Compare the elegant grace of a running wolf with the comical shuffle of a waddling dachshund, and you begin to understand what millennia of domestication and artificial selection can do to an animal. As dachshunds develop, the growing tips of their limb bones harden early, stunting their growth and leading to a type of dwarfism called chondrodysplasia. The same applies to at least 19 modern breeds including corgis, Pekingese and basset hounds, all of which have very short, curved legs.

These breeds highlight the domestic dog’s status as the most physically diverse of mammals. Now, a team of scientists led by Heidi Parker from the National Human Genome Research Institute have found the genetic culprit behind the stumpy limbs of