Long-range Transport of Materials

Even when mechanized or draft-animal-aided transport is excluded, all human societies carry objects while self-propelled, either individually or collectively. Distances vary over four orders of magnitude, from ones to thousands of kilometers, that is, from across a back garden to home from the corner shop to holiday trekking to seasonal migrations, e.g. transhumance. Foraging peoples may carry all of their belongings. Carrying devices, from fanny-pack to tumpline, seem to be a ubiquitous category of elementary technology. Data on apes carrying objects, either food or raw materials, are sparse, and no quantitative study has been done. Chimpanzees carry hammerstones between nut-cracking sites and fishing probes between termite mounds, over distances of tens of meters. No data are available on wild populations of other species of apes. When travelling quadrupedally and terrestrially, African apes transport objects in their knuckle-walking hands, mouth, or between the shoulder blades; when travelling arboreally, they carry objects in their groin or shoulder ‘pockets’.

Evolutionary explanations of universal and unique human long-range transport focus on the emergence of bipedal locomotion, which freed the hands to do other things. This correlation of number of limbs used in support or travel with extent of transport of materials is simplistic. Experimental pilot studies suggest that apes (and monkeys) will go bipedal to carry objects, subject to environmental constraints and the nature of the objects.

Long-range transport has a somewhat reified status in hominin evolutionary scenarios; such distances of several kilometers are presented as uniquely significant in hominization. Inference focuses on distance covered from lithic source to place of modification, e.g. knapped assemblage, implying that the hominins set out on one long journey. Equally likely is that stones may have moved that distance over centuries or millennia in countless smaller, random journeys, leading to the same result. Equifinality is a real problem.