Final answer:
The skeletal traits of a dorsal scapula and a backward oriented clavicle are adapted for climbing and swinging. These features, along with curved fingers, enhance the climbing abilities and grasping of branches. Evolutionary changes in land animals' skeletal systems, like the rotation of the femur and humerus, also facilitated the transition from water to land.
Step-by-step explanation:
The hominoid skeletal traits of a dorsal scapula and a backward oriented clavicle are adapted for climbing and swinging behaviors, such as those seen in brachiation. This is supported by the fact that primates, especially those adept at these activities, exhibit such skeletal characteristics. The dorsal position of the scapula allows for a greater range of upper arm movement, facilitating swinging through trees, whereas the backward orientation of the clavicle helps in stabilizing the shoulder joint during these movements. The addition of curved fingers indicates an adaptation for grasping branches, further enhancing climbing efficiency.
As an example of evolutionary adaptation, the skeletal structure of terrestrial animals evolved to place limbs under the body. This adaptation, which includes decreased adductor muscle size, an increased range of motion of the scapulae, and a rotation of the femur and humerus to point forward, enabled more efficient movement over land compared to the earlier splayed limb structure which was less energy-efficient.