
It is well-known that chimpanzees can fashion and make tools to obtain food. Now, a new study has found that humanity’s closest cousins also know how to choose the best materials for making tools.
A team of scientists from the Max Planck Institute for Evolutionary Anthropology, the Jane Goodall Institute in Tanzania, the University of Algarve and the University of Porto in Portugal, and the University of Leipzig found that chimps use plant material that is more flexible to fashion tools and fish out termites.
Lead researcher Alejandra Pascual-Garrido, Research Affiliate at the School of Anthropology and Museum Ethnography, University of Oxford, used a portable mechanical tester to measure the force required to bend the plant materials used by chimpanzees in Gombe Stream National Park in Tanzania. She also measured materials never used by the chimps to fish out termites, which are a good source of energy, fat, vitamins, minerals and protein for the great apes.
Pascual-Garrido found that plant species never used by chimpanzees were 175 per cent more rigid than their preferred materials.
Even among plants growing near termite mounds, those that showed obvious signs of regular use by the apes produced more flexible tools than nearby plants that showed no signs of use, a statement by the University of Oxford noted.
Interestingly, this ability to select plant material that is flexible and can bend to fashion twig tools is also found in chimpanzees living up to 5,000 kilometres away from Gombe.
This, according to the researchers, implies that the mechanics of these plant materials could be a foundation for such ubiquitous preferences, and that rudimentary engineering may be deeply rooted in chimpanzee tool-making culture.
The scientists hypothesise that wild chimpanzees may possess a kind of “folk physics” – an intuitive comprehension of material properties that helps them choose the best tools for the job.
“Their natural engineering ability is not just about using any stick or plant that is available; chimpanzees specifically select materials with mechanical properties that can make their foraging tools more effective,” according to the statement.
“This finding has important implications for understanding how humans might have evolved their remarkable tool using abilities,” the statement quoted Adam van Casteren, Department of Human Origins, Max Planck Institute for Evolutionary Anthropology, a specialist in biomechanics and evolutionary biology. “While perishable materials like wood rarely survive in the archaeological record, the mechanical principles behind effective tool construction and use remain constant across species and time,” he added.
Studying how chimpanzees select materials based on specific structural and/or mechanical properties can help researchers better understand the physical constraints and requirements that would have applied to early human tool use, according to the authors of the study.