This Feb. 20th Twitter thread from Trevor Bedford argues against the lab-escape scenario. Do read the whole thing, but I’d say that the key points not addressed in parent comment are:
Data point #1 (virus group): #SARSCoV2 is an outgrowth of circulating diversity of SARS-like viruses in bats. A zoonosis is expected to be a random draw from this diversity. A lab escape is highly likely to be a common lab strain, either exactly 2002 SARS or WIV1.
But, briefly, #SARSCoV2 has 6 mutations to its receptor binding domain that make it good at binding to ACE2 receptors from humans, non-human primates, ferrets, pigs, cats, pangolins (and others), but poor at binding to bat ACE2 receptors.
This pattern of mutation is most consistent with evolution in an animal intermediate, rather than lab escape. Additionally, the presence of these same 6 mutations in the pangolin virus argues strongly for an animal origin: https://biorxiv.org/content/10.1101/2020.02.13.945485v1…
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Data point #3 (market cases): Many early infections in Wuhan were associated with the Huanan Seafood Market. A zoonosis fits with the presence of early cases in a large animal market selling diverse mammals. A lab escape is difficult to square with early market cases.
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Data point #4 (environmental samples): 33 out of 585 environmental samples taken from the Huanan seafood market showed as #SARSCoV2 positive. 31 of these were collected from the western zone of the market, where wildlife booths are concentrated. 15⁄21http://xinhuanet.com/english/2020-01/27/c_138735677.htm…
Environmental samples could in general derive from human infections, but I don’t see how you’d get this clustering within the market if these were human derived.
One scenario I recall seeing somewhere that would reconcile lab-escape with data points 3 & 4 above is that some low-level WIV employee or contractor might have sold some purloined lab animals to the wet market. No idea how plausible that is.
Data point #3 (market cases): Many early infections in Wuhan were associated with the Huanan Seafood Market. A zoonosis fits with the presence of early cases in a large animal market selling diverse mammals. A lab escape is difficult to square with early market cases.
Given that there’s the claim from Botao Xiao’s The possible origins of 2019-nCoV coronavirus, that this seafood market was located 300m from a lab (which might or might not be true), this market doesn’t seem like it reduces chances.
We need to update down on any complex, technical datapoint that we don’t fully understand, as China has surely paid researchers to manufacture hard-to-evaluate evidence for its own benefit (regardless of the truth of the accusation). This is a classic technique that I have seen a lot in propaganda against laypeople, and there is every reason it should have been employed against the “smart” people in the current coronavirus situation.
This Feb. 20th Twitter thread from Trevor Bedford argues against the lab-escape scenario. Do read the whole thing, but I’d say that the key points not addressed in parent comment are:
But apparently SARSCoV2 isn’t that. (See pic.)
One scenario I recall seeing somewhere that would reconcile lab-escape with data points 3 & 4 above is that some low-level WIV employee or contractor might have sold some purloined lab animals to the wet market. No idea how plausible that is.
Given that there’s the claim from Botao Xiao’s The possible origins of 2019-nCoV coronavirus, that this seafood market was located 300m from a lab (which might or might not be true), this market doesn’t seem like it reduces chances.
If it was a lab-escape and the CCP knew early enough, they could simply manufacture the data to point at the market as the origin.
We need to update down on any complex, technical datapoint that we don’t fully understand, as China has surely paid researchers to manufacture hard-to-evaluate evidence for its own benefit (regardless of the truth of the accusation). This is a classic technique that I have seen a lot in propaganda against laypeople, and there is every reason it should have been employed against the “smart” people in the current coronavirus situation.