Migration to North America
Civilization in America began during the last Ice Age when nomadic Paleo-Indians migrated across Beringia.
Describe early inhabitants of the Americas and the environmental changes that made migration possible
- Beringia was an Ice Age land bridge that united the Eastern and Western hemispheres between Siberia and Alaska.
- Archeological evidence suggests that the Paleo-Indians' first dispersal into the Americas occurred near the end of the Last Glacial Maximum (LGM).
- Some genetic research indicates secondary waves of migration occurred after the initial Paleo-Indian colonization but prior to modern Inuit, Inupiat, and Yupik expansions.
- After multiple waves of migration, complex civilizations arose. One of the earliest identifiable cultures was the Clovis culture.
- nomadic: Leading a wandering life with no fixed abode; peripatetic, itinerant.
- Comparative linguistics: The study of languages of different tribes.
- Last Glacial Maximum (LGM): The last period in the Earth's climate history during the last glacial period when ice sheets were at their greatest extension.
- Beringia: The Bering land bridge was a land bridge roughly 1,000 miles (1,600 km) wide (north to south) at its greatest extent, which joined present-day Alaska and eastern Siberia at various times during the Pleistocene Ice Age.
America was inhabited by humans long before the first European set foot on the continent. The beginning of civilization in America occurred during the last Ice Age when the nomadic, ancestral peoples of the Americas—the Paleo-Indians—migrated into the current-day continental United States and Canada. Their exact origins, as well as the route and timing of their migrations, are the subject of much scholarly discussion.
The Land Bridge and Migrations
While some researchers may debate the “why” and “when” of migration patterns, all can agree that migration would not have been possible without a glacial epoch. The Last Glacial Maximum (LGM), which occurred between approximately 18,000 and 20,000 years ago, was the last period in the Earth's climate history when ice sheets were at their greatest extension. Extremely cold weather resulted in the formation of vast ice sheets across the Earth's northernmost and southernmost latitudes. As the ice surfaced formed, sea levels dropped worldwide. For thousands of years, the floors of many interglacial shallow seas were exposed, including those of the Bering Strait, the Chukchi Sea to the north, and the Bering Sea to the south.
Bering Land Bridge: It is believed that a small Paleo-Indian population of a few thousand survived the Last Glacial Maximum in Beringia. This group was isolated from its ancestor populations in Asia for at least 5,000 years before expanding to populate the Americas sometime after 16,500 years ago.
During this period, early inhabitants are believed to have traversed the ice into what is now North America. The traditional theory has been that these early migrants moved into the Beringia land bridge between eastern Siberia and present-day Alaska around 11,000 to 25,000 years ago. While there is general agreement that the Americas were first settled from Asia, the pattern of migration, its timing, and the place(s) of origin in Asia of the peoples who migrated to the Americas remain unclear.
In the 2000s, researchers sought to use familiar tools to validate or reject established theories, such as the Clovis First / Single origin hypothesis. The archeological evidence suggests that the Paleo-Indians' first dispersal into the Americas occurred near the end of the LGM. The Paleo-Indians are believed to have followed herds of now-extinct Pleistocene megafauna along ice-free corridors that stretched between the Laurentide and Cordilleran ice sheets. It is also thought that they migrated down the Pacific coast to South America either on foot or using primitive boats. Some genetic research indicates secondary waves of migration occurred after the initial Paleo-Indian colonization but prior to modern Inuit, Inupiat, and Yupik expansions.
The First American Civilizations
After multiple waves of migrations, it was several thousand years before the first complex civilizations arose. One of the earliest identifiable cultures was the Clovis culture, with sites dating from some 13,000 years ago. The Clovis culture permeated much of North America and parts of South America. It is not clear whether the Clovis people were one unified tribe or whether there were many tribes related by common technology and belief.
As early Paleo-Indians spread throughout the Americas, they diversified into many hundreds of culturally distinct tribes. Paleo-Indian adaptation across North America was likely characterized by small, highly mobile bands consisting of approximately 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.As time went on, many of these first immigrants developed permanent settlements. With permanent residency, some cultures developed into agricultural societies while others became pastoral. The North American climate stabilized around 8000 BCE to a climate that we would recognize today. Due to the vastness and variety of the climates, ecology, vegetation, fauna, and landforms, ancient peoples migrated and coalesced separately into numerous peoples of distinct linguistic and cultural groups. Some of these cultures developed innovative technology that encouraged cities and even empires. Comparative linguistics shows fascinating diversity, with similarities between tribes hundreds of miles apart, yet startling differences with neighboring groups.
Paleo-Indians subsisted as small, mobile groups of big game hunters, traveling light and frequently to find new sources of food.
Describe how the first settlers of the Americas adapted to environmental changes
- The Paleo-Indians carried highly efficient, fluted-style spear points as well as microblades used for butchering and hide-processing.
- The Paleo-Indian would eventually flourish all over the Americas, creating regional variations in lifestyles, while sharing a common style of stone tool production.
- As the climate changed and megafauna became extinct, Paleo-Indians were forced to employ a mixed foraging strategy that included smaller terrestrial game, aquatic animals, and a variety of flora.
- Environmental changes and multiple waves of migration led to the formation of distinct cultures, like the Clovis culture.
- megafauna: The large animals of a given region or time, considered as a group.
- Paleo-Indian: A classification term given to the first peoples that inhabited the Americas during the final glacial episodes of the late Pleistocene period.
- flora: Plants considered as a group, especially those of a particular country, region, time, etc.
- Clovis culture: Paleo-Indian culture, named after distinct stone tools found at sites near Clovis, New Mexico, in the 1920s and 1930s.
Paleo-Indians, or Paleo-Americans, were the first peoples who entered and subsequently inhabited the American continent. 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. However, the traditional theory has been that these early migrants moved into the Beringia land bridge between eastern Siberia and present-day Alaska around 40,000–17,000 years ago, when sea levels were significantly lowered due to the Quaternary glaciation. The Paleo-Indians are believed to have followed herds of now-extinct Pleistocene megafauna along ice-free corridors that stretched between the Laurentide and Cordilleran ice sheets.
Sites in Alaska (East Beringia) 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 eventually flourish all over the Americas, creating regional variations in lifestyles. However, all of the individual groups shared a common style of stone tool production, making knapping styles and progress identifiable. This early Lithic reduction tool adaptation was utilized by highly mobile bands consisting of approximately 20 to 60 members of an extended family. In addition to hunting large animals, these families would also live on nuts, berries, fish, birds, and other aquatic mammals, but during the winter, coastal fishing groups moved inland to hunt and trap fresh food and furs.
Eventually, 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, then broke into smaller direct family groups for the fall and winter. Family groups moved every 3–6 days, possibly covering up to 360 km (220 mi) a year. Diets were often sustaining and rich in protein due to successful hunting. Clothing was made from a variety of animal hides that were also used for shelter construction. During much of the Early and Middle Paleo-Indian periods, inland bands are thought to have subsisted primarily through hunting now-extinct megafauna. Large Pleistocene mammals were the giant beaver, steppe wisent, musk ox, mastodon, woolly mammoth, and ancient reindeer (early caribou).
Environmental changes and multiple waves of migration also led to the formation of distinct cultures. Perhaps the most significant civilization to develop in the Americas was the Clovis culture, which appeared around 11,500 BCE (13,500 BP). The Clovis peoples did not rely exclusively on megafauna for subsistence. Instead, they employed a mixed foraging strategy that included smaller terrestrial game, aquatic animals, and a variety of flora. These groups were efficient hunters and carried a variety of tools, which included highly efficient fluted style spear points, as well as microblades used for butchering and hide processing. Stone tools were traded and/or left behind from North Dakota and the Northwest Territories to Montana and Wyoming. Trade routes also have been found from the British Columbia Interior to the coast of California.
A hallmark of the toolkit associated with the Clovis culture is the distinctively shaped, fluted stone spear point, known as the Clovis point. 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. Nevertheless, Clovis people are considered to be the ancestors of most of the indigenous cultures of the Americas.
Eventually, the Clovis culture was replaced by several more localized regional cultures from the time of the Younger Dryas cold climate period onward, about 12,000 years ago. Post-Clovis cultures include the Folsom tradition, Gainey, Suwannee-Simpson, Plainview-Goshen, Cumberland, and Redstone. Each of these is commonly thought to derive directly from Clovis and in some cases, the only difference was the in their spears and the length of the fluting on their projectile points. Although this is generally held to be the result of normal cultural change through time, numerous other reasons have been suggested to be the driving forces for the observed changes in the archaeological record, such as the Younger Dryas' impact event or post-glacial climate change with numerous faunal extinctions.
Eventually, the glaciers that covered the northern half of the continent began to gradually melt, exposing new land for occupation around 17,500 to 14,500 years ago. At the same time as this was occurring, worldwide extinctions among the large mammals began. In North America, camels and horses eventually died off—the latter not to reappear on the continent until the Spanish reintroduced the species near the end of the 15th century CE. As the Quaternary extinction event was happening, the early inhabitants of the Americas began to rely more on other means of subsistence. These environmental changes would not only alter hunting and migration patterns, but would also lead to the evolution of diverse civilizations in the Americas.
Paleo-Indian Hunters: The Lithic peoples, or Paleo-Indians, were nomadic hunter-gatherers and are the earliest known humans of the Americas.
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