How I Learned to Love Spineless Wonders
They may lack backbones, says the author, but invertebrates clearly are extraordinary creatures that deserve our respect
One afternoon not long ago, a journalistic assignment about the English countryside took me to Northumberland, near the Scottish border. It was March, and snow still clung to the stone walls, cutting white stripes across the green fields. The sheep were spread out like gravestones on the misty hillsides, and curlews tumbled across the sky. In the middle of this moody, wonderful landscape, I suddenly saw myself as a stranger might: A bearded American running across a farm cradling in his hands a wriggling, cold lump of 133 earthworms.
There was a reason for what I was doing; I was interested in the way moles paralyze the worms and store them around their nest mounds. But reason be damned--it dawned on me what had become of my life.
I have spent much of the past few years studying what I think of euphemistically as "spineless wonders." These are invertebrates--ants, worms, mosquitoes, spiders and so on. This work was occasioned in part by a book I had undertaken about invertebrates. But it also developed out of my growing fascination with these creatures, which are not at all like us. Indeed, they are creatures sensible people commonly consider repellent.
Before I try to convince you that this is a fascination worth sharing, let me explain that I used to be a sensible person, too. I grew up in the suburbs of New Jersey, where the background hum to which my inner being resonated on summer afternoons wasn't crickets but the sound of trucks and cars pouring down Route 3 into Manhattan. I was never the kind of child who chases butterflies, or feeds tadpoles to dragonfly nymphs. The natural world was absent from my upbringing, both physically and philosophically.
My father liked to quote Horace: "You can pitch Nature out with a fork, but she will always come back." And, by God, we pitched, with lawnmowers, hedge clippers and the usual household arsenal of deadly chemicals.
Perhaps you grew up the same way. The absence of nature was typical for much of my generation of Americans, born in the suburbanized decades after World War II. Animals even in the agricultural context were alien. In college, I studied politics and English poetry. My friends and I called ourselves environmentalists, but zoology-- and above all invertebrate zoology--was a subject for geeks.
So I am a latecomer to the field. My education in zoology began when I walked away from my job as a reporter at a daily newspaper, where the diet of uninspired political corruption and routine murders had worn thin. Writing magazine articles about the natural world was a form of relief at first. Maybe it shouldn't have been such an epiphany to find that Hirudo medicinalis, the medicinal leech, could have more inherent dignity and complexity than a member of the county board of freeholders.
But for me, it was a revelation: All around us, even in our cities and suburbs, I discovered that there are creatures too strange, or often just too small, for us to recognize. My writing assignments gave me the chance to look at this life on its minute scale, with the help of microscopes and photomicrography. Scientific researchers supplied patient explanations, and I began to find the lives of the invertebrates compelling.
For example: Nature is not content merely to give us the quintessentially indolent sloth, hanging idle as a plant basket in the rain forest treetops. It also gives us an even more idle moth species that breaks off its wings and resides patiently in the sloth's fur, waiting to dine and lay its eggs on the sloth's weekly defecation. There are, of course, also mites on the moths on the sloths. Moreover, certain impatient beetles also cohabit in the sloth's fur and are unwilling to live with their host's dilatory schedule. They sometimes crawl up the sloth's behind to lay their eggs in the colon, giving the next generation a head start.
Much of what I learned had to do with our misconceptions about invertebrates. Despite the fearsome reputation of the tarantula, for instance, there is no reliable medical record of tarantula venom having killed any human anywhere, ever.
Invertebrates are extraordinarily varied creatures, united by only a single trait: They lack backbones. But in this modern age of scientific enlightenment, why should that matter? Aristotle was the first to divide the animal kingdom into two major groupings. He called birds, fish, reptiles, amphibians and mammals "Enaima," meaning red-blooded animals. The insects, mollusks, jellyfish, corals and other lifeforms were "Anaima," or animals lacking red blood. Though he was mistaken in using red-bloodedness as his criterion (earthworms, for one, are red-blooded), Aristotle had hit on what is, at least from a human point of view, a fundamental division: Animals in the first group share extensive similarities in the arrangement of organs, bones and other features. Animals in the second group exhibit startling and often bizarre variety in their design and construction.
About 2,000 years later, the French biologist Jean Baptiste Lamarck modernized and expanded on Aristotle's idea. He pointed out that the one thing animals in the first group all possessed, and those in the second all lacked, was a backbone. He coined the terms "vertebrate" and "invertebrate" and published them in his Philosophie Zoologique in 1809.
Lamarck also published the first systematic examination of the invertebrate world. By way of perspective, it is worth noting that the vertebrates are so minor in the overall scheme of animal classification that they constitute only a single subphylum--the Vertebrata. The invertebrates are so varied that they account for all of the 36 or so other phyla, from Annelida to Protozoa.
But back to my original question: Why should this matter? Or, to put the question another way: It's all very well for an oddball like me to wander off on an extended invertebrate odyssey, but why would any normal person care to travel in the realm of such indelicate creatures as the housefly, the tarantula, or the leech? Let me begin by appealing to baser instincts.
As readers about the natural world, most of us secretly crave what Harvard University scientist E.O. Wilson has described as "a sweet sensation of horror, the shivery fascination with monsters and creeping forms that so delights today even in the sterile hearts of the cities." Our splendid language actually has an obscure scientific word for it: "formication," the feeling that ants or other creeping things are crawling over one's flesh. Much as we crave the thrill of horror movies, good natural history writing gives us the chance--vicariously and often, alas, covertly--to find pleasure in this creepy-crawling sensation.
But with invertebrates, creepy-crawliness often is the only thing we notice; there's nothing covert about it. Our first response is usually, "eww, yuck." Then, if we continue looking, we might think "weird" or "interesting" or even "cool." The strangeness of invertebrates is what fascinates us. Studying them is an unabashed wallow in the joy of formication.
Apart from the entertainment value of these worlds, readers also have high-minded reasons to care about invertebrates: The truth is that we are the real geeks. The average person divides up the entire invertebrate kingdom into two or three major categories: bugs, worms, jellyfish. Because they repel us, each of these words almost automatically causes us to look no further, and thus we write off the dominant life forms of this planet. Our natural aversion has caused us to view the entire animal kingdom from a wildly distorted perspective.
This idea came to me forcefully at a natural-history film festival I attended in England a few years ago. There were 272 films entered in competition, and precisely 12 of them were about invertebrates. I suppose this shouldn't have been so surprising. Natural-history writers, television producers, and--until recently--zoos have tended to focus on familiar creatures like elephants and monkeys. But there are only 4,500 or so mammal species on the planet. There are, however, between 10 and 30 million invertebrate species. They represent more than 99.5 percent of all animal species. An alien spaceship visiting our planet would take them, not us, as the typical Earthlings. They dominate even by sheer body mass. In one study, researchers calculated (don't ask how) that there are 178 pounds dry weight of animal tissue in an acre of Amazonian rain forest, and 93 percent of it consists of invertebrates--billions of invertebrates, mostly ants and termites, versus a few dozen birds and mammals.
By the speed with which they can reproduce and evolve in the face of changing circumstances, invertebrates also wind up being more interesting than the common run of zoo animals. With invertebrates, Nature always seems to be one-upping itself. "Human beings are apt to regard their own personal structure as normal' and everything that differs from it as distinctly humorous," the British entomologist Miriam Rothschild has written. "It is difficult for them to realise that fleas breathe through holes in their sides...or that certain other arthropods lay eggs through their elbows, urinate through their heads and regularly practice virgin birth."
If the world of the invertebrates is often bizarre, it is also indispensable to life on Earth. In a typical acre of our own landscape, there are perhaps 45 million insects going about their business of pollination, predation, decomposition and so on. There are also 2.2 million spiders preying on the insects, and about 900 pounds of earthworms cleaning up the mess afterwards. We need these unseen invertebrate armies.
Bees, flies and moths are irreplaceable pollinators. Caterpillars are songbird fodder. Worms, not farmers, are the great plowmen of the Earth and if they ceased to till and fertilize the soil, or if insects no longer inhabited our fields and forests, we would soon starve. The bodies of invertebrates create the coral reefs and give rise to much of the life of the oceans.
I've found, in the course of my odyssey, that I am edging toward a healthier, more balanced perspective on the planet we share--however ambivalently--with the invertebrates. I'm not quite ready to argue against vertebrate-centrist thinking. Indeed, I haven't entirely given up pitching Nature out with a fork. But I've learned to admire Nature as it comes crawling and slithering back. Now, when my other journalistic work requires me to do something truly odious, like interview a president or a prince, I console myself with thoughts of invertebrates, which I have come to recognize as the little things that really run the world.
Connecticut writer Richard Conniff further explores his fascination with this subject in his latest book, Spineless Wonders: Strange Tales of The Invertebrate World (Henry Holt & Company, 1996).