Psychology and Neuroscience Seminar – Dr. Alejandra Pascual-Garrido
The School of Psychology and Neuroscience is hosting a seminar presented by Dr. Alejandra Pascual-Garrido from the University of Oxford.
Dr. Pascual-Garrido’s seminar is titled: ‘Living archaeology: Reconstructing technological behaviours from chimpanzee material records’.
Archaeological evidence of how early humans selected and used raw materials for stone tools informs us about the evolutionary origins of human technology. However, organic materials, especially from plants, that likely were used by our ancestors, hardly ever preserve. Thus, significant amounts of information about the origins of human technology remains invisible in the archaeological record. Studies of chimpanzee technology can provide valuable comparative insights. This study pioneers the use of traditional archaeological methods to study the use of plants associated with termite-fishing technology in three different populations of wild chimpanzees living in environments equivalent to early hominin habitats. Source plant species, raw material types, and locations relative to targeted termite mounds were recorded for populations at Gombe, Issa, and Mahale in western Tanzania. Chimpanzees behaved similarly in that they selected material from the immediate vicinity of termite mounds but also from further away, preferred certain plant species to make tools, and reused sources of raw material. However, compared to Gombe and Mahale, chimpanzees in the drier and more open habitat of Issa not only procured more raw material (plant parts) per individual plant, but also, the distance of the source plant to the targeted mound was a significant predictor of the number of times a source was used, with sources located further away used significantly less. These disparities are likely caused by environmental differences, in that Issa chimpanzees try to save transport-distance costs between material selected for tools and the location of tool use sites (termite mounds) in what is a comparably more open habitat, with less suitable sources near mounds. Apart from the influence of the habitat, Issa and Mahale chimpanzees preferred bark as tool material, while Gombe chimpanzees used various materials – differences that potentially reflect cultural variants. This study highlights how archaeological methods can reveal “invisible” aspects of technological behaviours. Albeit the “archaeology of the perishable” is still in its infancy, it may ultimately improve reconstructions of organic-based tool use in our ancestors.