Lab Girl (9 page)

“Hey, I found this chair in the Dumpster behind McDonald's,” he told me as I walked in. “It seems to work.” He examined it with satisfaction while still sitting upon it.

I felt deeply happy to see him. I had anticipated at least three more lonely hours of waiting for someone to talk to.

“I like it,” I told him. “Can anybody sit in it?”

“Not today,” he said. “Maybe tomorrow.” He considered and then added, “But maybe not.”

I stood and thought about how every single thing that came out of this guy's mouth was just a little on the weird side.

Against my Scandinavian instincts, I decided to tell Bill about the most important thing that I had ever done. “Hey, have you ever seen an x-ray of an opal?” I asked, holding up my paper readout.

Bill reached for his radio and silenced it by pulling out its nine-volt battery—the on-off switch had stopped working long ago. After he finished, he looked up at me. “I knew I was sitting here waiting for something,” he told me. “Turns out it was that.”

After I discovered that the hackberry pits contained opal, my next goal was to discern a way to back-calculate the temperature that governed its formation within the seed. While the scaffolding of the hackberry shell was indeed made of opal, the crumbly stuffing was made from a carbonate mineral called aragonite—the exact same mineral found in a snail's shell. Pure aragonite is easy to precipitate in the laboratory; one just mixes two supersaturated fluids, and the crystals rain out of the clear mixture like mist condensing within a cloud. The isotope chemistry of the crystals is strictly controlled by temperature, which means that by measuring the oxygen isotope signature of a single crystal, we could predict the exact temperature at which the solutions were mixed. I could make this work in the lab one hundred times out of a hundred. It was foolproof. My next task was to show that it also worked within a tree, that the same process was happening inside the fruit, where aragonite crystals formed as tree-sap solutions mixed.

My advising professor had pitched this idea as a fifteen-page grant proposal to the National Science Foundation, the peer-reviewers had liked it, and we were recommended for funding. And so, in the spring of 1995, I was headed back to the Midwest to look for the perfect trees to study. I decided upon three full-grown hackberry trees that I found growing on the banks of the South Platte River near Sterling, Colorado, less than a day's drive from a couch where I was always welcome. Under what felt like the biggest, bluest sky in the world I calculated how the composition of the river, taken with the composition of that summer's fruit, would allow me to solve for the average temperature of the season. Confident of success, I corded off the trees and began to monitor them like an expectant father—delighted in anticipation of the gift, but tangential to the proceedings. I also became similarly bewildered during the thick of things, because during that particular summer none of the hackberry trees at or near the site flowered or bore fruit.

Nothing in the world exposes human helplessness and folly quite like a tree that will not bloom. Unaccustomed to people—let alone things—that wouldn't eventually do what I wanted them to do, I took it hard. I analyzed the situation with my only friend in Logan County, Colorado: a guy named Buck who worked behind the counter in a liquor store at the highway crossing. I had gone into the store more desperate for air-conditioning than for beer, truth be told, but after Buck carded me he grudgingly admitted that I was “holding up pretty good for an old lady,” and I took it as an invitation to hang around. As the summer wore on, Buck was increasingly bemused that he was having more luck with his scratch-offs than I was with my trees, but he refrained from rubbing my nose in the irony of my prior lectures on lottery statistics.

Buck had grown up on a ranch nearby, and so I vaguely felt he was a party to the whole fruit debacle, or at least that he should be answerable to it. “But
why
didn't they bloom? Why
this
year?” I urged the question on Buck. I had pored over the local climate records and found nothing conspicuous in the weather.

“It just happens sometimes. Somebody around here could have told you that,” he said, dispensing the grim pity that is rarely to be had from cowboys.

I was convinced that the trees were giving me a sign and that my future career was unraveling. I was panicking, picturing myself on the assembly line, trimming the jowls off of dismembered hog heads, one after the other after the other, for six hours a day, just as the mother of my childhood friend had done for nearly twenty years. “That's not good enough,” I answered. “There has to be a reason.”

“Trees don't
have
a reason, they just do it, that's all,” Buck snapped. “In fact, they don't
do
anything, they're just trees, they just
are.
Shit, they're not
alive,
not like you and me.” He had finally gotten fed up, and something about me and my questions was irritating him.

“Ke-rist-on-a-crutch,” he added in frustration, “they're just
trees.
”

I left the shop and never went back.

I returned to California in failure. “Well, if I had a car that I thought could make it over the Concord Bridge I'd say let's go set one of those trees on fire,” Bill said as he concentrated the crumbs from the bottom of his Lay's potato chip bag using one of the lab's funnels. “We'll let the others watch that one burn for a while and then ask them if they don't feel a little more inclined to bloom.”

Bill had become a fixture in my advisor's laboratory. He appeared sometime around 4:00 p.m. each day and then stayed for eight or ten hours, as his spirit and our needs moved him. He couldn't see how the fact that he was given pay for only ten hours a week was relevant, and he was surprisingly content to listen to me talk obsessively about my trees for hours each night while we worked. Before my last trip to Colorado, Bill had urged me to take a BB gun and indulge in a couple of afternoons of shooting at leaves and branches.

I declined. “Not that I'm an arborist or anything, but I don't think it will help.”

“It will make you feel better,” he said emphatically. “Trust me.”

That whole summer in Colorado was a data-gathering bust, but it taught me the most important thing I know about science: that experiments are not about getting the world to do what you want it to do. While tending to my wounds that fall, I shaped a new and better goal out of the debris of the disaster. I would study plants in a new way—not from the outside, but from the inside. I would figure out why they did what they did and try to understand their logic, which must serve me better than simply defaulting to my own, I decided.

Every species on Earth—past or present, from the single-celled microbe to the biggest dinosaur, daisies, trees,
people
—must accomplish the same five things in order to persist: grow, reproduce, rebuild, store resources, and defend itself. At twenty-five, I could already see that my own reproduction was going to be complicated, were it ever to take place at all. It seemed outrageous to hope that fertility, resources, time, desire, and love could all come together in the right way, and yet most women did eventually walk that path. While in Colorado, I'd been so focused upon what the trees weren't doing that I hadn't made any observations of what they were doing. Flowering and fruiting must have taken a backseat to something else that summer, something that I had failed to notice. The trees were
always doing something:
when I kept this fact placed firmly in front of me, I got closer to making sense of the problem.

A new mind-set became imperative: perhaps I could learn to see the world as plants do, put myself in their place, and puzzle out how they work. As a terminal outsider to their world, how close could I come to getting inside? I tried to visualize a new environmental science that was not based on the world that we wanted with plants in it, but instead based on a vision of the plants' world with us in it. I thought of the different labs that I had worked in and the wonderful machines, chemicals, and microscopes that gave me so much happiness…What kind of hard science could I bring to bear on this weird quest?

The perversity of such an approach was seductive; what was there to stop me, aside from my own fear of being “unscientific”? I knew that if I told people I was studying “what it's like to be a plant,” some would dismiss me as a joke, but perhaps others might sign on just for the adventure. Maybe hard work could stabilize scientifically shaky ground. I didn't know for sure, but I felt the first delicious twinges of what would be my life's enduring thrill. It was a new idea, my first real leaf. Just like every other audacious seedling in the world, I would make it up as I went along.

EVERY PLANT CAN BE SEPARATED
into three components: leaf, stem, and root. Every stem functions the same way: as a bundle of bound straws, bales of microscopic conduits that carry soilwater up out of the roots and sugarwater down out of the leaves. Trees are a unique type of plant because their stems can be more than one hundred yards long and are made of this amazing substance that we call wood.

Wood is strong, light, flexible, nontoxic, and weather-resistant; thousands of years of human civilization have yet to produce a better multipurpose building material. Inch for inch, a wooden beam is as strong as one made from cast iron but is ten times more flexible and only one-tenth as heavy. Even in this age of high-tech man-made objects, our preferred construction material for housing remains lumber hewn from trees. In the United States alone, the total length of the wooden planks used during the last twenty years was more than enough to build a footbridge from the planet Earth to the planet Mars.

People slice up tree trunks, nail the pieces together into boxy shapes, and then go inside to sleep. Trees use the wood in their trunks for a different purpose—namely, they use it to fight with other plants. From dandelions to daffodils, from ferns to figs, from potatoes to pine trees—every plant growing on land is striving toward two prizes: light, which comes from above, and water, which comes from below. Any contest between two plants can be decided in one move, when the winner simultaneously reaches higher and digs deeper than the loser. Consider the tremendous advantage that wood confers to one of the contestants during such a battle: armed with a stiff-yet-flexible, strong-yet-light prop that separates—and connects—leaves and roots, trees have dominated the tournament for more than four hundred million years.

Wood is a static, utilitarian compound, constructed once and left to stand as inert tissue forevermore. From the tree's center (or “heartwood”) radiates a network of ray cells that bring cool xylem and sweet phloem to the cambium layer on the periphery. The cambium layer manufactures the living sheath that rests just below the bark. A tree grows by producing one new sheath after another. When a sheath is outgrown, its woody skeleton is left behind, progressively forming the rings that we can see in cross section after a tree is felled.

A tree's wood is also its memoir: we can count the rings to learn the tree's age, for every season of growth requires a new sheath from the cambium. There's a lot of additional information written into tree rings, but it is coded within a language that scientists don't speak fluently—yet. An unusually thick ring could signify a good year, with lots of growth, or it could just be the product of adolescence, a random spurt of growth hormones cued by an influx of unfamiliar pollen from a distant source. A ring that is thick on one side of the tree but thin on the other tells the story of a fallen branch. When a branch is lost, it upsets the balance of the tree, triggering cells within the trunk to reinforce the side that must now support the newly uneven burden of the crown.

For trees, losing limbs is the rule, not the exception. The vast majority of the branches that any tree produces are severed before they become large, usually by external forces like wind, lightning, or just plain old gravity. Misfortunes that cannot be prevented must be endured, and trees possess a ready strategy. Within a year after the loss, the cambium will cast a healthy new sheath fully over the broken base of what used to be the branch, and then layer upon it year after year until no scar is visible at the surface.

In the city of Honolulu, just where Manoa Road crosses Oahu Avenue, there stands a gigantic monkeypod tree (
Pithecellobium saman
). The trunk of this tree is fifty feet tall and its branches form a giant arch that spans clear across the busy intersection. Wild orchids grow on the branches: they sit in companionable bunches shaped like pineapple tops and their naked roots dangle down beneath them. Feral parrots hop from one orchid to another, flapping their lemon-lime wings and squawking abuse at the pedestrians below.

The monkeypod, like many trees of the tropics, lives in eternal bloom: great globs of silky, threadlike pink and yellow petals rain down on the tourists who pause to take a picture of the tree as they make their way up the valley to visit the famous Manoa waterfalls. On coffee tables all over the world, you can find photo albums containing photographs of the monkeypod tree at Manoa Road and Oahu Avenue, thousands of worm's-eye views of its magnificent eight-thousand-square-foot canopy, woven through with flowers.

From the tourists' perspective, this tree has achieved its perfect form: they do not see a tree that is less than it might have been, or one that was forced to grow a different way after its limbs were torn. If the monkeypod tree at Manoa Road and Oahu Avenue were to be cut down, we could count the knots and see the buried scars of the hundreds of branches that it has lost during the last century of its life. But as of today the tree stands, and while it is standing, we see only the branches that did grow and do not miss the ones that were lost.

Every piece of wood in your house—from the windowsills to the furniture to the rafters—was once part of a living being, thriving in the open and pulsing with sap. If you look at these wooden objects across the grain, you might be able to trace out the boundaries of a couple of rings. The delicate shape of those lines tells you the story of a couple of years. If you know how to listen, each ring describes how the rain fell and the wind blew and the sun appeared every day at dawn.