MONDAY, 9 APRIL 2012
An international team of researchers studying wild chimpanzees in Kyoto University’s “outdoor laboratory” in Bossou forest found that the animals spent more time walking upright when faced with competition for limited resources. The researchers provided the chimps with varying quantities of two types of nut: palm oil nuts, which are always readily available in the animals’ habitat, and coula nuts, which are not. When only palm oil nuts were supplied the chimps spent most of their time on all fours. However, when highly prized coula nuts were introduced, the number of incidences of upright walking increased four-fold as the chimps tried to carry away as many of the nuts as possible.
Over time, selection for two-legged prowess may have led to the evolution of a distinct bipedal species. As Dr Brian Richmond, one of the authors of the study in Current Biology, comments, “Something as simple as carrying – an activity we engage in every day – may have, under the right conditions, led to upright walking and set our ancestors on a path apart from other apes that ultimately led to the origin of our kind.”
Written by Louisa Lyon