New diseases have emerged throughout human history, and we have seen two major coronavirus outbreaks in the last two decades: SARS and MERS. So we shouldn’t be surprised by the arrival of the covid-19 virus.
However, rumours on social media suggest that the outbreak was human-made. Some say the virus leaked from a Chinese lab studying coronaviruses. Others suggest the virus was engineered to spread among humans.
Even the most secure laboratories do sometimes have accidents, and a human-engineered pandemic has been identified as a possible risk to our civilisation, but there is no good evidence that either has happened.
Many similar viruses are found in wild bats, and it seems likely that is the origin of this one, probably via an intermediate host. Similarly, we know that both SARS and MERS came from bats, so there is no reason to invoke a laboratory accident.
Researchers led by Shan-Lu Liu at the Ohio State University say there is “no credible evidence” of genetic engineering (Emerging Microbes & Infections, doi.org/dpvw). The virus’s genome has been sequenced, and if it had been altered, we would expect to see signs of inserted gene sequences. But we now know the points that differ from bat viruses are scattered in a fairly random way, just as they would be if the new virus had evolved naturally.