Re: the chimera vs mosaic, that's not particularly true.
If I take a known virus and make a single mutation (insertion of a furin site in this case), then I wind up with the same virus, + a furin. If I take that mutated virus, and then passage it through multiple generations in lab grown hosts, it will mutate at random throughout the genome.
The exact rate and the time it would take is heavily debated, but one important note is that viruses with an RNA-dependant RNA polymerase are, as an evolutionary strategy, quite poor at preserving their own genetic information. They have the highest error rate of replication of any known organism. Which means, after some discrete amount of generations, you could wind up with some sort of "mosaic" + "chimeric" virus. Again though, how many generations is under hot dispute. And how long that would take in nature vs in a laboratory is also under hot dispute.
100% of the evidence for lab leak is circumstantial. But we know two things:
1) If I set out to design a SARS-CoV 2, it's technically feasible. And there's reason to be interested in this type of research. And lab accidents involving pathogens can and do happen.
2) There's no single piece of evidence concretely and completely ruling it out. Which is unfortunate.
I'm a structural biologist, I primarily study viruses, I also engaged heavily in that topic you mentioned (against my better judgement). At the moment, I have a mental probability (which is probably incorrect) of wild virus 90% chance, lab leak 10% chance. I'd be extremely surprised if it was a lab leak, but I also can't sufficiently falsify that hypothesis to complete write it off.
Do you know if the early (March 2020) phylogenetic work[1] that showed that the most ancestral genomes extracted from early human samples weren't from Wuhan has stood up to scrutiny?
I just have a hard time understanding why so clear evidence of the epidemic starting outside Wuhan is missing from the debate, so I'd appreciate if you could comment on it.
In my opinion this is the single strongest piece of evidence against the lab-leak hypothesis (and it also refutes the whole "furin-site uses non-canonical amino acids which shows evidence of human involvement" hypothesis as well). I haven't found anything disproving it, and I have looked a fair bit. However, epidemiology is not anything I know about, so I'm about on the same level as anyone else there.
Primarily Occam's razor. The total area available to coronaviruses in the wild to replicate and mutate in is orders of magnitude greater than the area available in a laboratory.
It tilts the needle, yes, but there are numerous other pieces of evidence that tilt it in the other direction. Hence the 90%/10% split in my mind. But I won't fault anyone else for having a different split. I think that's reasonable.
I am not an expert in the field, but I don’t find this math convincing - I arrive at the opposite conclusion. This was not a random lab and the outbreak didn’t just start anywhere.
This is already answered in GP comment: a career in biology would suffer if biological research were to become more suspect to the general population, with a corresponding loss of prestige.
If I take a known virus and make a single mutation (insertion of a furin site in this case), then I wind up with the same virus, + a furin. If I take that mutated virus, and then passage it through multiple generations in lab grown hosts, it will mutate at random throughout the genome.
The exact rate and the time it would take is heavily debated, but one important note is that viruses with an RNA-dependant RNA polymerase are, as an evolutionary strategy, quite poor at preserving their own genetic information. They have the highest error rate of replication of any known organism. Which means, after some discrete amount of generations, you could wind up with some sort of "mosaic" + "chimeric" virus. Again though, how many generations is under hot dispute. And how long that would take in nature vs in a laboratory is also under hot dispute.
100% of the evidence for lab leak is circumstantial. But we know two things:
1) If I set out to design a SARS-CoV 2, it's technically feasible. And there's reason to be interested in this type of research. And lab accidents involving pathogens can and do happen.
2) There's no single piece of evidence concretely and completely ruling it out. Which is unfortunate.
I'm a structural biologist, I primarily study viruses, I also engaged heavily in that topic you mentioned (against my better judgement). At the moment, I have a mental probability (which is probably incorrect) of wild virus 90% chance, lab leak 10% chance. I'd be extremely surprised if it was a lab leak, but I also can't sufficiently falsify that hypothesis to complete write it off.