at all.

In fact, the paper doesn't even claim to demonstrate that COVID-19 was created in a lab, it just posits the theory and then says that others should disprove this theory because it is so "parsimonious".

That is…not very scientific.

It's a bit like saying "my explanation for magic existing is so robust YOU SHOULD PROVE IT WRONG" except they got worldwide attention while my Lord of the Rings Is Real Life blog is…less popular.

Moreover, the paper itself appears to fall apart even after quite minimal examination. This is not my area of expertise, but there are numerous scientists online who have picked apart the arguments made in the document, many of which appear to be fairly basic mistakes.

Indeed, even some of the quotes given to the Daily Mail appear to be very obviously wrong.

The authors state that "The laws of physics mean that you cannot have four positively charged amino acids in a row. The only way you can get this is if you artificially manufacture it", but as numerous scientists on Twitter have shown about a third of all human proteins have four positively charged amino acids in a row.

If you actually read the arguments from the paper, it gets somehow even weirder. After going over 5 ways in which they think the virus looks suspicious, the authors imply that China is hiding the lab leak evidence from the world but give no factual basis for this claim.

Even weirder.

The authors then posit a lengthy theory about how Chinese scientists could have created SARS-CoV-2, going over the story of a scientist at the Wuhan Institute of Virology, and calling it a "forensic" analysis.

Except, on closer reading, this appears to simply be a set of experiments where scientists were studying coronaviruses, with a narrative provided by the authors arguing that this all lead to the pandemic. But people study coronaviruses all the time - especially after SARS and MERS - so the fact that some scientists at the Wuhan Institute of Virology also did this is about as unsurprising as a fact can get.

Now, it's entirely possible that the authors have tons of new evidence in their unpublished work, but given that they have said that this new paper is based largely on the old one that seems unlikely. This "study" just shows that these scientists think the virus came from a lab, but three people with a theory does not provide convincing evidence of much.

Where does this all leave us?

Uncertainty

As with pretty much everything in the pandemic, the ultimate answer is that things are somewhat uncertain. We know that new diseases commonly spring from animal origins, and that this is quite likely when it comes to COVID-19.

However, as numerous scientists have noted, it is still not impossible that SARS-CoV-2 was leaked from a lab. While the initial World Health Organization report into the issue said that it was "extremely unlikely", this investigation was not aimed at disproving the lab leak hypothesis, and as a recent letter from some prominent scientists noted it's not definitive on its own.

That being said, the evidence from the WHO report is also not entirely useless. For example, there is no evidence that people from the Wuhan Institute of Virology had antibodies to SARS-CoV-2 before the outbreak, which they would if the disease had slipped controls in the laboratory.

Nevertheless, the WHO investigation doesn't provide strong enough evidence to dismiss entirely the idea that COVID-19 came from a lab, which leaves us in an interesting position.

On the one hand, naturally occurring novel pathogens happen all the time, and it's no surprise that labs set up to study these pathogens were nearby when they did eventually outbreak - global health experts have been predicting for decades that this exact thing would happen. On the other, we still aren't certain that the virus didn't somehow escape from the lab, which means that both theories are possible at this point in time.

Thing is, that doesn't make them equally likely. Zoonotic transfers happen routinely, but if this pandemic was caused by an entirely new disease crafted in a lab it would be a massive world-first.

Moreover, much of the evidence "proving" that COVID-19 escaped from a lab is impressively lackluster. The most recent paper is just one example in an ongoing chain - another one that happened recently is when the Wall Street Journal published an explosive piece saying that three researchers from the Wuhan Institute of Virology attended hospital with flu-like symptoms in November 2019.

Sounds like a clear evidence that COVID-19 emerged from a lab leak!

Except, in China the majority of primary care services are provided from hospitals, which includes things like sick certificates for people who miss a day of work due to a cold. In other words, three people going to a hospital for care might literally be what you'd expect of a normal flu season and have no nefarious connotations at all.

This was even noted in the Wall Street Journal piece, but since it was buried deep down towards the bottom the fact that these hospital attendances are proof of very little was lost in the noise.

And this is the problem with most discussions about whether COVID-19 could've come from a lab - it's so politicized that the evidence is pretty unimportant. A popular theory among people who argue for a lab leak is the idea that the furin cleavage site of the virus is so unnatural that it implies a laboratory origin, even though this idea has been untrue since the very start of the pandemic - furin cleavage sites are not unknown among 'wild' coronaviruses, and they don't necessarily make viruses more deadly either.

That the idea doesn't prove anything related to whether scientists engineered SARS-CoV-2 hasn't stopped it from being promulgated widely as proof that the pandemic was man-made.

It's also worth noting that the idea that the virus "leaked" from a lab does not necessarily mean that it was man-made - it is entirely possible that researchers studying existing coronaviruses that were natural in origin accidentally let the virus slip out.

However, even if true, this is a vastly different situation from the ideas that have gained the most prominence, which imply that COVID-19 must be man-made because of its structure and design.

So yes, there are two possibilities**. One happens regularly, and is the basis for most new human diseases. The other has never happened before, and is a pretty unlikely scenario requiring a massive cover-up from the Chinese government and WHO officials.

We can't exclude the possibility that COVID-19 was constructed in a lab, but on balance it is a much less likely explanation.

*Note: This is quite funny, because Science and Nature are the two biggest scientific publications in the world, they reject 90 percent + of papers that are submitted, so it's a wild stretch to say that simply because one paper wasn't accepted it means much at all. Like most scientists, I too have had papers rejected from both Nature and Science - it's something of a right of passage.

**Note: in a very technical sense, this is a false dichotomy. While these are the two explanations most commonly posited for the emergence of SARS-CoV-2, it's possible that other options exist. For example, it could've been aliens, or the CIA.

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Gideon Meyerowitz-Katz is an epidemiologist working in chronic disease in Sydney, Australia. He writes a regular health blog covering science communication, public health, and what that new study you've read about actually means.

Opinions expressed in this article don't necessarily reflect the views of ScienceAlert editorial staff.