One year ago, the first cases of a novel pneumonia were reported from Wuhan, China. While COVID-19 still rages, scientists are trying to discover where SARS-CoV-2 [sahrs-cō-vē-2] came from and how it infected people.

The virus is thought to have evolved from a bat coronavirus, but because the genetic codes of related bat coronaviruses and SARS-CoV-2 have differences, it likely passed through at least one other species in between. Researchers are conducting interviews, testing biologic samples and surveying environmental data to determine the origin.

Even the timeline is under investigation. The virus was found in samples from Italy collected in December 2019, raising questions of where and when the virus first emerged.

If scientists can identify the ecologic chain of events, we might be able to head off future pandemics. It’s a daunting task.