"Virus outbreak: research says COVID-19 likely synthetic," shouted the headline in the Taipei Times on February 23, 2020. The idea that the novel coronavirus SARS-CoV-2 arose in a virology lab in China – by accident or as a bioweapon – has sparked an undulation of accusation and explanation ever since.
The latest chapter: An "open letter" in the April 7, 2021 New York Times, calling for "a full investigation into the origins of COVID-19." The two dozen scientists who signed the letter cite the continuing absence of a "robust process" to examine critical records and biological samples. Their argument responds to the WHO's March 20 press event that barely considered an origin other than from a natural spillover.
But two types of new information may counter the lab escapee hypothesis: filling-in-the-blanks of mammals that may have served as "missing links" in the evolution of disease transmission, and the rapid rise of viral variants reflecting a tendency to mutate that may underlie SARS-CoV-2 seemingly bursting from out of nowhere.
So here is my view, as a geneticist, of three possible origins of SARS-CoV-2:
1. Bioweapon – an engineered pathogen or escape of a natural candidate
2. Gradual evolutionary change through intermediate animal hosts, mutating along the way and becoming more virulent
3. "Mutator" genes that trigger mutations in other genes, speeding evolution
To continue reading, go to my blog DNA Science at Public Library of Science.