Pripitomljavanje psa Clutton Brock, Skripte od Arheologija

Preuzmite Pripitomljavanje psa Clutton Brock i više Skripte u PDF od Arheologija samo na Docsity! SECOND EDITION A Natural History of Domesticated Mammals Juliet Clutton-Brock CAMBRIDGE UNIVERSITY PRESS sE Tue NATURAL HISTORY MUSEUM bBHBENMOT  > Dogs Lp Order Carnivora, Family Canidae The increase in the world's population of dogs matches that of humankind for there are dogs in every part of the world that is inhabited by people and today there are more than 400 breeds of domestic dog. Each of these breeds owes its existence to arti- ficial selection by humans, because every dog, whether it is a reat Dane or a Chihuahua, is the descendant of wolves that were tamed by human hunters in the prehistoric period. The I poress of taming probably began at least 15 000 years ago but much has changed in the actual relationship between ian and dog in that period it is difficult to assess. It may be atin fact there is very little difference and the relationship is the same now as it was thousands of years ago. This is use the remarkable kinship and powers of communication exist between human beings and dogs today have devel- dasanintegral part of the hunting ancestry ofourselvesand olf. It is a biological link based on social structures and our patterns thatare closely similar because they evolved both species in response to the needs ofa hunting team, but ch endure today and have become adapted to life in sophis- d, industrial societies. the end of the last ice age in an environment where wolf mans were competing for the same food it is not difficult ise how an alliance could be formed between them. The and children of the hunting communities would give ir to any animal that would stay near them and young would be tamed along with many other animals, both resand ungulates, the species depending on the locality. pe the canids would be the wolfwith jackal in the east, in America the wolf and coyote, in South America various “fox' and the bush dog, in Africa the jackals and he hunting dog, and in Asia the wolf, jackal, and dhole lost of these associations would be ephemeral; if the imals lived to be adults they would move off to find FIGURE 4.1. Jackal, Canis aureus  52 that were different in appearance from the wolf (translated by Forster & Heffner, 1968, p. 307): As guardian of the farm a dog should be chosen which is of ample bulk with a loud and sonorous bark in order thatit may terrify the malefactor, first because he hears it and then because he sees it; indeed, sometimes without being even seen it puts to flight the crafty plotter merely by the terror which its growling inspires. It should be the same colourall over, white being the colour which should rather be chosen fora sheep-dog and black fora farmyard dog; fora dog ofvaried colouring is not to be recommended for either purpose. The shepherd prefers a white dog because it is unlike a wild beast, and sometimes a plain means of distinction is requi d in the dogs when one is driving off wolves in the obscurity of early morning or even at dusk, lest one strike a dog instead ofa wild beast. The farmyard dog, which is pitted against the wicked wiles of men, if the thiefapproaches in the clear light of day, hasa more alarming appearance ifit is black... (XI13) ANIMAL PARTNERS FIGURE 4.4. Australian Aborigines with their tamed dingoes (Canis dingo). Although dingoes have lived wildin Australia for thousands of years they are not indigenous wild animals butare descended from domestic dogs that travelled to the continent from southeastem. Asia with the early human immigrants. In their morph- ology dingoes are closely related to the Indian pariah and New Guinea dogs. They are most interesting relics of the dogs that must have been widespread throughout western and eastern Asia during the prehistoric period and as such they should be conserved (photo Illustrated London News, 1937).  FIGURE 4.5. Mosaic from Pompcii (photo The Mansell Collection). During the Roman period dogs were already as highly domes- ticatedas theyare today although the diversity ofbreeds was not nearly so great. It is probable, however, that some pure lines were already differentiated and, for example, it is likely that dogs resembling the present-day Pekingese were already being bred in China. There are many breeds of dog that appear to bear no resem- blance whatsoever to the wolf and the creation of such an ani- mal as the Pekingese is surely one of the greatest achievements of artificial selection, although it took, maybe, thousands of years to produce. But although the outward appearance of the Pekingese is so dramatically different from that of the wolf its anatomy and physiology are still remarkably similar. The gen- eralmorphology of the bones, apart from their proportions, are the same, so is the dentition, and the shape of the brain and the gut. The food of the Pekingese is digested in the same way as the wolfs, it has the same internal and external parasites and its young take the same length of time to develop in the uterus. Also, despite the ratherabsurd and babyish look of this little dog itsbehaviour can still be remarkably wolf-like. The word babyish is actually the clue to the way in which the wolf has been trans- formed into this other creature because it is the retention of juvenile or even foetal characters in the adult animal that is responsible for the change. The very short facial region of the skull, large brain case, big eyes, short legs, curly tail, and soft fur areall characters thatare found in the foetal wolfbut in the wild animal are lost either before birth or before the period of growth is completed. DoGs 53 The domestic dog has one capability that is never well devel- oped in any canid living wild, and this is the propensity to bark. Wolves and coyotes will bark occasionally in the wild and other members of the canid family will learn to vocalize in captivity but the deep bark of the large breeds of dog, the baying of the Bloodhound, and the yapping of the toy dogs is a product of domestication.A few breeds such as the primitive Basenji do not bark although they can learn to do so, but most dogs have a low level of arousal and it requires little incentive to start them off. Asitis obviously useful for a guard dog to bark at strangers it is most probable that this form of vocalization has been highly selected for. In addition some dogs may bark in an effort to communicate with humans and it could be that they are even attempting to mimic the human voice. The bark is an attention- seeking device that can be associated with play-soliciting, hunting, oraggression. Although the wolf does not normally bark in the wild it can learn to do so in captivity and in general the vocalization patterns of the wolf and the dog are very similar. Those of the jackal, however, are quite different and provide sound evidence that the jackal has had little to do with the ancestry of the dog. In 1950 J.P. Scott, who carried out fundamental investiga- tions in the USA into the social behaviour of the wolfand how it relates to socialization in the dog, wrote that the patterns of behaviour of dogs in human society are the same as those of wolves in wolf society. Since that time much further work has been carried outon behaviour patterns in wildand tame wolves, in dogs, and in people, so that it is now possible to state that wolves also behave in human society as they do in wolf society. Many social animals depend on a hierarchical system of differentiation between individuals with reference to reproduc- tion and maintenance of territory, but it is only in the large car- nivoresand in some primates that there is such a rigid structure of personal relationships between individuals as is found in the wolf and in humans. For this to occur there has to be not only dominance behaviour buralso submissive behaviour. Submission has been defined by Schenkel (1967), for the wolfand the dog, as an impulse and effort on the partof the inferior animal towards friendly and harmonic social integration. It is ritualized behav- iour that is characterized by the combination of inferiority and a positive social tendency, or in common language, “love' and it does not contain any element of hostility. The form that the submissive behaviour will take depends on the attitude and behaviour of the superior individual. Ifhe responds ina negative ANIMAL PARTNERS  many different populations of wolves in different parts of the World gave rise to many separate lineages of dogs. The wolf ancestry of the dog has been known for many years, but what is > newand dramatic is that the molecular distance between wolf and dog is so great that, according to Vila and his collaborators, the two species must have separated more than 100 000 years before the present, that is around the time that the earliest evidence for Homo sapiens appears in the fossil record. However, > thereareno remains of canids thatare morphologically similar to the domestic dog until around 15 000 years ago. Further- more, although it is possible to believe that wolves have been > closely associated with hominids, from perhaps even earlier than the evolution of Homo sapiens, it seems more than improb- able that these wolves were reproductively isolated from the wild species to the extent that they became genetically distinct so many thousand years ago. Vila et al. maintain that the earliest domestic dogs could indeed have been genetically distinct, although they did not look any different from wolves. These authors postulate that the change around 15 000 to 10 000 years ago from nomadic hunters to the beginnings of settlement could have imposed new selective regimes on the dogs that resulted in marked morphological divergence from wild wolves atthat period. The majority of the remains of the earliest domestic dogs have been retrieved from archaeological sites in western Asja, although small numbers have also been found in North and South America, north-west Europe (England and Denmark), Fastern Europe, Russia, and Japan. They are nowhere very com- mon until the Neolithic period when livestock animals are of course also represented. These widely distributed but sparse finds give support to the molecular evidence that humans tamed wolf pups in many parts of the world where both species were living as hunters of large mammals and that therefore sev- eral subspecies of wolf have contributed to the ancestry of the dog. In western and southern Asia the subspecies would have been the Arabian and Indian wolves, Canis lupus arabs and Canis lupus pallipes, whilst in Europe and North America it would have FIGURE 4.8. Left mandibular ramus ofan early domestic dog from Palegawra Cave, Iraq, . 8 cm long (photo O Field Museum of Natural History, Chicago). 58 been the much larger wolf Canis lupus lupus that was adapted to life in a colder climate (Fig. 4.9). Although it appears reasonable to assume that these large northern wolves have contributed to the early ancestry of the dog there is very little evidence for it from the skeletal remains. All the finds from the Upper Palaeo- lithic and Mesolithic periods that can be said with certainty to represent domestic dog are from rather small animals, with teeth that are closer in size to the small Asiatic wolves than to the large northern subspecies. At present, the earliest find of a morphologically distinct domestic dog consists of a mandible from a late Palaeolithic grave at Oberkassel in Germany (Nobis, 1979), which is dated to 14 000 years ago. This is 2000 years earlier than the sites in western Asia from where a cluster of canid remains has been identified as dog (Dayan, 1994; Clutton-Brock, 1995; Tchernov & Valla, 1997). These finds have mostly come from Israel but an exception isa mandible with dog-like compacted teeth from the site of Palegawra in Iraq (Turnbull & Reed, 1974; Fig. 4.8). The relatively small size of this jaw and the compacted teeth, particu- larly in the premolar region, are characteristic of early domestic dogs. The earliest cultural evidence for the dog comes from the site of Ein Mallaha in Israel where, in a stone covered tomb, an elderly person, probably a woman, had been buried with her left hand placed on the thorax of a puppy. Although the people who lived at this Natufian site, 12 000 years ago, were still hunter-gatherers, they lived in stone houses and they probably stored the wild cereals that they collected as a staple food. It is not possible to tell from the skeleton of the canid whether itwas a tamed wolf, a jackal, or a dog, because the bones are too frag- mentary and too young, but it can be assumed that the animals was tamed and that it was highly valued by the person with whom it was buried (Davis, 1987). From the early Neolithic period there are some remains from What appear to be large dogs, notable amongst these are the 53 cranialand mandibular fragments from the site ofJarmo (c. 6600 BC) in the foothills of the Zagros mountains in northern Iraq, some of which have large teeth almost comparable in size with those of the European wolf whose range extends to this moun- tainous region. It is difficult to know for certain whether these remains represent wild or tamed wolves or large dogs. Another site that has provided canid remains that appear to be inter- mediate between dog and wolf is the setlementat Vlasac on the Danube at the Iron Gates gorge in Romania. This site is very ANIMAL PARTNERS FIGURE 4.9. Skulls ofthe small Arabian wolf, Canis lupsš arabs, above, and the much larger European wolf, Canis lupus lupus.  interesting because although it is rather late in date (c. 5400- 1600 BC) it has a Mesolithic culture and there is no evidence for domestic animals other than the dog or for cultivated grain. This is probably because of the mountainous and isolated nature of the terrain which made it suitable only fora hunting and fishing community rather than for agriculture. A great many fragments of canid bone were retrieved from this site (1914 specimens) and most of these were from small domestic dogs some ofwhich had been certainly eaten because the bones had been chopped. There were, however, a few jaw fragments and teeth which appear to be between wolf and dog in size and Bokonyi (1975), who described this fauna, suggested that these specimens represent dogs that were domesticated in situ from local wolves, but such finds are very uncommon. The dogs of these early periods, before the invention or wide- spread use ofagriculture, werealready quite variable in size and they probably also varied in their pelage, length of earsand tail, and shape of facial region. Some would have hada more marked 'stop' to the skull (i.e. a greater cranio“facial angle) than others and some would already have had the look ofa greyhound, with a long muzzle and long rather fine-boned limbs (Fig. 4.10). As described in the chapter on breeds, however, itisnotacceptable to divide these dog remains into separate categories or sub- species, let alone into breeds. Examination of a population of scavenging curs associated with any single peasant community atthe present day would be likely to produce all the shapes and sizes of skull that have been found throughout the world from pre-Neolithic times. That is not to say that local populations of prehistoric dogs did not differ from each other, only that it is inaccurate and inappropriate to describe them in terms of modern breeds. The only assessment that should be made from skeletal remains is one of size and proportions drawn from direct measurement of the bones and teeth. An example of how this is done can be quoted from the description of the complete skull and skeleton of a dog that has been excavated recently from the Neolithic flint mines at Grime's Graves in Norfolk, England. Detailed measurements were recorded for all the bones and teeth and compared with other remains of dogs from British sites of the same period, that is about 2000 BC. From this metrical data it can be shown that the skeleton from Grime's Graves is similar to the two equally complete skeletons from the nearly contem- porary sites of Windmill Hill and Easton Down in Wiltshire, and that these dogs all had a shoulder height of about 50 cm FIGURE 4.10. Skull ofa short- faced domestic dog with a marked “stop' arrowed, to compare with thatofa greyhound. Dogs 59