New research has found a gene that looks to be the reason why rabbits, and perhaps all bouncing mammals hop. Using an unusual type of rabbit, called a sauteur d'Alfort, which doesn't hop, but runs on its front paws like a handstand, scientists have found a specific gene called RORB, that's missing in these rabbits. Defects in this gene may have damaging effects in all mammals though, not just rabbits. Adam Murphy spoke to Leif Andersson from Uppsala University about these bizarre bunnies... Like this podcast? Please help us by supporting the Naked Scientists