Dogs Our Friends Since Long Ago-www.kepu.net.cn

Pets Early in human history, man domesticated an early ancestor of the modern day dog. For its part, this creature helped protect people from wild animals and guarded his domestic animals such as goats and sheep. In return, it received food and shelter. Over time, man and dog came to trust each other. These first "dogs" were mostly likely especially gentle jackals, or perhaps ailing wolves exiled from their packs. Traces of an indigenous dog family can be found in almost all parts of the world. There are several exceptions –in New Zealand, the Polynesian Islands, Madagascar, the eastern islands of the Malaysian Archipelago and the West Indian Islands have no evidence of any dog, fox or wolf existing as a native animal. In the ancient Oriental lands, and generally among the early Mongolians, the dog remained savage and neglected for centuries, prowling in packs, gaunt and wolf-like, as it prowls today through the streets and under the walls of every Eastern city. No attempt was made to allure it into human .panionship or to improve it into docility. It is not until we .e to examine the records of the higher civilizations of Assyria and Egypt that we discover any distinct varieties of canine form. The great multitude of different breeds of the dog and the vast differences in their size, points, and general appearance are facts which make it difficult to believe that they could have had a .mon ancestry. One thinks of the difference between the Mastiff and the Japanese Spaniel, the Deerhound and the fashionable Pomeranian, the St. Bernard and the Miniature Black and Tan Terrier, and is perplexed in contemplating the possibility of their having descended from a .mon progenitor. Yet the disparity is no greater than that between the Shire horse and the Shetland pony, the Shorthorn and the Kerry cattle, or the Patagonian and the Pygmy; and all dog breeders know how easy it is to produce a variety in type and size by studied selection. In considering the question of dogs and wolves sharing a .mon origin, we should first look at their skeletal structures, or the osseous system. These are close enough in both species that their transposition from one to the other could hardly be noticed. 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 .mon wolf has so much the appearance of a large, bare-boned dog, that a popular description of the one would serve for the other. Nor are their habits different. The wolf’s natural voice is a loud howl, but when confined with dogs he will learn to bark. Although he is carnivorous, he will also eat vegetables, and when sickly he will nibble grass. In the chase, a pack of wolves will divide into parties, one following the trail of the quarry, the other attempting to intercept its retreat, exercising a considerable amount of strategy, a trait which is exhibited by many of our sporting dogs and terriers when hunting in teams. Yet another similarity between canis lupus and canis familiaris is the gestation period, which is sixty=three days for each. The wolf’s litter usually has from three to nine cubs. These are blind for twenty-one days. After two months of being suckled, they are capable of eating half-digested flesh which their dam or even sire has disgorged for them. The dogs and wolves native to almost all regions closely resemble each other in size, coloration, form and habit, a fact too widespread to be simply coincidental. An observer in 1829, Sir John Richardson, .mented that the only difference he could see between the wolves of North America and the domestic dog of the Indians was the greater size and strength of the wolf. It has been suggested that the one incontrovertible argument against the lupine relationship of the dog is the fact that all domestic dogs bark, while all wild canidae express their feelings only by howls. But the difficulty here is not so great as it seems, since we know that jackals, wild dogs, and wolf pups reared by bitches readily acquire the habit. On the other hand, domestic dogs allowed to run wild f.et how to bark. The presence or absence of the habit of barking cannot, then, be regarded as an argument in deciding the question concerning the origin of the dog. We might consider Darwin’s belief that domestic dogs descended from several species of wolf from places as diverse as Europe, India and North Africa, as well as several species of jackal, and possibly from one or more species now extinct. This suggestion that our modern dogs had such a diverse ancestry could be the truest explanation we will find. About the Author: 相关的主题文章: