Centuries of selective breeding by humans has resulted in dogs being considerable more genetically diverse than most other mammals, and as such dogs are the only animal with such a wide variation in appearance without speciation, "from the Chihuahua to the Great Dane".
Centuries of selective breeding by humans has resulted in dogs being more genetically diverse than most other mammals by a considerable margin. As such, dogs are the only animal with such a wide variation in appearance without speciation, "from the Chihuahua to the Great Dane".