It began, almost certainly, in a bat. Then, just as SARS jumped to civets from bats, the virus that causes COVID-19 passed to another mammal, possibly a pangolin. Finally, late last year, the new coronavirus most likely jumped to humans in a wildlife market in Wuhan, China, a densely populated city...

In March, as people struggled to understand how the precursor of the virus that causes COVID-19 emerged from horseshoe bats in southern China and reached humans in the central city of Wuhan, Humane Society International policy specialist Peter Li fielded one question again and again: “Why do Chinese...