Final answer:
Eocene primates exhibited increased vision, a reduced sense of smell, and larger brains compared to their Paleocene ancestors. These changes were adaptations to an arboreal lifestyle and indicate a shift from olfactory to visual sensory reliance.
Step-by-step explanation:
Eocene primates differ from Paleocene primates in several ways, including increased vision, reduced sense of smell, and having a larger brain. These adaptations are related to the requirements of an arboreal lifestyle, where good vision is crucial for navigating through the trees, and a larger brain helps with processing the complex sensory inputs and motor behaviors required for this environment. The reduction in the sense of smell reflects a shift in sensory reliance from olfactory to visual cues. As a result, Eocene primates also possessed traits such as color vision, forward-facing eyes for stereoscopic vision, modified nails instead of claws, and a more upright body posture, all suitable for arboreal life. Over time, these traits supported the evolutionary success of primates.