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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