Data_Sheet_1_Human Occupation of the North American Colorado Plateau ∼37,000 Years Ago.pdf

Calibrating human population dispersals across Earth’s surface is fundamental to assessing rates and timing of anthropogenic impacts and distinguishing ecological phenomena influenced by humans from those that were not. Here, we describe the Hartley mammoth locality, which dates to 38,900–36,250 cal BP by AMS 14C analysis of hydroxyproline from bone collagen. We accept the standard view that elaborate stone technology of the Eurasian Upper Paleolithic was introduced into the Americas by arrival of the Native American clade ∼16,000 cal BP. It follows that if older cultural sites exist in the Americas, they might only be diagnosed using nuanced taphonomic approaches. We employed computed tomography (CT and μCT) and other state-of-the-art methods that had not previously been applied to investigating ancient American sites. This revealed multiple lines of taphonomic evidence suggesting that two mammoths were butchered using expedient lithic and bone technology, along with evidence diagnostic of controlled (domestic) fire. That this may be an ancient cultural site is corroborated by independent genetic evidence of two founding populations for humans in the Americas, which has already raised the possibility of a dispersal into the Americas by people of East Asian ancestry that preceded the Native American clade by millennia. The Hartley mammoth locality thus provides a new deep point of chronologic reference for occupation of the Americas and the attainment by humans of a near-global distribution.

精准校准人类种群在全球地表的扩散历程，是评估人类活动影响的速率与时间节点、区分受人类影响与未受人类影响的生态现象的核心基础。本研究对哈特利猛犸象遗址进行了系统介绍：通过对骨胶原蛋白中的羟脯氨酸开展加速器质谱碳十四（AMS ¹⁴C）分析，确定该遗址的年代为38900~36250校准年前（cal BP）。本研究采用学界主流观点：欧亚旧石器时代晚期的复杂石器技术，是在约16000校准年前随美洲原住民支系迁入美洲大陆而传入的。据此可推论，若美洲存在更早的文化遗址，或许仅能通过精细化的埋藏学方法方能完成鉴定与确认。本研究采用了此前未应用于美洲古代遗址研究的计算机断层扫描（CT和μCT）等前沿技术手段。该研究揭示了多组埋藏学证据：表明曾有两头猛犸象被使用简易石器与骨器技术进行屠宰，同时还发现了可控用火的鉴定性佐证。美洲人类存在两支奠基人群的独立遗传学证据，进一步佐证了该遗址可能为古代文化遗址的推论——该遗传学证据此前已提出：拥有东亚血统的人群可能比美洲原住民支系早数千年就已向美洲扩散。因此，哈特利猛犸象遗址为美洲大陆的人类定居史以及人类实现近乎全球分布的演化历程，提供了全新的深层年代学参照基准。