Remembering Smell (16 page)

And as long as the description doesn't get put on a billboard, if a whisky tastes like Bazooka bubblegum, why not say so? The nose—that is, the aroma—of one whisky was described as reminiscent of cotton candy and lipstick. Another had a "smoky, oily quality," and its smell was compared to both bacon fat cooking in a tractor shed and heather in a closet. "Smoldering slag heaps with brown sauce" from a chip shop, anyone? Or how about a combination of carnations, roses, and "the rubberiness of school erasers"?

Smells are like love: Irrational. Elusive. Just the thing to get the similes flowing, to spark the imagination. In 2000, a team of French researchers found that "the world of smells is difficult to pin down in words" for what they felt was one of two reasons: either the ancient olfactory system is encumbered by its weak neural connections to the "youngest language brain structures," or verbal descriptions of smells simply aren't necessary. Maybe because smelling predates self-awareness and speech, smell doesn't need words. And, I hoped, words don't need smell.

I also hoped that the poet and essayist Andrei Codrescu was being facetious when he remarked on National Public Radio that the human "smell-descriptive vocabulary" became "more impoverished the more our language developed." Codrescu says the first time he took his dog to New Orleans, the "layers of funk made her so excited she didn't sleep the whole time. Later she told me it was an encyclopedia of smells you'd need a million years of brilliant poets to find a language for. She told me this in dog, with her nostrils trembling. She chooses not to speak human, and from an olfactory point of view, I can see why."

Purported to be a purebred bichon frisé and sold for eighty bucks in a Burger King parking lot, our dog Mel was a last-minute Valentine's gift from a boyfriend to my daughter Alex. The dog turned out to be a rat terrier with a soupçon of bichon frisé evident in his affectionate nature and his upward-curling tail. He's hard-wired with a single idée fixe (that would be the bichon part talking):
I don't want to go back to that puppy farm.

Mel's circus act is one of the more impressive results of Alex's six-figure college education. Over the span of two years spent in a tiny campus apartment crammed with homesick, dog-worshiping females, Mel developed a routine that grew to include not just the obligatory
shake
and
sit
but also
roll over
(three times),
stand
(for half a minute, paws flailing), and
take a bow
(head on front paws, rump high in the air, tail wagging). The first time Alex put Mel through his paces for me, I was astounded by what he would do for a Milk-Bone.

When Mel and I talk to each other, I speak English, so it's a fairly one-sided conversation. But when we smell each other, I'm the idiot and he comes away enlightened. Mel can't tell steak from hamburger, but he knows if I've been gardening, driving, or hanging out with Cam. He knows if I'm nervous or just need a bath. He knows if I'm angry, hungry, happy. What do I know back? My nose can tell me if he's been rolling in deer scat.

Mel can smell me coming a block away and runs around to the gate to greet me with his high-pitched whine-bark. He licks my face to absorb and revel in its scent, then licks himself afterward to transfer the scent of safety and comfort so that the smell will be there when I'm not. He loves me, but my personality—my sense of humor—is lost on Mel, and he has to put up with my insensitivity regarding many of his emotional needs. That's all due, at least in part, to the most glaring difference between us: the language barrier.

Dogs talk to each other all the time with no trouble at all. They don't even need to be in the same vicinity. Better if they're not, in fact. Their habit of marking territory is as close to language as they get, and it is a communication system derived from smell. Scientists are just as inventive in developing theories about the method behind what looks like madness as those whisky tasters are in coming up with word pictures that capture the scent of a Scotch.

Mel becomes quite the social butterfly when we're out walking, darting from tree to telephone pole, picking up messages and leaving his own, livelier in his "conversations" than a teenager on Facebook. Some friends he's never laid eyes on. Makes no difference. His nose tells him everything he needs to know. Male or female? Sweet-tempered or a possible threat? Long-time resident or new in the neighborhood? On some level of consciousness accessible only to canines, he knows. If I forget to take him out, he lifts the latch on the gate with his nose and sets off on his own. He never goes very far or stays away long. Maybe we have his early-childhood trauma to thank for that.

Marking is the canine equivalent of talking. But dogs get right to the point. They look out for those with whom they live, regardless of whether home is a cardboard box or a cozy bungalow with a fireplace and central air. The following dumbed-down distillation of several academic treatises on marking may still sound like jargon, but it goes beyond the image of a dog lifting its leg to convey the sophistication of canine communication: A nonresident dog adds up the number of identical marks (in piles of poop or on pee-streaked fire hydrants and so on) to find out who's in charge in this neck of the woods. It's that guy with the weak bladder. I have noticed that Mel lifts his leg more often the closer he gets to home. Dogs also become much more aggressive when they're on their own turf. Uh-oh, dogfight. (I've noticed that too.) Dogs have pheromone-producing glands around the anus. Sniffing another dog's behind tells the intruder that this is indeed the resident—the dog whose presence was heralded by the smell fingerprint left on its feces. It also works the other way around. The remembered odor of that pile of poop lets intruders know if they're trespassing. All they have to do when another dog nears is get a good whiff of its rear end.

Zoologists describe marking as a way to give intruders a heads-up should they happen to run into the resident canine (the dog who lives there). Marking says,
Back off.
Miraculously, the intruder obeys. By keeping "agonistic encounters" to a minimum, marking protects the entire species from extinction.

Lest we get all teary-eyed over what lengths our pets are willing to go to protect us, consider what is going through their minds as they sniff a bush damp with pee. They're not thinking about us at all but responding to a complicated message that has been condensed into a split-second call to action. Scent-gland secretions, feces, and saliva impart vital clues as to the whereabouts, age, gender, social status, and emotional state of the dog involved. Intruders compare new scents with remembered images of a previously sniffed one. Only the most recent scent image left by a dog is meaningful to the intended receiver. A dog that can defend its turf long enough to mark it comprehensively is sending a strong message, namely, that it's quite the athletic brute. The intruder knows that of the two of them, the resident is more motivated to fight. This is his home. He knows it cold. He has more to lose than some unwary passerby, which is why intruders almost always withdraw. Sorry, must run.

Why do dogs roll in their own feces? This isn't to gross out human companions but to let intruders know who's been marking this territory—the resident. Likewise, a dog that bolts out the door and barks at passing dogs is making his scent available for matching.
Yeah, I'm
that
dog,
he's saying. And when you're out walking your dog and he sniffs another dog's poop, it's not because you forgot to feed him. He needs to know for sure that the barking dog he's just passed lives here and means business.

The ancient Komodo dragon doesn't behave all that differently from Mel when it comes to marking. It deposits fecal pellets to mark its territory; a young, intruding Komodo will sample one (by nose and by mouth), and if it determines that the owner is older, meaner, manlier, and more invested in the turf than the younger one is, the new Komodo will make an appeasement display.

Intrigued by these creatures, I went hunting online for footage showing a live Komodo in action. Forget Mel's humanlike traits—the giant lizard's similarities to humans are even more striking, though in an extremely macabre way, I admit. A short video showed a Komodo on the hunt: the slow, patient pursuit of prey first detected by the forked tongue stabbing the ground for scent; the gleam in the eye when a fat water buffalo sensed that it was in danger; the saliva dripping like a bead of wax from the Komodo's immense jaw as the lizard anticipated the coming feast; the kill itself—a single chomp delivered to a rear leg. Then, creepiest of all, the Komodo's two-day death watch as the buffalo weakened and dropped to its knees, then to its belly, and finally lowered its magnificent horned head into a pool of water and drank to quench its insatiable thirst as infection set in, rendering it defenseless (but still conscious) as the Komodo's feast began.

Here was an animal programmed by evolution to assemble all the tools nature provided for its survival—not only power, quickness, vision, and smell, but also cunning and patience. This is why the late evolutionary biologist Paul MacLean considered Komodos to be kindred spirits. The reptilian brain is alive and well in humans. We have as much in common with a near-extinct lizard as we have in common with our pets.

How dogs and reptiles differ is evident in their family arrangements. Male and female Komodos often mate for life, yet this too is a territorial imperative. The couple share the onerous task of guarding the perimeters of their adjoining kingdoms. They do not, MacLean wryly noted, share the same bedroom. And they would just as soon have their babies for lunch as care for them.

If I were a spiritual person, I'd say Mel and I are soul mates. Would I say that about the climbing hydrangea that was my pride and joy for twelve years until it blew over in a storm? There'd been a death in my family; the hydrangea was expressing its sympathy, a friend suggested. Being a gardener, I was tempted to agree, knowing that some plants do look out for each other.

In plants the survival instinct is all about protecting the species. An
individual
survival mechanism is not built in. Strawberry, clover, reed, and ground elder put out long underground runners that form networks—information highways, if you will. A Dutch botanist found that if one of the network plants is attacked by caterpillars, the other members receive a signal telling them to make their leaves hard to chew on and less desirable to hungry caterpillars. Word spreads fast. Bamboo and many invasive grasses use the same system. The network's only drawback is analogous to what happens when a hacker invades a computer's operating system. Viruses may enter the plant via the leaves, find their way into the stems, and be passively transported to all the network members, where they cause new infections.

What interested me about this research wasn't that plants communicated with one another but what their conversational style said about where they fit in the evolutionary scheme of things. Smell marks the beginning of brain development, the seminal moment that sent plants in one direction and moving (and eventually thinking) creatures in another.

The tiny sea squirt has a brain and notochord (a sort of backbone that is a precursor to the nervous system) only while it's young and swimming in the ocean. The creature ditches this pintsize organ once it anchors itself to a rock. No movement, no brain. Olfaction may have been a navigational tool unique to species that were built to explore and migrate. Among animal species some patterns are clear: Komodo dragons are antisocial creatures who interact (fight) with their own only to protect their turf, which represents the most basic ingredient of survival: food. Rats, dogs, birds, and bees run in packs, and to them personal safety depends on the group. That means family, so their chatter centers on mating and reproduction. Humans are a blend of those instincts, but our species' talk is mediated by a strong sense of self. Language allows people to speak with one another about our place in nature and the universe, and about paradox—good and evil, the sense of being alone, like the lizard, but also connected by intelligence and curiosity to every other living thing. We talk about that.

Scientists are beginning to understand the neural substrates humans share with other species, from songbirds to dolphins to our closest relatives, the primates. Neuroscientist Joseph LeDoux believes that even in humans, language is instinctive. Forming a sentence is an unconscious act; imagine how long it would take to get the sentence out otherwise. You don't start from scratch and put words together according to the rules of grammar every time you speak. Talking and marking aren't really so different, are they? This suggests that language, which is only slightly better understood than smell, is not the slave of the thinking brain, as is usually assumed, but is tethered to emotion. When you use language to communicate your feelings, the neocortex has limited authority. It can't tell you that your feelings are silly or wrong. Its role is to help you get in touch with feelings and then get them out by tapping into learned responses stored in the limbic system. "Consciousness is important," LeDoux wrote in
Synaptic Self
, "but so are the underlying cognitive, emotional, and motivational processes that work unconsciously."

So while language isn't intelligence, it's probably what made us smart. It's what makes all species smart. The world's first aroma cues sent urgent messages regarding, for example, the presence of a disgusting (read: maybe toxic) food. Eventually the repertoire grew. The more humans evolved as a social species, the less they relied on physical prowess to survive. Strategic collaboration required a means of communicating that was complicated, quick, and neuron-intensive. Then
Homo sapiens
needed a bigger brain so communication could continue to develop, but the skull couldn't hold a bigger brain. Something had to go.

Olfaction was one obvious place to make cuts. Ever since primates began standing upright—bipedalism improved visual awareness—smelling had been compromised by the simple fact that heavy odor molecules never rise to nose level. Dogs still sniff to say hello and mark territory, but in primates, visual communication cues grew more subtle and nuanced. In humans, these cues (a curled lip to register a foul odor is still part of our human DNA) developed into spoken words. The curled lip meant "rotten," which also came to mean "faulty," as in a "rotten" idea. Out of language evolved abstract thinking. Evolution didn't put words and smell totally at odds. Studies of nasal cycles in humans indicate that a constant strong flow of odors to the left hemisphere, the language side, of the brain makes a person more articulate. Maybe that's because odors arouse the memories behind the words.