The Great Basin is the largest area of contiguous endorheic watersheds in North America. It spans nearly all of Nevada, much of Oregon and Utah, portions of California and Wyoming, it is noted for both its arid climate and the basin and range topography that varies from the North American low point at Badwater Basin to the highest point of the contiguous United States, less than 100 miles away at the summit of Mount Whitney. The region spans several physiographic divisions, biomes and deserts; the term "Great Basin" is applied to hydrographic, floristic, physiographic and ethnographic geographic areas. The name was coined by John C. Fremont, based on information gleaned from Joseph R. Walker as well as his own travels, recognized the hydrographic nature of the landform as "having no connection to the ocean"; the hydrographic definition is the most used, is the only one with a definitive border. The other definitions yield not only different geographical boundaries of "Great Basin" regions, but regional borders that vary from source to source.
The Great Basin Desert is defined by plant and animal communities, according to the National Park Service, its boundaries approximate the hydrographic Great Basin, but exclude the southern "panhandle". The Great Basin Floristic Province was defined by botanist Armen Takhtajan to extend well beyond the boundaries of the hydrographically defined Great Basin: it includes the Snake River Plain, the Colorado Plateau, the Uinta Basin, parts of Arizona north of the Mogollon Rim; the Great Basin physiographic section is a geographic division of the Basin and Range Province defined by Nevin Fenneman in 1931. The United States Geological Survey adapted Fenneman's scheme in their Physiographic division of the United States; the "section" is somewhat larger than the hydrographic definition. The Great Basin Culture Area or indigenous peoples of the Great Basin is a cultural classification of indigenous peoples of the Americas and a cultural region located between the Rocky Mountains and the Sierra Nevada.
The culture area covers 400,000 sq mi, or just less than twice the area of the hydrographic Great Basin. The hydrographic Great Basin is a 209,162-square-mile area. All precipitation in the region sinks underground or flows into lakes; as observed by Fremont, streams, or rivers find no outlet to either the Gulf of Mexico or the Pacific Ocean. The region is bounded by the Wasatch Mountains to the east, the Sierra Nevada and Cascade Ranges to the west, the Snake River Basin to the north; the south rim is less distinct. The Great Basin includes most of Nevada, half of Utah, substantial portions of Oregon and California and small areas of Idaho and Mexico; the term "Great Basin" is misleading. The Great Salt Lake, Pyramid Lake, the Humboldt Sink are a few of the "drains" in the Great Basin; the Salton Sink is another closed basin within the Great Basin. The Great Basin Divide separates the Great Basin from the watersheds draining to the Pacific Ocean; the southernmost portion of the Great Basin is the watershed area of the Laguna Salada.
The Great Basin's longest and largest river is the Bear River of 350 mi, the largest single watershed is the Humboldt River drainage of 17,000 sq mi. Most Great Basin precipitation is snow, the precipitation that neither evaporates nor is extracted for human use will sink into groundwater aquifers, while evaporation of collected water occurs from geographic sinks. Lake Tahoe, North America's largest alpine lake, is part of the Great Basin's central Lahontan subregion; the hydrographic Great Basin contains multiple deserts and ecoregions, each with its own distinctive set of flora and fauna. The ecological boundaries and divisions in the Great Basin are unclear; the Great Basin overlaps four different deserts: portions of the hot Mojave and Colorado Deserts to the south, the cold Great Basin and Oregon High Deserts in the north. The deserts can be distinguished by their plants: the Joshua tree and creosote bush occur in the hot deserts, while the cold deserts have neither; the cold deserts are higher than the hot, have their precipitation spread throughout the year.
The climate and flora of the Great Basin is dependent on elevation: as the elevation increases, the precipitation increases and temperature decreases. Because of this, forests occur at higher elevations. Utah juniper/single-leaf pinyon and mountain mahogany form open pinyon-juniper woodland on the slopes of most ranges. Stands of limber pine and Great Basin bristlecone pine can be found in some of the higher ranges. In riparian areas with dependable water cottonwoods and quaking aspen groves exist; because the forest ecosystem is distinct from a typical desert, some authorities, such as the World Wildlife Fund, separate the mountains of the Great Basin desert into their own ecoregion: the Great Basin montane forests. Many rare and endemic species occur in this ecoregion, because the individual mountain ranges are isolated from each other. During the last ice age, the Great Basin was wetter; as it dried during the Holocene, some species retreated to the higher isolated mountains and have high genetic diversity.
Other authorities divide the Great Basin depending on their own criteria. Armen Takhtajan defined the "Great Basin floristic province"; the U. S. Environmental Protection Agency divides the Great Basin into three ecoregions according to latitude: the Northern B
The Clovis culture is a prehistoric Paleo-Indian 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 radiocarbon years before present at the end of the last glacial period, 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 13,200 to 12,900 calendar years ago. Clovis people are considered to be the ancestors of most of the indigenous cultures of the Americas; the only human burial, directly associated with tools from the Clovis culture included the remains of an infant boy researchers named Anzick-1. Paleogenetic analyses of Anzick-1's ancient nuclear, Y-chromosome DNA reveal that Anzick-1 is related to modern Native American populations, which lends support to the Beringia hypothesis for the settlement of the Americas.
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, Suwannee-Simpson, Plainview-Goshen and Redstone; each of these is thought to derive directly from Clovis, in some cases differing only in the length of the fluting on their projectile points. Although this is held to be the result of normal cultural change through time, 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. 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 New World. However, this theory has been challenged, in the opinion of many archaeologists, by several archaeological discoveries, 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 site in Texas, Cueva Fell in Chile, Monte Verde in Chile.
The oldest claimed human archaeological site in the Americas is the Pedra Furada hearths, a site in Brazil that precedes the Clovis culture and the other sites mentioned by 19,000 to 30,000 years. This claim has 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. 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 fluted on both sides. 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; the culture is named after artifacts found between 1936 at Blackwater Locality No. 1, an archaeological site between the towns of Clovis and Portales, New Mexico. These finds were deemed 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, several cutting tools made on stone flakes. Clovis sites have since been identified throughout much of the contiguous United States, as well as Mexico and Central America, into northern South America. Clovis people are accepted to have hunted mammoths, as well as extinct bison, gomphotheres, tapir, camelops 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; the oldest Clovis site in North America is believed to be El Fin del Mundo in northwestern Sonora, discovered during a 2007 survey. It features occupation dating around 13,390 calibrated years BP. In 2011, remains of gomphotheres were found; the Aubrey site in Denton County, produced an identical radiocarbon date. The most 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.
After this time, Clovis-style fluted points were replaced by other fluted-point traditions with an uninterrupted sequence across North and Central America. An continuous cultural adaptation proceeds from the Clovis period through the ensuing Middle and Late Paleoindian periods. Whether the Clovis culture drove the mammoth, other species, to extinction via overhunting – the so-called Pleistocene overkill hypothesis – is still an open, controversial, question, it has been hypothesized that the Clovis culture had its decline in the wake of the Younger Dryas cold phase. This'cold shock', lasting 1500 years, affected many parts of the world, including North America; this appears to have been triggered by a vast amount of meltwater – from Lake Agassiz – emptying into the North Atlantic, disrupting the thermohaline circulation. The Younger Dryas impact hypothesis, or Clovis comet hypothesis proposed that a large air burst or earth impact of a comet or comets from outer space initiated the Younger Drya
European colonization of the Americas
The European colonization of the Americas describes the history of the settlement and establishment of control of the continents of the Americas by most of the naval powers of Western Europe. Systematic European colonization began in 1492, when a Spanish expedition headed by the Italian explorer Christopher Columbus sailed west to find a new trade route to the Far East but inadvertently landed in what came to be known to Europeans as the "New World", he ran aground on the northern part of Hispaniola on 5 December 1492, which the Taino people had inhabited since the 9th century. Western European conquest, large-scale exploration and colonization soon followed. Columbus's first two voyages reached the Bahamas and various Caribbean islands, including Hispaniola, Puerto Rico, Cuba. In 1497, Italian explorer John Cabot, on behalf of England, landed on the North American coast, a year Columbus's third voyage reached the South American coast; as the sponsor of Christopher Columbus's voyages, Spain was the first European power to settle and colonize the largest areas, from North America and the Caribbean to the southern tip of South America.
The Spaniards began building their American empire in the Caribbean, using islands such as Cuba, Puerto Rico, Hispaniola as bases. The North and South American mainland fell to the conquistadors, with an estimated 8,000,000 deaths of indigenous populations, argued to be the first large-scale act of genocide in the modern era. Florida fell to Juan Ponce de León after 1513. From 1519 to 1521, Hernán Cortés waged a campaign against the Aztec Empire, ruled by Moctezuma II; the Aztec capital, became Mexico City, the chief city of what the Spanish were now calling "New Spain". More than 240,000 Aztecs died during the siege of Tenochtitlan. Of these, 100,000 died in combat. Between 500 and 1,000 of the Spaniards engaged in the conquest died; the areas that are today California, New Mexico, Texas, Missouri and Alabama were taken over by other conquistadors, such as Hernando de Soto, Francisco Vázquez de Coronado, Álvar Núñez Cabeza de Vaca. Farther to the south, Francisco Pizarro conquered the Inca Empire during the 1530s.
The de Soto expedition was the first major encounter of Europeans with North American Indians in the eastern half of the United States. The expedition journeyed from Florida through present-day Georgia and the Carolinas west across the Mississippi and into Texas. De Soto fought his biggest battle at the walled town of Mabila in present-day Alabama on October 18, 1540. Spanish losses were 148 wounded; the Spaniards claimed. If true, Mabila was the bloodiest battle fought between red men and white in the present-day United States; the centuries of continuous conflicts between the North American Indians and the Anglo-Americans were secondary to the devastation wrought on the densely populated Meso-American and Caribbean heartlands. Other powers such as France founded colonies in the Americas: in eastern North America, a number of Caribbean islands and small coastal parts of South America. Portugal colonized Brazil, tried colonizing the eastern coasts of present-day Canada and settled for extended periods northwest of the River Plate.
The Age of Exploration was the beginning of territorial expansion for several European countries. Europe had been preoccupied with internal wars and was recovering from the loss of population caused by the Black Death. Most of the Western Hemisphere came under the control of Western European governments, leading to changes to its landscape and plant and animal life. In the 19th century over 50 million people left Western Europe for the Americas; the post-1492 era is known as the period of the Columbian Exchange, a widespread exchange of animals, culture, human populations and communicable disease between the American and Afro-Eurasian hemispheres following Columbus's voyages to the Americas. Henry F. Dobyns estimates that before European colonization of the Americas there were between 90 and 112 million people in the Americas. Norse journeys to Greenland and Canada are supported by archaeological evidence. A Norse colony in Greenland was established in the late 10th century, lasted until the mid 15th century, with court and parliament assemblies taking place at Brattahlíð and a bishop located at Garðar.
The remains of a Norse settlement at L'Anse aux Meadows in Newfoundland, were discovered in 1960 and were dated to around the year 1000. L'Anse aux Meadows is the only site accepted as evidence of pre-Columbian trans-oceanic contact, it was named a World Heritage site by UNESCO in 1978. It is notable for its possible connection with the attempted colony of Vinland, established by Leif Erikson around the same period or, more broadly, with the Norse colonization of the Americas. Early explorations and conquests were made by the Spanish and the Portuguese following their own final reconquest of Iberia in 1492. In the 1494 Treaty of Tordesillas, ratified by the Pope, these two kingdoms divided the entire non-European world into two areas of exploration and colonization, with a north to south boundary that cut through the Atlantic Ocean and the eastern part of present-day Brazil. Based on this treaty and on early claims by Spanish explorer Vasco Núñez de Balboa, discoverer of the Pacific Ocean in 1513, the Spanish conquered large territories in
Paleo-Indians, Paleoindians or Paleoamericans is a classification term given by scholars to the first peoples who entered, subsequently inhabited, the Americas during the final glacial episodes of the late Pleistocene period. The prefix "paleo-" comes from the Greek adjective palaios, meaning "old" or "ancient"; the term "Paleo-Indians" applies to the lithic period in the Western Hemisphere and is distinct from the term "Paleolithic". Traditional theories suggest that big-animal hunters crossed the Bering Strait from North Asia into the Americas over a land-and-ice bridge; this bridge existed from 45,000–12,000 BCE. Small isolated groups of hunter-gatherers migrated alongside herds of large herbivores far into Alaska. From c. 16,500 – c. 13,500 BCE, ice-free corridors developed along the Pacific coast and valleys of North America. This allowed animals, followed by humans; the people used primitive boats along the coastline. The precise dates and routes of the peopling of the New World remain subjects of ongoing debate.
Stone tools projectile points and scrapers, are the primary evidence of the earliest human activity in the Americas. Archaeologists and anthropologists use surviving crafted lithic flaked tools to classify cultural periods. Scientific evidence links Indigenous Americans to eastern Siberian populations. Indigenous peoples of the Americas have been linked to Siberian populations by linguistic factors, the distribution of blood types, in genetic composition as reflected by molecular data, such as DNA. There is evidence for at least two separate migrations. From 8000–7000 BCE the climate stabilized, leading to a rise in population and lithic technology advances, resulting in more sedentary lifestyle; the specifics of Paleo-Indian migration to and throughout the Americas, including the exact dates and routes traveled, are subject to ongoing research and discussion. The traditional theory has been that these early migrants moved into Beringia between eastern Siberia and present-day Alaska 17,000 years ago, when sea levels were lowered due to the Quaternary glaciation.
These people are believed to have followed herds of now-extinct pleistocene megafauna along ice-free corridors that stretched between the Laurentide and Cordilleran ice sheets. Another route proposed is that, either on foot or using primitive boats, they migrated down the Pacific coast to South America. Evidence of the latter would since have been covered by a sea level rise of hundreds of meters following the last ice age. Archaeologists contend that Paleo-Indians migrated out of Beringia, ranging from c. 40,000 – c. 16,500 years ago. This time range promises to continue as such for years to come; the few agreements achieved to date are the origin from Central Asia, with widespread habitation of the Americas during the end of the last glacial period, or more what is known as the late glacial maximum, around 16,000–13,000 years before present. However, alternative theories about the origins of Paleoindians exist, including migration from Europe. Sites in Alaska are where some of the earliest evidence has been found of Paleo-Indians, followed by archaeological sites in northern British Columbia, western Alberta and the Old Crow Flats region in the Yukon.
The Paleo-Indian would flourish all over the Americas. These peoples were spread over a wide geographical area. However, all the individual groups shared a common style of stone tool production, making knapping styles and progress identifiable; this early Paleo-Indian period lithic reduction tool adaptations have been found across the Americas, utilized by mobile bands consisting of 20 to 60 members of an extended family. Food would have been plentiful during the few warm months of the year. Lakes and rivers were teeming with many species of fish and aquatic mammals. Nuts and edible roots could be found in the forests and marshes; the fall would have been a busy time because foodstuffs would have to be stored and clothing made ready for the winter. During the winter, coastal fishing groups trap fresh food and furs. Late ice age climatic changes caused plant communities and animal populations to change. Groups moved from place to place as preferred resources were depleted and new supplies were sought.
Small bands utilized hunting and gathering during the spring and summer months broke into smaller direct family groups for the fall and winter. Family groups moved every 3–6 days traveling up to 360 km a year. Diets were sustaining and rich in protein due to successful hunting. Clothing was made from a variety of animal hides that were used for shelter construction. During much of the Early and Middle Paleo-Indian periods, inland bands are thought to have subsisted through hunting now-extinct megafauna. Large Pleistocene mammals were the giant beaver, steppe wisent, musk ox, woolly mammoths and ancient reindeer; the Clovis culture, appearing around 11,500 BCE, undoubtedly did not rely on megafauna for subsistence. Instead, they employed a mixed foraging strategy that included smaller terrestrial game, aquatic animals, a variety of flora. Paleo-Indian groups carried a variety of tools; these included efficient fluted style spear points, as well as microblades used for butchering and hide processing.
Projectile points and hammerstones made from many sources are found traded or moved to new locations. Stone tools were traded and/or left behind fro
Mesoamerican chronology divides the history of prehispanic Mesoamerica into several periods: the Paleo-Indian, the Archaic, the Preclassic or Formative, the Classic, the Postclassic and Postcolonial. The periodization of Mesoamerica is based on archaeological and modern cultural anthropology research; the endeavor to create cultural histories of Mesoamerica dates to the early twentieth century, with ongoing work by archeologists, ethnohistorians and cultural anthropologists. 10,000–3500 BCE The Paleo-Indian period or era is that which spans from the first signs of human presence in the region, to the establishment of agriculture and other practices and subsistence techniques characteristic of proto-civilizations. In Mesoamerica, the termination of this phase and its transition into the succeeding Archaic period may be reckoned at between 10,000 and 8000 BCE, although this dating is approximate only and different timescales may be used between fields and sub-regions. Before 2600 BCEDuring the Archaic Era agriculture was developed in the region and permanent villages were established.
Late in this era, use of pottery and loom weaving became common, class divisions began to appear. Many of the basic technologies of Mesoamerica in terms of stone-grinding, pottery etc. were established during this period. 2000 BCE–250 CEDuring the Preclassic Era, or Formative Period, large-scale ceremonial architecture, writing and states developed. Many of the distinctive elements of Mesoamerican civilization can be traced back to this period, including the dominance of corn, the building of pyramids, human sacrifice, jaguar-worship, the complex calendar, many of the gods; the Olmec civilization developed and flourished at such sites as La Venta and San Lorenzo Tenochtitlán succeeded by the Epi-Olmec culture between 300–250 BCE. The Zapotec civilization arose in the Valley of Oaxaca, the Teotihuacan civilization arose in the Valley of Mexico, the Maya civilization began to develop in the Mirador Basin and the Epi-Olmec culture in the Isthmus of Tehuantepec expanding into Guatemala and the Yucatán Peninsula.
250–900 CEThe Classic Period was dominated by numerous independent city-states in the Maya region and featured the beginnings of political unity in central Mexico and the Yucatán. Regional differences between cultures grew more manifest; the city-state of Teotihuacan dominated the Valley of Mexico until the early 8th century, but we know little of the political structure of the region because the Teotihuacanos left no written records. The city-state of Monte Albán dominated the Valley of Oaxaca until the late Classic, leaving limited records in their undeciphered script. Sophisticated arts such as stuccowork, sculptural reliefs, mural painting and lapidary developed and spread during the Classic era. In the Maya region, under considerable military influence by Teotihuacan after the "arrival" of Siyaj K'ak' in 378 CE, numerous city states such as Tikal, Calakmul, Copán, Palenque, Cobá, Caracol reached their zeniths; each of these polities was independent, although they formed alliances and sometimes became vassal states of each other.
The main conflict during this period was between Tikal and Calakmul, who fought a series of wars over the course of more than half a millennium. Each of these states declined during the Terminal Classic and were abandoned. 900–1521 CEIn the Postclassic Period many of the great nations and cities of the Classic Era collapsed, although some continued, such as in Oaxaca and the Maya of Yucatán, such as at Chichen Itza and Uxmal. This is sometimes seen as a period of increased warfare; the Postclassic is viewed as a period of cultural decline. However, it was a time of technological advancement in architecture and weaponry. Metallurgy came into use for jewelry and some tools, with new alloys and techniques being developed in a few centuries; the Postclassic was a period of rapid movement and population growth—especially in Central Mexico post-1200—and of experimentation in governance. For instance, in Yucatán,'dual rulership' replaced the more theocratic governments of Classic times, whilst oligarchic councils operated in much of Central Mexico.
It appears that the wealthy pochteca and military orders became more powerful than was the case in Classic times. This afforded some Mesoamericans a degree of social mobility; the Toltec for a time dominated central Mexico in the 9th–10th century collapsed. The northern Maya were for a time united under Mayapan, Oaxaca was united by Mixtec rulers in the 11th–12th centuries; the Aztec Empire arose in the early 15th century and appeared to be on a path to asserting dominance over the Valley of Mexico region not seen since Teotihuacan. Spain was the first European power to contact Mesoamerica and its conquistadores and a large number of native allies conquered the Aztecs. By the 15th century, the Mayan'revival' in Yucatán and southern Guatemala and the flourishing of Aztec imperialism evidently enabled a renaissance of fine arts and science. Examples include the'Pueblan-Mexica' style in pottery, codex illumination, goldwork, the flourishing of Nahua poetry, the botanical institutes established by the Aztec elite.
1521-1821 CEThe Colonial Period was initiated with Spanish conquest, which ended the hegemony of the Aztec Empire. It was accomplished with
The Pre-Columbian era incorporates all period subdivisions in the history and prehistory of the Americas before the appearance of significant European influences on the American continent, spanning the time of the original settlement in the Upper Paleolithic period to European colonization during the Early Modern period. While the phrase "pre-Columbian era" refers only to the time preceding Christopher Columbus's voyages of 1492, in practice the phrase is used to denote the entire history of indigenous Americas cultures until those cultures were exterminated, diminished, or extensively altered by Europeans if this happened decades or centuries after Columbus's first landing. For this reason the alternative terms of Precontact Americas, Pre-Colonial Americas or Prehistoric Americas are in use. In areas of Latin America the term used is Pre-Hispanic. Many pre-Columbian civilizations established hallmarks which included permanent settlements, agriculture and monumental architecture, major earthworks, complex societal hierarchies.
Some of these civilizations had long faded by the time of the first permanent European colonies and the arrival of enslaved Africans, are known only through archaeological investigations and oral history. Other civilizations were contemporary with the colonial period and were described in European historical accounts of the time. A few, such as the Maya civilization, had their own written records; because many Christian Europeans of the time viewed such texts as heretical, men like Diego de Landa destroyed many texts in pyres while seeking to preserve native histories. Only a few hidden documents have survived in their original languages, while others were transcribed or dictated into Spanish, giving modern historians glimpses of ancient culture and knowledge. Indigenous American cultures continue to evolve after the pre-Columbian era. Many of these peoples and their descendants continue traditional practices while evolving and adapting new cultural practices and technologies into their lives.
Before the development of archaeology in the 19th century, historians of the pre-Columbian period interpreted the records of the European conquerors and the accounts of early European travelers and antiquaries. It was not until the nineteenth century that the work of men such as John Lloyd Stephens, Eduard Seler and Alfred P. Maudslay, of institutions such as the Peabody Museum of Archaeology and Ethnology of Harvard University, led to the reconsideration and criticism of the European sources. Now, the scholarly study of pre-Columbian cultures is most based on scientific and multidisciplinary methodologies. Asian nomads are thought to have entered the Americas via the Bering Land Bridge, now the Bering Strait and along the coast. Genetic evidence found in Amerindians' maternally inherited mitochondrial DNA supports the theory of multiple genetic populations migrating from Asia. Over the course of millennia, Paleo-Indians spread throughout South America; when the first group of people migrated into the Americas is the subject of much debate.
One of the earliest identifiable cultures was the Clovis culture, with sites dating from some 13,000 years ago. However, older sites dating back to 20,000 years ago have been claimed; some genetic studies estimate the colonization of the Americas dates from between 40,000 and 13,000 years ago. The chronology of migration models is divided into two general approaches; the first is the short chronology theory with the first movement beyond Alaska into the Americas occurring no earlier than 14,000–17,000 years ago, followed by successive waves of immigrants. The second belief is the long chronology theory, which proposes that the first group of people entered the hemisphere at a much earlier date 50,000–40,000 years ago or earlier. Artifacts have been found in both North and South America which have been dated to 14,000 years ago, accordingly humans have been proposed to have reached Cape Horn at the southern tip of South America by this time. In that case, the Eskimo peoples would have arrived separately and at a much date no more than 2,000 years ago, moving across the ice from Siberia into Alaska.
The North American climate was unstable. It stabilized by about 10,000 years ago. Within this time frame pertaining to the Archaic Period, numerous archaeological cultures have been identified; the unstable climate led to widespread migration, with early Paleo-Indians soon spreading throughout the Americas, diversifying into many hundreds of culturally distinct tribes. The Paleo-Indians were hunter-gatherers characterized by small, mobile bands consisting of 20 to 50 members of an extended family; these groups moved from place to place as preferred resources were depleted and new supplies were sought. During much of the Paleo-Indian period, bands are thought to have subsisted through hunting now-extinct giant land animals such as mastodon and ancient bison. Paleo-Indian groups carried a variety of tools; these included distinctive projectile points and knives, as well as less distinctive implements used for butchering and hide processing. The vastness of the North American continent, the variety of its climates, vegetation and landforms, led ancient peoples to coalesce into many distinct linguistic and cultural groups.
This is reflected in the oral histories of the indigenous peoples, described by a wide range of traditional creation stories which say that a given people have been living in a certain territory since the creation of the world. Over the course of thousands of years, paleo-Indian