Chimps \'r\' not us: anatomic locomotion differences (Introduction)

by David Turell , Tuesday, March 20, 2018, 18:12 (2441 days ago) @ David Turell

Apes and chimps knuckle walk because of their heavy shoulder arm size for climbing. We walk upright in part because of our springy arched feet:

https://phys.org/news/2018-03-humans-knuckle-walkers.html

"Researchers at Case Western Reserve University have cracked the evolutionary mystery of why chimpanzees and gorillas walk on their knuckles: The short explanation is that these African apes climb trees and they are mobile on the ground.

"Their bodies—more specifically, their hands—represent a compromise adaptation allowing both forms of travel.

***

"Latimer said much of the research ties anatomy with its relationship to Newton's laws of motion: For every action, there is an equal and opposite reaction.

"'When you walk, there's a reaction from the ground pushing up," he said. "Chimps and gorillas are large bodied animals and, as a consequence, they have trouble dissipating all that ground reaction energy."

"This is especially true given the anatomical adaptations they have for climbing, Latimer said.

"'In running humans, these reaction forces, can be multiples of body weight on a single supporting foot," he said. "That's why we have a uniquely human adaptation the arch in our foot—it's a shock absorber."

"This also why the old saw rings true that people with flat feet can't join the infantry, Latimer said. "Without the shock absorbing properties of the arch, long marches would result in damage to the bones of the foot and ankle."

"In chimps and gorillas, climbing adaptations don't allow them to walk upright. They have long arms, short legs, stiff backs and cone shaped torsos.

"Their triangle-shaped torsos allows for better rotation at the shoulder which also serves as a shock dissipater during knuckle walking, according to the research. In addition, chimps and gorillas also utilize their forearm muscles for climbing and for impact absorption when on the ground.

"'Clearly, when humans stood up, we completely forfeited the use of our upper limbs for locomotion," Latimer said."

Comment: To because us in six million years it took enormous changes with a series of beneficial mutations in rapid sequence. Obviously it required design.