Across Atlantic Ice Read online

  But old ideas, pet theories, vested research, and intellectual jealousies don’t go away easily. When Dennis and Bruce first let on in the late 1990s that they were thinking about developing the hypothesis that Clovis derived from Upper Paleolithic Solutrean cultural roots in southwestern Europe and that the process included plying the North Atlantic in boats, the collective gasp of the archaeological community was audible. The tone quickly became ugly. After Dennis gave an overview of the idea as the banquet address at “Clovis and Beyond” in Santa Fe in 1999, a senior colleague leaned over to me and said, “I just hate seeing Dennis throw away his career like this.” Spirited objections to almost every aspect of this hypothesis have dogged Dennis, Bruce, and any fellow travelers for the ensuing dozen years, but there has also been an increasing willingness among many colleagues and the public to at least give a listen. One major obstacle has been what I call chronoracism, the denigration by our contemporaries of the intellectual and technological capabilities of our Homo sapiens ancestors, as for example their forceful resistance to the idea of boats in the Paleolithic. In January 2011 one of my colleagues angrily dismissed my discussion of the Solutrean-to-Clovis hypothesis with “Just show me the boats—where are the boats?”

  Good science requires critical examination of evidence and ideas, but it is not served by the unsupported dismissal of either. Thoughtful, well-argued, and evidence-based challenges like that of Westley and Dix are what will advance, modify, or refute the Solutrean hypothesis. Let the march of science begin.

  Michael B. Collins

  January 27, 2011

  INTRODUCTION

  The First Americans?

  If at first the idea is not absurd, then there is no hope for it.

  ATTRIBUTED TO ALBERT EINSTEIN

  Christopher Columbus stumbled across the so-called New World while on a voyage to discover a more direct trade route to India, or so the story goes. Certainly, in his mind, he had found that route, and thus he called the inhabitants “Indians” and the place “the Indies.” It wasn’t long afterward that this monumental misjudgment of geography was recognized, but the misnomer stuck. But if the New World was not India and its inhabitants were not Indians, who were these people, where did they come from, how did they get here, and when did they arrive?

  These questions have fascinated Westerners since Columbus’s assumptions were found to be in error, and they are still the major unresolved mysteries of American archaeology. Were these people one of the lost tribes of Israel? Did the universe create them in their own private Eden? As early as 1590, the Spanish Jesuit missionary José de Acosta recognized that Native American physical characteristics were generally similar to those of Asians, so he postulated the existence of a land bridge that once connected the two continents.1 His logic preceded the proof of the existence of such a land bridge by some 350 years.

  Some American Indians like the idea of sharing ancestors with Genghis Khan. Many others oppose the theory that their ancestors came across a land bridge from Asia—or from anywhere else. Their ancestors, they argue, were created in their traditional American homelands; they did not migrate from another continent. Anchored in these spiritual beliefs, these present-day Native Americans are secure in the knowledge that their people were the first in the Americas and have been here forever, or since time immemorial. Some of them may wonder about origin stories that contradict these ideas: to get here their ancestors crossed a sea on the back of a huge turtle; when they arrived they had to “fight off the giants” who were already living on the land. But then again, how long is forever? Might not 450 or so generations be as good as forever to mortal beings?

  For Western science the story of the Americas, and for that matter of the earth itself, unfolded at a glacier’s pace. In the early nineteenth century scientists began to realize the deep time required for the creation of the earth and recognized evidence that massive glaciers once covered much of the world’s surface.2 Charles Darwin’s notions of biological evolution followed these discoveries, setting science against fundamental Christian teachings. Scholars made comparative studies of humans around the world and classified human variation into races and societies, which they assumed to be transitional on an evolutionary scale. As part of an effort to classify Native Americans, Aleš Hrdlička of the Smithsonian Institution suggested in 1923 that they had emigrated from Asia at the end of the most recent ice age, or thirteen thousand years ago.3 He had little evidence to calibrate the timing of this event, but he suggested that the migration took place as recently as 5,000 years earlier and argued vociferously against those who suggested earlier human occupations of the New World.

  EARLY HUNTERS OF THE AMERICAN SOUTHWEST

  As early as the late eighteenth century evidence was noted relative to these questions, but our present understanding of the “first Americans”—wherever they came from—began to take shape in 1908, when a late summer storm poured an unprecedented amount of water across the basalt mesas and canyons that straddle the high borderland between New Mexico and southern Colorado.4 The rolling storm created walls of water that cascaded down normally dry streambeds and cut deeply into prehistoric sediments. The turmoil of rain, hail, and crashing lightening scattered range cattle far and wide. After the storm, ranch hands, including George McJunkin, worked to bunch up the cattle and survey the damage. As McJunkin rode down Wild Horse arroyo he noticed large animal bones protruding from newly exposed canyon walls, and even more fossils were scattered downstream. McJunkin’s curiosity was piqued because the newly exposed bones were much larger than the cow and buffalo bones he was so familiar with, and because these bones had been buried beneath twenty feet of dirt and clay.

  Over the years, McJunkin talked about his discovery, and the legend of the prehistoric monster buffalo spread through the local communities around Folsom, New Mexico. In 1926, when the Colorado Museum of Natural History was looking for ice age remains for new exhibits, a crew went to New Mexico to seek the giant bison and excavate specimens to take back to Denver for display. Although McJunkin had long since passed away, several of his friends knew of the site, and indeed many bones were still visible.

  As the museum team dug among the remains, they found a broken flint spear point in the soil encasing a rib cage. Another point fragment unearthed nearby fit onto the broken point. Moreover, this point had a distinctive feature not seen on the ones they were familiar with: longitudinal flakes had been removed from the base on both faces, producing a grooved appearance (figure Intro.1a). The flaking that produced this form is now called fluting in archaeological parlance.

  INTRO.1.

  Early fluted point finds: (a) Folsom point from the Folsom type site, New Mexico; (b) first Clovis point found with a mammoth at the Dent Site, Colorado; (c) fluted point from the Utukok River, Alaska.

  That fall the news of their finds spread through an unreceptive archaeological community. Scholars were skeptical of an association between the point and the fossil bones because the accepted scientific wisdom was that Native Americans had migrated to the New World thousands of years after the giant bison had become extinct, 10,000 years or more ago. Still, excavations continued at the site for three years, and many more spear points were found. Newly uncovered artifacts were left undisturbed so that visiting scholars could examine the geological context and decide if the weapon tips could have been used to kill the giant bison. By 1928 most researchers considered the Folsom discovery proof that giant bison had been hunted and killed by humans—more than 10,000 years earlier.

  Four years later, on the outskirts of Dent, Colorado, another summer gully washer carved a deep ravine along a railroad track embankment.5 While assessing the damage, Frank Garner, a section foreman for the Union Pacific Railroad, observed that the flood had uncovered a mass of large bones below the track. Very large! These bones dwarfed McJunkin’s buffalo bones. These were the remains of mammoths, huge North American pachyderms that went extinct shortly after the end of the last ice age. While examining th
e bones, Garner found a fluted stone projectile point. (Projectile points are artifacts that were used as the heads of spears, darts, and arrows.) Sensing the importance of the finds, he notified Father Conrad Bilgery of Denver’s Regis College about his discovery. Its location is now known as the Dent Site.

  Father Bilgery and several of his students removed the remains of several mammoths. While they were working, they found a long, slender, fluted point of red jasper lying just beneath a mammoth’s hipbone. This spear point was similar to the one found by Garner, and both were somewhat larger than, not so precisely flaked as, and with less pronounced flutes than the points from the Folsom bison kill (figure Intro.1b). But because both sets of distinctive weapon tips were fluted, it was thought that the same ethnic group must have made them. It seemed logical that the prehistoric hunters used the smaller Folsom points for killing bison and the larger points for spearing mammoths.

  During the same summer that Father Bilgery was excavating the Dent bones, a gravel mining operation began to expose quantities of animal bones and fluted points in uneroded deposits at Blackwater Draw, south of Clovis in eastern New Mexico.6 Blackwater Draw, now a shallow trough several miles wide, had once been a major river, but it was deprived of water from the upland drainage systems when it was truncated by the headward cutting of the Pecos River during the late Pliocene. Robbed of flowing water, the riverbed filled with wind-blown sand. Then, from time to time, underlying aquifer waters emerged as cool springs onto this parched landscape, known as the Llano Estacada. When the springs had a high enough discharge, they joined the rare rainstorms to form small, ephemeral lakes or ponds along the draw. In seasons when the Llano was dry, the draw and springs were magnets for ice age animals and the people who hunted them. Through alternating wet and dry cycles of the ice age and the subsequent modern environments of the western plains, the ponds, springs, seeps, and interconnecting rivulets were the scenes of life-and-death struggles—now buried in successive geologic layers just waiting for scientists to excavate and interpret.

  Skittering back and forth among the jumble of mammoth and bison bone fragments as well as gravel on the shaker screens, projectile points were found at Blackwater Draw—some categorized as Folsom and others looking like those from Dent, suggesting that the same people made all these artifacts. But after the first discoveries in the gravel quarries, controlled stratigraphic excavations disproved that archaeological interpretation. Stratigraphy is the sequence of natural or artificial layers of deposits; in most cases the lowest is oldest, and they become younger toward the surface. These layers represent different depositional events and may tell us how and when they were deposited. Larger, more robust points and mammoth bones were emerging from a deposit situated below the soil that encased the bones of bison killed by Folsom hunters. If there was any doubt, the advent of radiocarbon dating (a method that uses the naturally occurring radioisotope carbon-14 to estimate the age of organic materials) in the 1950s confirmed that Folsom was, indeed, younger than this deeper material. Later paleoecological studies would suggest that the Clovis and Folsom peoples faced radically different environments and that the differences in their weaponry reflected hunting strategies adapted to exploit new climatic and animal behaviors. The Folsom points, it seems, represented a new weapon technology that was more effective for bison hunting.

  The distinctive weapon tips found with mammoth bones at Blackwater Draw were named after the nearby town, and the people who produced these points have since been known as Clovis. Over the years, when these spear points were found along with other characteristic Clovis artifacts in stratified archaeological sites, they were invariably in the deepest, or earliest, cultural strata. Accordingly, they were believed to be the oldest North American artifacts—made and used by the first Americans. Although geologists at the time of discovery estimated the age of these artifacts remarkably accurately, it was not until radiocarbon dating was available that scientists determined that Clovis peoples lived in the American Southwest between 13,500 and 13,000 years ago.7 This was after the last ice age but during a remarkably cold and dry period of the earth’s environment, when many animal genera that had survived the ice age went extinct.

  In the decades after the publication of the original Clovis discoveries, Clovis artifacts were documented throughout most of North America and as far south as Venezuela. The standard archaeological interpretation of this wide geographic distribution was that, after arriving in the New World, Clovis people found such an abundance of game animals that they were able to spread rapidly and prosper, their populations filling all of the Americas within several hundred years. But from where, when, and how had they arrived?

  MIGRATION FROM ASIA

  At about the same time that Clovis artifacts were found at Blackwater Draw, W. A. Johnston of the Geological Survey of Canada pointed out that the formation of massive glaciers during the last ice age had caused the sea level to decline, creating de Acosta’s hypothesized “land bridge” connecting Siberia to North America. This bridge, the unglaciated portions of Alaska, and far eastern Siberia are known today as Beringia. Beringia, it seemed, provided a dry land expanse for people—presumably Clovis people—to cross as they migrated from Asia to the Americas.8

  To complete the logic of this hypothesis, Johnston noted that the glaciers that covered much of North America and Europe began to melt at the end of the last ice age. In particular, he suggested that as the two interconnected glaciers of North America—the Laurentian and the Cordilleran—melted, they left an ice-free corridor that early humans, who had already crossed the land bridge, could use to travel from the Arctic southward into the rest of the Americas. They also released an enormous volume of water back into the oceans, eventually inundating the land bridge (figure Intro.2). This highly logical hypothesis was quickly adopted by the archaeological profession and locked investigators into the nearly unshakable notion that hunters walking over from Asia peopled the Americas.

  If there was proof of Johnston’s land bridge / ice-free corridor theory, it would be evidence in Alaska and Canada of Clovis-like mammoth hunters leaving Asia for an unknown new world. The first expedition to test this idea was mounted in 1938 by a group of intrepid graduate students from the University of New Mexico.9 Supported by a grant from the American Philosophical Society to Wes Bliss, the leader of the expedition, they paddled canoes some two thousand miles down the Mackenzie River to the Beaufort Sea on the Arctic Ocean and explored along rivers over the border into Alaska. Although the Bliss party found several human sites, including caves that contained fossil bones around Bluefish Lake, Yukon Territory, they did not find conclusive proof of early Clovis migrations through the ice-free corridor.

  INTRO.2.

  Hypothetical route of early migration from Asia through Beringia.

  Thoughts of the ice-free corridor soon took a backseat as new Clovis mammoth kill sites were found in New Mexico, Texas, and Oklahoma, drawing archaeological attention away from the Arctic to lower North America. But in the late 1940s Edward Sable, a geologist working on a mapping expedition for the United States Geological Survey in the Utukok River area in northwestern Alaska, found a fluted, Clovis-like point (figure Intro.1c).10 As one might imagine, this was major news, and archaeologists were excited about the discovery. Especially noteworthy was the fact that the point was made somewhat differently from Clovis points, and so it might be an earlier or ancestral variety. This find refocused scholarly attention on the North Country and to thoughts about Siberian connections. Within months of Sable’s find, Ralph Solecki of the Smithsonian mounted an expedition to the same area in the hopes of finding a site that would produce additional fluted points and resolve the question of Clovis origins.11 Solecki located more surface finds, but he did not encounter any fluted point sites worthy of excavation.

  While Solecki was surveying the North Slope of Alaska, the archaeologists Marie Wormington and Richard Forbis launched a program to assess the ice-free corridor theory from its southern
terminus in Alberta.12 Their hypothesis was that if Clovis peoples had traveled southward through the corridor, their sites would be found in the unglaciated areas of the Alberta plains, since they would have spread not only farther south but also east and west. Along with William T. Mulloy, who later became an expert on the archaeology of Easter Island, Wormington and Forbis conducted the first archaeological survey of Alberta and recorded the presence of prehistoric artifacts found by local collectors. But they found scant evidence of Clovis in private collections—and the farther north they went, the fewer Clovis-like artifacts they found. They did not achieve their goal of proving the peopling of the Americas by Asians, but they did make a major contribution to the knowledge of the northern plains’ prehistory.

  Since Sable’s early find in northern Alaska and Wormington and Forbis’s Alberta survey, countless other explorers have sought evidence for the first Americans in the corridor, but the few datable fluted points recovered are no older than the Clovis artifacts they were imagined to precede. Today, after nearly sixty years of research, there is still no archaeological proof that Clovis peoples or anyone before them passed between the glaciers while moving from Asia to the plains of North America. In spite of this lack of evidence, the widely held perception that all Native Americans are closely related to northeast Asians had still convinced many researchers that the mystery of Clovis origins would be uncovered in Siberia. They thought that detailed information about that vast area had been just beyond their grasp, but with the opening up of China for research and the later collapse of the Soviet Union it appeared that this major piece of the puzzle might be forthcoming. Scholars were increasingly allowed to work in Siberia and other areas of Asia in search of evidence to support this model. Dennis was invited, along with the geologist C. Vance Haynes Jr. and the paleontologist Russell Graham, to examine archaeological collections at museums in China and survey for Paleolithic sites along the Heilongjian River on the border between Siberia and northern Manchuria.13 But they found neither artifacts in any of the museum collections nor archaeological sites that provided evidence of an ancestral Clovis technology.