Applied Force as a Determining Factor in Lithic Use-Wear Accrual: An Experimental Investigation of its Validity as a Method with which to Infer Hominin Upper Limb Biomechanics

Abstract

The advent of flake technology represented a fundamental shift in the capability of hominins to effectively access and process animal food sources. As such, the efficiency with which these tools were utilized is often widely implicated in palaeoanthropological debate, most pertinently, with regards to the evolution of upper limb biomechanics. Hence, it would then be of significance if the force, and by association efficiency, with which these tools were used is able to be determined. Presented here is the first attempt to correlate the force with which flaked tools are used to the associated microwear polish accrued on the lithics worked edge. This would potentially allow biomechanical inferences to be taken from stone artifacts and subsequently be applied to the populations that were using them. Twenty five participants of varying strength carried out a simple cutting task using small, unhafted flakes made from English chalk flint. Both maximum and mean applied force was recorded during these tasks by a sensor placed under the worked material while all other variables, including stroke count and flake size, were controlled for. Lithic polish was quantified through seven textural analyses of SEM micrographs. Results indicated that there were no statistically significant relationships between lithic polish and both maximum and mean applied force at low levels of variation. It is, however, suggested that given more archaeologically inferable experimental conditions then polish accrual may have displayed higher developmental distinctions, thus allowing lithic wear to differentiate between applied forces.

Keywords:

• lithic use-wear
• force
• hominin butchery
• biomechanics
• flake tool use

Acknowledgements

Funding and support was provided by the Lithics Lab at the UCL Institute of Archaeology. I wish to thank all those who took part for their patience and continued participation despite some discomfort and repetitiveness. I am grateful to Chris Dunmore, Metin Eren, Stephen Lycett, Ignacio de la Torre, and the anonymous reviewers for their helpful and constructive comments on an earlier version of this paper.

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Notes on contributors

Alastair J.M. Key

Alastair Key is a biological anthropology Ph.D. candidate at the University of Kent, Canterbury (U.K.). His principle research interests center around the biomechanics of hominin tool production and use. Primarily, he tests evolutionary inferences about the relationship between technology and human evolution via laboratory experiments and stone tool knapping replication.