The Common Ancestors Of Dogs By Grant Carroll

The great multitude of different breeds of dog and the vast differences in their size, points, and general appearance are facts which make it hard to believe that they have a shared ancestry. One thinks of the difference between the Mastiff and the Japanese Spaniel, the Deerhound and the puffy Pomeranian, the St. Bernard and the Miniature Black and Tan Terrier as well as the beloved Chihuahua, and is perhaps confused by the possibility of their having descended from a common progenitor. However, the difference is no greater than between types of horses, cattle or even humans; and all dog breeders know the simple steps needed to produce a variety in type and size by breeding.

Before one can fully understand that all dogs as well as their wild counterparts share a close relation, one must start by learning the basic physical similarities between them. The skeletal system of the two animals is an ideal place to begin study since they are virtually interchangeable. The spine of the dog consists of seven vertebrae in the neck, thirteen in the back, seven in the loins, three sacral vertebrae, and twenty to twenty-two in the tail. In both the dog and the wolf there are thirteen pairs of ribs, nine true and four false. Each has forty-two teeth. They both have five front and four hind toes, while outwardly the common wolf has so much the appearance of a large, bare-boned dog, that a popular description of the one would serve for the other.

The habits of both species are similar as well. In the wild, wolves are known to howl in their packs, but as soon as a wolf is grouped with dogs, he takes on barking behavior. Although he is carnivorous, he will also eat vegetables, and when sickly he will nibble grass. Hunting behavior is also very similar among wolves and sporting dogs; they both hunt in packs and divide up strategically to catch their victims.

A further significant point of resemblance between the wild wolf and the Canis familiaris lies in the fact that the period of gestation in both species is sixty-three days. There are from three to nine cubs in a wolf's litter, and they are blind for twenty-one days. They are nursed for two months, but at the end of that time they can eat half-digested flesh regurgitated for them by their dam or even their sire.

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