There has been an extensive analysis by a virologist on Reddit[¹], who claimed that, very simply, SARS-COV2 is a so-called "mosaic" virus, while man-made viruses are inevitably "chimera" ones. The article does not seem to make this distinction.
The virologist also chimed on HN (besides, calling BS on people who were, out of ignorance, spreading false beliefs), but it seems he's not participating to this post.
It'd be best to have the opinion of a specialized scientist, in order to to have scientific clarity before starting the political arguments.
[¹]=https://www.reddit.com/r/science/comments/gk6y95/covid19_did...
The link you provided does discuss the probability of the virus accidentally leaking from a laboratory, however the reasons provided does not really provide much facts, seemingly more speculation (except for facts regarding who we think is patient zero):
"The WIV, and Dr. Zhengli-Li Shi’s lab group, are extremely well-respected in the virology community. As well respected as many US scientists.
● All the WIV’s sampling of bats and the genomes that they find in bats are publicly available information. Why isn’t SARS-CoV-2 on any of those lists? We would know.
● This doesn’t look anything like any laboratory accident that we’ve seen before.
● The evidence we have points to Patient Zero being nowhere near the City of Wuhan." (https://drive.google.com/file/d/1kAHSEx9-eIyVIahczH8itHaUm9j...)
Occam's Razor, to me, suggests that it's more likely the virus came from the nearby infectious disease lab than from the wet market that operated probably for centuries.
You've generated 2 possible outcomes and gone "yes these are the only possibilities". But why? There was a whole train of transportation bringing things into the city for the lab.
Of course, if it was from that timeline, then the whole "lab escape" thing becomes a bit problematic doesn't it? Because, why would it need to be by activities of the lab specifically? It wouldn't - coz it could really just have rode in on anything. Which would of course mean that actually, it's probably way more likely that a virus which can infect humans, starting out in the wild, and being sample by a lab, probably infected a bunch of humans anyway because it didn't stop being in the wild when it was collected by researchers...
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.
On your latter point, I'll just say that the virus likely needed some time to mutate into a human infectious form, and most of what we're talking about is, where and how did that happen?
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.
Wouldn't the fact that it started in Wuhan point the razor in the direction of lab-escape theory?
He does come off as very arrogant, a lot of his replies were like "yeah but we'd know".
You're not taking a logical position, you're starting from one conclusion "it was a Chinese lab!" and iterating around that, for the sole reason that the only reason the lab is being considered was the usual suspects of conspiracy theory began pushing "Chinese bioweapon" from the outset (and we all know bioweapons require labs, so one had to be found).
Forgive my preference not to generate verbal diarrhea into the page for your reading pleasure. It should be simple to extrapolate many more possibilities from what I stated if someone were willing to put an ounce of thought into it. Which you already did.
Anyway, I presume you are reacting to my summation of comparing the wet market vs lab theories and stating that one, when expanded to include several closely related possibilities, seemed far more likely to me. I stand by my framing, which doesn't preclude that there is another third possible factor, or many more.
I'm not starting from any conclusion like that, and in fact, my whole post was saying that it was likely NOT a bioweapon even if there was a lab escape. Please stop imputing talking points you have heard elsewhere to my argument. It's actually quite rude.