According to the Solutrean hypothesis, people associated with the Solutrean culture migrated from Ice Age Europe to North America, bringing their methods of making stone tools with them and providing the basis for the later Clovis technology that spread throughout North America. The hypothesis rests upon proposed similarities between European Solutrean and Early American Clovis lithic technology. The presence of mtDNA Haplogroup X2A in Native American populations has also been adduced in support of the hypothesis.
Though adherents of the theory appeal to recent archaeological finds, their position has in general not been well received. Many archaeologists have criticized the proposed similarities as insignificant and just as likely to be due to chance as to shared origins. As one recent scholar has put it, "Few if any archaeologists—or, for that matter, geneticists, linguists, or physical anthropologists—take seriously the idea of a Solutrean colonization of America."[4] Two recent DNA studies serve to weaken the case that Haplogroup X2A migrated to the Americas by way of the Atlantic.
The thesis was popularized by a 2005 Discovery Channel docudrama.
Solutrean culture prevailed in present-day France and Spain from roughly 21,000 to 17,000 years ago. The manufacture of stone tools from this period is distinguished by bifacial, percussion, and pressure-flaked points. The Solutrean toolmaking industry disappeared almost completely from Europe around 15,000 years ago, replaced by the lithic technology of the Magdalenian culture.
Clovis tools are characterized by a distinctive type of spear point, known as the Clovis point. Solutrean and Clovis points share common traits: points are thin and bifacial, and both make use of the "outrepassé", or overshot flaking technique, which quickly reduces the thickness of a biface without reducing its width.
The Clovis blade differs from the Solutrean in that some of the former have bifacial fluting. (Fluting refers to a long groove carved into the basal end of a point, designed to help secure the point to a spear foreshaft; bifacial fluting describes blades on which this feature appears on both of its sides.) Clovis toolmaking technology appears in the archaeological record in eastern North America roughly 13,500 years ago. Older blades with this attribute have yet to be discovered from sites in either Asia or Alaska.
Stanford and Bradley, in their book Across Atlantic Ice, muster a range of evidence in support of the Solutrean hypothesis. They cite similarities between artifacts of the the Clovis culture and certain finds from Maryland, Pennsylvania, Virginia and Delaware. In addition, they claim to be able to carbon-date many new discoveries from the Delmarva Peninsula in Maryland to between 26,000 and 19,000 BC—the period in which comparable artifacts were being created in Europe. According to their book, no materials of human manufacture from before 15,000 years BP have been found on the West Coast anywhere near the time that the Siberian ancestors of the Amerinds are thought to have first crossed into the New World
The Solutrean hypothesis posits that Ice Age Europeans crossed the North Atlantic along the edge of the pack ice that extended from the Atlantic coast of France to North America during the last glacial maximum. The model postulates that these people made the crossing in small watercraft, using skills similar to those of the modern Inuit people: hauling out on ice floes at night, getting fresh water by melting iceberg ice or the first-frozen parts of sea ice, getting food by catching seals and fish, and using seal blubber as heating fuel. Among other evidence, they cite the discovery in the Solutrean toolkit of bone needles, similar to those still in use among modern Inuit.[6] As well as enabling the manufacture of waterproof clothing from animal skins, these needles could, in theory, have also been used to construct kayaks from hides.
Supporters of the Solutrean hypothesis had pointed to the presence of haplogroup X, the global distribution of which is strongest in Anatolia and the northeast of America, a pattern supposedly consistent with their position. Michael Brown in a 1998 article identified this as evidence of a possible Caucasian founder population of early Americans spreading from the northeast coast.[7]
But a 2008 article in the American Journal of Human Genetics by researchers in Brazil took up the argument against the Solutrean hypothesis. "Our results strongly support the hypothesis that haplogroup X, together with the other four main mtDNA haplogroups, was part of the gene pool of a single Native American founding population; therefore they do not support models that propose haplogroup-independent migrations, such as the migration from Europe posed by the Solutrean hypothesis."[8]
A 2011 article in the American Journal of Physical Anthropology further tends to discredit the Solutrean theory on genetic grounds. Researchers in Italy argued that the distinctively Asian C4c and the disputed X2a had "parallel genetic histories." They note that "C4c is deeply rooted in the Asian portion of the mtDNA phylogeny and is indubitably of Asian origin."
Arthur J. Jelinek, an anthropologist who took note of (superficial) similarities between Solutrean and Clovis styles in a 1971 study, observed that the great geographical and temporal separation of the two cultures made a direct connection unlikely, since the dates of the proposed transitional sites and the Solutrean period in Europe only overlap at the extremes. He also argued that crossing the Atlantic with the means available at the time would have been difficult, if not impossible. The opinion is shared by Lawrence G. Straus, who wrote that "there are no representations of boats and no evidence whatsoever either of seafaring or of the ability to make a living mainly or solely from the ocean during the Solutrean."[10] Straus excavated Solutrean artifacts along what is now a coastline in Cantabria, which was some ways inland during the Solutrean epoch. He found seashells and estuarine fish at the sites, but no evidence that deep sea resources had been exploited. However, holdouts in the Solutrean camp counter that evidence of Solutrean-era seafaring may have been obliterated or submerged, since the coastlines of western Europe and eastern North America during the Last Glacial Maximum are now under water.
Yet another challenge to the hypothesis involves the paucity of non-technological evidence of a kind we would expect to find transmitted from east to west; cave paintings of a kind associated with the Cave of Altamira in Spain, for instance, are without close parallel in the New World.[11] In response, Bradley and Stanford contend that it was "a very specific subset of the Solutrean who formed the parent group that adapted to a maritime environment and eventually made it across the north Atlantic ice-front to colonize the east coast of the Americas" and that this group may not have exhibited the full range of Solutrean cultural traits.[12] Recently a carved piece of bone depicting a mammoth found near the Vero man site in Florida has been dated to between 20,000–13,000 BP. It is described as possibly being the oldest art object yet found in the Americas and, in the view of some, may yet provide hope for the Solutrean hypothesis.[13] Art historian Barbara Olins has compared the Vero carving to "Franco-Cantabrian" drawings and engravings of mammoths. She notes that the San of southern Africa developed a realistic manner of representing animals similar to the "Franco-Cantabrian" style, hinting that such a style could have evolved in North America independently.[14]
A 2008 study of relevant oceanographic data from the time period in question, co-authored by Kieran Westley and Justin Dix, concluded, however, that "it is clear from the paleoceanographic and paleo-environmental data that the LGM in the North Atlantic does not fit the descriptions provided by the proponents of the Solutrean Atlantic Hypothesis. Although ice use and sea mammal hunting may have been important in other contexts, in this instance, the conditions militate against an ice-edge-following, maritime-adapted European population reaching the Americas."[15] Relying on the location of the ice shelf at the time of the putative Atlantic crossing, they are skeptical that a transoceanic voyage to North America, even allowing for the judicious use of glaciers and ice floes as temporary stopping points and sources of fresh water, would have been feasible for people from the Solutrean era
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