Archaeological evidence Settlement of the Americas

figure 2. schematic illustration of maternal (mtdna) gene-flow in , out of beringia (long chronology, single source model).



figure 3. illustration of hypothetical chronology migration through beringia (long chronology model). not authoritative on timing of glacial features , not constrained archaeological data.

pre-last glacial maximum migration across beringia americas has been proposed explain purported pre-lgm ages of archaeosites in americas such bluefish caves , old crow flats in yukon territory, , meadowcroft rock shelter in pennsylvania. earlier c date bone artifact @ old crow flats site has been supplanted accelerator mass spectrometry c date indicates holocene age. interpretations of butcher marks , geologic association of bones @ bluefish cave , old crow flats sites have been called question. ages of earliest positively identified artifacts @ meadowcroft site constrained compiled age estimate c in range of 12k-15k c years bp (13.8k-18.5k cal years bp). meadowcroft rockshelter site , monte verde site in southern chile, date of 14.8k cal years bp, archaeosites in americas oldest dates have gained broad acceptance.

stones described probable tools, hammerstones , anvils, have been found in southern california, @ cerutti mastodon site, associated mastodon skeleton appeared have been processed humans. mastodon skeleton dated thorium-230/uranium radiometric analysis, using diffusion–adsorption–decay dating models, 130.7 ± 9.4 thousand years ago. no human bones found, , claims of tools , bone processing have been described not plausible . michael r. waters commented demonstrate such occupation of americas requires presence of unequivocal stone artefacts. there no unequivocal stone tools associated bones... site interesting paleontological locality. chris stringer said extraordinary claims require extraordinary evidence - each aspect requires strongest scrutiny, adding high , concentrated forces must have been required smash thickest mastodon bones, , low energy depositional environment seemingly provides no obvious alternative humans using heavy cobbles found bones.

the yana river rhino horn site (rhs) has dated human occupation of eastern arctic siberia 27k c years bp (31.3k cal years bp). date has been interpreted evidence migration beringia imminent, lending credence occupation of beringia during lgm. however, yana rhs date beginning of cooling period led lgm. but, compilation of archaeosite dates throughout eastern siberia suggest cooling period caused retreat of humans southwards. pre-lgm lithic evidence in siberia indicate settled lifestyle based on local resources, while post-lgm lithic evidence indicate more migratory lifestyle.

the oldest archaeosite on alaskan side of beringia date 12k c years bp (14k cal years bp). possible small founder population had entered beringia before time. however, archaeosites date closer last glacial maximum on either siberian or alaskan side of beringia lacking.