Elongation as a factor in artefacts of humans and other animals: an Acheulean example in comparative context

Abstract

Elongation is a commonly found feature in artefacts made and used by humans and other animals and can be analysed in comparative study. Whether made for use in hand or beak, the artefacts have some common properties of length, breadth, thickness and balance point, and elongation can be studied as a factor relating to construction or use of a long axis. In human artefacts, elongation can be traced through the archaeological record, for example in stone blades of the Upper Palaeolithic (traditionally regarded as more sophisticated than earlier artefacts), and in earlier blades of the Middle Palaeolithic. It is now recognized that elongation extends to earlier Palaeolithic artefacts, being found in the repertoire of both Neanderthals and more archaic humans. Artefacts used by non-human animals, including chimpanzees, capuchin monkeys and New Caledonian crows show selection for diameter and length, and consistent interventions of modification. Both chimpanzees and capuchins trim side branches from stems, and appropriate lengths of stave are selected or cut. In human artefacts, occasional organic finds show elongation back to about 0.5 million years. A record of elongation achieved in stone tools survives to at least 1.75 Ma (million years ago) in the Acheulean tradition. Throughout this tradition, some Acheulean handaxes are highly elongated, usually found with others that are less elongated. Finds from the million-year-old site of Kilombe and Kenya are given as an example. These findings argue that the elongation need not be integral to a design, but that artefacts may be the outcome of adjustments to individual variables. Such individual adjustments are seen in animal artefacts. In the case of a handaxe, the maker must balance the adjustments to achieve a satisfactory outcome in the artefact as a whole. It is argued that the need to make decisions about individual variables within multivariate objects provides an essential continuity across artefacts made by different species.

Variability in an early hominin percussive tradition: the Acheulean versus cultural variation in modern chimpanzee artefacts

“…Very rarely, wood or other material confirms that we may be seeing just the tip of the iceberg of past activities [54,92]. This additional element would of course be very important in making comparisons with primate artefacts [93,94]. The recurrent 'variable sameness' of the Acheulean suggests that the same basic subsistence rstb.royalsocietypublishing.org Phil.…”

The handaxe reconsidered

“…In general, nonhuman primates neither curate nor pay much attention to their tools outside of the immediate circumstances of use. Even so, they deal with the same physical problems as do hominin tool makers and users, and that involves dealing with multiple variables at the same time …”

Tool use as adaptation

“…Our final contribution [50] examines the animal and hominin archaeological record for evidence of deliberate orientation and imposition of a ‘long-axis’ on tools, with some tantalizing suggestions that exaggerated design can allow objects manufactured for a specific mechanical purpose to assume novel roles within the symbolic realm.…”

“…Gowlett [50] focuses on one particular aspect of multivariate tool design: elongation. Defined as extending the length of an object in relation to its width, elongation produces tools that serve a variety of purposes, and involves the imposition of discrete, use-related, axes on a material object.…”