It sounds like a conundrum that Rudyard Kipling would have tackled in his Just So stories, but it turns out the reason why rabbits hop is rooted not in fables but genetics.
Researchers say that by studying an unusual breed of bunny that walks on its front paws, they have pinpointed a key gene that is necessary for animals to adopt a typical gait. For rabbits, as well as animals such as hares and kangaroos, that is the ability to hop.
“If you [were to] introduce the same mutation [seen in these unusual rabbits] in humans, you would not remove hopping but you will change our locomotion in some other way,” said Prof Leif Andersson, co-author of the research, from Uppsala University in Sweden.
Writing in the journal Plos Genetics, Andersson and colleagues reported how they made their discovery by focusing on the sauteur d’Alfort breed of domestic rabbit. Rather than hopping, these animals adopt a “handstand” pose and walk forward on their front paws. The breed is also known for having eye problems, including blindness and cataracts.
Both characteristics were known from breeding experiments to be caused by a mutation in a single gene. However, which gene contained the mutation was unknown.