Everything at stake in the hunt for COVID-19’s origins

Since the early days of the pandemic, there's been broad scientific consensus that the coronavirus that causes COVID-19 originally developed in bats before eventually moving to humans, just as the viruses behind SARS and MERS did. An alternate explanation, that the virus escaped from a Chinese lab, was largely dismissed as something between highly unlikely and wildly conspiratorial.

Over time, however, the lab leak theory has gained more traction among respected scientists as circumstantial evidence has piled up and proof of animal transmission hasn’t emerged. To be clear, no explanation of the origins of...