RESUMO
The Paisley Caves in Oregon record the oldest directly dated human remains (DNA) in the Western Hemisphere. More than 100 high-precision radiocarbon dates show that deposits containing artifacts and coprolites ranging in age from 12,450 to 2295 (14)C years ago are well stratified. Western Stemmed projectile points were recovered in deposits dated to 11,070 to 11,340 (14)C years ago, a time contemporaneous with or preceding the Clovis technology. There is no evidence of diagnostic Clovis technology at the site. These two distinct technologies were parallel developments, not the product of a unilinear technological evolution. "Blind testing" analysis of coprolites by an independent laboratory confirms the presence of human DNA in specimens of pre-Clovis age. The colonization of the Americas involved multiple technologically divergent, and possibly genetically divergent, founding groups.
Assuntos
Arqueologia , Cavernas , Fósseis , Animais , DNA/análise , Emigração e Imigração/história , Fezes , História Antiga , Humanos , Dados de Sequência Molecular , América do Norte , Oregon , Dinâmica Populacional , Datação Radiométrica , Roedores , Tecnologia/história , TempoRESUMO
The timing of the first human migration into the Americas and its relation to the appearance of the Clovis technological complex in North America at about 11,000 to 10,800 radiocarbon years before the present (14C years B.P.) remains contentious. We establish that humans were present at Paisley 5 Mile Point Caves, in south-central Oregon, by 12,300 14C years B.P., through the recovery of human mitochondrial DNA (mtDNA) from coprolites, directly dated by accelerator mass spectrometry. The mtDNA corresponds to Native American founding haplogroups A2 and B2. The dates of the coprolites are >1000 14C years earlier than currently accepted dates for the Clovis complex.
Assuntos
DNA Mitocondrial , Emigração e Imigração , Fezes , Fósseis , Animais , Sequência de Bases , Canidae/genética , Humanos , Dados de Sequência Molecular , América do Norte , Oregon , Reação em Cadeia da Polimerase , Polimorfismo de Nucleotídeo Único , Sciuridae/genética , Sigmodontinae/genética , TempoRESUMO
Waters and Stafford (Reports, 23 February 2007, p. 1122) provided useful information about the age of some Clovis sites but have not definitively established the temporal span of this cultural complex in the Americas. Only a continuing program of radiometric dating and careful stratigraphic correlations can address the lingering ambiguity about the emergence and spread of Clovis culture.