Across Atlantic Ice is an account of two complex and treacherous journeys, one long ago and the other very recent. One is postulated to have occurred across a perilous mosaic of periglacial environments of the Northern Hemisphere during the peak of the last major glaciation some eighteen or twenty millennia ago. The other is a twenty-year intellectual excursion far outside the academic mainstream by two scholars to explore possible answers to the questions of who first came to the Americas, when, whence, and how.
We long thought that we knew the story of the initial peopling of the Americas: Nomadic mammoth hunters moved out of the Russian steppe, across the ice age Bering land bridge, down an ice-free corridor between the major ice sheets of Canada, and onto the northern Great Plains. This brought them to an American Serengeti of giant bison, mammoth, mastodon, horse, camel, and many other worthy game animals. Once in America some 13,500 years ago, these big game hunters coined a new technology, dubbed Clovis by archaeologists who crafted the romantic notion that these specialized hunters were the first Americans. This story has been dying slowly over the past thirty or so years and is now defunct. However, no consensus theory has replaced “Clovis First” in spite of a large, vigorous, diverse, and sometimes contentious cadre of scholars in many fields of science looking for the evidence to set the story straight.
This is not a trivial quest, because the Western Hemisphere affords 25 percent of the habitable surface of the earth and was colonized quite late in human history. What people were doing across the entire Northern Hemisphere over the past 50,000 years or so is the focus, along with what the changing terrestrial and marine environments of that expanse of time and space were like.
Relevant data from archaeology, earth sciences, human DNA, and other fields are cascading in at such a startling pace that almost all of the targets are moving almost all of the time. And it’s not just the data that are changing; the concepts, techniques, and tools scholars use are improving almost daily. This is an exhilarating time in an exciting pursuit.
Dennis J. Stanford and Bruce A. Bradley draw on ethnography (some of it their own), archaeology (some of it their own), paleoclimatology, oceanography, geology, experimentation (some of it their own), human biology, and more to formulate a hypothesis that accounts for why the Americas seem to have been first peopled during the last glacial period and evidently by way of the harsh artic realm. Since humankind has evolved and thrived in tropical and temperate climes for more than 98 percent of its existence, the circumstances that drove this expansion of range must have been extraordinary.
Extraordinary they were, with great expanses of the earth falling barren under the advance of glaciation, pushing humans into refugia including the continental margins of southwestern Europe and eastern Asia. From these ocean edges, people were drawn toward enormous populations of marine invertebrates, fish, mammals, and birds, particularly in the northerly latitudes. Boats were needed, tailored clothing that was insulated and waterproof was imperative, ingenuity and new knowledge were essential, and new harvesting technologies were required. So with both a push and a pull, the rich maritime environments of the North Pacific and the North Atlantic increasingly became part of the human niche. As people expanded this niche, it brought them to the shores of North America—the immense human journey across the globe had reached a new continent, whence it continued until the Americas were fully colonized. This new story is at the moment just an outline, and filling it in is the ongoing work of many scholars. Their efforts have been productive because they have approached the peopling of the Americas as a process rather than an event.
Among this throng of scholars, Dennis and Bruce have tackled the specific question of the origin of Clovis and here formulate a hypothesis that its technological antecedents reached North America from across the North Atlantic and out of Cantabrian Solutrean roots of circa 18,000 years ago. The technology continued developing in eastern North America, ultimately becoming what we call Clovis. This is a hypothesis worthy of full testing.
Already, in fact, testing is under way. For example, based primarily on nascent accounts of this hypothesis published by Dennis and Bruce in 2004 and 2006 in World Archaeology, Kieran Westley and Justin Dix challenged the “Solutrean Atlantic Hypothesis” in the pages of the first issue of the first volume of the Journal of the North Atlantic (2008). They presented a comprehensive review of the status of the ice pack margins of the North Atlantic for the entire duration of the Solutrean (16,000–21,000 years ago) and found that throughout most of that time, it is highly unlikely that conditions along the margin were suitable for sustaining even well-outfitted human mariners. They do note, however, that during a brief interval, conditions may well have been favorable. That interval, near the onset of the Heinrich I event, coincides with that part of the La Riera Cave sequence of northern Spain that Dennis and Bruce identify as the probable time of expanding maritime subsistence by Solutreans.
This book brings clear focus to the competing notions that America was peopled out of Siberia or out of Iberia. The authors and I agree that, most likely, it was from both and that the early archaeology of the Americas reflects the first heat in the melting pot of the Western Hemisphere. We hold this view in spite of a prevailing interpretation of DNA evidence favoring a Siberian origin of all Native Americans, a view based on modern and recent DNA. But until confirmed by samples of ancient DNA, this is little more than a hypothesis as regards the earliest peoples in America. Asian styles and technology prevail in the early archaeological record along the western parts of North and South America, while a more European Upper Paleolithic flavor—especially Solutrean—is found along the eastern margins of the hemisphere. It is important to note that the geographic extent of submerged archaeological potential is much greater on the Atlantic side of the Western Hemisphere than it is on the Pacific side. This almost surely translates to greater potential for future ice age discoveries on the submerged Atlantic continental shelf than on that of the Pacific.
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.