Before ever a word was written, at least five thousand generations of human beings had lived out their lives on this earth, among them extraordinary innovators and adventurers who planted the first crops, created the first art, and discovered and settled entire continents. Yet except in the most extraordinary circumstances, nothing but stone tools and broken bones remain to tell us of their lives and triumphs. It is to shed light into this void that archaeologists delve into the earth, and—as one might imagine—the stories they emerge to tell are open to interpretation. Few, however, have proven as contentious as those concerning the peopling of the Americas.
The very first human discovery of the Americas must have unleashed enormous opportunity for those tribes that crossed from Asia, for at a swoop they and their descendants occupied 28 percent of the globe’s land surface—including some of its richest, most diverse, and most spectacular landscapes. Today the details of that conquest have been obscured by the mists of time, and so scientists continue to argue the basics of who, when, and how.
The traditional view is that the earliest Americans were the Clovis people, who arrived around 13,200 years ago by way of a narrow land corridor which was just then opening in the ice sheet that had long divided temperate North America from Asia. For at least thirty years, however, some archaeologists have been suggesting that the first Americans were already in residence 16,000 years ago, and that they arrived by skirting the ice barrier in boats. Their work has received much recent popular coverage, including an extended article in National Geographic magazine.1
While inherently interesting, the debate also has wider dimensions, for many traditionalists think that the Clovis were big-game hunters who exterminated America’s megafauna (including the mammoth, mastodon, and other ice-age beasts) much as hunters of the historic frontier nearly did to the buffalo. The champions of a pre-Clovis presence, on the other hand, read into bones and stones the story of a gentle people who caused no detectable environmental disturbance. Whatever the case, it is becoming clear that the debate is about even more than that, for it touches on the very way we conduct science.
J.M. Adovasio is a passionate believer in a pre-Clovis human presence in America. His book, The First Americans, which was written with the assistance of Jake Page, a former editor of Natural History magazine, presents what the authors claim to be indisputable proof that people inhabited the Americas some 16,000 years ago.
Adovasio has spent much of his professional career excavating a single site—the Meadowcroft Rockshelter in southwestern Pennsylvania—and it is this site that provides most of the evidence presented in his book. His team began work there in 1972, and over the past thirty years they have dug through eleven identifiable layers, recovered more than two million artifacts, and obtained fifty-two radiocarbon dates, using the technique by which age is established through measuring the amount of carbon-14 remaining in them.2 Consequently, Meadowcroft Rockshelter is today the litmus test for a pre-Clovis human presence in North America. If it and its sister site of Monte Verde in southern Chile (excavated by Tom Dillehay of the University of Kentucky) are invalid, the core data supporting a pre-Clovis presence in the Americas would collapse.
The First Americans commences with a long and interesting summary of speculation on the origins of the Native Americans. The extensive ancient mounds built in the Ohio River Valley and other places first piqued interest in the subject. Thomas Jefferson undertook the first scientific excavation in the history of archaeology when, in 1784, he excavated one such mound—a twelve-foot-high rise on his property near the Rivanna River, Virginia. Other early inquirers were not so rigorous. In 1839 Cornelius Mathews wrote the novel Behemoth: A Legend of the Mound-Builders, which posits that the civilization responsible for the mounds was all but destroyed by a rogue and monstrous woolly mammoth. Another fanciful nineteenth-century theory was that Noah’s Ark came to rest on the mounds. The Mormons also posit a biblical involvement, holding that the Jews came to America around 600 BC and built great cities atop the mounds, after which one group of Israelites fell from the ways of God and became red-skinned. Adovasio assures us that well into the second half of the twentieth century, Mormon missionaries were telling Native Americans and blacks that this history was proof that their skins would whiten if they joined the church. American prehistory, it seems, has often served political ends.
By the beginning of the twentieth century, rigor and professionalism were beginning to make their mark on American archaeology. William Henry Holmes, an artist turned geologist, was employed by John Wesley Powell (who was then director of both the US Geological Survey and the Smithsonian’s Bureau of Ethnology) to investigate claims of a human presence in America during the ice age. Through patient research and close observation, he was able to dismiss all such claims, thus distinguishing North America from Europe, where a considerable body of evidence of human presence during the ice age had been accumulated.
By the early 1920s it seemed to researchers that humans had entered the Americas as recently as four or five thousand years ago, but then a black cowboy made an extraordinary discovery. George McJunkin was born into slavery, and when at age fourteen he was freed by Union forces, he had not had a single day’s education. Like so many with slim prospects he decided to go west, settling on the Crowfoot Ranch in New Mexico. There he got the sons of the rancher to teach him to read, and eventually became ranch foreman, as well as a much-sought-after fiddler, surveyor, astronomer, and instrument maker.
But McJunkin’s real passion lay in the study of natural history, and he kept a small museum at his home that included fossil animal bones. One day in 1908, while out breaking wild horses, he spotted something protruding from the side of a gully. It proved to be the bone of an enormous extinct bison, and he wrote to friends telling them of the find. He returned frequently to excavate at the place, but it was not until 1926—four years after McJunkin’s death—that a team from the Colorado Museum of Natural History organized their own dig. They unearthed the near-perfect skeletons of several giant bison, and between the ribs of one lay a beautifully crafted stone spear point. This association of now-vanished giant fauna with human artifacts convinced even the most skeptical that humanity had a long pedigree in America.
A few years later, in 1933, the earlier Clovis culture was discovered. Exquisite stone spearheads, some up to twenty-three centimeters long, are its signature pieces. They were made for just three hundred years—between about 12,900 and 13,200 years ago—yet these deadly, beautiful weapons have been found across much of the US and Mexico. To me they are evocative of the deadly beauty of the Colt pistol and Winchester rifle. Just as production of these weapons coincided with the demise of the buffalo and passenger pigeon, so does the Clovis period coincide with the extinction of America’s megafauna—the mammoth, mastodon, and other ice-age giants. And the Clovis, like American frontier people, were evidently mobile, shifting their campsites frequently as they pursued their livelihoods.
Adovasio describes how he had to work with a sometimes difficult crew at Meadowcroft. Managing large field crews is never easy, for the work is tedious and unrelenting. “After twelve hours of troweling thin layers of dirt and dust, you go crazy at night,” says Adovasio. “Running, weight lifting, drinking, fornicating, staring off into space and babbling incoherently—you do almost anything for relief. It takes a truly bizarre person to live that way for months on end, and we had tents full of them.”
Adovasio says of his work, “I did not think much about my nearly fanatical drive to make Meadowcroft the best excavation ever, but I realize now with utter clarity that it was me showing [my doctoral supervisor] Jennings that I could be even better than he at his own game.” Jesse Jennings was, by Adovasio’s own account, a callous man who crushed many of those who worked with him. Adovasio called him the “Dark Lord,” and his shadow seems to have hung over his student like the influence of a saturnine father.
At the core of Adovasio’s pre-Clovis claim lie the Meadowcroft dates derived from radiocarbon analysis, which he believes are unassailable evidence. Yet only a half-dozen or so of the dates directly relate to human artifacts during the contentious 12,000–16,000 year interval, and the dating was for the most part completed before the benefits of new technology were available, including sophisticated means of purifying carbon samples, and Accelerator Mass Spectrometry, which directly counts the radioactive atoms, allowing much smaller samples to be analyzed. These tools are critical when dealing with carbon samples where contamination with material of different ages is suspected, and there have been suspicions of contamination at Meadowcroft.
Meadowcroft Rockshelter was formed in Pennsylvanian-age sandstone, which elsewhere yields the coal for which the state is famous. Some researchers have suggested that ancient coal has somehow got into the samples. But how could this have occurred? Adovasio points out that to obtain the kind of results seen at Meadowcroft, many samples would have to be contaminated in a systematic manner. There is one possible way that this could occur naturally. If groundwater carrying humic acid rose through the site, it could have deposited a gradient of contaminant through samples that already contained coal. Yet Adovasio strenuously denies that such groundwater ever existed at Meadowcroft and, prima facie, it does seem unlikely.
Of the Smithsonian-based laboratory that did most of the radiocarbon dating, Adovasio says that it was “utterly professional and almost always totally reliable.” But recent history has shown that dates produced by even the best radiocarbon laboratories are far from unassailable. Many dates processed in the 1980s and before have been reexamined using modern techniques and were found to be in error. Even worse, instances of negligence and even alleged scientific fraud have come to light, with one such spectacular case having been recently published in Science.3
Sloppy reporting may have contributed to the confusion at Meadowcroft. Dates from the lowest levels of the site—before it was occupied by humans—were processed by what Adovasio refers to as “the distinguished Oxford Radiocarbon dating facility in England,” which, he says, “explicitly stated that no indications of contamination could be found.” Dr. Richard Gillespie, the chemist responsible for preparing those samples, has been able to confirm this, but in a rather peculiar manner. It is his belief that the samples consisted entirely of coal. Thus there was “no contamination” because the entire sample was contaminant! Despite this, the report sent to Adovasio at the time identified the sample as charcoal, a porous form of carbon produced by burning wood. Gillespie believes that this mistake occurred because the sample arrived at the lab labeled as charcoal, and this was not contradicted “because of the strange British reluctance to offend, particularly [on the part of] Gowlett, the archaeologist who handled sample acquisition & sent dating reports.”4
Such stumbles make the alleged reaction of Robert Stuckenrath (the nowdeceased radiocarbon-dating expert who provided many Meadowcroft dates) to skepticism about his findings seem hardly professional. In The First Americans Adovasio reports him as saying, “If they don’t believe the evidence, fuck ’em,” though elsewhere he indicates that Stuckenrath said, “F——’em if they can’t read!”5 Professor Vance Haynes, of the University of Arizona at Tucson, recalls that Stuckenrath offered to send him samples from the critical layers for independent evaluation, but the samples never turned up, and subsequently Stuckenrath blamed Adovasio for the delay, and vice versa.6
It is becoming increasingly evident that reliance on radiocarbon dates alone (even if the most modern techniques are applied) is frequently insufficient to resolve chronologies. Fortunately, several new dating techniques have recently become available. Amino Acid Racemisation dating relies on the fact that amino acids degrade from a “left-handed” form to a “right-handed” form at a predictable rate. The technique is particularly suited to dating bird eggshells, and is inexpensive and rapid, meaning that hundreds of dates can be easily obtained. Two preliminary dates have been obtained from Meadowcroft, yet little has been made of them, and there is surely scope for more work here.
Optically Stimulated Luminescence dating involves the dating of sand grains. It is based upon the discovery that electrons accumulate in the flaws on quartz-crystal lattices at predictable rates. It is particularly useful in dating cave and rockshelter sediments, and has an excellent record in helping sort out strata that are difficult to identify. Electron Spin Resonance dating is yet another technique, based on cumulative, radiation-caused damage to the enamel of ancient teeth. Increasingly, two or more of these techniques are being used alongside radiocarbon dating. Because they are largely independent in the way they work, they highlight flaws and errors resulting from one or another technique caused by particular circumstances such as contamination.
In the final chapters of The First Americans Adovasio recounts what happened when a team of experts went to examine Tom Dillehay’s supposedly pre-Clovis site at Monte Verde, Chile. The site has one of the most remarkable collections of preserved objects found anywhere in the world. Hunks of meat, hides, and even human footprints have been discovered, alongside a wealth of wooden artifacts and bones. Dillehay contends that people inhabited the site around 14,000 years ago, and even possibly 33,000 years ago, so it has created much interest.
In 1989 researchers began organizing a panel of experts to visit Monte Verde to see the evidence for themselves. It took until 1997 for the visit to be arranged, and by then the main site had been destroyed by logging roads and a meandering stream. Nevertheless the visit seems to have gone off reasonably well until the archaeologists gathered one evening at a bar called La Caverna in a nearby town.
According to Adovasio, he and Tom Dillehay were feeling badgered by the detailed examination of what remained of the site, and after the pair had “ordered up” at the bar—or “‘looned down’ in archaeological vernacular,” as Adovasio puts it—Dillehay went on the offensive. He accused Vance Haynes of knowing nothing about sites like Monte Verde, and in response to a question from another expert, retorted, “What have you done for the past twenty years?” Talk then turned to Meadowcroft, with Haynes remarking that if Adovasio would date just one seed or nut from the lowest levels, he might believe the antiquity of the site. Haynes had an important point, for seeds and nuts cannot be contaminated by coal in the way that charcoal from an old hearth can. Yet Adovasio burst out into derisive laughter at the suggestion, before replying “Horseshit,” and adding that he would never accede to any more dating requests from Haynes. Adovasio and Dillehay then stormed out of the bar.
This recollection is contradicted by Vance Haynes, who recalls that no one left the meeting early, and that Adovasio offered to send him the “damn seeds,” though he never did, and has subsequently said he never will. Rarely have we been given such frank insider accounts of how disagreements in science are fought out. But why in this case has the debate become so bitter?
The First Americans is as much an autobiography as it is an account of the peopling of the Americas, and what Adovasio has to say of himself goes a long way toward explaining the tone of the debate. He writes, “I have always pretty much responded in kind to bullies and other people who knock the work of my colleagues, teammates, and students.” It seems fair to say that Adovasio sees most criticism and scrutiny of the Meadowcroft dates as “knocking.” He attributes his pugilistic style to growing up in Youngstown, Ohio, “a mob town,” he calls it, with the highest rate of car bombing in the US, and where, he tells us, he associated with some pretty rough people.
As one might imagine, Adovasio can be tough on his colleagues when they disagree with him. Stuart Fiedel published a detailed reanalysis of the Monte Verde site, which Adovasio says contains a “thinly disguised inference that some evidence had been faked.” Adovasio characterizes Fiedel as “a man whom very few archaeologists had ever heard of…[who works] with a company that engages in… what used to be called salvage archaeology, on contract with highway departments, local governments, federal agencies, and so forth.” What goes unsaid is that Fiedel is also author of the highly esteemed Prehistory of the Americas, published by Cambridge University Press in several editions.
There are a number of things about Meadowcroft Rockshelter that seem anomalous. The pollen from layers supposedly dating to 16,000 years ago is characteristic of plants growing under warmer conditions than are thought to have prevailed in Pennsylvania at that time. Adovasio suggests that this is merely evidence that climatic conditions were in fact variable close to the ice sheet that then existed just north of the site. Meadowcroft also lacks any remains of the megafauna that was so abundant in America until 13,000 years ago. This could of course be a matter of chance, or a preference by the people and animals that brought the remains into the cave. But the nebulous nature of the alleged pre-Clovis people is another cause of concern. Adovasio says, “We do not have what archaeologists would call a pre-Clovis culture: we have a number of pre-Clovis cultures, none of which appears to be the parent technology of Clovis or even a distant relative.”
Further difficulties lie in the idea that the pre-Clovis humans had entered North America by 16,000 years ago, but for the next 3,000 years remained so rare that only two well-investigated sites have been discovered in all of the Americas—one in southern Chile, the other in Pennsylvania. The rareness of putative pre-Clovis sites has been attributed to two factors: the supposedly unproductive nature of North America before 13,000 years ago, and the use by pre-Clovis cultures of a rudimentary stone-tool technology that is difficult to recognize. There is a perfect test for this hypothesis—one that shows its inadequacy. Australia is a continent the size of the lower forty-eight states. Most of it is highly unproductive desert, and its indigenous peoples had a relatively rudimentary stone-tool technology. Yet Australia’s few archaeologists (Australia has a population of just 19 million) have documented nearly two hundred archaeological sites older than 13,000 years.
Clearly, the most extensive dating program afforded by modern science should be applied at Meadowcroft, yet Adovasio has shut the door on this option. Is this because he is content that he has achieved near-total victory over his opponents? Just in case the reader still hasn’t got the message, Adovasio includes in his book a cartoon of three people gathered around a gravestone inscribed “Clovis First 1933–1999.” Disturbingly, the book’s final chapter mentions several supposed, but as yet unconfirmed, pre-Clovis sites. It provides many tantalizing clues but no real data, and is about as useful in clarifying the situation as throwing a handful of clay into a glass of clean water. The entire feel of the book is one of Adovasio triumphant, a man who sees no need for further tests or dates. In effect, an end to science.
How do other prehistorians deal with Meadowcroft? Vance Haynes is clearly highly skeptical of it, while Alice Beck Kehoe, in her book America Before the European Invasions, dismisses it in a single sentence, stating merely that samples seem to have been contaminated by ancient coal dust; though on just how this occurred she does not speculate. Kehoe’s book gives a splendid account of the development of human cultures in North America north of Mexico. Its strength lies in the author’s deep empathy with the people who lived their lives in vanished and barely imaginable civilizations, as well as with contemporary indigenous cultures. She marvels over how the nomadic Clovis hunted mammoth armed only with handheld spears and possibly spear-throwers, and coped with the tremendous climatic changes that occurred at the end of the last ice age. Each chapter deals with a coherent geographic region and time period, but most of the book is about the cultures that developed over the last two thousand years. She gives a particularly evocative account of the diverse Indian cultures of California, whose scant to nonexistent clothing led to their being classified as “savages” by the Christian invaders, and whose treatment at the hands of trigger-happy gold diggers was particularly cruel. Chapters end with “research puzzles” pointing to the ambiguities and uncertainties of the archaeological record, while those dealing with historic cultures include accounts by Native Americans of their own origin stories and histories.
As Kehoe makes clear, the politics of prehistory have been particularly vicious in the US. Under the doctrine of Manifest Destiny the indigenous Americans were dispossessed and characterized as primitive tribes of savages. Yet as she points out, some of the political entities encountered by the early Spanish and the Virginia colonists were as large and sophisticated as the European states and principalities that the colonists had departed from. In prehistory much larger entities existed. The mound builders of Cahokia, near modern-day St. Louis, created vast edifices and clearly had far-reaching cultural influence. Kehoe likens North America after the collapse of Cahokia culture in the twelfth century to Europe following the collapse of Rome. By the time Columbus arrived, truly large empires existed only in Mexico.
My one regret is that Kehoe does not draw on the region south of the Rio Grande. As she points out, Mexico has long been the engine of cultural change for much of North America. Crops, captive birds such as macaws, and even cultural concepts and people originating in the south have long found their way deep into the North American heartland. Startling evidence of this influence was recovered from the only mound to be carefully excavated at Cahokia. Known as mound 72, it was a mere 9 feet high and 150 feet long, yet within it were buried the carefully arranged bodies of a nobleman and 260 adults, most of them young men and women. That number recalls both the number of human sacrifices made at the Feathered Serpent Pyramid in Teotihuacán, a Mexican cultural center which flourished several centuries before Cahokia, and the 260-day Mesoamerican ritual calendar.
Intriguingly, a few skeletons have been recovered from Cahokia that possess filed front teeth. Tooth filing is unknown in the US except for skeletons from Cahokia and a few others from the Chaco region of the American Southwest, but the practice was widespread in Mexico. Kehoe suggests that these individuals were visitors, perhaps traders or technicians from the south, who carried cultural innovations into the vast northern hinterland.
Kehoe’s book does a great service to Americans. For decades the issues surrounding race in the US concentrated tightly on blacks and whites. Elsewhere in the world, including Australia, Canada, South Africa, and the Middle East, people have been struggling with the legacy of colonialism and the dispossession of indigenous cultures. In view of the sorry treatment of the Native Americans of the US, it is time that their voice was heard a little more clearly in contemporary American society.
June 12, 2003
See Michael Parfit, “The Dawn of Humans: Hunt for the First Americans,” with photographs by Kenneth Garrett, National Geographic, December 2000, pp. 40–67. ↩
The following elementary explanation of the origins of radiocarbon dating is taken from the account at www.unmuseum.org/radiocar.htm: ↩
W. Beck et al., “Ambiguities in Direct Dating of Rock Surfaces Using Radiocarbon Measurements,” Science, June 26, 1998, pp. 2132–2139. ↩
Personal communication by e-mail, March 4, 2003. ↩
Ice Age People of North America: Environments, Origins, and Adaptations, edited by Robson Bonnichsen and Karen L. Turnmire (Oregon State University Press/Center for the Study of First Americans, 1999), p. 429. ↩
Personal communication by fax, March 3, 2003. ↩