4 ms·

Looking at the report, most of the likelihood is from a single "prior". The whole likelihood basically hinges on the fact that the outbreak occurred in Wuhan a

Looking at the report, most of the likelihood is from a single "prior". The whole likelihood basically hinges on the fact that the outbreak occurred in Wuhan and that the Wuhan Institute of Virology has been working for decades on enhancing coronavirus strains. That's quite strongly circumstantial but it's not evidence. Possible chimerization and furin-cleavage insertion seem a lot more interesting imo but are weighted much lower. Based on their report [1], most of the likelihood of lab-escape (almost 50x weight) just stems from the fact that the outbreak is in Wuhan. They state that it's because of the proximity to Wuhan Institute of Virology (WIV) and the lab's gain-of-function research - only one of 5 locations world-wide. That single "bullet-point" re-weights zoonotic origin from 97% to 56% and lab-escape from 1.4% to 42%. Otherwise their final likelihoods would be: "zoonotic" 85.5%, "lab-escape" 8.5%, "bioweapon" 6%. [1] https://www.rootclaim.com/analysis/what-is-the-source-of-covid-19-sars-cov-2 https://www.rootclaim.com/analysis/what-is-the-source-of-cov...

nwah1 6y ago
And that is very solid bayesian logic. Wuhan has the only BSL-4 lab in China, and was specifically working on gain-of-function research on coronaviruses. The initial prior of zoonotic origin simply because that was usually the case in the past is just as circumstantial, but also just as solid in bayesian terms.
- malcolmgreaves 6y ago
  Belief in the posterior update is still completely circumstantial. It's not direct evidence, nor an explained cause other than proximity. I'd argue they miscalcualted the probability change with respect to this piece of information.
- someperson 6y ago
  > Wuhan has the only BSL-4 lab in China The Harbin Veterinary Research Institute in Heilongjiang is another BSL-4 lab
  - nwah1 6y ago
    Fair enough, but it had only been operational for a year at the time of the outbreak and is focused on veterinary science.
glenstein 6y ago
In addition to that, one of their other priors supporting lab escape appears to be plainly wrong: >Furin cleavage sites are not common in other related coronaviruses. However, this claim appears to have been investigated and debunked [1] >Furin cleavage sites occurred independently for multiple times in the evolution of the coronavirus family, supporting the natural occurring hypothesis of SARS-CoV-2. [1] https://www.sciencedirect.com/science/article/pii/S1873506120304165 https://www.sciencedirect.com/science/article/pii/S187350612...
- JoshTko 6y ago
  This is key since the entire analysis hinges really on 2 or 3 key assumptions and furin cleavage is one of them.
  - MichaelZuo 6y ago
    “With four parameters I can fit an elephant, and with five I can make him wiggle his trunk.” - John von Neumann

nwah1 6y ago

And that is very solid bayesian logic. Wuhan has the only BSL-4 lab in China, and was specifically working on gain-of-function research on coronaviruses. The initial prior of zoonotic origin simply because that was usually the case in the past is just as circumstantial, but also just as solid in bayesian terms.

malcolmgreaves 6y ago
Belief in the posterior update is still completely circumstantial. It's not direct evidence, nor an explained cause other than proximity. I'd argue they miscalcualted the probability change with respect to this piece of information.
someperson 6y ago
> Wuhan has the only BSL-4 lab in China The Harbin Veterinary Research Institute in Heilongjiang is another BSL-4 lab
- nwah1 6y ago
  Fair enough, but it had only been operational for a year at the time of the outbreak and is focused on veterinary science.

glenstein 6y ago

In addition to that, one of their other priors supporting lab escape appears to be plainly wrong: >Furin cleavage sites are not common in other related coronaviruses. However, this claim appears to have been investigated and debunked [1] >Furin cleavage sites occurred independently for multiple times in the evolution of the coronavirus family, supporting the natural occurring hypothesis of SARS-CoV-2. [1] https://www.sciencedirect.com/science/article/pii/S1873506120304165 https://www.sciencedirect.com/science/article/pii/S187350612...

JoshTko 6y ago
This is key since the entire analysis hinges really on 2 or 3 key assumptions and furin cleavage is one of them.
- MichaelZuo 6y ago
  “With four parameters I can fit an elephant, and with five I can make him wiggle his trunk.” - John von Neumann