Catarrhine Locomotion

Abstract

Bipedal Locomoting using only hind limbs for support and propulsion. Brachiation Below branch, handover hand suspensory locomotion, where body weight is supported by the forelimbs. This is also sometimes known as "arm-swinging." Bridging Crossing a gap in the canopy where contact with one support is maintained while contact is made with another. Climbing Progression up a vertical or nearvertical support Digitigrade A locomotor posture where the mass of the forelimb is supported by the digits and metacarpal heads of the hand. The palm does not contract the substrate. Knucklewalking A form of quadrupedal locomotion where the mass of the forelimb is supported by the second to fifth middle phalanges of the hand. Leaping Propulsion, primarily by the hind limbs, as a means of crossing gaps in the canopy. Palmigrade A locomotor posture where the palm and fingers of the hand contact the substrate, which is either ground or branch. Quadrupedal Locomoting using all four limbs for support and propulsion. Above-branch quadrupedalism is progressing by walking or running on top of tree branches, with terrestrial quadrupedalism on the ground. Scrambling An above or below branch progression in which each limb grasps a different support.

Insights into human evolution from 60 years of research on chimpanzees at Gombe

“…Savanna monkeys show the least obvious degree of genetic adaptation, with bodies closely resembling those of their cousins, the forest guenons (Cercopihtecus spp. ; Selby, 2018). Patas monkeys have evolved long limbs and fleet bodies like greyhounds, enabling them to flee predators and travel efficiently among widely dispersed food resources (Selby, 2018).…”

“…; Selby, 2018). Patas monkeys have evolved long limbs and fleet bodies like greyhounds, enabling them to flee predators and travel efficiently among widely dispersed food resources (Selby, 2018). Baboons have evolved large body size and broad diets, but are also highly selective feeders (Barton & Whiten, 1994), and are the most widely distributed of African primates, besides humans.…”

“…One likely factor is that monkeys were already well adapted to quadrupedal locomotion. When in trees, they walk quadrupedally along the tops of limbs (Selby, 2018). Apes, in contrast, have evolved an orthograde posture for feeding and climbing (Selby, 2018).…”

“…When in trees, they walk quadrupedally along the tops of limbs (Selby, 2018). Apes, in contrast, have evolved an orthograde posture for feeding and climbing (Selby, 2018). Adaptations for manoeuvring their large bodies in trees have made apes inefficient quadrupeds on the ground.…”