<div>Reverse studies — getting samples of viral material from patients and working backward — are immediately hindered by complications such as the question below: </div><div>
“We found that the sequence of viruses isolated from one patient that lived in the United States on January 21 (USA_2020/01/21.a, GISAID ID: EPI_ISL_404253) had the genotype Y (C or T) at both positions 8,782 and 28,144, differing from the general trend of having either C or T. Although novel mutations could lead to this result, the most parsimonious explanation is that this patient may have been infected by both the L and S lineages (Fig. 6). The sample of USA_2020/01/21.a was collected from a 63-year-old female patient living in Chicago (from GISAID). Based on the report from the United States Centers for Disease Control and Prevention (https://www.cdc.gov/media/releases/2020/p0124-second-travel-coronavirus.html).”
On the origin and continuing evolution of SARS-CoV-2
Working backwards, from the samples of SARS-CoV-2 taken from infected humans, to the speculation of this coronavirus being (or not being) related to nature, is going to produce many theories of virus origin.