The Human Age: The World Shaped by Us

by Diane Ackerman

  “You’ve got to try the wild, but obviously that’s all going to go west if one’s being realistic.”

  For a moment, I think perhaps she means the expanse of America’s West, then quickly realize she means die, as in following the setting sun.

  Ann says firmly, “You’ve got to have parks. And you’ve got to manage your wild.”

  “Managed wilderness. You don’t think we can afford to just let nature run wild anymore?”

  “No,” she says with conviction. “We really can’t.”

  Nature has become too fragmented to just run wild.

  Ann tells me of a local solution that works: how in English towns, where terraced housing is commonplace, small back-to-back walled gardens lead onto each other and combine to create long fertile corridors for wildlife.

  “So when I go into Cambridge and do a bit of gardening,” she says, “I’m surrounded by all sorts of insects and mosses and butterflies. But in our country home’s garden, there’s nothing. Consider starlings. They put their beaks down about four centimeters into the soil—that’s how they feed—and that’s where all the pesticides are accumulating in the agricultural areas. The environment would be absolutely fine for them if there just weren’t any pesticides in it!”

  Hoping to lure pollinators back, what’s known as Plan Bee rewards landowners for planting wildflower meadows for knapweed, bird’s-foot trefoil, red clover, and other weeds favored by insects, butterflies, and bees. They’re called “bee roads,” perhaps in keeping with the Anglo-Saxon tradition of referring to the ocean as the “whale road.” Other English bees have become prosperous city-dwellers, unassailed by agricultural pesticides, and there are now more sparrows, starlings, and blackbirds in the town gardens than in the open countryside.

  A sorry image of the English countryside, silent at dawn and devoid of wings, slinks through my mind. All the more reason I like Ann’s “try everything” mindset. Yes to national parks, to rewilding preserves, to wildlife corridors, to city shades of green, to DNA banking, and to any other strategy we can think of that will allow animals to pursue their dusty, feral ways and nature to stay replete with potent life forms.

  The office door swings gently open, and Chris Wade pokes his head in to take me on a tour of the lab. A tall man with dark curly hair, Chris does DNA analysis on the samples that arrive by mail, and he’s looking forward to being part of the Ark’s upcoming expedition to Vietnam to collect fresh DNA samples. Walking across the outer office, we enter a shared college lab with pale-blue walls, workbenches, microscopes, and a bevy of white lab coats hanging on one wall like a colony of albino bats.

  Chris explains that they take the DNA field samples in several forms to be sure of backups. Dropping a tissue slice into a tube and topping it up with ethanol essentially pickles the tissue. That state of DNA isn’t ideal; it’s not as high-quality as fresh-frozen DNA. But if they put a specimen in a freezer, and the freezer were to break—and in a lot of countries that’s often a problem—then it would be completely destroyed.

  You’d think freezing would kill the cells, but the arkmasters control the rate of cooling, at only a degree a minute, and that slow-motion plunge keeps the cells intact. For safety, they prefer a three-way approach:

  “One: Ethanol. Tough as nails,” Chris says, “but there for you in the end—the freezer can go off, everything can go wrong, you will still have that preserved bit. Two: We’ve also got our fresh-frozen tissue slice, which is perfect, it’s got everything. Three: And then we’ve got another sample for later cell culture. That’s the ideal scenario, all three methods.”

  He leads me to the far end of the lab, through a doorway painted cornflower blue, into a small room, where four tall white Sanyo freezers stand, looking surprisingly humdrum, suitable perhaps for a wintering farm family, not the biggest snow survival fort the world has ever known. I put on green latex gloves to protect my primate skin.

  He tugs opens a freezer door that gusts a small white cloud, like the combined souls of ten thousand animals exhaling in unison on an ice floe. Inside the freezer sit row after row of frost-covered drawers. Pulling one open with a gloved hand, I’m surprised to find only carefully arranged rows of short frost-covered vials, each with a label.

  “You can lift one out,” Chris says in a tone of voice warning But carefully!

  When I do, I see that I’m holding the future of an African lion. If I blink, a tawny-colored male lion with a shaggy mane is standing on the veldt of my palm. I blink again and the whole animal is nestled in my hand, with room to spare for tall grass, heat mirage, and his pride. What an unlikely way to safeguard the future of animal-kind.

  PART IV

  NATURE,

  PIXILATED

  AN (UN)NATURAL

  FUTURE OF THE SENSES

  What about us? Are we natural anymore? How can we be, when we’ve morphed into superheroes? Our ancestors adapted to nature according to the limits of their senses. But over the eons, by extending our senses through clever inventions—language, writing, books, tools, telescopes, telephones, eyeglasses, cars, planes, rocket ships—we’ve changed how we engage the world and also how we think of ourselves. We just assume now that human beings can move across the skies at 500 mph. Or spot a hawk across a valley. Or do colossal calculations at speed. Or watch events unfolding halfway around the world. Or safely repair someone’s heart. Or wage war. Our attitude about our own nature, what sort of creatures we are, now includes the novelties we’ve pinned to our senses.

  All these add-ons are a perfectly ordinary part of daily life. The use of tools and technology has become an innate part of our being, as we extend ourselves deeper and deeper into our environment. In the past decades a fundamental change has evolved in the idea of the universe we inhabit, and also what a human being is and may become. We don’t worry if we can’t see a splinter in a child’s finger. We automatically don glasses and become an animal with keener eyesight. That may save the child from infection, but it also revises what a human being is. How will that continue changing in our lifetime?

  Already, we’re masters of the invisible. Just as we accept that the universe is mainly invisible dark matter and dark energy, we accept the reality of protozoans and viruses even though we can’t see them without a microscope, or perhaps as stationary oddities in the pages of a textbook—which few people are tempted to do. We believe in television and radio waves, gnomelike quarks, GPS, microwaves, the World Wide Web, gosling photons, a mantilla of nerve endings in the brain, the voiceless hissing of background fizz from the Big Bang, planets orbiting many stars in the night sky—some hospitable to life. Then there’s all the panting eyes, throbbing jellies, iridescent bladders, and glowing mouths haunting the remote sunless abysses of the deep sea.

  Our mental cosmos teems with a thicker texture of invisibles than ever before. Living with invisible forces used to mean spirits, ghosts, gods, angels, and ancestors. Our view of nature now supplies different familiar ghosts, including all the wispy tangles, tinctures, and driblets of a working body being revealed to us as never before through technology and nanotechnology. We take for granted the vast invisible worlds surrounding and inside of us. It’s a sort of high-tech shamanism (the belief that spirits inhabit all things, living or nonliving). Some entities may hide in the holly bush at the front door; others float light-years away.

  We can forge so many invisibles in our mind’s eye because enough of our kind have witnessed them firsthand, through microscopes, telescopes, or computers, and smeared that knowledge far and wide. As a result, the air gyrates with invisibles I can hear but not see, and yet take for granted like distant relatives whose photos I’ve framed.

  In autumn, a season of night fiddlers, I know summer is fraying away because the air brims with their eerie music, although I don’t see the hidden musicians—katydids and crickets playing their marimbas, as they lift their wings high and rub a sharp edge of one wing over a ridge of pegs on the other. It’s not easy to spot cellophane-winged
aerobats among late summer’s wild chicory, Queen Anne’s lace, and clover-scented milkweed—kingdom of the giant, much showier monarch butterfly.

  Nonetheless, I can picture them all combing strands of song from their wings, picture them in microscopic hair-perfect detail. Katydids are rasping a tattletale: Katy did! Katy did! Katy did!! Cicadas, buckling and unbuckling their stomach muscles, are yielding the sound of someone sharpening scissors. Fall field crickets, the thermometer hounds, are adding high-pitched tinkling chirps to the jazz. Carolina crickets are furnishing a buzzing trill. Grasshoppers sound like they’re shuffling decks of cards. Snowy tree crickets are lending an evenly spaced chirping melody to the ensemble. It’s the ultimate jug band, using body parts as instruments.

  I don’t see any of their courtship, since they’re small and hidden in the darkness. But I’ve learned enough from scientist-seers and their technology to trust that the males do all the serenading, horny for females, each of whom waits in the dark loins of the night, listening with ears in rather odd places—on the abdomen or the knees. She homes in on a winged dude, lured by his siren song. Then the happy male croons a different courtship tune. But they haven’t much time for dalliance before the first heart-stopping frost. According to folklore’s timetable—and I still believe in folklore—frost creeps in ninety days past the katydids’ first song. In my insect-loud yard, I heard the first katydid call about a week early this year, round about the middle of July, and sure enough frost fell in mid-October.

  Alongside this buzzing-chirping-tinkling-fiddling in the night, and choreographed to it, there’s the raw sexcapade drama. And, although I don’t ogle thousands of bugs in flagrante all over the woods, and tens of thousands, maybe millions, yodeling their lust downtown, up in the forest leaf-parlors, and along sinewy country roads, I was a college student once; I get it.

  All of this happens unseen, which is a haunting thought, but even without laying our eyes on the crickets, grasshoppers, cicadas, and katydids, we hear them shrilling in this season and trust that they’re the tiny living gargoyles scientists claim. We believe the katydids exist in their scratchy little corner of the invisible—an act of faith that suits us just fine. Most don’t wish to search in the dark buzz of night for the multieyed and antenna-ed.

  Anyway, these days, we know we can verify the existence of creatures we can’t see easily enough in books, films, or bug Facetime on the Internet. The ancients believed the gods were angry when storms crackled and boomed. We check the Weather Channel’s radarscope.

  Our ancient understanding of nature (faith, lore, hearsay, story) has a new level, one changing almost every day, proxy sine nomina from technology-equipped scientists and other researchers, the designated witnesses who behold, listen, and chronicle as the likes of insect love parties on. We agree en masse to believe these professionally designated seers.

  Or we become citizen-seers ourselves. A smartphone will do. Walking on a trail in New Forest, in southern England, I stopped in a sunlit clearing when I heard the distinctive rasp of Buddhist monks creating a sand mandala by rubbing brass scrapers down ribbed brass funnels to release single brightly colored grains. A quick spin around: trees, pastures, a perching woodland warbler falling into flight, shadows dancing along the trail. No monks. I smiled at the sleight of ear. Weeks before, at Keystone College in Pennsylvania, I had watched, enchanted, as Tibetan monks sand-dribbled a mandala, producing what sounded like the trills and quiverings of invisible cicadas.

  Pulling my iPhone out of my pocket, I opened the Cicada Hunt app, a brainchild of entomologists at the University of Southampton. Over a thousand people sent in reports this past summer. On the iPhone, a green card appeared with a white cicada icon sitting on black velvet at its center. When I held it up and tapped the cicada icon, a white outer ring fanned open around it and the cicada glowed orange. For eighteen seconds, the app tested the soundscape for the exact frequency of rare New Forest cicadas. No luck. Only a scant few New Forest cicadas have been detected by the thousands of citizen scientists in England since 2000, but that’s enough to offer proof of their whereabouts and need for protection. Though I knew it was a long shot, I found the app doesn’t register the calls of my homely New York variety of cicada.

  The Buddhist mandala-makers may live in a cosmos dancing with colorful deities, just as they always have. But now they and the Dalai Lama (a science aficionado) are also aware, from mindful moment to moment, of an invisible dimension that includes neurons, quarks, Higgs bosons, MRIs, condensation nuclei, white dwarfs, DNA, and a googolplex of others.

  Elsewhere on Earth, over 5.2 million Internet-connected computers, citizen scientists are helping SETI (Search for Extraterrestrial Intelligence) monitor radio telescope data through the SETI@home project, hoping to catch a message from alien life forms in some distant star system. SETI’s senior astronomer, Seth Shostak, believes that the first calling card from aliens may well be detected on home computers, not by official scientists at radio telescopes arrayed in India, Australia, Puerto Rico, or Chile.

  More than ever, our technology allows us to peer into worlds far beyond our outmoded senses, into a realm where cells loom large as lakes, pores are chasms, the body is just another kind of ecosystem, and the idea of cartography no longer applies only to landforms. We’ve mapped galaxies and genomes. We keep projecting ourselves into landscapes we’re not equipped to cross in the flesh. Computers have shed light on biological processes invisible to humankind until very recently. In 1990, I wrote about our sensory grasp of the world in A Natural History of the Senses. Only twenty years later, the basic experience is the same, but its scope has been vastly amplified. For example, our proprioception, the sense of where we are in space, now spins far beyond the physical body. We can spy on ourselves in sly, public, or cloak-and-dagger ways, from lavish perspectives, inside and out. By satellite, a drone’s eye, via Skype, on security cameras, through electron microscopes. Some of us are even relaxed about, or excited by, the promise of connecting our brains to the world outside of the body. In such sweeping sensory adventures, our cameo of who and what we are shifts, and also how we may decide to know ourselves in the future.

  What we see and think when we look at the night sky has also changed. Two decades ago, the only planets were here in our own solar system. Now we know that the cosmos is littered with them. We know now that the Milky Way, the backbone of night, is twice as large, even heavier, and spinning faster than we previously thought. Also that it has four arms, not two. Our telescopes listen with cupped ears for whispers from the beginning of time, when the whole universe was no larger than a grapefruit, a small solid object, before the light of stars and the destiny of planets. How could something that small give birth to more space than the mind’s eye can fathom?

  Although the brain’s star chamber is sealed and invisible in its cave of bone, we’re craning our high-tech senses (MRI, fMRI, PET scan, etc.) to peer in as never before at networks lit like night views of Earth from space. Thanks to digital displays, scalpel-less dissecting of live patients is commonplace, as is cut-free slicing of gray matter into wafer-thin sheets that can be viewed three-dimensionally and rotated as if the conscious, alert, and no doubt mind-wandering occupant had set his actual brain on an anatomy bench for anyone to probe. All sorts of abnormalities and diseases, such as schizophrenia and autism, have bared some of their bones, and we’ve begun exploring the mental haunts of such notorious intangibles as religion, addiction, and compassion. By studying busy neural work sites, increased traffic flow, and where thought-crews guzzle oxygen as they toil, we’re forming insights about everything from lying to love. For the first time, we’re able to see some of the ties that bind us. The verb we use, “scan,” which used to mean a brief skim with the eyes, has evolved into its opposite: a machine’s searching stare. People gamely volunteer to have their heads examined so that researchers can witness emotional regattas in full sail (or, sometimes, on the rocks).

  Nightly news often reports the lates
t nugget about concussion, depression, rejection, multitasking, empathy, risk-taking, fear, and other states of mind—explained in terms of the neural architecture and wiring of the brain. In 2012, when President Obama proposed a federally funded $100 million brain-mapping project, stressing that “as humans we can identify galaxies light-years away, study particles smaller than an atom, but we still haven’t unlocked the mystery of the three pounds of matter that sits between our ears,” some people balked at the expense, but few believed it wasn’t possible and a worthy goal.

  A new field, called interpersonal neurobiology, draws its vigor from one of the great discoveries of our age: the brain is rewiring itself daily, and all relationships change the brain—but especially our most intimate bonds, which foster or fail us, altering the delicate circuits that shape memories, emotions, and that ultimate souvenir, the self. Love is the best school, but the tuition is high, and the homework can be physically painful. As imaging studies by the UCLA neuroscientist Naomi Eisenberger show, the same areas of the brain that register physical pain are active when someone feels brutalized by love. That’s why rejection hurts all over the body, but in no place you can point to. Or rather, you’d need to point to the dorsal anterior cingulate in the brain, the front of a collar wrapped around the corpus callosum, the bundle of nerve fibers zinging messages between the hemispheres, that registers both rejection and physical assault. Whether they speak Armenian or Mandarin, people around the world use the same images of physical pain to describe a broken heart, which they perceive as crushing, crippling, a real blow that hurts so bad they go all to pieces. It’s not just a metaphor for an emotional punch that’s too shadowy to name. As our technology is beginning to reveal, social pain—rejection, the end of an affair, bereavement—can trigger the same sort of sensations as a stomachache or a broken bone.