From Newsweek:
Cambridge University researchers “…have created a network analysis using over 1,000 coronavirus genomes. This includes patient infection date and the “type” of virus the person was infected with. There are three types—A, B and C. A is closest to the coronavirus found in bats and is thought to be the original human virus genome. This type was found in Chinese and American individuals, with mutated versions in patients from Australia and the U.S.
However, A was not the virus type found in most cases in Wuhan, the city in China where COVID-19 was first identified. Instead, most people there had type B. Researchers suggest there was a “founder event” for type B in Wuhan. Type C, the “daughter” of type B, is what was identified in early cases in Europe, as well as South Korea, Singapore and Hong Kong—but appears absent from mainland China.”