page_title: Paleo-Indians
section_title: Migration into the Americas
hierarchical_section_title: Paleo-Indians / Migration into the Americas
context_page_description: Paleo-Indians, Paleoindians or Paleo-Americans, were 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, 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".
  Traditional theories suggest that big-animal hunters crossed the Bering Strait from North Asia into the Americas over a land bridge. This bridge existed from 45,000 to 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, to migrate south into the interior of the continent. The people went on foot or used primitive boats along the coastline. The precise dates and routes of the peopling of the New World remain subjects of ongoing debate.
context_section_description: Researchers continue to study and discuss the specifics of Paleo-Indian migration to and throughout the Americas, including the exact dates and routes traveled. The traditional theory holds that these early migrants moved into Beringia between eastern Siberia and present-day Alaska 17,000 years ago,at a time when the Quaternary glaciation significantly lowered sea levels. 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. An alternative proposed scenario involves migration - either on foot or using primitive boats - 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 (western Alaska), between c. 40,000 and c.  16,500 years ago. This time range remains a source of substantial debate. The few areas of agreement 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 specifically 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.
caption: Map of early human migrations based on the Out of Africa theory; figures are in thousands of years ago (kya)[9]