Tuesday, June 15, 2021

Coincidence Theory and the Corona Virus

 As should be clear from other posts here, I don't like Donald Trump and I think his presidency was a disaster and I hope he ends up in jail for a long time.

And I also think that his insistence for so long that the coronavirus was the "China virus" and that it had escaped from the Wuhan lab was irresponsible given his inability to actually explain why he was so sure that happened.

But now, it sounds like even Joe Biden, the democrats, and the mainstream media are coming around to the idea that Trump might well have been right, just like the proverbial broken watch.

The facts, as recounted in today's NY Times, are that a famous Chinese scientist who was famous for her work on the coronavirus was researching the corona virus at a Wuhan lab, under containment conditions that were somewhat less than the most restrictive.

So she literally had animals carrying the virus in her lab.  And she had lab assistants working with those animals.  And, according to some reports, three of those lab assistants got sick with flu-like symptoms in November 2019.

She led expeditions into caves to collect bat samples, and had over 10,000 of them.  She was doing experiments on how these viruses could jump from animals to humans.  She denies that they were "gain of function" modifications to the viruses, but that might be semantics.  Here's a quote from the article:.

But some of her most notable findings have since drawn the heaviest scrutiny. In recent years, Dr. Shi began experimenting on bat coronaviruses by genetically modifying them to see how they behave.

In 2017, she and her colleagues at the Wuhan lab published a paper about an experiment in which they created new hybrid bat coronaviruses by mixing and matching parts of several existing ones — including at least one that was nearly transmissible to humans — in order to study their ability to infect and replicate in human cells.

Proponents of this type of research say it helps society prepare for future outbreaks. Critics say the risks of creating dangerous new pathogens may outweigh potential benefits.

The article also says that some of the experiments were conducted under biosafety 2 containment conditions, while biosafety 4 is the maximum (and was also available at the Wuhan lab).

We know the virus first made the leap to humans in Wuhan.

So one obvious explanation is that during one of the experiments, one or more of those lab assistants contracted the coronavirus, and spread it to others, until it had spread beyond the possibility of containment.  Note that there's no reason to assume that the virus that made the "jump" was one that was modified.  There were 10,000 unmodified samples, any of which might have made the jump.  So the "fact" (as asserted by some) that the corona viruses that are out there don't show any signs of having been modified in a lab does not necessarily exculpate the Wuhan lab from being the source.

Of course, that's not the only explanation.  Many species of animal that could potentially carry the virus make their way to Wuhan, which has a thriving outdoor market, where such animals are bought and sold.  (Slight update -- a group of diehard believers in the "it wasn't the Wuhan lab" hypothesis recently presented some data on how many animals were at the Wuhan market that might potentially have carried the virus.  I think it

Let's assume China never cooperates, and we need to decide which of the two possible explanations is more likely.

Can't we do it almost mathematically?  

We have a situation with two possible solutions, one of which involves ascribing something to coincidence.  That's what's called circumstantial evidence, and it's routinely used to convict people of crimes under the "beyond a reasonable doubt" standard.

But perhaps not in the way I'm going to propose.

For me, the question is how many open air markets comparable to Wuhan's in relevant respects are in locations that could conceivably have been reached by a coronavirus capable of making the jump to humans that originated in the wild.  And of those open air markets, how many of them are in the vicinity of a research lab studying the leap from coronaviruses to humans.  I'm guessing the latter number is 1 -- Wuhan only.  

If that's right, the only question is, for any given open air market (like Wuhan) what are the odds that it would be the first (and only!) market where a human coronavirus outbreak occurs.  

I haven't been able to find anything that tells me how many markets like Wuhan's are in China or in other countries where the coronavirus might exist in animals.  This article gives some useful information, including that there are 44,000 "wet markets" in China, that a "wet market" is one that, at a minimum, sells live seafood.  The article doesn't spell it out, but I'm guessing that's why they are called "wet" markets -- there must be a lot of water around to contain all the marine life.  Unfortunately, the article resorts to handwaving and anecdote rather than hard data when discussing the practice of selling live animals, including exotic wildlife, at these kinds of markets:

Problems can arise, however, in the rare circumstances when live animals (and in particular rare and/or wild species) are introduced to such markets, as was the case in Wuhan. With everything from snakes to wolf cubs being sold and slaughtered to order, the Huanan Seafood Market was in fact a wildlife market, not a wet market. Alan Laine, a 57-year-old physics teacher from the UK who has been living in Wuhan since 2002, describes stumbling across the market’s “exotic” section. “On one side was mostly meat. The other side was mostly seafood. But I went through one small area and there were several caged animals, including hedgehogs, porcupines and some other animals I didn’t really recognise,” he says.

Elsewhere though, it makes clear that catching and selling wildlife is big business in China:

Wuhan is by no means the only place in China that’s home to markets with poor hygiene and animal rights practices. Cities south of the Yangtze River are largely responsible for the stigma of China’s exotic-meat obsession. The people of Guangzhou are said to eat anything with four legs, Yulin is known for its annual dog meat festival, and markets in Guangxi sell everything from pangolin scales to bear paws along the China-Myanmar border. Apart from some shady and specialised spots in the south and rural China, however, Chinese people are typically less interested in, and even put off by, atypical meat.

While welcomed by the international community, the ban introduced by China’s National People’s Congress in February is not a fix-all solution. It only covers the trading of wild animals for the purpose of eating, so it fails to cover the trade of exotic species for medicinal or entertainment purposes or the trade of live farmed animals for eating. Such bans leave plenty of room for sketchy operations within grey areas, which can be more dangerous than outright black markets, according to experts.

“Bans don’t always work the way we want, and they often have a lot of side effects, especially if you try to implement them very suddenly and broadly,” says Petr Matous, a senior lecturer in environmental and humanitarian engineering at the University of Sydney. “In many cases, you get much worse consequences by banning something and driving it underground.”

Hastily implemented bans also have a history of lax enforcement in China. While the sale of live poultry was prohibited in Guangzhou in 2015, for example, it was still a fixture at many markets and unregulated backstreet stalls as recently as December 2019.

One huge problem is the number of people who rely on the wildlife trade, which was until this year promoted by the government as a means of alleviating poverty in rural China. The industry was valued at 520 billion yuan ($74bn) in 2017, and the recent shutdown of farms and the mass culling of animals will leave scores of families destitute. While Matous believes that animal welfare and hygiene improvements at markets should be made, he says concentrating only on one area of the supply chain is not helpful. He urges policymakers to look both upstream, at how food is farmed and produced, and downstream, at how cities are built and run, in a bid to prevent future outbreaks.

Ultimately, spates of disease will always be a risk when humans and unfamiliar animal populations mix. China’s desire for so-called “warm meat” – where animals are kept live in markets and slaughtered onsite – will diminish with time and education. Bans may drive such activities underground without treating the problem of the demand being there in the first place. China’s wet markets may be changing, but the problems they amplify will persist.

In other words, while the article at one point seems to be suggesting that Wuhan's life-wildlife sales are the rare exception, by the end of the article, the reader has the strong sense that it's not the exception at all -- buying and selling wildlife at wet markets is still a way of life in much of China, as evidenced by the fact that it's a $74 billion industry.

The article is also a bit confusing since it talks about the clampdown on poultry sales as suggesting that the markets might not be as dangerous, and yet there doesn't seem to be any significant clampdown on sales of wildlife.

Assuming everything else is equal, the odds are 1/n, where n is the number of comparable wet markets.  In other words, if there are 10 comparable markets, the chance that the outbreak will occur in any one of them is 1 in 10.  If there are 100, then the chance for Wuhan was 1/100.  If there are 10,000, then the chance for Wuhan was 1 in 10,000.

Put another way, assume there's a corona virus out there waiting to make the jump to humans.  And assume one of these markets is where it would do that.  The chance that it does it at any one of a thousand equally likely markets means the chance of that happening was 1/1,000.

If that's right, doesn't that mean that the chance that it actually originated in the lab was n-1/n, i.e. 90% for 10 markets, 99% for 100 markets, 99.9% for 1,000 markets?  To be honest, I'm not sure it really does, and I'm not sure it totally avoids the inquiry -- the Chinese scientist claims that the viruses she was studying are miles apart (genetically) from Covid-19 and thus could not possibly have given rise to Covid-19.  If that's true, then clearly we're back to the open air market theory, since the probability of Covid-19 coming from the Wuhan lab is basically zero.  Even though the odds that the virus would first break out at a Wuhan market are very small, if the Wuhan lab could not have been the source, the Wuhan market is the best explanation we've got, however improbable.  So really, it's a question of comparing the probabilities.  If there's a 10% probability of escape from the lab, and 1% probability of it coming from a wild bat, then that means (I think) that odds are 10 to 1 that it came from the lab.

Here's one more point that would skew the odds even more:  let's say the virus existed in nature and was capable of making the jump to humans, which is necessarily the Wuhan market hypothesis.  Why would it have made that jump in only one place?

I'm sensing that you're not persuaded, but let's just make a little shift for demonstration purposes.

Let's say you have two identical twins with identical DNA.  One of them lives in Wuhan.  The other one lives out in the country, and the only time he ever leaves the country is once a year, to visit a zoo.  His way of selecting a zoo to visit is to throw a dart at a map that consists of a 200 mile radius from his house in the country.  Wuhan is one of 100 cities on that map that have zoos.  A crime is committed in Wuhan and the police figure out that it was committed by someone having the same DNA as the twins; i.e it must have been committed by one of the twins.

Without any more information (such as an iron tight alibi for the Wuhan twin), isn't it at least 99% likely that it was committed by the Wuhan twin?

Obviously we are missing a lot of data here -- I have no idea where the virus might have originated; apparently it's quite unlike any coronavirus found in nature (which one might think is one more reason to think that it did NOT come about purely naturally).  But it seems unlikely that Wuhan is even the most likely open air market; at best it's one of many.  And the more open air markets -- and not to mention other possible ways for the virus to leap from animals to humans somewhere other than in Wuhan -- the more UNLIKELY it is that the coronavirus first leapt to humans at a particular open air market in Wuhan.

And yes this is all circumstantial.  Without China's cooperation, there is no direct evidence.  But even direct evidence often leaves probabilistic questions.  90% is a very high probability; 99% is near certainty, and should be enough to shift the burden to China to show that the virus was even less likely to have originated at the Wuhan lab.

One more line of inquiry.  I read somewhere that China reported another outbreak at a wet market in June 2020, for a wet market in Beijing.  It would be good to find out if that was "real" or not.  Seems like it could have been part of a coverup.  China might have come to realize how improbable it was for the virus to show up at Wuhan and only Wuhan, and made up a story about how it made the leap from animals to humans in Beijing as well.  Indeed, the fact that there don't seem to be any other places (except maybe Beijing) where the virus made the leap is yet one more astonishingly small likelihood scenario that the Wujan wetmarket hypothesis has to explain.


 

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