Wikipedia
Paleo-Indians, Paleoindians or Paleoamericans is a classification term given to the first peoples who entered, and subsequently inhabited, the Americas during the final glacial episodes of the late Pleistocene period. The prefix "paleo-" comes from the Greek adjective palaios (παλαιός), meaning "old" or "ancient". The term "Paleo-Indians" applies specifically to the lithic period in the Western Hemisphere and is distinct from the term " Paleolithic".
Evidence suggests big-animal hunters crossed the Bering Strait from Eurasia into North America over a land and ice bridge ( Beringia), that existed between 45,000-12,000 BCE (47,000-14,000 BP). Small isolated groups of hunter-gatherers migrated alongside herds of large herbivores far into Alaska. From 16,500-13,500 BCE (18,500-15,500 BP), ice-free corridors developed along the Pacific coast and valleys of North America. This allowed animals, followed by humans, to migrate south into the interior. The people went on foot or used primitive boats along the coastline. The precise dates and routes of the peopling of the New World are subject to ongoing debate.
Stone tools, particularly projectile points and scrapers, are the primary evidence of the earliest human activity in the Americas. Crafted lithic flaked tools are used by archaeologists and anthropologists to classify cultural periods. Scientific evidence links Indigenous Americans to Asian peoples, specifically eastern Siberian populations. Indigenous peoples of the Americas have been linked to Siberian populations by linguistic factors, the distribution of blood types, and in genetic composition as reflected by molecular data, such as DNA. There is evidence for at least two separate migrations. Between 8000-7000 BCE (10,000-9,000 years BP) the climate stabilized, leading to a rise in population and lithic technology advances, resulting in more sedentary lifestyle.