Chimpanzee feet allow scientists a new grasp on human foot evolution

Chimpanzee and man foot

The researchers painted markers on the feet of both humans and chimpanzees in order to figure out how different bones and joints within the foot move in 3-D. Credit: Stony Brook Primate Locomotor Laboratory

Read more at: https://phys.org/news/2017-02-chimpanzee-feet-scientists-grasp-human.html#jCp

Published: February 8, 2017

From: New York Institute of Technology

 

A research paper published in the latest issue of Journal of Human Evolution investigates the evolution of human walking by observing how chimpanzees walk on two legs

 

The paper identifies that the human foot is distinguished from mans closest living relatives the African ape by the presence of the longitudinal arch. This structure is thought to be a critical adaptation for bipedal locomotion, or walking on two legs.

The paper is led by Nathan Thompson, Ph.D., assistant professor of Anatomy at New York Institute of Technology College of Osteopathic Medicine (NYITCOM). Professor Thompson is one of 4 researchers questioning some long-held ideas about the function and evolution of the human foot by investigating how chimpanzees use their feet when walking on two legs.

Using high-speed motion capture to compare foot movement between man and ape, the researchers tested the common theory that the human foot is a rigid lever for standing and walking long distances, and that the chimpanzee’s foot is a grasping device, much more mobile and less effective at walking on two legs. Fossil feet of early human ancestors are nearly always compared with chimpanzee feet, making knowledge of their foot biomechanics crucial for understanding how the human foot evolved. However, prior to this research, no one has been able to actually investigate whether differences existed between humans and chimpanzees in how the foot works during walking on two legs.

The paper concludes that: contrary to expectations, the researchers found that human feet are more — not less — mobile than chimpanzees when walking on two limbs.