Yet another reason to be suspicious of common assumptions..
RaTG13 is the name, rank and serial number of an individual horseshoe bat of the species Rhinolophus affinis, or rather of a sample of its feces collected in 2013 in a cave in Yunnan, China. The sample was collected by hazmat-clad scientists from the Institute of Virology in Wuhan that year. Stored away and forgotten until January this year, the sample from the horseshoe bat contains the virus that causes Covid-19.
The scientists were mostly sampling a very similar species with slightly shorter wings, called Rhinolophus sinicus, in a successful search for the origin of the virus responsible for the SARS epidemic of 2002-03. That search had alarming implications, which were largely ignored.
In Shitou Cave, south of Kunming, the capital of Yunnan, they found viruses in the bats’ droppings and anal swabs that were more similar to human SARS than anything found in palm civets, the small mammals that until then were presumed to be the source of human infection. Back in the laboratory, they found that one of the viruses from bat droppings, called WIV1, could thrive in monkey and human cells specially engineered to activate the gene for ACE2 receptors, the lock to which a coronavirus’s spike protein can fit as a key. This suggested that people could catch SARS directly from a bat dropping.
Then in 2016, Ralph Baric and colleagues at the University of North Carolina at Chapel Hill showed that the same bat virus could infect live mice that had been engineered to express the human gene for the ACE2 receptor. The virus was “poised for human emergence,” as the title of Dr. Baric’s paper put it.
https://www.google.com/amp/s/www.wsj.co ... 1586440959
So if you go back to that chart, the original bat virus they used as the precursor to type A coronavirus, if I am not mistaken, came from bat RaTG13. Sure, that bat was collected from a cave in Yunnan province, but it also made its way to that research lab in North Carolina. Now, given that the first cluster of mutations (type A) are monopolized by Americans, and it is mostly found in samples taken here in the United States, I would argue for the possibility (maybe even the higher likelihood) of this actually starting from a lab leak in North Carolina.
Obviously the genomic data is sparse. But I think there are too many coincidental interactions between humans and this virus to dismiss a lab leak, and the assumption that any lab leak
had to be from a Chinese lab unsupportable based on evidence. It is possible it leaked from one of these two labs, but also possible it leaked from the lab in North Carolina.