[16] Imposed form in the Early Acheulean? Evidence from Gona, Afar, Ethiopia

Abstract: The appearance of “large cutting tools” in the early Acheulean is widely regarded as the first evidence for the imposition of intended forms on artifacts, with major implications for hominin cognitive and cultural capacities. However, the nature and extent of explicit design documented by these forms remains open to debate. To address this issue, we analyzed the complete collection of early Acheulean (ca. 1.7–1.2 Ma) flaked pieces from four sites (BSN17, DAN5, OGS12, and OGS5) in the Gona Project Area and compared these with all of the flaked pieces from two published Oldowan (> 2.5 Ma) sites at Gona. By comparing shape variation to measures of flaking intensity and coverage, we sought to identify technological patterns indicative of intent. Current results provide little evidence for the presence of discrete tool types or imposed morphological norms in our sample. We do, however, observe systematic patterns of raw material selection and core surface modification aimed at the production and maintenance of useful cutting edges on relatively large supports (cobbles and large flake blanks). This is consistent with prior characterizations of Acheulean tool form as arising from functional and ergonomic design imperatives for large hand-held cutting tools. Although the generalizability of these results to other sites remains to be seen, we propose that distinctive early Acheulean artifact forms may have arisen as secondary accommodations to the primary goal of increasing tool size to meet the novel demands (e.g., extended use-life, enhanced transportability, utility for heavy-duty cutting) of a more general shift in hominin behavioral ecology at this time. Our results provide support for the presence of Acheulean design at Gona, not necessarily in the sense of shared morphological norms, but certainly in the broader sense of deliberate technological choices made in view of behavioral goals and material constraints.