Anthropology
In reply to the discussion: Discovery in Mexican Cave May Drastically Change the Known Timeline of Humans' Arrival ... [View all]wnylib
(21,464 posts)when people arrived in the Americas has been the assumption that land travel had to be the only means.
Several years ago I visited the Arch/Anthro institute at Mercyhurst University in Erie, PA. The director at that time was James Adovasio, the archeologist who led the excavation of Meadowcroft Rockshelter north of Pittsburgh, where dates went back to 14,000 years ago and earlier.
I talked with Dr. Adovasio's assistants about arrival timing and how it happened. They discussed not just a water route, but a maritime culture extending from eastern Asia to western North America, which would look like an upside down horseshoe shape on a map.
I was skeptical then, but not any more. We know now that modern humans have been in Australia for over 50,000 years. Even accounting for exposed land during glaciation, there are still about 70 miles of open water they would have crossed to reach Australia. They knew how to "sail" or jyst drift on rafts that long ago.
DNA studies of human migrations out of Africa show that some groups of people hugged coastlines of India and southeastern Asia for millennia during expansion into Asia. Homo sapiens adapted to marine cultures very early. Water became roadways, not obstacles.
There are numerous islands off the coast of northeastern Asia. There are the Aleutian Islands extending out from southern Alaska almost to Asia. A maritime culture could live off of fish and marine and land animals. They could use wood and stone from the islands for tool making, as well as animal bones, skin, and sinew.
Beringia did not emerge overnight. Centuries of glacial expansion caused land to appear gradually, connecting some islands to mainland Asia and to other islands, or narrowing the distance. As less Arctic waters seeped into the Pacific while Beringia was developing, the climate was a little less severe.
Following Asian islands to the Aleutians and down the Pacific coast of North America, a marine culture could have skirted the glaciers and the bogs of Beringia. Once on the Pacific coast of North America, there were options to settle North American islands (now submerged), continue down the coast to even warmer climates, or take water routes (rivers, lakes) inland into North America, south of the glaciers.
Inland, the regions on the southern borders of the glaciers were rich with seasonal meltwater and the plants that grew there as well as animals attracted to watering holes. People could expand inland to the east in North America fairly quickly.
Or, follow the western coast of North America to Central and South America.
Early dates for people in the Americas are not confined to the limits in time of Beringia and glaciers. They can be as old as the evidence from scientific dating methods indicate. Follow the evidence and then figure out what happened instead of assuming what happened and then discounting evidence that doesn't support the assumptions.