[riyadparvez]

According to this

> Sep 9, 2003 (CIDRAP News) – Chinese scientists found that animals sold at street markets in Guangdong, China, carried a coronavirus nearly identical to the SARS coronavirus, according to a report published recently in Science.

> The animal viruses were found in Himalayan palm civets and raccoon dogs, which were sold for food in the markets, according to the report. The findings indicate a route of transmission between species but do not reveal whether these animals are the virus's natural reservoir or contracted it from another source, according to the report.

Source [1].

The same thing didn't happen for SARS-CoV2. I believe none of the animals in the wet market has been tested positive for SARS-CoV2 or SARS-CoV2-like viruses [2].

[1] https://www.cidrap.umn.edu/news-perspective/2003/09/animals-...

[2] https://www.technologyreview.com/2021/03/26/1021263/bat-covi...

[sudosysgen]

Wait what? So we agree that they didn't find the oroginal reservoir, just a similar virus, right? Meaning, that it's not a zootoc link, as you previously asked for. You understand that it isn't possible anymore, because the current SARS-CoV-2 would almost certainly displace them now that it's endemic, correct?

So why do you expect the same thing to happen now that it's very unlikely, knowing that there is no way to know that these viruses actually are the ancestors and may very well have been cousins of SARS, that would have disappeared if SARS was more contagious.

To find an actual virus that is actually an ancestor of SARS, we had to wait until 2017. What you cited wouldn't meet the criteria you yourself set forth, and for this virus it would be impossible to find on the same timeframe. So I really don't get neither how this validates your point that we would expect to find the zoonitc link in a year, nor even how it would fit into an argument that it's unexpected we didn't find this.

[tripletao]

I think you've misunderstood the difference between the proximal and reservoir hosts, because your comment is almost entirely wrong. As noted in the article linked above, scientists researching the original SARS found the exact (within the few mutations expected on any short transmission chain) virus that infected humans in palm civets and raccoon dogs, within about a year. These are the proximal hosts, i.e. the hosts believed to have infected humans. Once a proximal non-human animal host is found, we can be very confident that the virus is zoonotic.

Much later, Dr. Shi discovered that the greatest diversity of similar viruses was in bats. The bat viruses are less closely related to human SARS than the palm civet or raccoon dog viruses; but there's a lot of them, and they look ancestral. We therefore believe that the virus mostly evolved in bats, then was transmitted to the palm civets and raccoon dogs, evolved a little bit more there, and finally was transmitted to humans. This was very important in understand the evolutionary history of the virus, but provided no new information on how humans were first infected.

Knowing one of the classes of host doesn't imply knowing the other:

1. For the original SARS, we found the proximal host within about a year. Much later, Dr. Shi found the reservoir host.

2. For SARS-CoV-2, we knew the reservoir host immediately, because it's closely related to the original SARS. After two years of searching, we still haven't found the proximal host.

If one exists, the proximal animal host of SARS-CoV-2 is probably in China. Since China has seen low human spread (probably more than their official statistics, but clearly far less than the rest of the world), I don't see why you'd expect a human variant to displace the original zoonotic variant. There's also no particular evolutionary pressure for that--a variant evolved in humans might happen to be more transmissible in the proximal host animal, but that's not what's getting selected for when the virus is transmitted between humans.