Final answer:
Primates are adapted for an arboreal lifestyle with rotating shoulder joints, opposable thumbs and big toes for gripping branches, stereoscopic vision for depth perception, larger brains, and some with prehensile tails for additional grasping ability.
Step-by-step explanation:
Primates exhibit various characteristics indicative of their adaptations to an arboreal lifestyle. These include rotating shoulder joints that support swinging through trees, the opposable thumbs and big toes (except in humans) for grabbing branches effectively, and stereoscopic vision for precise depth perception. Primates have also evolved larger brains compared to most mammals, flattened nails in place of claws, a reduced rate of reproduction typically resulting in a single offspring per pregnancy, and a tendency to maintain an upright body posture.
All of these features facilitate locomotion in arboreal environments by enhancing their ability to navigate, grasp, and balance among the treetops. Even though not all modern primates are strictly tree-dwellers, their morphology bears the hallmarks of their tree-adapted ancestors with prehensile tails in some species like spider monkeys. These traits combined make primates uniquely equipped for life above ground.