A finding on a hox gene pushes common ancestry back even further. According to the story in Foxnews:

"[Zerina] Johanson and her colleagues found that the genes involved in creating the Australian lungfish's fins made proteins in a nearly identical pattern as in tetrapods by acting on the small fin bones but not the rest of the limb.

"Because of the similarities, we can say that fish fins have similar structures to tetrapod digits, [and that] tetrapod digits are no longer unique to the group," Johanson told LiveScience.

Further evidence of evolution in the works.