SARS-CoV-2 is closely related to the virus that causes severe acute respiratory syndrome (SARS) that swept the world nearly 20 years ago. The scientists looked at how SARS-CoV differs from SARS-CoV-2 -- several key letter changes in the genetic code. In computer simulations, however, the mutations in SARS-CoV-2 did not appear to help the virus bind to human cells very well. If scientists had intentionally engineered the virus, they wouldn't have selected mutations that computer models showed didn't work. But it turns out that nature is smarter than scientists, and research has found that the novel coronavirus has found a better way to mutate -- and it's completely different -- unlike anything scientists can create.
https://www.livescience.com/coronavirus-not-human-made-in-lab.html