Wednesday, October 7, 2009

The Glamour of the Moment of Discovery

The glamour, the mystique of the moment of discovery in the sciences is, to me, irresistible. Though I’m drawn to its depiction whether it occurs in the lab, the field, or the mind, it’s the discovery in the field that I probably find most compelling. This is, I suspect, what pulls many into the sciences, particularly such fields as paleontology. It certainly is at the heart of what makes the “wannabes,” the amateurs like me, invest inordinate amounts of time learning about paleontology and going on fossil hunts, the latter offering some actual, though admittedly tenuous, connection to doing the science (the less exciting curating and trying to make sense of what one finds on the hunt probably get closer).

Carter and Tut

One of my favorite descriptions of a discovery moment was written by C.W. Ceram about English archaeologist Howard Carter and the tomb of Tutankhamen (Gods, Graves, and Scholars: The Story of Archaeology, 1951, p. 212-213). It’s 1922 and Carter is about to break through the door to the tomb’s antechamber. His patron and partner Lord Carnarvon is among those gathered with him. For a moment they fear the worst – that this tomb is a common one, has never been completed, or is lying beyond those doors plundered and laid to waste.

Their hopes, in short, for a time were dashed. The tension increased once more, however, when rubble was taken away from the second door. “The decisive moment had arrived,” Carter says. “With trembling hands I made a tiny breach in the upper left hand corner.”

Taking an iron testing rod, Carter poked it through the door and found an emptiness on the other side. He lit candles to ensure against poisonous gases. Then the hole was enlarged.

Everyone interested in the project now crowded about. . . . Nervously Carter lit a match, touched it to the candle, and held it toward the hole. As his head neared the opening – he was literally trembling with expectation and curiosity – the warm air escaping from the chamber beyond the door made the candle flare up. For a moment Carter, his eye fixed to the hole and the candle burning within, could make out nothing. Then, as his eyes became gradually accustomed to the flickering light, he distinguished shapes, then their shadows, then the first colors. Not a sound escaped his lips; he had been stricken dumb. The others waited for what seemed to them like an eternity. Finally Carnarvon could no long contain his impatience. “Can you see anything?” he inquired.

Carter, slowly turning his head, said shakily: “Yes, wonderful things.”

Doesn’t get much better than that.

Johanson and Lucy

These are heady days in the study of early hominids, those predecessors to the genus Homo. Fifteen years after the first description of a specimen of the early hominid Ardipithecus ramidus, paleoanthropologist Tim White and a phalanx of other scientists with a wide range of specialties have just presented a detailed picture of this hominid, the world in which it lived, and how it interacted with that world (see the 11 research articles published in the October 2, 2009 issue of Science -- requires a free registration – link here) White et al. have tipped over a cornucopia of findings from their research on Ar. ramidus. Even some scientists who complained about that 15 year gap between discovery and full publication have reveled in this wealth of scientific riches.

Although some 110 specimens of Ar. ramidus have been found at this site, one of them is “by far the most complete of the earliest specimens [of hominids]. It includes most of the skull and teeth, as well as the pelvis, hands, and feet.” (A New Kind of Ancestor: Ardipithecus Unveiled, article by Ann Gibbons, Science, October 2, 2009, p. 36 -- link here] The first pieces of this skeleton were found in 1994. Here's a picture of the assembled pieces of this specimen.

Of course, this striking find brings to mind another one that enthralled our collective imagination. Twenty years earlier, on November 24, 1974, paleoanthropologist Donald Johanson found the first pieces of a 40 percent complete skeleton of an Australopithecus afarensis specimen (from roughly 3.7 million years ago). Dubbed “Lucy,” this was the earliest known hominid until the discovery of Ar. ramidus (from roughly 4.4 million years ago).

In his book, Lucy: The Beginnings of Humankind (1981), Johanson describes the moment of discovery. At the end of a day in the field with Tom Gray, an American graduate student, Johanson follows an impulse to check out a gully bottom, one more time (p. 16-17):

It has been thoroughly checked out at least twice before by other workers, who had found nothing interesting. Nevertheless, conscious of the "lucky" feeling that had been with me since I woke, I decided to make that small final detour. There was virtually no bone in the gully. But as we turned to leave, I noticed something lying on the ground partway up the slope.

“That’s a bit of a hominid arm,” I said.

“Can’t be. It’s too small. Has to be a monkey of some kind.”

We knelt to examine it.

“Much too small,” said Gray again.

I shook my head. “Hominid.”

“What makes you so sure,” he said.

“That piece right next to your hand. That’s hominid too.”

[Yes, indeed it was hominid – the back of Lucy’s skull. As they surveyed the slope, they found a femur, vertebrae, a piece from a pelvis.]

An unbelievable, impermissible thought flickered through my mind. Suppose all these fitted together? Could they be parts of a single, extremely primitive skeleton? No such skeleton had ever been found – anywhere.

“Look at that,” said Gray. “Ribs.”

[That night in the celebrating camp, with the strains of The Beatles’ Lucy in the Sky with Diamonds filling the night air, Lucy received her name.]

Not too shabby a moment of discovery. It resonates with particular strength because anyone who has spent the day staring at the ground, trying to match a mental search image with the myriad objects littered around, will recognize that desire to have just one last look, even over terrain that has been scoured repeatedly.

White and Ar. ramidus?

But what about this newly publicized find, this remarkable Ar. ramidus skeleton that some insist on calling Ardi? Is there a “Lucy moment” waiting to be told (perhaps in a forthcoming book written for a popular audience) for this particular specimen?

One of White’s research articles describes the initial discovery of this particular specimen in, not unexpectedly, bloodless terms (this is, after all, Science):

[O]n 5 November 1994, Y.H.S. [Yohannes Haile-Selassie] collected two hominid metacarpal fragments . . . from the surface of an exposed silty clay ~3 m below the upper tuff . . ., 54 m to the north of the point that had 10 months earlier yielded the Ardipithecus holotype dentition.
(Ardipithecus ramidus and the Paleobiology of Early Hominids, White et. al, Science, October 2, 2009, p. 76 -- link here)

From that small start, over the course of two years, White and his teams painstakingly teased out the many pieces of the skeleton from the matrix in which they were found:

In the field, the fossils were so soft that they would crumble when touched. They were rescued as follows: Exposure by dental pick, bamboo, and porcupine quill probe was followed by in situ consolidation. We dampened the encasing sediment to prevent desiccation and further disintegration of the fossils during excavation. Each of the subspecimens required multiple coats of consolidant, followed by extraction in plaster and aluminum foil jackets, then additional consolidant before transport to Addis Ababa. (p. 77)

Wait, that sounds like a lot of excruciatingly precise work . . . so, probably not a Lucy moment. But, frankly, that’s the problem with the popular account of the discovery moment or, at least, what we, the uninitiated, remember. Its lingering image is of the moment, of that instant when Carter says, “Yes, wonderful things.” The image no longer retains (if it ever did) any remnant of his six years of fruitless searching in that small area of Egypt, or the months required to deal with the finds in the antechamber before going on into Tut’s chamber itself where the real treasures were. Then, we conveniently forget that it took ten years to remove and catalogue what was in the tomb. (Let’s also ignore the curse.) We need to be reminded, continuously that there’s so much, much more to it, long before and long after the discovery.

A Matter of Choices

A good friend raised a question that always lurks in the mental shadows for a person pursuing an avocation or interest full throttle. She asked, If I had it to do all over again, and everything else that mattered in my life would remain the same (family, steady job, nice place to live, etc.) would I have become a paleontologist? Clearly recognizing how seductive I find the fossil hunt, that hard work in the outdoors, she added a critical coda describing the intellectual and other challenges that would await a practitioner of this profession – it’s not all that grand moment of discovery in the field, she was saying, so choose wisely. In our exchange over this coda, the words spoken or mostly implied included technical, theory, research, bureaucratic demands, academic infighting, death by a thousand cuts, etc.

I gave her a glib response, but found myself continuing to ponder the basic question.

Shortly after she posed it, I stumbled across an old essay by Stephen Jay Gould reviewing John McPhee’s Basin and Range (1981 – B&R is still fun on rereading). McPhee’s book is an accessible, personal view of deep time and plate tectonics (the new geology), illustrated through a journey across the country, from roadcut to roadcut along Interstate 80, primarily in the company of geologist Kenneth Deffeyes. As much as he liked the book, Gould was critical of what he saw as McPhee’s exalting of field work:

[H]e has been beguiled by the mystique of field work. No geologist worth anything is permanently bound to a desk or laboratory, but the charming notion that true science can only be based on unbiased observation of nature in the raw is mythology. Creative work, in geology and anywhere else, is interaction and synthesis: half-baked ideas from a barroom, rocks in the field, chains of thought from lonely walks, numbers squeezed from rocks in a laboratory, numbers from a calculator riveted to a desk, fancy equipment usually malfunctioning on expensive ships, cheap equipment in the human cranium, arguments before a roadcut. (An Urchin in the Storm: Essays about Books and Ideas, 1987, p. 98)

McPhee, Gould argues, is positing that science advances only through the objective analysis of the data steadily accumulated from observation in the field. Wrong, says Gould, this ignores the fact that the scientist can never divorce himself or herself from the cultural milieu. In reality, science advances through an admixture of ideas and facts, and those ideas aren’t newly generated solely from the data (I would add, no matter how much Francis Bacon would have had it so).

Given where this post started, I would argue that there’s something else going on in this criticism, at least, there is to me. For an amateur like McPhee, field work has a mystique in the first place because there he is walking a road cut with a geologist who whacks off a piece of rock exposing, in McPhee’s words “[i]ts fresh surface . . . asparkle with crystals – free-form, asymmetrical, improvisational plagioclase crystals, bestrewn against a field of dark pyroxene.” (Basin and Range, p. 5) Listen to that language . . . it reveals how, to the amateur, even something as prosaic as this little roadcut vignette is magical and the scientist is breaking through the door and shedding light on wonderful mysteries inside. So, how could it be otherwise that, in the popular imagination (my imagination), those stories of the glorious moments of discovery in the field are what is remembered and exalted?

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