It took 9 months to find the source of MERS (camels). It took 14 months to find the origin of SARS1 (bats).
What evidence do you have that this was transmitted from an animal carrier? What mammal in China (it's not like there are that many mammal species living in the Wuhan metropolitan area) has been identified that easily catches COVID? The answer is zero.
The most likely explanation for this, which fits with all the other circumstantial data, is that the zoonotic origin was a genetically engineered mouse with human ACE2 receptors lining it's lungs. Note that I'm saying the mouse was genetically engineered, not the virus itself. The virus could easily evolve to infect humans by repeatedly exposing the humanized mice to the original, completely natural origin bat viruses.
Calling out "mental gymnastics" when you are acting as if it's a pure coincidence that a bat virus pandemic originated in a city containing the world's leading bat-borne virus research facility is the height of hypocrisy and cognitive dissonance. And before you say that the lab is in Wuhan because that's where the viruses are, no, it's not. The viruses historically have emerged in Yunnan province, in remote caves 1000 KM away from Wuhan.
https://reporter.nih.gov/search/xQW6UJmWfUuOV01ntGvLwQ/proje...
It's right at the bottom of the summary.
"3. Test predictions of CoV inter-species transmission. Predictive models of host range (i.e. emergence potential) will be tested experimentally using reverse genetics, pseudovirus and receptor binding assays, and virus infection experiments across a range of cell cultures from different species and humanized mice."
But sure, it's fringe and unlikely that the virus leaked out of a lab where it was specifically stated by the scientists applying for the grant that the funding would be used for testing interspecies transmission of bat coronaviruses with humanized mice. The lab doing this being in Wuhan, where the pandemic originated is also totally fringe and unlikely, is totally unrelated, right?
Gain of function proponents are ignoring research that indicates it's not possible to generate a virus dangerous to humans without leaving specific telltales. While this study isn't necessarily conclusive or a door slam in the face of lab leak, it's pretty huge data point that makes it far less likely.
I also forgot to mention that he deliberately ignored the humanized mice being the location of the serial passage work, and straw manned a "petri dish". Completely misrepresenting the fact that was most crucial.
In the future, using a Twitter account with locked comments is inadvisable. He blocked comments for a reason.
His entire argument is very straightforward. Zoonotic origin is highly plausible, has caused previous SARS outbreaks, has no evidence against it. Lab leak is possible, though it has no precedent and there's evidence that makes it less likely. There's no conclusive evidence for either. The balance of evidence and history leans heavily to zoonotic. There is absolutely nothing anyone has said in this thread that he didn't directly address nor anything that weakens his argument. Anyone on the lab leak train right now is basing it purely on bias.
There was a lab leak of SARS1 in 2004 which infected a lab worker and the people he came in contact with. https://www.google.com/amp/s/www.the-scientist.com/news-anal...
We've seen lab leaks and this is supposedly different because it's not disclosed and numerous other reasons making it hard to prove. We know about lab made viruses which this is supposedly different because it somehow looks like a virus of zoonotic origin. We've seen the Chinese government cover up embarrassing situations but this is different because there was heavy involvement from American researchers and American public educational institutions and they are in on the cover up too for some reason. We've seen the US government dislose previously classified information but this is different because all of the government officials who say they saw classified information about a lab leak (and were in a position to declassify said information) did not accompany their accusations with gathered intelligence. At some point we should recognize that these necessary mental gymnastics put the theory well into crank territory.