Thanks cutworm!

COVID-19: Did Omicron evolve in mice?

https://www.medicalnewstoday.com/articles/covid-19-did-omicron-evolve-in-mice

• The origin of the Omicron variant of SARS-CoV-2 is uncertain because it contains a large number of mutations that are rare in other known human variants.
• The most popular theory is that Omicron evolved during a protracted infection of an individual with a compromised immune system.
• Scientists at the Chinese Academy of Sciences now report that they have found a pattern of mutations in Omicron that is typical of a virus that has infected mice.
• They believe SARS-CoV-2 jumped from a human to a mouse in mid-2020, then back into a human in late 2021.
• They say it is unlikely that the intermediate host was a laboratory mouse

metmike: The less we know about something or how to completely explain it, the more powerful speculation in that realm is.

I have no idea how it evolved. Maybe the explanation will be more clear at some point but they still haven't been able to explain where COVID came from based on objective science that doesn't get take over by politics.