by Gordon Grice
The boundaries of canine species constitute a mystery in which we are intimately involved, and its roots reach into prehistory.
When predators come out of the trees, they change.
There was, forty million years ago, a primeval carnivore, ancestor to the ones we know today, the animals like wolf, tiger, otter, wolverine, skunk, and all the others that shear the meat from the bodies of other animals with a scissorslike modification of the side teeth. The primeval carnivore lived in jungles, climbing trees with its formidable claws, finding prey with its sharp senses and its stalking skills. Its evolution took two different paths. One branch stayed in the trees, maintaining the solitary life of a climbing hunter that can still be seen today in the leopard and the feral cat.
The other branch came down to the ground, where it eventually diverged further to fill many ecological niches, from the omnivorous lifestyle of the bear to the semiaquatic habits of the otter.
But the divergence from this branch that interests me here is the one that became canid. The wrists that had flexed for climbing in the primeval carnivore stiffened for running, because the canid line specialized in running down prey. That specialty affected more than the structure of the limbs. It led to cooperation in hunting. Stalking had worked in the trees, but on open savanna the chase was everything, and predators in groups could chase more effectively than solitary ones.
Cooperation in hunting led to an elaborate social structure. Wolf society is built around extended families: a dominant couple of breeders, a system of care in which the young grow into supportive subordinates or else leave the pack to join another, an elaborate body language, a vocal language, gestures of appeasement and unity and anger.
The same pattern has recurred several times. The cat line diverged again later to produce the hyenas, which developed into running, gang-fighting predators with an elaborate social system. Later still, another group of cats, this one staying anatomically close to the ancestral line, came down to the savannas. The lion is a social pack-hunter, unlike other cats.
The cat lifestyle never ceased to be workable, though. The fox rediscovered the ways of his precanid ancestors. His behavior is more like a cat’s than a dog’s: solitary except to breed, a stalker instead of an endurance runner, a climber of trees, an eater of mice and grubs; his tiny kits are the prey of the owl and the eagle.
The general canid pattern is pervasive enough to crop up in other, unrelated lines. Baboons have not only the social structure but even some of the anatomy of dogs, to which they aren’t related—an example of convergent evolution. The obvious case among primates, however, is the human line. We, too, descended from trees, became hunters of fleet ungulates, and consequently developed a complex social system.
The similarities between human and wolf are profound: vocal language, complex society, body language so similar we can read each other, a deep predatory pleasure in killing that causes both species to sometimes slaughter far more than necessary. The affinity runs deep in our patterns of development. Both animals have clumsy young with large heads and feet. Adults respond protectively to children of their species, but the cues that cause the response are general enough to transcend species. That’s why humans are capable of adopting puppies. There’s evidence (though disputed) that wild wolves sometimes protect human children, presumably because of the same broad instincts.
Wolves and humans both go through phases of intense learning in particular areas. Certain tasks have to be learned during these “imprinting” phases, or they will never be learned at all. For wolves, hunting is an imprintable skill. For humans, language is one. But a canid’s hunting instinct can, during imprinting, be modified to fit the society it’s in. For example, it can be trained to serve human wants.
These affinities make it possible for human and wolf to mingle in a hybrid society. One more ingredient completes this symbiosis: neoteny, the retention of juvenile traits into later life. For the dog, as for the pig, neoteny is an evolutionary shortcut. It allows the animal to pluck adaptations from anywhere in its individual development, without having to evolve them gradually. It’s what separates the dog from the wolf. The dog is a perpetually childish wolf. He fits into human society by retaining his infantile desire for constant affection, making humans love him. He retains also his youthful submission to authority.
More important for man’s interest in the dog as a living tool, neoteny opens an enormous range of physical potential, a plasticity inherent in the changes mammals undergo as they mature. Imagine your own body had become stuck at the age of thirteen, when you were having a growth spurt. You would have grown larger than most humans. Neoteny allows dogs, with a few generations of selective breeding, to get smaller or larger. But size is only one example; any trait that changes with stages of development can become “frozen” at some stage. That abnormal development can be passed to offspring. We can therefore breed dogs that are, for example, fiercer or more dependent. Most specialized dog skills have some neotenous component. In short, neoteny gave us different breeds of dog.
When dogs go wild, they tend to be skulkers on the fringes of human settlements, living on our trash. They are more like juvenile delinquents than independent adults. They lose the specific breed qualities we inculcate and become generic, like teenagers growing away from their parents before forming their adult personalities.
We humans, as I’ve said, are domesticated too, though we think we are masters. Hundreds of nights I have trudged out, snow or flood, to feed and water the dogs: I serve them. I have staggered with heavy buckets to the hog feeder: I serve the swine. I have curried the burrs from the hide of a horse, brought bread to migrant ducks, scattered feed for chickens, shoveled dung from the pens of cattle: these are all services I perform for “lower” animals.
The care of animals, along with the tending of crops, is a root of our social structure. It dictates our need for permanent homes, our construction of walls and fences, ultimately our economy and culture. The dog makes this possible, because it was the dog, with his keener nose and ears, that made it feasible for us to protect livestock from nocturnal predators. Our tools, intelligence, and eyesight complement his senses; we share a territorial instinct that gives us a common goal.
Early European explorers of North America sometimes found themselves trailed by lone wolves who scavenged their garbage and woke them to passing bears or strange wolves. This must be how the partnership of human and canid started in prehistory. Probably humans eventually took the pups of wolves and jackals from dens and raised them. This partnership caused the divergence of dog from wild canid by putting certain wolves and jackals in the domestic situation that brought out neotenous characters over the generations. In short, the difference between a wolf and a dog is the human touch. It is not a case of conscious control. As a fungus captures an alga to form the symbiote known as a lichen, we have captured the dog in a symbiosis that has remade us both.
A human who decides to cross dog with wolf is also trying to cross an ancient rift between tame and wild, between what lives with us and what moves unseen in the night. We made that rift thousands of years ago when we took in the pups of wolves and jackals that scavenged our middens. We deepened it when we set these adopted canids against their wild brothers, girding them with spiked iron collars and teaching them to protect human habitation and stock from their own kind.
Ancient as that rift is in human terms, it is young in the longer perspective. The earliest evidence of cohabitation between human and dog is no more than fourteen thousand years old: a mere wink before we began to record our own histories, a fraction of our existence as social hunting animals of the savannas, which measures in the millions of years. The relationship progressed differently from place to place—the dog revered in northern Europe, reviled in Palestine. But those differences reside mostly in our perception. Dogs everywhere are tangled in the conduct of human life, as the lowest members of our societies.
Everywhere in the world, at virtually the same
time, human and wolf formed a partnership. That is the strangest part of it all: the sudden universality of a bond across species. This bond distinguishes the dog from other canids. It also distinguishes modern humanity from its older branches, because it is an essential element of the change from hunter-gatherer to the settled life.
If we humans died out tomorrow, the dogs and wolves would begin the healing of their long rift. The dog would bring its adaptability and genetic diversity to the wolf; the wolf would bring its independence and social structure. The special breeds would disappear in a few generations, the weak hearts of the pure dying out in competition with the vigor of the mongrels. The jackal would slouch through the streets of our ghost towns.
RECLUSE
Syndrome 1: The Rotting
A friend of mine, an amateur herpetologist, owned a Haitian anole, a lizard about half a foot long from snout to vent, with another three inches of tail. The anole escaped in the man’s house. The man found and recaptured the lizard within a couple of days, much to the delight of his family.
He noticed something strange about his pet. There were two wounds just inside its mouth, and they quickly developed into abscesses. A discolored knot appeared over the anole’s left eye. The man guessed from the mouth wounds that the lizard must have eaten something that injured it. He searched his house and found a number of brown recluse spiders, but no insects, no other arthropods of any kind. The brown recluse is smallish, dull in color, plain except for a mark on its back that gives it the common names fiddleback and violin spider.
The man knew what the brown recluse and its cousins were capable of. (There are, depending on whom you ask, about a dozen recluse species in the United States.) He deduced that the anole had eaten one of the spiders, which had bitten the lizard’s mouth on its way down.
Soon the anole’s symptoms gave him gruesome confirmation of his diagnosis. The knot over its eye turned into a soupy mass of gray-brown dead tissue—a necrosis, as the scientists call it. The wounds inside its mouth grew and softened into cheesy masses as opportunistic fungi infected the dead tissue there. The anole was dead within two days of its recapture.
Several animals react as the anole did. Rabbits bitten by the recluse invariably develop necrotic lesions, and sometimes die from them. The same is true of guinea pigs. Scientists use rabbits and guinea pigs to research the recluse’s venom because of their consistent reactions.
The woman noticed a pain on her calf. It felt like a bruise. The area turned red and began to swell. A black point appeared in the center of the red. The pain was bad enough to send her to the emergency room, where the diagnosis was “loxocelism,” a condition caused by the bite of a recluse spider. The woman had been working around her house and garage, but she had no idea precisely when or where she’d been bitten.
The doctors couldn’t do much for her. The antidote to recluse toxin works only if it’s administered within half an hour or so of the bite, and the bite, as in this case, usually goes unnoticed. She went home with instructions to keep the wound clean.
A few days later she noticed a red streak running down her leg from the original red bruise. The doctors said the bite had become infected. A long and tedious treatment with antibiotics followed. One drug would fail; the doctors would try another; and all the while the painful wound worsened, its center seeping fluid like a weeping eye. The area of dead tissue was growing, and as it grew, new infections set in. The doctors eventually sent the woman to a plastic surgeon.
The surgeon cut a necrotic mass the size of a ripe plum from her calf. The stitches stayed in for another two months. The spider bite had impinged on, and sometimes dominated, her life for almost half a year. It left her with a patchwork scar.
Call her experience a midpoint: people have better and worse times with the recluse’s necrotic lesions.
A friend of mine camped in a log cabin on the North Platte River in Wyoming. The paneling job in the cabin was shoddy; as my friend learned later in researching his problem, loose paneling is ideal habitat for recluses. Their habit of hiding in crevices is probably the origin of the name recluse, though their predatory habits don’t mark them as shy. My friend woke one morning with a sore at the inner crease of his elbow. It grew to a painful pimple with a discolored penumbra the size of a dime, from which red streaks radiated. The sore tissue slowly withered, and eventually a little plug of flesh fell out of it, leaving a scar. The healing took six or eight weeks.
This man’s uncle, who was bitten decades earlier, wasn’t as lucky. No one in his family remembers the circumstances of the bite. They only remember that the lower part of his bitten leg “dissolved.”
In another case, an active and powerful three-hundred-pound man was the victim. His friends found it amusing that this Goliath lay in bed whimpering with pain because of a tiny spider. They were less amused after he showed them the rotting portion of his leg.
The flesh affected by a recluse’s necrosis never heals. Somehow, the venom turns off the immune system and the body’s capacity for repairing itself in that patch of flesh. The victim can only hope the dead area stays small. But sometimes it doesn’t.
One woman who made a photograph of her injury available to researchers had a grapefruit-sized chunk of black flesh in her thigh. She eventually survived, but her ordeal left her unable to walk without a cane. Another woman had a basketball’s diameter of flesh trimmed from her upper torso to save her life. A few people have died of gangrene following a bite; others have submitted to surgical disfigurement or amputation.
A young woman found herself constantly weary and nauseous. The illness lingered for months. She also kept breaking out in odd sores that healed slowly—purple dimples ringed with raised yellow flesh. It was the number of sores that fooled her doctor. She broke out with a new one every few days, and he couldn’t explain why. He could only offer speculations about allergies. He suggested she look through her apartment carefully for possible allergens.
After she had looked for the obvious, she and her friends moved all the furniture, hoping to find some hidden factor. When they tried to dismantle the waterbed, they had their answer. Beneath the mattress were dozens of recluses.
Syndrome 2: Immunity
The white rat, that symbol of laboratory experimentation, is useless to toxicologists researching the venom of recluses. Rats do not react to recluse venom. It’s hard to study the effects of the venom on people, since people so rarely notice the bite while it’s happening. The recluse’s fangs pinch in toward the middle, gathering the upper layer of skin in folds and injecting venom between layers, causing very little mechanical injury. But apparently most people share the rat’s good fortune: they don’t react to a recluse bite at all.
Syndrome 3: Sudden Death
Mice are no good to recluse researchers either. A bitten mouse reacts with a precipitous drop in blood pressure and dies before any useful data can be collected.
The young woman with the infested waterbed reported nausea, exhaustion, headache, and malaise. These symptoms fall under the heading of “systemic reaction,” the doctors’ term for anything that’s not “local.” The young woman’s mild systemic symptoms are common. But the systemic symptoms of a recluse’s bite don’t have to be mild.
A man was carrying wood. He put down an armload and noticed a spider hooked fangs-first into the skin of his arm. He caught the spider in a jar and took it with him to the emergency room, where he dropped dead. The spider was a recluse.
Syndrome 4: A Failure of Immunity
I met a woman who was always sick. Every flu bug that hit town gave her at least one round of illness. She never felt right, even when she had no outward symptoms of a sickness. She said she had been in normal health until fifteen years before, when she was bitten.
The bite of the recluse had cost her some tissue from her leg, but she had recovered with only the usual scar. Her tendency toward sickness developed slowly after that. It was years before she faced the fact that something was deeply wro
ng with her, that her numerous bouts with common illnesses betrayed some fundamental dysfunction. That’s when she drew a chart of her medical history, a chart on which one event she’d always considered insignificant now stood out. The spider bite that had given her a few weeks’ trouble and a scar stood at the beginning of her decline.
I listened politely to her story and took notes. I had no reason to doubt her facts, but I didn’t believe the spider bite could have anything to do with everything else she’d been through. Privately, I suspected she had some undiagnosed disease of the immune system, like lupus. I even entertained the notion that she was a hypochondriac.
The two of us went to hear a lecture given by a toxicologist who specialized in recluse venom. His response to her story boiled down to two main ideas. One: he had heard of such long-term reactions to recluse venom before. Specialists had known about them for several years, and plenty of anecdotal evidence supported the connection. Two: it’s extraordinarily difficult to research such a slowly developing, amorphous phenomenon, so nobody knows why it happens or how to cure it. Despite the bad news, the woman left smiling in her vindication.
The toxicologist told me strange things about what the venom does. In some people it convinces the white blood cells to turn traitor and attack the body that made them. That’s what causes necrosis. But the venom’s interaction with a human immune system is an intricate dance whose implications are breathtaking and terrifying. If you could turn the body’s defenses on selectively, as the venom does, you might know more about AIDS and all the other unravelers of the immune system. You could cure cancers without a scalpel or radiation or health-threatening chemicals. You could make white blood cells devour tumors of the brain.