Mutts are mixed breeds of dogs that has two species of dogs in them. Mutts have a less chance of having a type of medical problem.
Mutts come in all shapes and sizes.
Originally it was thought that dogs came from a cross between the Jackal or Jackal/Wolf. Scientists now believe that dogs first originated in Eurasia, between 12000-14000 years ago, from a smaller southern strain of a Gray Wolf called, Canis Lupus Pallipes, which can still be found in India today. Although called the "Gray Wolf," the coat comes in a wide variety of coat colors. It was distributed throughout Europe, North America, and Asia. Some other possible ancestors of the dog include the Woolly Wolf of North India and Tibet, and the Desert Wolf of the Middle East. It is known for certain that all domestic dogs first originated from one or a combination of these sources. The domestic dog is not genetically connected with any other species. From the beginning of the Bronze Age, circa 4500 BC, five distinct types of dog have been identified from fossil remains. Among them were Mastiff, wolf-like dogs, Greyhounds, Pointer-type and Sheepdogs. These basic types proliferated by natural genetic mutation and selective breeding produced the approximately 400 different types of dog breeds we know today. A "pure bred" dog is a group of dogs that look alike and are the product of parents with a similar appearance and which, when mated together, reproduce their kind. A mongrel or Mutt is a dog whose parents are unknown or is not considered to be purebred.