Magnum photographer Elliott Erwitt's DogDogs is the result of 50 years of observing dogs. Big dogs, little dogs; stay-at-home dogs, feral dogs; top dogs, stray dogs; a dogdog here, a dogdog there, everywhere a dogdog - from a pampered poodle at the hairdressers in New York to a scavenger sharing a moment of prayer with monks in Thailand; from the dancing dog of a Bath busker to working dogs (lets face it, dogs like killing things) on a Virginia fox-hunt. The original idea was to include a thousand dogs and one cat; Erwitt has had to settle for a mere 820 dogs. And a few cats. The cats all look pretty much the same - collected, smug and aloof - while the dogs register all states of being from ecstatic enthusiasm to wretched misery, with everything in between.
The Czech novelist Milan Kundera, who knows a thing or two about dogs, calls them merry ambassadors from the mute world of nature. True enough, like the world they represent, they dont have language; but that doesn't mean they don't communicate. And, just as most of us have no contact with the law apart from the odd encounter with a traffic cop, for many of us dogs mark our real contact with the world of nature, of other species.
If we are indeed living through the sixth extinction, a catastrophic and man-made reduction of the number of species the Earth supports, one of the best ways of appreciating what the myrmecologist E.O.Wilson calls biophilia, the natural affinity of human beings with other species, before it is too late and the biosphere changes forever, is to get to know an animal really well. Some people will choose cats, of course, while some (members of the staff of this magazine included) have an inexplicable love for guinea-pigs; a man I used to know grew melancholy whenever he remembered the death of the stick insect he owned when he was a schoolboy (death? Murder, by his father, in a bottle of formaldehyde. On holiday, when it was taken ill in France. Its name was Sticky). For Wilson, I suppose it is ants. For most people, however, insects are not really serious contenders for close relationships. In the urban domestic context, we can rule out the large mammals, while the really small ones, whatever rodent-fanciers may say, are insignificant; what it really comes down to is cats and dogs.
I have never really understood the attraction of cats: beautiful they may be but, as Erwitt's book demonstrates, they don't exactly participate; not the most promising recruits, then, for the diplomatic service of the natural world. Whereas the thing about dogs, for humans with an interest in other species, is that they're prepared to share everything about themselves, and so open a door - or dig a hole, perhaps one should say; dogs have difficulties with handles, not to mention locks and keys - to the natural world beyond. Biophilia, of course, is more than just a pretty name for talking to the animals, or personalising biodiversity, or even knowing ones place in God's creation. For the human race could never have got where it is today without the help of various co-species. And not necessarily fellow animals, either. Without the easily domesticated wild plants of the eastern Mediterranean, for example - its many varieties of large-seeded grasses, leading to the cereal staple crops; its peas, its lentils, its chickpeas; its flax - the people of the Fertile Crescent would never have ceased being nomads and settled down as farmers and begin to invent what was to become western civilisation. And without the major five species of big herbivorous domestic mammals of the ancient world - sheep, goats, cattle, pigs and horses - humankind would have remained without easy sources of meat, milk products, fertiliser, land transport, leather, military assault vehicles, plough-power and wool.
Not to mention the dog. The dog is by far the oldest of man's animal associates. Recent research suggests that the relationship between the dog and man, traditionally estimated as about 14,000 years old, has actually been going on for much, much longer. So wide is the variation in kinds of dog - ranging, as DogDogs shows, from the earliest photograph in the book, a tiny Chihuahua Erwitt photographed in 1946 to a mongrel he snapped in Ayutthaya in 1998 by way of his own primus inter pares, Sammy, the cairn terrier (a breed officially recognised only in the 1920s) and hundreds more in between - that Charles Darwin and other scientists surmised that dogs must have descended from a mixed pack of wild ancestors including jackals. But, according to recent work carried out at the University of California under the direcion of Professor Robert Wayne, dogs all share a single ancestor species: the wolf. If this is so, the development of the enormous range of dogs which Erwitt chronicles - something that is rivalled only by one other species: humans - must have taken far more than 14,000 years. Using DNA dating techniques, the Wayne team has estimated that the transition from wolf to dog may have taken place as much as 100,000 years ago, or even more.
If that is so, it raises an intriguing possibility: for that date takes us back to a time before the existence of modern man, Homo sapiens sapiens and, as Dr Colin Groves of the Australian National University has argued, the story of his emergence may be inseparably entwined with the story of the emergence of the canine species. For the dog, a scavenging animal, access to the scraps left by human beings was clearly attractive, as was a place by the fire. And, able to rely on dogs ability to hear, smell and see for them, man directed far more of his cerebral cortex to thinking and speaking, developing the intelligence which was to make him the sole occupant of the cognitive niche that, as the anthropologists John Tooby and Irven DeVore have suggested, was eventually to make him master of all he surveyed. In other words, so the argument goes, it was dogs that made humans human.
But it is, of course, equally clear that humans made dogs dogs. There are dogs for hunting, dogs for tracking, dogs for guarding, dogs for intimidating; dogs for digging, dogs for pulling sledges, dogs for rescuing people at sea, dogs for keeping people warm at night (giving rise, among the native Australians, to the expression five-dog night for when the temperature plummeted) and even, in some benighted societies with nothing better to put in their stomachs, dogs for eating. But most of all, there are dogs for friendliness. Far above all their other qualities, dogs have been bred throughout our long, long association for their capacity to act as companions to human beings. It is this quality, lovingly nurtured by both sides of the relationship, that DogDogs celebrates most eloquently of all. As I used to remark to the dog I knew best, a cairn terrier called Natasha (who, to judge by the pictures, bore a very close resemblance to Erwitt's Sammy), it was no surprise that we got along so well; our two species had, after all, been practising for a very long time to reach this peak of perfection. She used to look back at me wisely; knowing, I suspect, that in those dim beginnings 100,000 years ago, when dogs were wolves and men were not yet men, it was they who chose us.