Two years after the known human case of COVID-19, the mystery of the origin of SARS-CoV-2 remains unresolved. Did the virus emerge from an animal in nature, or could it have accidentally leaked from a research lab in Wuhan, China? Shockingly, the world appears to be no closer to knowing the crucial answer.

In this first of two episodes, we get a brief explanation of the growing controversy from our co-host, Jim Meigs, who has written about allegations of a scientific cover-up. Molecular biologist Alina Chan, a postdoctoral fellow in a gene therapy lab at the Broad Institute, is our interview guest.

Dr. Chan first became widely known last year for suggesting that COVID-19 could have escaped from a laboratory. Her early research was called a "conspiracy theory" by leading scientists and mainstream media journalists. But in recent months, expert views of this mystery have decisively changed.