Of course, the buffalo is still changing—maybe more rapidly now than at any other time. We may not know until much later, maybe thousands of years from now, when we have a distant point of perspective from which to look at it.
I often wondered how my own buffalo skull fit into the grand scheme of the animal’s history. Was it actually what I’d been calling it, an American buffalo, or was it from one of those remnant forms of the past? I worried that perhaps it belonged in a museum, or maybe had some value to science. I studied a system of bison skull diagnostics known as “cranial characteristics and horn-core morphology”; you take a bunch of measurements of a buffalo skull, with particular focus on the horns, and those measurements help you extrapolate what sort of skull you’re looking at. I got my hands on a list of twenty-six of those measurements and felt like I was holding a secret code that would unravel a great mystery. However, the measurement descriptions were somewhat puzzling; I was supposed to measure the “rostral width at maxillary-premaxillary suture,” the “transverse diameter of core at right angles to longitudinal axis,” and the “width of skull at masateric process above M1.” Not only did I not know what any of those parts were, but I felt that the measurements were callously indifferent to the reality of my skull’s condition: it wasn’t all there, and much of what was there was crumbled and chipped.
My next attempt at identifying the skull brought me all the way to Oxford University, in England. I had read an academic article titled “Rise and Fall of the Beringian Steppe Bison,” which appeared in a 2004 issue of the journal Science. The article provides a timetable supporting a claim that the bison began sliding toward extinction across the northern extent of its range about thirty-five thousand years ago. The article’s primary author is Beth Shapiro, a leading expert on ancient DNA who works at Oxford University. In researching the article, Beth and her colleagues had extracted genetic material from the skeletal remains of around five hundred bison that lived in Alaska and northern Canada thousands of years ago. Ancient DNA tends to be highly degraded and eroded—it would be virtually impossible to use it for cloning—though it can be used to reveal the effective population size of a breeding group, as well as how the particular animal fits into the overall evolutionary history of its species. I called Beth Shapiro one day, introduced myself, and asked if she could work some of her magic on my buffalo skull. She told me she’d be happy to try.
It was wintertime when I arrived in Oxford. The snowfall was so light that the flakes looked like drifting campfire ash. Underdressed students hustled from building to building with their chins tucked into their collars and their hands pulled up into their sleeves. I walked to the Henry Wellcome Ancient Biomolecules Centre and waited outside for Beth Shapiro.
Beth arrived on a bicycle. She mentioned that she was suffering from a mild hangover as she fiddled with her belly button ring, which seemed to have snagged itself on an article of her clothing. Beth grew up in Rome, Georgia, where she landed a job in tenth grade as the news anchor on her local television station. She’d go to work at 6:00 a.m., do the news, and then get to school during the second hour. After school, she’d go back to the television station and work until 6:00 p.m. After graduating from high school with honors, she got a university degree in ecology in 1999 and then landed a Rhodes scholarship to study evolutionary biology at Oxford. She’s been there long enough to pick up a touch of an accent, and she’s fond of words such as “bloody” and “rubbish.”
Beth led me around to the back of the biomolecules center. No one is allowed to use the front door because they’ve found that genetic contaminants have a way of coming in off the street. Beth told me several stories of people who’d made “great” discoveries with ancient DNA only to find that they hadn’t: a genetic researcher looking for DNA from an extinct saber-toothed cat found some feline DNA all right, but it turned out to come from someone’s house cat.
Another time, a team of researchers working in England claimed to extract from salt crystals a form of bacterial DNA that was tens of millions of years old. Until then, the oldest successfully extracted samples of DNA came from organisms that were only forty to eighty thousand years old. “We got their data and looked at it and said, ‘Piss off,’ ” Beth told me. “We later got the same DNA from dirt that I collected on the roof of Oxford University’s Museum of Natural History. So either that roof has bacterial DNA that’s associated with salt crystals that are a hundred million years old, or they were dealing with a contaminant.”
To avoid such contaminants, we stripped out of our outer clothes and stepped into one-piece white lab outfits with rubber bootees, latex gloves, skintight hoods, and full face masks. We looked like we were going to clean up a chemical spill. Then we stepped through a series of doors, closing each set behind us before opening the next. We arrived in a room that was piled here and there with sealed plastic bags containing some alarming labels. There were several bags of “unused plague samples.” There were samples of thirty-five-thousand-year-old giant ground sloth shit, taken from a cave in South America. (“Poop’s great,” said Beth. “You can get the animal’s own DNA, and also the DNA from its intestinal parasites.”) There were mammoth bones, bones from extinct horses, saber-toothed cat bones, and short-faced bear bones. Beth opened a freezer to show me two complete human skeletons. “Dead Victorians,” she said. “Some archaeologists turned them up. No markings on the graves. I’m trying to give them away because they’re taking up space. I’ve offered to throw in this bloody freezer to whoever will come and get them.”
We went into a small room containing workbenches and several devices that looked like elaborate refrigerators with labels reading “Thermo Cryotechnics.” I unsheathed the skull and laid it on the counter. Beth fitted a cutting wheel that was the size of a quarter to a Dremel tool and plugged the tool in. It made a faint whirring sound. “With bison, I like to cut right here,” she said, pointing to a thick section of bone between the horn’s base and the eye socket.
To reduce surface contaminants, Beth used the tool to scrape away the outside of the bone. She only needed about a gram, so the area she cleaned was less than an inch square. The bone on the surface turned to fine powder, and the smell of burning hair filled the room and penetrated my face mask. “Ancient DNA is already in shitty condition,” she said, “so I want to get as good a sample of bone as I can. Usually, I can tell by the way they smell whether they still have good DNA in them.”
Author and skull at the Henry Wellcome Ancient Biomolecules Centre at Oxford University.
“Does it have the right smell?” I asked.
“Pretty good,” she said.
“So you think it’s going to work, then?” I asked.
Beth continued cutting. “I give it fifty-fifty,” she said.
When she turned off the saw, Beth picked up a small tool that looked like a dentist’s implement and used it to pry out the rectangular block of bone that she’d cut. It was about as big as two Chiclets set side by side, and twice as thick. She cut the block into two squares and gave me one in case I decided to submit it to a laboratory for radiocarbon dating. She placed the second sample of bone in a heavy-duty stainless steel canister containing a steel ball bearing. The canister was fitted into a machine labeled “Mikro-Dismembrator.” The machine shook the canister so fast that it was a blur. The ball bearing inside the canister pulverized the bone into a fine powder. Beth then poured the powder into a test tube and capped the tube. She labeled it No. 43, and it went into a rack of a hundred such tubes containing powdered bone from extinct species of Siberian yaks and bison. Mixed in at random were empty tubes. She makes sure that the results from those empty tubes are negative, to ensure that they are not contaminated with ambient bits of modern DNA.
That was as much of the process as Beth could show me, and it was as much as I could readily understand. The actual act of extracting the DNA is mind-boggling in its complexity, and mostly takes place inside elaborate, sensitive machinery. As Beth walked me to a b
us stop, she told me that it would take about a month before she had results. I flew home, as anxious as if I were waiting for the outcome of a girlfriend’s pregnancy test. I counted down the days until I hit the number thirty, and then I placed a call to Beth’s office. She sounded dejected. “I was hoping to get some really old bison DNA from Montana,” she said.
“So it’s not old?” I asked. “It’s not some weird, ancient form of bygone buffalo?”
“I can’t tell you how old it is,” she said. “But I can tell you that, genetically, it matches a modern bison.”
“A regular ol’ American buffalo?” I asked.
“If that’s how you want to put it, then yes,” she said. “An American buffalo.”
At this point, the gram-sized piece that Beth had given me began to burn a hole in my pocket. It costs about $700 to get a radiocarbon date from a piece of bone, and I’d been waiting for Beth’s results before I dropped the money. If she determined that my skull was from an ancient form of the animal, I’d save my cash. But if it was from a modern form of the animal, I thought it would be cool if I could link it to some specific date that pertained to human history. Plus, by now I’d become addicted to the highs and lows of scientific inquiry. I padded a one-gram piece of the skull with cotton balls and stuffed it into an empty Tic Tac container along with a check for $675. I placed that into a padded envelope and addressed it to Beta Analytic of Miami, Florida. Again, the pleasure of anticipation coursed through my veins.
Radiocarbon dating works something like this: Through photosynthesis, plants take up carbon-14, a naturally occurring radioactive isotope that is produced by cosmic rays entering the earth’s atmosphere. Through the consumption of plant materials, or through the consumption of organisms that eat plant materials, the carbon-14 passes into every other living organism on earth—it’s inside of you, your dog, your goldfish, your house plants, and your goldfish’s food. Organisms accumulate the isotope at the same ratio as it occurs in the atmosphere, and the accumulation process stops when the organism dies. From then on, the carbon-14 begins to decay with a half-life of 5,730 years. Through some laboratory wizardry, it’s possible to examine the rate of decay of the remaining carbon-14 in an organism’s tissues and then infer how long the thing’s been dead.
I waited over a month for my results. In the meantime, I followed a somewhat related series of articles that appeared in the Billings Gazette about the U.S. Mint’s ten-year, fifty-state commemorative-quarter program. Montana’s quarter was scheduled for a 2007 release, and the state had begun its selection process in the summer of 2005, when Governor Brian Schweitzer’s office put out a call for designs.
Hundreds of proposals were submitted. Suggestions included a flaming skeleton riding a motorcycle; a can of beer and a pork chop sandwich; a grizzly bear; “dudes riding three-wheeled ATVs on a hill”; a picture of Lewis and Clark; and the Unabomber’s cabin in Lincoln, Montana. Some ideas were thrown out for being obscene, some were thrown out for being illegal (you can’t use the state symbol on a coin), and others were rejected for being non-coinable, which is the U.S. Mint’s term for a design that is too complicated. The governor proposed the novel idea that Montana’s quarter be minted in palladium, a white metal mined in Montana, but federal law mandates the use of silver.
The six-person selection committee appointed by Schweitzer eventually nominated four ideas: a bull elk; a landscape featuring the sun; a landscape featuring a river; and a buffalo skull. The four ideas were submitted to the U.S. Mint for preliminary design, and the U.S. Mint returned the four ideas in coin form. The images were placed on an Internet-based ballot. The Billings Gazette announced the final decision on June 30, 2006, just as I was struggling with my radiocarbon purchase. The story appeared amid a collection of state headlines dominated by stories about car crashes, crystal meth, murder, and a plan to give birth control to wild horses: the elk pulled 30 percent, the sun and the river each nabbed around 18 percent, and the buffalo skull landed 34 percent of the vote. The choice seemed to tear the state apart. Someone pointed out that more people had voted against the skull than had voted for it. Comments flooded in to the Gazette:
“That quarter is UG-LY.”
“Man, that coin is dumb! A floating cow skull, what the heck does that have to do with anything?”
“The skull is easily the worst of the four. Carrion has always been such a great beacon for prosperity.”
“I think it was a wonderful choice. We were competing in the ugly quarter contest, weren’t we?”
“Why in the world would Montana choose a symbol of death for its new quarter?”
“Can’t Montana do anything right? A quarter to honor Montana and we choose a dead animal’s skull?”
“UGH!”
The entire process made me feel as though my personal feelings (and cash expenditures) were being put to a public forum. By now, a couple of years had passed since I’d found the skull, and I’d been carrying it from home to home and state to state, trying to find some way to describe what it meant. Not just what it meant to me, but also what it meant meant, in a larger way. All I could come up with was that I liked being near it and that I enjoyed staring at it. I described it as somehow symbolic of the American experience, but I could never really put this sentiment into the proper words. Now I felt as though my whole enterprise with the buffalo skull was being mocked. I pictured myself as an oddball variant of those folks who spend their time and money trying to prove that they are descended from European royalty.
But the story with the skull had a satisfactory ending after all. When my radiocarbon results arrived in the mail, I discovered that my buffalo skull’s official age was, in the jargon of radiocarbon dating, 150 +/– 40 BP. Calibrated to calendar years, that meant the buffalo was no older than A.D. 1660. Because the bone did not contain radioactive bomb carbon from atmospheric testing of nuclear warheads, it was no younger than A.D. 1960.
The first thing I said was, “A three-hundred-year span of time was the best that these people could do for $675?” I was tempted to call the Better Business Bureau, but first I dialed up Darden Hood, of Beta Analytic, to see what he had to say for himself. He politely explained a few things to me, such as the “heliomagnetic modulation of the galactic cosmos,” “geomagnetic variations,” and the “intercepts between the average radiocarbon age and the calibrated curve timescale.” That information helped him to explain, in a roundabout way, why organic materials from the past few hundred years are less reliably datable than materials from the past few thousand years.
I sank into a mild carbon-dating depression. Then one day I was reading something by an archaeologist with the National Park Service named Kenneth P. Cannon. He was discussing a buffalo skull with the exact same radiocarbon date as mine, 150 +/– BP, which was analyzed by Beta Analytic of Miami, Florida. Cannon writes, “Statistically, this bison likely died in the early to mid-18th century.”
I called Kenneth Cannon at his office in Lincoln, Nebraska, and told him about my little problem.* He knows Darden, has worked with him for years. He explained that Darden’s job is to accurately calculate radiocarbon dates, “not interpret results.” “There’s always going to be a level of variability in calculation and interpretation,” explained Ken. But he did help shed some light on my results. He explained that there’s a 95 percent chance that my buffalo died between A.D. 1720 and A.D. 1880, and a 66 percent chance that it died within a few decades of A.D. 1750. For the sake of patriotic nostalgia, it’s fun to think that my American buffalo might have died in 1776. And because the animal was found at such a high elevation, nine thousand feet, it’s apparent that he died in the snow-free season of summertime. While I’m not going so far as to suggest that he died on July 4, 1776, you can’t say for sure that he didn’t. Now, when people come over to my house, I’ll usually point at the skull and say, “See that? That buffalo might have been alive when they signed the Declaration of Independence.” I can never decide if there is irony in that statemen
t, or nostalgia, or what, so I usually just let the statement stand on its own. People fill the silence by walking over and picking it up.
5
THINK OF THE SHAPE of the letter D. The curved arc of the letter’s right side is the fifty-mile stretch of the Copper River that I’m going to float in search of buffalo. The vertical line at the letter’s left side is the forty-mile stretch of highway south of Copper Center, a small village that lies just south of Glennallen. Where the two lines meet, at the top and bottom of the D, are two places where my partners and I can get a truck close enough to the river to load and unload gear into a raft. The lower part is near the town of Tonsina, where there’s a little road off the highway that salmon fishermen use to access their fish traps. I’ve got a buddy’s truck parked down there with the keys hidden under the front-left tire. We’ll use that truck at the end of the trip, rather than hitchhiking back to where we are now, at the top of the D.
Specifically, the top of the D is where the Klutina River passes below the Richardson Highway just before flowing into the Copper River, which is less than a mile downstream from me. My brother Danny and I are staring at a bunch of gear strewn up and down the riverbank while two of our buddies, Matt Rafferty and Jeff Jessen, inflate the raft with a pair of hand-powered pumps. The four of us are going to travel downriver and hunt together for a few days. If we don’t find a buffalo in that amount of time, I’ll stay behind in Wrangell–St. Elias and they’ll come back with the raft to pick me up at some later date.
Jeff Jessen near the Copper/Klutina confluence.
American Buffalo Page 5