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> and that there were two separate lineages of the virus found in humans The "two lineages" are two mutations (SNPs) apart, and SARS-CoV-2 averages something a

> and that there were two separate lineages of the virus found in humans The "two lineages" are two mutations (SNPs) apart, and SARS-CoV-2 averages something around a third of an SNP per human-to-human transmission. So intuitively, it would seem near-impossible to distinguish two spillovers from a mutation during early, unsampled human spread. Pekar et al. built a complicated numerical model that purports to; but it's filled with arbitrary parameter choices, and no model of that form has ever demonstrated significant predictive value. See the criticisms at https://www.biorxiv.org/content/10.1101/2022.10.10.511625v1 https://www.biorxiv.org/content/10.1101/2022.10.10.511625v1 https://nitter.net/nizzaneela/status/1677583662836056065#m https://nitter.net/nizzaneela/status/1677583662836056065#m > The scientists working on this have always acknowledged that uncertainty and have never said the probability of a lab leak was zero. I've linked here to a Lancet correspondence where top scientists "strongly condemn conspiracy theories suggesting that COVID-19 does not have a natural origin". I guess that's not quite the same thing as "probability zero"; but isn't it even worse?

fasterik 3y ago
Sure, scientists can continue to debate the fine points of these issues. The evidence doesn't hinge on the two lineages argument. The following review paper lists a bunch of other reasons why a zoonotic spillover is more likely including genomic structure, similarity to other endemic coronaviruses which had zoonotic origins, epidemiological evidence surrounding the seafood market, etc. https://www.cell.com/cell/pdf/S0092-8674(21)00991-0.pdf https://www.cell.com/cell/pdf/S0092-8674(21)00991-0.pdf Notice that the review seriously considers the possibility of a lab leak, indicating that this wasn't some off-limits topic even back in 2021. The Lancet letter cites evidence of a natural origin and condemns conspiracy theories. I think that's still largely consistent with the current consensus. Since none of the known samples at the WIV were related to SARS-CoV-2, by definition the truth of the lab leak hypothesis would imply a conspiracy and coverup. I don't think "strongly condemning" something is the same as suppressing public debate about it.
- toomim 3y ago
  That article has biased interpretations of the data. It discounts circumstantial evidence of a lab origin, while foregrounding circumstantial evidence of zoonotic origin. Neither theory has direct evidence. Nobody has found covid at WIV, and nobody found an animal reservoir that could prove zoonotic origin. All we have are two pieces of circumstantial evidence: (1) Lab origin: Covid was discovered close to the WIV, while it was researching gain-of-function on coronaviruses. (2) Zoonotic origin: Covid was discovered in a wet market, where past coronaviruses have been known to evolve and leap to humans. Yet, that article completely discounts (1) as evidence, while calling the evidence of it occurring near WIV "a coincidence": > There is currently no evidence that SARS-CoV-2 has a laboratory origin. There is no evidence that any early cases had any connection to the WIV, in contrast to the clear epidemiological links to animal markets in Wuhan, nor evidence that the WIV possessed or worked on a progenitor of SARS-CoV-2 prior to the pandemic. The suspicion that SARS-CoV-2 might have a laboratory origin stems from the coincidence that it was first detected in a city that houses a major virological laboratory that studies coronaviruses That is a biased interpretation. Then it goes on to say that (2) does count as evidence, even though there's no reservoir animal that could make the direct connection: > We contend that although the animal reservoir for SARS-CoV2 has not been identified and the key species may not have been tested, in contrast to other scenarios there is substantial body of scientific evidence supporting a zoonotic origin. Certainly, if you discount all the evidence coming from your opposition, and foreground all the evidence that agrees with you, it's going to look like your side is right.
  - fasterik 3y ago
    It's not circumstantial evidence in the case of the market, there is direct evidence. You're ignoring the fact that contact tracing of early cases pointed to employees of the market and people who visited the market, and that SARS-CoV-2 was found in environmental samples from the market. On the other hand, there is no contact tracing and no biological sample that leads to the WIV or its employees.
    - tripletao 3y ago
IanCal 3y ago
> I've linked here to a Lancet correspondence where top scientists "strongly condemn conspiracy theories suggesting that COVID-19 does not have a natural origin". I guess that's not quite the same thing as "probability zero"; but isn't it even worse? I remember conspiracy theories that it had been designed and deliberately released, so no it's not really the same.
- tripletao 3y ago
  Is there anything in that article that makes you think their condemnation is limited to theories of deliberate release? I don't see it, and I don't think e.g. Facebook did either--they justified their ban with the (false) scientific consensus established by papers like that Lancet correspondence, and their ban applied to accidental release too.

fasterik 3y ago

Sure, scientists can continue to debate the fine points of these issues. The evidence doesn't hinge on the two lineages argument. The following review paper lists a bunch of other reasons why a zoonotic spillover is more likely including genomic structure, similarity to other endemic coronaviruses which had zoonotic origins, epidemiological evidence surrounding the seafood market, etc. https://www.cell.com/cell/pdf/S0092-8674(21)00991-0.pdf https://www.cell.com/cell/pdf/S0092-8674(21)00991-0.pdf Notice that the review seriously considers the possibility of a lab leak, indicating that this wasn't some off-limits topic even back in 2021. The Lancet letter cites evidence of a natural origin and condemns conspiracy theories. I think that's still largely consistent with the current consensus. Since none of the known samples at the WIV were related to SARS-CoV-2, by definition the truth of the lab leak hypothesis would imply a conspiracy and coverup. I don't think "strongly condemning" something is the same as suppressing public debate about it.

toomim 3y ago
That article has biased interpretations of the data. It discounts circumstantial evidence of a lab origin, while foregrounding circumstantial evidence of zoonotic origin. Neither theory has direct evidence. Nobody has found covid at WIV, and nobody found an animal reservoir that could prove zoonotic origin. All we have are two pieces of circumstantial evidence: (1) Lab origin: Covid was discovered close to the WIV, while it was researching gain-of-function on coronaviruses. (2) Zoonotic origin: Covid was discovered in a wet market, where past coronaviruses have been known to evolve and leap to humans. Yet, that article completely discounts (1) as evidence, while calling the evidence of it occurring near WIV "a coincidence": > There is currently no evidence that SARS-CoV-2 has a laboratory origin. There is no evidence that any early cases had any connection to the WIV, in contrast to the clear epidemiological links to animal markets in Wuhan, nor evidence that the WIV possessed or worked on a progenitor of SARS-CoV-2 prior to the pandemic. The suspicion that SARS-CoV-2 might have a laboratory origin stems from the coincidence that it was first detected in a city that houses a major virological laboratory that studies coronaviruses That is a biased interpretation. Then it goes on to say that (2) does count as evidence, even though there's no reservoir animal that could make the direct connection: > We contend that although the animal reservoir for SARS-CoV2 has not been identified and the key species may not have been tested, in contrast to other scenarios there is substantial body of scientific evidence supporting a zoonotic origin. Certainly, if you discount all the evidence coming from your opposition, and foreground all the evidence that agrees with you, it's going to look like your side is right.
- fasterik 3y ago
  It's not circumstantial evidence in the case of the market, there is direct evidence. You're ignoring the fact that contact tracing of early cases pointed to employees of the market and people who visited the market, and that SARS-CoV-2 was found in environmental samples from the market. On the other hand, there is no contact tracing and no biological sample that leads to the WIV or its employees.
  - tripletao 3y ago

IanCal 3y ago

> I've linked here to a Lancet correspondence where top scientists "strongly condemn conspiracy theories suggesting that COVID-19 does not have a natural origin". I guess that's not quite the same thing as "probability zero"; but isn't it even worse? I remember conspiracy theories that it had been designed and deliberately released, so no it's not really the same.

tripletao 3y ago
Is there anything in that article that makes you think their condemnation is limited to theories of deliberate release? I don't see it, and I don't think e.g. Facebook did either--they justified their ban with the (false) scientific consensus established by papers like that Lancet correspondence, and their ban applied to accidental release too.