Covid-19 virus originated in Wuhan "wet market", where freshly-slaughtered wild meat is preferred. It's a perfect setting to facilitate virus movement from animal to animal and from animal to human.

https://www.theguardian.com/environment/2020/feb/25/coronavi...

And it happened before, with SARS in 2003:

https://en.wikipedia.org/wiki/Severe_acute_respiratory_syndr...