In the five years since the COVID-19 pandemic erupted in Wuhan, China, a bitter international debate has raged among scientists, politicians, and journalists over the virus’s origin and who is to blame for the more than 7 million deaths it’s caused worldwide.It’s a debate in which legitimate scientific arguments vie for attention with partisan attacks and wild conspiracy theories. But so far, there is no smoking-gun evidence to definitively resolve whether COVID-19 spilled over naturally from an...