Beringia in the context of "Wisconsin glaciation"

The Pleistocene (/ˈplaɪstəˌsiːn, -stoʊ-/ PLY-stə-seen, -⁠stoh-; referred to colloquially as the Ice Age) is the geological epoch that lasted from c. 2.58 million to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name comes from Ancient Greek πλεῖστος (pleîstos), meaning "most", and καινός (kainós), meaning "new, recent".

The aridification and cooling trends of the preceding Neogene were continued in the Pleistocene. The climate was strongly variable depending on the glacial cycle, oscillating between cold glacial periods and warmer interglacials, with the sea levels being up to 120 metres (390 ft) lower than present at peak glaciation, allowing the periodic connection of Asia and North America via the Beringia land bridge, and the covering of most of northern North America by the large Laurentide Ice Sheet.

The human history of the Americas is thought to begin with people migrating to these areas from Asia during the height of an ice age. These groups are generally believed to have been isolated from the people of the "Old World" until the coming of Europeans in 1492 with the voyages of Christopher Columbus.

The ancestors of today's American Indigenous peoples were the Paleo-Indians; they were hunter-gatherers who migrated into North America. The most popular theory asserts that migrants came to the Americas via Beringia, the land mass now covered by the ocean waters of the Bering Strait. Small lithic stage peoples followed megafauna like bison, mammoth (now extinct), and caribou, thus gaining the modern nickname "big-game hunters." Groups of people may also have traveled into North America on shelf or sheet ice along the northern Pacific coast.

The Bering Strait (/ˈbɛərɪŋ, ˈbɛrɪŋ/ BAIR-ing, BERR-ing, US also /ˈbɪərɪŋ/ BEER-ing; Russian: Берингов пролив, romanized: Beringov proliv) is a strait between the Pacific and Arctic oceans, separating the Chukchi Peninsula of the Russian Far East from the Seward Peninsula of Alaska. The present Russia–United States maritime boundary is at 168° 58' 37" W longitude, slightly south of the Arctic Circle at about 65° 40' N latitude. The Strait is named after Vitus Bering, a Danish-born Russian explorer.

The Bering Strait has been the subject of the scientific theory that humans migrated from Asia to North America across a land bridge known as Beringia when lower ocean levels – a result of glaciers locking up vast amounts of water – exposed a wide stretch of the sea floor, both at the present strait and in the shallow sea north and south of it. This view of how Paleo-Indians entered America has been the dominant one for several decades and continues to be the most accepted one. Numerous successful crossings without the use of a boat have also been recorded since at least the early 20th century.

Paleo-Indians (also spelled Paleoindians) were the first peoples who entered and subsequently inhabited the Americas towards the end of the Late Pleistocene period. The word comes from the prefix paleo-, taken from the Ancient Greek adjective: παλαιός, romanized: palaiós, lit. 'old; ancient', and "Indian", which has been historically used to refer to Indigenous peoples of the Americas. The term Paleo-Indian applies specifically 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 bridge (Beringia). This bridge existed from 45,000 to 12,000 BCE (47,000–14,000 BP). Small isolated groups of hunter-gatherers migrated alongside herds of large herbivores far into Alaska. From c. 16,500 – c. 13,500 BCE (c. 18,500 – c. 15,500 BP), ice-free corridors developed along the Pacific coast and valleys of North America. This allowed land animals, followed by humans, to migrate south into the interior of the continent. The people went on foot or used boats along the coastline. The dates and routes of the peopling of the Americas remain subjects of ongoing debate. There were likely three waves of ancient settlers from the Bering Sea to the American continent.

The mammoth steppe, also known as steppe-tundra, was once the Earth's most extensive biome. During glacial periods in the later Pleistocene, it stretched east to west from the Iberian Peninsula in the west of Europe, then across Eurasia and through Beringia (the region including the far northeast of Siberia, Alaska and the now submerged land between them) and into the Yukon in northwest Canada; from north to south, the steppe reached from the Arctic southward to southern Europe, Central Asia and northern China. The mammoth steppe was cold and dry, and relatively featureless—though climate, topography, and geography varied considerably throughout. Certain areas of the biome, such as coastal areas, had wetter and milder climates than others. Some areas featured rivers which through erosion naturally created gorges, gulleys, or small glens. The continual glacial recession and advancement over millennia contributed more to the formation of larger valleys and different geographical features. Overall, however, the steppe is known to be flat and expansive grassland. The vegetation was dominated by palatable, high-productivity grasses, herbs and willow shrubs. Although it was primarily a Eurasian and Beringian biome, an analog of the mammoth steppe existed on the southern edge of the Laurentide ice sheet in North America as well, and contained many of the same animals such as woolly mammoths, muskoxen, scimitar cats, and caribou.

The fauna was dominated by species such as reindeer, muskox, saiga antelope, steppe bison, horses, woolly rhinoceros and woolly mammoth. These herbivores, in turn, were followed and preyed upon by various carnivores, such as wolves, brown bears, Panthera spelaea (the cave or steppe-lion), cave hyenas, wolverines, among others, as well as scimitar-toothed cats and giant short-faced bears in east Beringia (with scimitar-toothed cats also having rare records from the mammoth steppe in Eurasia).

The Ancient Beringian (AB) is a human archaeogenetic lineage, based on the genome of an infant found at the Upward Sun River site (dubbed USR1), dated to 11,500 years ago. The AB lineage diverged from the Ancestral Native American (ANA) lineage about 20,000 years ago. The ANA lineage was estimated as having been formed between 20,000 and 25,000 years ago by a mixture of East Asian (~65%) and Ancient North Eurasian (~35%) lineages, consistent with the model of the peopling of the Americas via Beringia during the Last Glacial Maximum.

The Seward Peninsula is a large peninsula on the western coast of the U.S. state of Alaska whose westernmost point is Cape Prince of Wales. The peninsula projects about 200 mi (320 km) into the Bering Sea between Norton Sound, the Bering Strait, the Chukchi Sea, and Kotzebue Sound, just below the Arctic Circle. The entire peninsula is about 210 mi (330 km) long and 90–140 mi (145–225 km) wide. Like Seward, Alaska, it was named after William H. Seward, the United States Secretary of State who fought for the U.S. purchase of Alaska.

The Seward Peninsula is a remnant of the Bering land bridge, a roughly thousand-mile-wide swath of land connecting Siberia with mainland Alaska during the Pleistocene Ice Age. This land bridge aided in the migration of humans, as well as plant and animal species, from Asia to North America. Excavations at sites such as the Trail Creek Caves and Cape Espenberg in the Bering Land Bridge National Preserve as well as Cape Denbigh to the south have provided insight into the timeline of prehistorical migrations from Asia to the Seward Peninsula.

Haringtonhippus is an extinct genus of equine from the Pleistocene of North America The genus is monospecific, consisting of the species H. francisci, initially described in 1915 by Oliver Perry Hay as Equus francisci. Members of the genus are often referred to as stilt-legged horses, in reference to their slender distal limb bones, in contrast with those of contemporary "stout legged" caballine true horses.

Haringtonhippus fossils have only been discovered in North America. Specimens have been found from southern Mexico to southern South Dakota and in Alberta, Canada, at sites such as Gypsum Cave and Natural Trap Cave, as well as eastern Beringia in Yukon A later study found that Equus cedralensis from the Late Pleistocene of Mexico also belonged to this species. The earliest species of the lineage appeared in North America during the Late Pliocene to Early Pleistocene, around 2 to 3 Ma. It became extinct at the end of the Late Pleistocene, around 12,000 years ago as part of the end-Pleistocene extinctions, along with most other large mammals in the Americas.