Dog Sense (4 page)

Tracing the canids back to their origins reveals that their social intelligence was likely one of the early traits that set dogs' ancient ancestors apart. Canids probably first evolved some 6 million years ago in North America, where they eventually replaced another type of dog-like mammal, the borophagine. This was a large, hyena-like animal that specialized in scavenging and had massive bone-crushing jaws to match. The original canids, which probably looked more like foxes than dogs, must have been little Davids to the cumbersome borophagine Goliaths, outcompeting them in speed, cunning, and intelligence and ultimately helping to drive them to extinction. If we then fast-forward a mere 1.5 million years, we find that the surviving canids had spread all over the world and split into several types, one of which was the ancestor of today's dogs, wolves, and jackals—collectively referred to as
Canis
.
²
Subsequently, further diversification produced three strands of evolution, any one of which could potentially have culminated in a domestic animal, for there is nothing in the behavior of any of the canid lineages to suggest that they could not have produced an animal that was suitable for domestication. Indeed, it is likely that at least two of the three did produce domestic animals and entirely possible that the wolf was not the only species in its lineage to be domesticated.

The first evolutionary break within the
Canis
genus occurred in North America, and eventually (about 1 million years ago) gave rise to today's coyote, still confined to that continent. Another group emerged in South America, where they live to this day, and are classified as
Dusicyon
rather than
Canis
. Rather misleadingly, they are collectively
known as South American foxes, though they are only distantly related to the much better known red fox of hunting fame. The other six species of
Canis
all evolved in the Old World, most likely in Eurasia, although some possibly in Africa. Four of these are jackals, although one of these, the Simien jackal, is sometimes confusingly referred to as the Ethiopian wolf; they include the golden jackal that Lorenz thought might have been the origin of some breeds of dog. The other is the grey wolf
Canis lupus
, the ancestor of our domestic dogs. Of the Eurasian canids, only the grey wolf reached North America, migrating across the Baring land bridge a hundred thousand years ago during one of the periods when Alaska was joined to Asia.

Many of these species superficially seem to be potential candidates for domestication, thanks to a number of social tools that they share with the domestic dog. All can, when conditions are favorable, live in family groups or “packs.” All seem able to adapt their lifestyle—specifically, whether they live alone or in small or large groups—to the circumstances they find themselves in.
³
(Nowadays, the most important such “circumstance” for all wild canids is often our own species' activities, whether direct persecution or incidental provision of food at garbage dumps.) The current consensus is that the canid genome is rather like a Swiss Army knife,
⁴
a social toolkit that has remained resistant to evolutionary change and can be used to cope with a wide variety of circumstances, ranging from solitary living when times are hard to complex societies when food is plentiful and persecution is at a minimum. The success of the domestic dog in adapting so well to life with humans can therefore be seen not as a specific set of changes that began only with the grey wolf but, rather, as a new use for this ancient canid social toolkit—one that allowed the dog to socialize not just with other members of the same species but also with members of ours.

While we are now certain that the grey wolf is the domestic dog's one and only direct ancestor, the dog shares its earlier ancestors with many other still-living relatives, each of whom may offer us a new perspective on these ancient forebears. The dog's lineage, after all, goes back much further than that of the grey wolf—specifically, to canids that are now extinct but were themselves the ancestors of all of today's living canids. Each of the latter has something to tell us about the ways that canids can adapt to fit different circumstances—that is, construct their social groups—and therefore each provides a different set of clues as to what the canid “toolkit” may have looked like as it emerged some 5 million years ago. As all of these canids carry the same “toolkit,” the fact that none apart from the wolf has been successfully domesticated will also need to be accounted for.

Golden jackals

The golden jackal,
Canis aureus
, is one of the dog's most social relatives and therefore a seemingly ideal candidate for domestication. It is the only jackal to be found in the Fertile Crescent, the cradle of civilization, where many other domestications (including sheep, goats, and cattle) occurred; all the other jackals are restricted to Africa. Like many of the other canids, the golden jackal shows considerable flexibility in its social arrangements. A few hunt alone, but most live in male-female pairs, often bonding for life, which can be six to eight years in length. If one partner dies, the other rarely finds a new mate. Very often, some of the first litter that a pair produces will stay with their parents until the next litter is born the following year, and will then help to bring them up, before leaving to find their own mates a few months later. They protect the young at the den while their parents are off hunting or, if they catch something themselves, will often bring it back
to share with the cubs. Cubs are more likely to survive if their elder brothers and sisters stay on to help, so their contribution is valuable. Jackals often hunt in pairs, enabling them to tackle larger prey than they could alone, and sometimes the helpers may hunt with them to make up a pack of three or four. The family members have a rich vocabulary for communicating with one another, just as wolves do. Based on its wealth of social skills, there seems little reason why the golden jackal could not have become domesticated as the grey wolf did.

In fact, a recent archaeological find provides hints that the golden jackal may, indeed, have been domesticated in Turkey. Gobekli Tepe, an Early Neolithic hilltop site in the southeastern region of that country, appears to be a temple—an arrangement of huge stones erected a staggering eleven thousand years ago, more than twice as old as Stonehenge. These stones, which predate agriculture and metal tools, are covered in highly stylized carvings of people and animals and birds. Some are T-shaped, with the head of the T representing the head of a person; and the upright part, the body. Many of the animals portrayed are potentially menacing—lions, snakes, spiders, vultures, scorpions. The absence of domesticated animals is unsurprising; these stones were carved by hunter-gatherers, long before any animal was domesticated for food. A few of the carvings clearly depict dog-like animals, which archaeologists have labeled as foxes, just another sort of potentially harmful animal. Yet on one stone, a “fox” is depicted in the crook of a man's arm, more the place for a pet than an enemy—making it unlikely that the drawing depicts a red fox, as that animal is solitary and therefore a very unlikely candidate for domestication. And although it's hard to be sure, the carving does not look much like a wolf, either; its fox-like features and bushy tail make it much more likely to be a jackal, and the only jackal native to that area is the golden jackal. Perhaps Konrad Lorenz's idea of a jackal origin for dogs was only half wrong: Maybe jackals were domesticated once, over ten thousand years ago, but were less well adapted to living with humans than wolves were, and so died out or returned to the wild.

To find a similar example of a failed domestication, but one that survived into recorded history, we need to travel to South America. Coincidentally, this example also involves a “fox,” one of a group of fox-like dogs that evolved in South America some 3 million years ago. One of these, the culpeo fox (
Dusicyon culpaeus
), was domesticated—or at least tamed (living with people, but still only breeding in the wild). These animals came to be known as Aguara dogs. At the end of the eighteenth century, the English soldier turned scientist and explorer Charles Hamilton Smith noted that these dogs could be found in hunter-gatherer villages. They would accompany the men on hunting trips, although they appear not to have made themselves particularly useful, and would often come home on their own after a few hours. In the villages they would scavenge for food, or go off on short hunting expeditions of their own, where they would eat almost anything they could find, including fish, crabs, limpets, lizards, toads, and snakes. By the middle of the nineteenth century, however, Aguara dogs had disappeared, replaced by the much more obedient and useful dogs that the Europeans had brought with them to the continent. It is difficult to work out why the Aguara dog did not progress to full domestication, because very little is known about the habits of its wild ancestor, the culpeo fox. However, none of the South American foxes regularly form groups of more than two, so it is likely that their social abilities were just too undeveloped to be adapted to include relationships with humans.

A T-shaped stone pillar, thought to represent a man's head and torso, at Gobekli Tepe, an archaeological site on the borders of modern Turkey and Syria. The arm carved into the vertical stone appears to be holding a canid.

Culpeo fox

In North America, the most likely candidate for domestication, apart from the immigrant grey wolf, is the coyote (
Canis latrans
). The traditional image of this member of the dog family is that of a solitary hunter, but the coyote is in fact a highly social animal, whose appetite for livestock has led it to be persecuted by humans. Left to their own devices, coyotes live in pairs, and, as with the golden jackal, these can turn into small packs when one year's offspring remain with their parents to assist with the next litter. This is most likely to be possible when large prey, such as elk and white-tailed deer, are available, providing both the necessity and the opportunity for the coyotes to hunt as a pack. In this, they may rival the wolf in terms of the sophistication of their social lives; nevertheless, neither they nor, as we shall see, the wolves of North America ever appear to have been domesticated. The reason may simply be that by the time humans colonized North America, they already had dogs and thus no need for any alternative. It is possible, however, that some coyote genes have found their way into modern American dogs. The reverse has certainly happened, inasmuch as about 10 percent of “wild” coyotes carry genes from domestic dogs. Although it is possible that these are the progeny of matings between female coyotes and male dogs, it is unlikely that a domestic dog would be sufficiently bold to impress a wild coyote bitch. More likely, they are the result of male coyotes forcing themselves on female dogs, whose puppies then escaped and joined the local coyote population. The more tractable of these offspring might have subsequently bred with other dogs, inserting coyote genes permanently into the dog population.