Bearded capuchin monkeys use joint synergies to stabilize the hammer trajectory while cracking nuts in bipedal stance.

ABSTRACT: The transition from occasional to obligate bipedalism is a milestone in human evolution. However, because the fossil record is fragmentary and reconstructing behaviour from fossils is difficult, changes in the motor control strategies that accompanied this transition remain unknown. Quadrupedal primates that adopt a bipedal stance while using percussive tools provide a unique reference point to clarify one aspect of this transition, which is maintaining bipedal stance while handling massive objects. We found that while cracking nuts using massive stone hammers, wild bearded capuchin monkeys (Sapajus libidinosus) produce hammer trajectories with highly repeatable spatial profiles. Using an uncontrolled manifold analysis, we show that the monkeys used strong joint synergies to stabili

SUBMITTER: Mangalam M 

PROVIDER: S-EPMC6234892 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature