A Clovis projectile point created using bifacial percussion flaking (that is, each face is flaked on both edges alternately with a percussor) The Clovis culture is a prehistoric Paleoamerican culture, named for distinct stone tools found in close association with Pleistocene fauna at Blackwater Locality No. 1 near Clovis, New Mexico, in the 1920s and 1930s. It appears around 11,500–11,000 uncalibrated years before present (YBP)[1] at the end of the last glacial period and is characterized by the manufacture of "Clovis points" and distinctive bone and ivory tools. Archaeologists' most precise determinations at present suggest this radiocarbon age is equal to roughly 13,200 to 12,900 calendar years ago.[1] The only human burial that has been directly associated with tools from the Clovis culture included the remains of an infant boy researchers named Anzick-1.[2][3] Paleogenetic analyses of Anzick-1's ancient nuclear, mitochondrial, and Y-chromosome DNA[4] reveal that Anzick-1 is closely related to modern Native American populations, which lends support to the Beringia hypothesis for the settlement of the Americas.[5] The Clovis culture was replaced by several more localized regional societies from the Younger Dryas cold-climate period onward. Post-Clovis cultures include the Folsom tradition, Gainey, Suwannee-Simpson, Plainview-Goshen, Cumberland, and Redstone. Each of these is thought to derive directly from Clovis, in some cases apparently differing only in the length of the fluting on their projectile points. Although this is generally held to be the result of normal cultural change through time,[6] numerous other reasons have been suggested as driving forces to explain changes in the archaeological record, such as the Younger Dryas postglacial climate change, which exhibited numerous faunal extinctions.[7][8] After the discovery of several Clovis sites in eastern North America in the 1930s, the Clovis people came to be regarded as the first human inhabitants who created a widespread culture in the Americas, and the ancestors of most of the indigenous peoples of the Americas.[9][10][11] However, several archaeological discoveries have cast significant doubt on the Clovis-first theory, including sites such as Cactus Hill in Virginia, Paisley Caves in the Summer Lake Basin of Oregon, the Topper site in Allendale County South Carolina, Meadowcroft Rockshelter in Pennsylvania, the Friedkin[12] site in Texas, Cueva Fell in Chile, White Sands[13] site in New Mexico, and especially Monte Verde also in Chile.[14] The oldest claimed human archaeological site in the Americas is the Pedra Furada hearths in Brazil, controversially dated to 19,000 to 30,000 years before the earliest Clovis sites.[15][16][17] Description[edit]Clovis points from the Rummells-Maske Cache Site, Iowa A hallmark of the toolkit associated with the Clovis culture is the distinctively shaped, fluted-stone spear point, known as the Clovis point. The Clovis point is bifacial and typically fluted on both sides. Clovis tools were produced during a roughly 300-year period.[18] Archaeologists do not agree on whether the widespread presence of these artifacts indicates the proliferation of a single people, or the adoption of a superior technology by diverse population groups.[19] The culture is named after artifacts found between 1932 and 1936 at Blackwater Locality No. 1, an archaeological site between the towns of Clovis and Portales, New Mexico. These finds were deemed especially important due to their direct association with mammoth species and the extinct Bison antiquus. The in situ finds of 1936 and 1937 included most of four stone Clovis points, two long bone points with impact damage, stone blades, a portion of a Clovis blade core, and several cutting tools made on stone flakes.[19] Clovis sites have since been identified throughout much of the contiguous United States, as well as in Mexico and parts of Central America, and even into northern South America.[20] Clovis people are generally accepted to have hunted mammoths, as well as extinct bison, mastodon, gomphotheres, sloths, tapir, camelops, horse, and other smaller animals. More than 125 species of plants and animals are known to have been used by Clovis people in the portion of the Western Hemisphere they inhabited.[21][22] The oldest Clovis site in North America is believed to be El Fin del Mundo in northwestern Sonora, Mexico, discovered during a 2007 survey. It features occupation dating around 13,390 calibrated years BP.[23] In 2011, remains of gomphotheres were found; the evidence suggests that humans did, in fact, kill two of them there.[23] Also, the Aubrey site in Denton County, Texas, produced an almost identical radiocarbon date.[24] Disappearance of Clovis[edit]The most commonly held perspective on the end of the Clovis culture is that a decline in the availability of megafauna, combined with an overall increase in a less mobile population, led to local differentiation of lithic and cultural traditions across the Americas.[6][25] After this time, Clovis-style fluted points were replaced by other fluted-point traditions (such as the Folsom culture) with an essentially uninterrupted sequence across North and Central America. An effectively continuous cultural adaptation proceeds from the Clovis period through the ensuing Middle and Late Paleoindian periods.[26] Whether the Clovis culture drove the mammoth, and other species, to extinction via overhunting – the Pleistocene overkill hypothesis – is still an open, and controversial, theory.[27] It has also been hypothesized that the Clovis culture experienced decline in the wake of the Younger Dryas cold phase.[28] This "cold shock", lasting roughly 1,500 years, affected many parts of the world, including North America. This appears to have been triggered by a vast amount of meltwater – possibly from Lake Agassiz – emptying into the North Atlantic, disrupting the thermohaline circulation.[8] The Younger Dryas Impact hypothesis, or Clovis Comet hypothesis, originally proposed that a large air burst or earth impact from a comet or comets initiated the Younger Dryas cold period about 12,900 BP calibrated (10,900 14C uncalibrated) years ago.[29][7][30] This hypothesis has been largely contradicted, with research showing that most of the original findings cannot be replicated by other scientists. This hypothesis is criticized because of its misinterpretation of data and the lack of confirmatory evidence.[31][32][33][34] However, proponents of the hypothesis have responded, disputing the accusation of irreproducibility of their findings.[35][36][37][38][39][40] In 2013, a group from Harvard reported finding a layer of increased platinum (Pt) composition exactly at the Younger Dryas onset in a Greenland ice core, followed in 2017 by a report that the Pt spike had been also been found at an additional 11 continental Younger Dryas sites.[41][42] Discovery[edit]On 29 August 1927, the first evidence of Clovis presence in the Americas was discovered near Folsom, New Mexico. At this site they found the first in situ Folsom point with the extinct B. antiquus bones. This confirmation of a human presence in the Americas during the Pleistocene inspired many people to start looking for evidence of early humans.[43] Another earlier example was discovered by George McJunkin, a cowboy, who found an ancient bison (Bison antiquus, an extinct relative of the American bison) skeleton in 1908 after a flash flood.[44] The site was first excavated in 1926 under the direction of Harold Cook and Jesse Figgins. In 1929, 19-year-old Ridgely Whiteman, who had been closely following the excavations in nearby Folsom in the newspaper, discovered the Clovis site near the Blackwater Draw in eastern New Mexico. Despite several earlier Paleoindian discoveries, the best documented evidence of the Clovis complex was collected and excavated between 1932 and 1937 near Clovis, New Mexico, by a crew under the direction of Edgar Billings Howard until 1935 and later by John Cotter from the Academy of Natural Sciences/University of Pennsylvania. Howard's crew left their excavation in Burnet Cave, New Mexico, (the first truly professionally excavated Clovis site) in August, 1932, and visited Whiteman and his Blackwater Draw site. By November, Howard was back at Blackwater Draw to investigate additional finds from a construction project.[45] The American Journal of Archaeology (January–March, 1932 V36 #1) in its "Archaeological Notes" mentions E. B. Howard's work in Burnet Cave, including the discovery of extinct fauna and a "Folsom type" point 4 ft below a Basketmaker burial. This brief mention of the Clovis point found in place predates any work done at the Dent site in Colorado. The reference is made to a slightly earlier article on Burnet Cave in The University Museum Bulletin of November, 1931.[46] The first report of professional work at the Blackwater Draw Clovis site was published in the November 25th issue of Science News (V22 #601) in 1932.[47] The publications on Burnet Cave and Blackwater Draw directly contradict statements by several authors (for example see Haynes 2002:56 The Early Settlement of North America[48]) that Dent, Colorado was the first excavated Clovis site. The Dent site, in Weld County, Colorado, was simply a fossil mammoth excavation in 1932. The first Dent Clovis point was found on November 5, 1932, and the in situ point was found July 7, 1933.[49] The in situ Clovis point from Burnet Cave was excavated in late August, 1931 (and was reported in early 1932).[50] Another Clovis burial site was found in Montana in 1968. There the remains of a two-year-old child were found and studied. These remains have been named as Anzick-1 and recently, in 2014, have been used in scientific research.[4] Clovis Paleo-Indians[edit]Available genetic data show that the Clovis people are the direct ancestors of roughly 80% of all living Native American populations in North and South America, with the remainder descended from ancestors who entered in later waves of migration.[51][52] As reported in February 2014, DNA from the 12,600-year-old remains of Anzick boy, found in Montana, has affirmed this connection to the peoples of the Americas. In addition, this DNA analysis affirmed genetic connections back to ancestral peoples of northeast Asia. This adds weight to the theory that peoples migrated across a land bridge from Siberia to North America.[11] Clovis First[edit]This theory, known as "Clovis First", has been the predominant hypothesis among archaeologists in the second half of the 20th century. According to Clovis First, the people associated with the Clovis culture were the first inhabitants of the Americas. The primary support for this claim was that no solid evidence of pre-Clovis human habitation had been found. According to the standard accepted theory, the Clovis people crossed the Beringia land bridge over the Bering Strait from Siberia to Alaska during the ice age when there was a period of lowered sea levels, then made their way southward through an ice-free corridor east of the Rocky Mountains, located in present-day Western Canada, as the glaciers retreated.[53] This hypothesis came to be challenged by ongoing studies that suggest pre-Clovis human occupation of the Americas.[54] In 2011, following the excavation of an occupation site at Buttermilk Creek, Texas, a group of scientists identified the existence "of an occupation older than Clovis."[12][55] At the site in Buttermilk, archaeologists discovered evidence of hunter-gatherer grouping living at and making projectile spear points, blades, choppers, and other stone tools. The tools found were made from a local chert and could be dated back to as early as 15,000 years ago.[55] According to researchers Michael Waters and Thomas Stafford of Texas A&M University, new radiocarbon dates place Clovis remains from the continental United States in a shorter time window beginning 450 years later than the previously accepted threshold (13,200 to 12,900 BP).[9] Recently, the scientific consensus has changed to acknowledge the presence of pre-Clovis cultures in the Americas, ending the "Clovis first" consensus.[56][57][58] Alternatives to Clovis First[edit]Evidence of human habitation before Clovis[edit]Map of the Americas showing pre-Clovis sites There have been a great number of archaeological findings across the Americas that date the arrival of humans to the Americas as prior to 11,500–11,000 uncalibrated years before present (YBP). The Buttermilk Creek Complex, located in Salado, Texas, is a site where over 15,000 artifacts have been found. These artifacts are composed of a variety of small stone tool assemblages. These artifacts stratigraphically underlie previously excavated Clovis assemblages, meaning that they were deposited prior to the Clovis artifacts. These pre-Clovis assemblages are dated to between 13,200 and 15,500 years ago.[59] Predecessors of the Clovis people may have migrated south along the North American coastlines, although arguments exist for many migrations along several different routes.[60] Radiocarbon dating of the Monte Verde site in Chile places Clovis-like culture there as early as 18,500 to 14,500 years ago.[61] Remains found at the Channel Islands of California place coastal Paleoindians there 12,500 years ago. This suggests that the Paleoindian migration could have spread more quickly along the Pacific coastline, proceeding south, and that populations that settled along that route could have then begun migrations eastward into the continent. The Pedra Furada sites in Brazil include a collection of rock shelters, which were used for thousands of years by diverse human populations. The first excavations yielded artifacts with carbon-14 dates of 48,000 to 32,000 years BP. Repeated analyses have confirmed this dating, carrying the range of dates up to 60,000 BP.[62] The best-analyzed archaeological levels are dated between 32,160 ± 1000 years BP and 17,000 ± 400 BP. These claims have become an issue of contention between North American archaeologists and their South American and European counterparts, who disagree on whether it is conclusively proven to be an older human site.[15][16][17] In 2004, worked stone tools were found at Topper in South Carolina that have been dated by radiocarbon techniques possibly to 50,000 years ago.[63] But, there is significant scholarly dispute regarding these dates.[64] Scholars agree that evidence of humans at the Topper Site date back to 22,900 cal yr BP.[65] A more substantiated claim is that of Paisley Caves, Oregon, where rigorous carbon-14 and genetic testing appear to indicate that humans related to modern Native Americans were present in the caves over 1000 14C years before the earliest evidence of Clovis.[66] Traces and tools made by another people, the "Western Stemmed" tradition, were documented.[67] A study published in Science presents strong evidence that humans occupied sites in Monte Verde, Chile, at the tip of South America, as early as 13,000 years ago.[68] If this is true, then humans must have entered North America long before the Clovis culture – perhaps 16,000 years ago. The Tlapacoya site in Mexico is located along the base of a volcanic (remnant) hill on the shore of the former Lake Chalco. Seventeen excavations along the base of Tlapacoya Hill between 1956 and 1973 uncovered piles of disarticulated bones of bear and deer that appeared to have been butchered, plus 2,500 flakes and blades presumably from the butchering activities, plus one unfluted spear point. All were found in the same stratum containing three circular hearths filled with charcoal and ash. Bones of many other animal species were also present, including horses and migratory waterfowl. Two uncalibrated radiocarbon dates on carbon from the hearths came in around 24,000 and 22,000 years ago.[69] At another location, a prismatic microblade of obsidian was found in association with a tree trunk radiocarbon dated (uncalibrated) at roughly 24,000 years ago. This obsidian blade has recently been hydration dated by Joaquín García-Bárcena to 22,000 years ago. The hydration results were published in a seminal article that deals with the evidence for pre-Clovis habitation of Mexico.[70] Other sites, like White Sands National Park, located in New Mexico, also demonstrate archaeological findings that predate Clovis populations. In White Sands, excavated surfaces uncovered multiple in situ human footprints that were stratigraphically located between layers of material that were radio carbon dated to be from between 21,000 and 23,000 years ago. The findings from this site predate previous theories about the timeline of human migration of the Americas by several thousand years. Archaeologist working on the site believe that their findings indicates that humans had been present in the region since 23,000 years prior. This would mean that humans were occupying North America during the Last Glacial Maximum (LGM) – a theory that had previously been dismissed.[13] Though it is not currently the "widely-accepted theory", these archaeological sites point support alternative theories of early human migration such as a coastal migration route or the Solutrean hypothesis. This archaeological evidence is also supported by genetic mapping of ancestral mitochondrial DNA. Archaeological sites that predate Clovis that are well documented include:
Coastal migration route[edit]Studies of the mitochondrial DNA of First Nations/Native Americans published in 2007 suggest that the people of the New World may have diverged genetically from Siberians as early as 20,000 years ago, far earlier than the standard theory suggests.[54] According to one alternative theory, the Pacific coast of North America may have been free of ice, allowing the first peoples in North America to come down this route prior to the formation of the ice-free corridor in the continental interior.[96] No evidence has yet been found to support this hypothesis[citation needed] except that genetic analysis of coastal marine life indicates diverse fauna persisting in refugia throughout the Pleistocene ice ages along the coasts of Alaska and British Columbia; these refugia include common food sources of coastal aboriginal peoples, suggesting that a migration along the coastline was feasible at the time.[97] Some early sites on the coast, for example Namu, British Columbia, exhibit maritime focus on foods from an early point with substantial cultural continuity.[98] This lack of evidence is likely due to the change in sea level since the time of migration. During the Last Glacial Maximum the global sea level was more than 400 feet lower than it is today. Starting about 15,000 years ago, glaciers began retreating and sea levels began rising. Sea levels reached their current level about 8,000 years ago and have fluctuated slightly since then.[99] This drastic change in sea level may prevent the discovery of sites located along what was once the coastline and is now located under over 400 feet of water. As of now, genetic analysis is one of the only means of tracking early human movements. In February 2014, researchers reported on their DNA analysis of the remains of Anzick boy (referred to as Anzick-1) of Montana, the oldest skeleton found in the Americas and dated to 12,600 years ago. They found the mtDNA to be D4h3a, "one of the rare lineages associated with Native Americans."[4] This was the same as the mtDNA associated with current coastal populations in North and South America. The study team suggest that finding this genetic evidence so far inland shows that "current distribution of genetic markers are not necessarily indicative of the movement or distribution of peoples in the past."[4] The Y haplotype was found to be Q-L54*(xM3). Further testing found that Anzick-1 was most closely related to Native American populations (see below).[4] Solutrean hypothesis[edit]The controversial Solutrean hypothesis proposed in 1999 by Smithsonian archaeologist Dennis Stanford and colleague Bruce Bradley (Stanford and Bradley 2002), suggests that the Clovis people could have inherited technology from the Solutrean people who lived in southern Europe 21,000–15,000 years ago, and who created the first Stone Age artwork in present-day southern France.[100] The link is suggested by the similarity in technology between the projectile points of the Solutreans and those found at Clovis (and pre-Clovis) sites. Its proponents point to tools found at various pre-Clovis sites in eastern North America (particularly in the Chesapeake Bay region) as progenitors of Clovis-style tools.[101] The model envisions these people making the crossing in small watercraft via the edge of the pack ice in the North Atlantic Ocean that then extended to the Atlantic coast of France, using skills similar to those of the modern Inuit, making landfall somewhere around the then-exposed Grand Banks of the North American continental shelf. In a 2008 study of the relevant paleoceanographic data, Kieran Westley and Justin Dix concluded that "it is clear from the paleoceanographic and paleo-environmental data that the Last Glacial Maximum (LGM) 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."[102] University of New Mexico anthropologist Lawrence G. Straus, a primary critic of the Solutrean hypothesis, points to the theoretical difficulty of the ocean crossing, a lack of Solutrean-specific features in pre-Clovis artifacts, as well as the lack of art (such as that found at Lascaux in France) among the Clovis people, as major deficiencies in the Solutrean hypothesis. The 3,000 to 5,000 radiocarbon year gap between the Solutrean period of France and Spain and the Clovis of the New World also makes such a connection problematic.[103] 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 shared all Solutrean cultural traits.[104] Genetic evidence of east/west dichotomy[edit]Mitochondrial DNA analysis in 2014 has found that members of some native North American tribes have a maternal ancestry (called haplogroup X) linked to the maternal ancestors of some present-day individuals in western Asia and Europe, albeit distantly. This has also provided some support for pre-Clovis models. More specifically, a variant of mitochondrial DNA called X2a found in many Native Americans has been traced to western Eurasia, while not being found in eastern Eurasia.[105] Mitochondrial DNA analysis of Anzick-1 concluded that the boy belonged to what is known as haplogroup or lineage D4h3a. This finding is important because the D4h3a line is considered to be a lineage "founder", belonging to the first people to reach the Americas. Although rare in most of today's Native Americans in the US and Canada, D4h3a genes are more common among native peoples of South America, far from the site in Montana where Anzick-1 was buried. This suggests a greater genetic complexity among Native Americans than previously thought, including an early divergence in the genetic lineage 13,000 years ago. One theory suggests that after crossing into North America from Siberia, a group of the first Americans, with the lineage D4h3a, moved south along the Pacific coast and, over thousands of years, into Central and South America, while others may have moved inland, east of the Rocky Mountains.[4] The apparent early divergence between North American and Central plus South American populations may or may not be associated with post-divergence gene flow from a more basal population into North America; however, analysis of published DNA sequences for 19 Siberian populations does not favor the latter scenario.[4] Spearheads and DNA found at the Paisley Caves site in Oregon suggest that North America was colonized by more than one culture, and that the Clovis culture was not the first. There is evidence to suggest an east/west dichotomy, with the Clovis culture located to the east.[106] But in 2014, the autosomal DNA of a 12,500+-year-old infant from Montana was sequenced.[4][5][107][108] The DNA was taken from a skeleton referred to as Anzick-1, found in close association with several Clovis artifacts. Comparisons indicate strong affinities with DNA from Siberian sites, and virtually rule out close affinity with European sources (the "Solutrean hypothesis"). The DNA shows strong affinities with all existing Native American populations, which indicated that each of them derives from an ancient population that lived in or near Siberia, the Upper Palaeolithic Mal'ta population. Mal'ta belonged to Y-DNA haplogroup R and mitochrondrial macrohaplogroup U.[4][109] The data indicate that Anzick-1 is from a population directly ancestral to present South American and Central American Native American populations. This rules out hypotheses which posit that invasions subsequent to the Clovis culture overwhelmed or assimilated previous migrants into the Americas. Anzick-1 is less closely related to present North American Native American populations (including a Yaqui genetic sample), suggesting that the North American populations are basal to Anzick-1 and Central and South American populations.[4] The apparent early divergence between North American and Central plus South American populations might be due to post-divergence gene flow from a more basal population into North America; however, analysis of published DNA sequences of 19 Siberian populations do not suggest this scenario.[4] Anzick-1 belonged to Y-haplogroup Q-L54(xM3),[4] which is by far the largest haplogroup among Native Americans. Megafaunal migrations[edit]Although there is no archaeological evidence that can be used to direct support a coastal migration route during the Last Glacial Maximum, genetic analysis has been used to support this thesis. In addition to human genetic lineage, megafaunal DNA linage can be used to trace movements of megafauna – large mammalian – as well as the early human groups who hunted them. Bison, a type of megafauna, have been identified as an ideal candidate for the tracing of human migrations out of Europe because of both their abundance in North America as well as being one of the first megafauna for which ancient DNA was used to trace patterns of population movement. Unlike other types of fauna that moved between the Americas and Eurasia (mammoths, horses, and lions), Bison survived the North American extinction event that occurred at the end of the Pleistocene. Their genome, however, contains evidence of a bottleneck – something that can be used to test hypothesis on migrations between the two continents.[110] Early human groups were largely nomadic, relying on following food sources for survival. Mobility was part of what made humans successful. As nomadic groups, early humans likely followed the food from Eurasia to the Americas – part of the reason why tracing megafaunal DNA is so helpful for garnering insight to these migratory patterns.[111] The grey wolf originated in the Americas and migrated into Eurasia prior to the Last Glacial Maximum – during which it was believed that remaining populations of the grey wolf residing in North America faced extinction and were isolated from the rest of the population. This, however, may not be the case. Radiocarbon dating of ancient grey wolf remains found in permafrost deposits in Alaska show a continuous exchange of population from 12,500 radiocarbon years BP to beyond radiocarbon dating capabilities. This indicates that there was viable passage for grey wolf populations to exchange between the two continents.[112] These faunas' ability to exchange populations during the period of the Last Glacial Maximum along with genetic evidence found from early human remains in the Americas provides evidence to support pre-Clovis migrations into the Americas. Other sites[edit]In approximate reverse chronological order:
See also[edit]
References[edit]
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External links[edit]
Where are most Clovis points found?points found in the Clovis archaeological site, located near Clovis, New Mexico, originated in Beringia and were carried south as people migrated.
Which regions of the United States have the most Clovis points?Since their discovery in 1929, more than 10,000 individual Clovis points have been found in 1,500 distinct locations across North and South America. The oldest points were discovered in Texas. The highest density of points have been found in the eastern states and the eastern part of what is now Canada.
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