Published online by Cambridge University Press: 18 July 2016
Ever since José de Acosta's prescient speculation, in 1590, that Native Americans were descended from “savage hunters” who had followed game animals across a land bridge from northeastern Asia into northwestern America (Acosta 1604), most serious scholars have assumed that this was the migration route. The main point of dispute has been the date when the ancestral Asians made the crossing. After many nineteenth-century claims of the discovery of stone tools or bones of “early man” failed to withstand scientific scrutiny, a conservative reaction set in, embodied by the hyper-skeptical Aleš Hrdlička of the Smithsonian Institution. Hrdlička dismissed all claims of a human presence in the Americas prior to about 5000 years ago.