Can a fin become a limb?

Researchers examine what's happening at genetic level to drive patterns in fin skeleton versus limb skeleton and find mutants with modified fins in a more limb-like pattern by adding new bones, complete with muscles and joints. The results reveal the ability to form limb-like structures was present in the common ancestor of tetrapods and teleost fishes and has been retained in a latent state which can be activated by genetic changes.

source https://www.sciencedaily.com/releases/2021/02/210204144032.htm