J Archaeol Sci 28 (7)

describes the sampling methods and processes of analysis employed in study

Presents a geometric model that permits controlled manipulation of a few of the key parameters defining Levallois core morphology. The models indicate that Levallois cores are relatively efficient at minimizing raw material waste while at the same time maximizing productivity in terms of total number of tool blanks and amount of cutting edge produced. Deviations from an ideal Levallois geometry produce significant declines in both efficiency and productivity. These results implicate mechanical and economic constraints as factors underlying the broad geographic distribution and temporal persistence of Levallois core technologies during the Middle and Late Pleistocene.

This study is the first to report DNA recovery from a 9,800-year-old specimen. Reports methods used to extract mitochondrial DNA and obtain accelerator mass spectrometry radiocarbon dates (AMS-14C) from sheep hairs found in the USA. The ability to obtain reliable radiocarbon dates and DNA sequences from single ancient hairs opens new possibilities for addressing biological questions in prehistory.