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The nearest relatives to SARS-CoV-2 are found in Yunnan and Laos. The only known link to Wuhan is the Wuhan Institute of Virology sampled both areas.

They refuse to share their records with WHO or the NIH. That's a crucial caveat when saying there is no evidence they held a precursor. We don't know as they have refused to share their database.

The Times article is interesting as it suggests the work in DEFUSE to add furin cleavage sites went ahead and they passaged the virus in humanized mice. This would explain the furin site not seen in other sarbecoviruses and why humans topped the list for binding affinity from the outset.

Note the cases near the market are based on what David Relman described as "hopelessly impoverished" early case data. There was also sampling bias in retrospectively counting cases as market link was often required. WHO hasn't accepted market origin in part as there were likely much earlier cases than those in December linked to the market where no animals tested positive.

> why humans topped the list for binding affinity from the outset

This is an unbelievable coincidence that makes the zoonotic spillover hypothesis laughable. To a biologist, the likelihood of this happening by chance is clear: virtually 0. But explaining the size of the space of optimal solutions to a given binding problem versus the space of good solutions to the general public, well, that's really hard too. So an obvious and completely non-circumstantial piece of evidence is the last one in the public's mind. And we are still acting like there is a question of where the virus came from, and we will be for decades, or at least until the average level of biology education is raised by a few sharp degrees.

That's untrue. Viruses which spillover may spread across humans at a low level of efficiency for months, mutating for higher affinity towards humans, and only becoming pandemic once a high level of affinity has been achieved.

All viruses which have higher affinity for humans spilled over, didn't they?

That's what happened with H1N1 but we know that hasn't happened with Sars2 because Sars2 only spreads efficiently with a furin cleavage site but the furin cleavage site also makes it more pathogenic so it would definitely not spread undetected.

Studies have found that people living near bats in Yunnan have immunity against this class of coronaviruses due to exposure, which would strongly blunt pathogenicity. There is also more to pathogenicity than you let on.

> If it was transported to the seafood market by someone who worked at the lab that is highly coincidental that the place they infected first just happened to be the most likely place for zoonotic spillover

If we're going with highly coincidental pairings, it seems like we can't ignore "the disease originated in the only city in China to have an institute that specializes in virology, viral pathology and virus technology."

I'm not convinced of any particular conclusion as to COVID's origin, but I don't down-weight the coincidence of the city of origin hosting WIV nearly as much as you appear to.

Also, zoonotic transfer happening naturally in any particular time and place is extremely unlikely, even in places where the conditions are optimal.

I always thought this was a good test for whether someone can apply Bayesian reasoning. It turns out not many can, including a lot of highly educated people.

Without hard evidence to contradict it, lab leak should have always been the default hypothesis. That it hasn’t is a case of political propaganda winning out over basic statistics.

Bayesian reasoning is that your prior is a 99.999% chance that the virus is natural, as all other viruses are.

The probability that a virus would crop up in Wuhan out of all cities in China is 1/70.

Feel free apply Bayes' formula.

Where's the part with the virus being collected and brought to a lab in Wuhan where gain of function research was done prior to the outbreak? Feel free to include that in your formula.

There is no evidence SARS-COV-2 was being studied.

But even if you were to accept that, the bayesian reasoning would be that you'd say that the probability it's from Wuhan it's a leak is 100%, and 0% for any other city. You could go further and look at the viruses that have caused zoonoses in China in the past (the evidence is that hundreds of SARS-like coronaviruses have) and compare it to what was being studied. Even then, if you apply Bayes' formula, you'd have overwhelming odds towards a natural origin.

Your prior should be that it was just like the SARS-CoV-1 outbreak which happened in a different city without this research lab and also involved in a spillover in wet market of a virus whose closest known relative was found hundreds of miles away in bats (in close to the same area that RatG13 was found).

At this point can we not just state plainly, the whole denial argument is predicated on politics?

Which one do you mean by “the denial argument”? (and why do you use that term instead of something unambiguous like “lab leak” or “zoonotic origin” hypotheses?)

As to which of the two hypotheses is more predicated on politics, I think there are more generally left-leaning people who are swayed by the lab leak (circumstantial) evidence, than there are right-leaning people who are swayed by the zoonotic origin (circumstantial) evidence. This perception may be mistaken, but assuming I’m correct, this would suggest that the zoonotic origin hypothesis is more likely to be predicated on politics.

Edit: typo

> The spread of SARS-CoV-2 looks exactly like it originated in the Seafood market.

Huh? No it doesn’t. The discussion of a possible SARS outbreak started weeks before the seafood market incident. The lab leak theory started in China BEFORE the seafood market was pinned as the cause.

A source would be helpful, if you can provide one.

https://www.medrxiv.org/content/10.1101/2020.02.24.20026682v...

I would share family chats if they hadn’t been deleted. But we heard about it a few days before Xmas.