Where did it come from?
Although the natural reservoir of the virus is believed to be bats with a 96·2% sequence identity, as it’s reported by Shi et al.(P. Zhou et al., 2020b), however, its intermediate host is not yet determined.
Experiment carried out by researchers from HK (Lam et al.) also displayed 85·5% to 92·4% sequence identity with that of the pangolin-derived coronavirus, together with some other evidence suggesting that Malayan pangolins in southern China could be the intermediate host.(Lam et al., 2020)
However, plenty of issues are still vague, whereas the theory itself still is not fully proved. Some scholar points out that the result only indicates that the virus is possibly originated from pangolins but not firmly confirm the pangolin must be the intermediate host. Lam’s research group also stated their confusion that the pangolin has actually a comparatively limited population and they are entitled to be endangered in many places and the high sequence identity between the viruses may be explained by convergent evolution. And therefore, further investigation on this subject is needed.
Other than pangolins, snakes and minks was suspected to be the intermediate host for a short period of time, but after an intense debate, all proposal was rejected.
To be short, most debate about the intermediate host of SARS-CoV-2 can be found on website Biorxiv (https://www.biorxiv.org/). Discussion of which animal is the intermediate host end up with nothing, leaving the question still in mystery. The only thing that had been determined is the virus originates from bats.(P. Zhou et al., 2020b)