What do you do with half a leg?

Yesterday, I told you about new research involving Tiktaalik, an ancient sort-of-fish that represents the first known example of legs. Only the Tiktaalik's legs aren't exactly legs as you and I would think of them, especially the back ones. They're still kind of more like fins. Weird fins. Weird fins that Tiktaalik used to support its own weight in short jaunts across land. So how did that work? At Not Exactly Rocket Science, Ed Yong writes about new research into the neural and physical changes that might have allowed ancient sort-of-fish to use their weird fins in new ways.