A Jamestown Skeleton is Unearthed, but Only Time—and Science—will Reveal His True Identity

History
سه شنبه 2 مرداد 1397 ساعت 21:49
1339
Smith sonian mag
Dead men tell no tales—but a skeleton in a church gravesite has given Jamestown Rediscovery archaeologists quite the story.
This week, Rediscovery scientists uncovered new evidence , including a skull and teeth, of a skeleton that may belong to Sir George Yeardley in the remains of a church in Jamestown, Virginia. Yeardley, the colonial governor who presided over the first representative assembly in the Western hemisphere, was also one of America’s first slaveholders.
This assembly , which took place in 1619, was a momentous first step in ushering in a new age of colonial rule, though it would be decades before modern democracy would be established in the region. Still, many scholars hail Yeardley for his role in championing the participation of citizens in their own government. Yeardley died at Jamestown in 1627 at the age of 39, and was likely honored with a grand commemoration at the time of his passing.
Since 1994, scientists have been excavating Jamestown, the site of the first permanent English settlement in North America, where three ships first docked in April of 1607. A project originally pioneered by archaeologist Bill Kelso, Jamestown Rediscovery has already unearthed two million artifacts, painting an increasingly intricate portrait of this cornerstone of American history—but the discovery of this early American may be their most groundbreaking yet.
According to David Givens , director of archaeology at Jamestown Rediscovery, Yeardley’s identity is far from definitive and confirmation awaits further analyses, including DNA sequencing. "We believe this person to be Sir George Yeardley, “ says Givens. “Now we’re going to let science tell us if we’re right or wrong."
Ground-penetrating radar (top) reveals a high-resolution image of a skeleton to archaeologists before they broke ground to capture an actual photo (bottom). (David Givens)
The skeleton in question appears to be of the right age, and is largely intact, enabling estimates of several of the body’s original features. Additionally, the specimen was unearthed from a grave positioned in a place reserved for only those of high status: in the central aisle, intersecting with what colonists referred to as the “ quire ” (choir) of what was once the town’s second church, a wooden structure erected in 1617. Additionally, a large tombstone commemorating a knighthood—another mark of prestige bequeathed on Yeardley—once occupied the same church that now bears Yeardley’s supposed remains, and was believed to have sealed his grave. The grave appears to be aligned with the church’s foundations and is devoid of any deconstruction rubble, tentatively indicating that it was dug before the church was dismantled in 1639, 12 years after Yeardley’s death.
Notably, this is the first time that high-frequency ground-penetrating radar has been used in the identification of archaeological skeletal remains. The technique pulses radar deep into the soil and sends back signals of remains beneath the surface, enabling researchers to visualize the evidence without disturbing the artifacts. Such a precaution not only gives a complete picture of a pristinely preserved specimen, but also informs the excavation strategy.
“When we’re digging an archaeological site, we’re going in blind,” explains Peter Leach , an archaeologist at Geophysical Survey Systems, Inc. who collaborated on the project. “Excavation is destructive. . . so being able to look through the soil is powerful.”
Typically, only lower-frequency pulses have been used at previous sites, as these tend to penetrate deeper into the earth. However, the further down the signals go, the poorer the resolution is. High-frequency versions, which have, up until this point, been used almost exclusively to detect rebar and wiring in slabs of concrete during deconstruction and remodeling, were considered impractical for archeological purposes: they had the precision, but not the depth.
But Leach was willing to take that gamble. In the hunt for a gravesite, shallow treasure was a given—and the perfect opportunity to see if high-frequency ground-penetrating radar could visualize bones. Leach encouraged Givens to stop digging just above the lid of a coffin, then give Leach a call.
And hit pay dirt they did.
“The radar was so detailed that when we dug [the skeleton] up, it was like, ‘That’s exactly what we were seeing,” says Givens.
Excavation revealed well-preserved arms, legs and ribs, and even a large number of teeth. For a while, the head was MIA—but then the scientists remembered an orphan skull that had been mysteriously unearthed from a nearby grave the previous year. Perhaps it belonged to their mystery man, and had simply been dislodged by a second burial. They’d be able to potentially confirm a match with DNA analysis—but in the meantime, there was a faster, albeit messier way to tell: they had a jaw bone and a handful of loose teeth—did the keys fit the lock?
They did. This confirmation was—literally—the crowning jewel on their find. They had a head—one that could be scanned to generate a 3D reconstruction of the body’s original face. But the vast majority of the work is yet to come: archaeology is arduous and delicate, far more than a group of researchers playing around in dirt.
“We’re trying to reconstruct a jigsaw puzzle, but sometimes someone comes in and kicks the table,” says Leach.
A skeleton is revealed in the excavation of a prestigious church burial at Jamestown, Virginia. (Smithsonian Channel)
Doug Owsley , lead forensic anthropologist at Smithsonian’s National Museum of Natural History, will head the analysis of the skeletal remains back in Washington, D.C. Since 1996, Owsley has been “reading” human remains at Jamestown—over half of his 40-year career in physical anthropology. “We’re studying this whole process of becoming American through a record written in the bones,” he says.
For him, the excavation goes far beyond what first meets the eye: Owsley notes that each skeleton emerges with a personal history that dictates sex, age, health, lifestyle, ancestry and more. The teeth alone are a wellspring of information: cavities betray grain or sugar consumption, while abscesses shed light on painful illnesses.
Advances in chemical testing will also enable the researchers to learn the skeleton’s diet and travel history. Radiocarbon dating , for instance, can approximately bracket when the body was buried. The bones in our bodies have different regenerative capacities: teeth, for instance, stop growing in early childhood, and make a good snapshot of what you were eating and drinking in youth. Femurs, on the other hand, might reveal the last ten or 15 years of growth; ribs, the last two to five. And so, by pulling samples from all over this skeleton’s body, archaeologists can reconstruct an incredibly accurate life history.
Nitrogen in the bones, for instance, could reveal how much meat was in this man’s diet, which might hint at his social status (Yeardley, while not born noble, quickly rose to prominence in Jamestown). Similarly, different species of oxygen molecules can be matched to country-specific rainwater. If the bones are Yeardley’s, one might expect a layering of oxygen flavors: one for his early years in England, overlaid by a stripe indicative of the Americas. Finally, different types of carbon molecules exist in plants native to either England or the Americas: Corn, a true American classic, would not be expected to appear in the teeth—which preserve only our earliest eating habits—of a native Englishman, but would rear its head in the legs and ribs if he traveled to America.
But the lynchpin of this investigation is perhaps the most elusive puzzle piece of all. Over the next six to eight months, geneticist and archaeologist Turi King of the University of Leicester will do some excavating of her own—but this time, entirely above ground. Her laboratory has already played an instrumental role in identifying the remains of Richard III , and many of the same techniques will be deployed anew in the search for Yeardley.
To confirm his identity, King will need to carefully extract DNA from bits of bone, which involves crushing samples to liberate the necessary molecules. She’ll then compare the fragments she isolates to DNA from known living descendants of Yeardley—but not just any relative will do. King is searching for mitochondrial DNA or Y chromosomes in all-female or all-male lineages, respectively, from Yeardley’s line. These genetic traits are passed through only one sex or the other, putting tough constraints on her search. And while sampling DNA from a living person in modern times has become a breeze, “ancient DNA is a different kettle of fish,” King says. “It tends to be very damaged.” And as her team works, King must take every precaution against contaminating the 400-year-old skeleton’s DNA—a costly mistake that could be as simple as breathing on or brushing up against the samples.
The team hopes to have definitive findings by mid-2019, when they will be profiled by the Smithsonian Channel as a part of its series “American Hidden Stories.” Next year also marks the 400th anniversary of Yeardley’s two legacies as an assembly leader and as a slaveholder. The clash of these two hallmarks of American history further illuminate a period of immense sociopolitical turmoil: in its early years, Jamestown survived several sieges by the region’s natives, an abandonment by leadership, and famines that drove its residents to occasional cannibalism .
Jamestown Rediscovery weds a team of dizzying expertise from around the world, assembling support from the Skeletal Biology Program at the Smithsonian’s National Museum of Natural History; specialists in ground penetrating radar from Geophysical Survey Systems, Inc. ; King’s lab at the University of Leicester; dental specialists Joshua Cohen of Virginia Commonwealth University and Martin Levin of the University of Pennsylvania; and many others.
“One of the things that excites me the most, as an archaeologist, is to work with a team of world class archaeologists, and to experience the camaraderie and collaborations,” says Leach. “It’s really a dream come true.”
In the months ahead, the team will continue to gather evidence for (or perhaps against) the identification of Sir George Yeardley in these remains. But regardless of the skeleton’s identity, this particular investigation is only a piece of the culmination of decades of work in the nation’s first settlement. Yeardley or not Yeardley, this individual will weave a thread to the ever-growing tapestry of Jamestown’s colorful history—and far more remains to be discovered.
“And if it’s not [Yeardley],” says Givens, “then who got such a prominent burial in the church?”
لینک اصل محتوا در Smith sonian mag
برچسب ها