Sometimes it is difficult to believe that all dogs are related. How can the tiny chihuahua be from the same species as the massive Great Dane? A male beagle is usually between 14 and 16 inches tall; a male English Mastiff can be as tall as 28 to 36 inches. One does not see similarly massive size disparities in other species, much less humans. (This would be the equivalent of adult humans regularly varying from two feet to six feet tall.)
Clearly there is something in the canine genetic code that explains this, just as doggie DNA has unlocked secrets regarding sled dogs, brachycephalic heads and self-domestication. For years scientists have attempted to solve the biological puzzle that can cause up to 40-fold size differences between dogs — and now, thanks to authors of a recent paper published in the journal Current Biology, we have the answer.
