Arboreal theory and feet that were capable of grasping. This was also a result of arboreal life, which required a great deal of crawling along branches, and reaching out for fruit and other food. These early primates were likely to have eaten foods found in trees, such as flowers, fruits, berries, gums, leaves, and insects. They are thought to have shifted their diets towards insects in the early Cenozoic era, when insects became more numerous. Arboreal theory This theory is proposed by Grafton Elliott-Smith (1912) who was a neuroanatomist who was chiefly concerned with the emergence of the primate brain. The arboreal
Sexual dimorphism in non-human primates to the likelihood of higher vulnerability to predators. Another hypothesis suggests that arboreal primates have limitations on their upper body size, given that larger body size could disrupt their usage of terminal branches for locomotion. However, among some species of guenons ("Cercopithecus"), arboreal blue monkeys ("C. mitis") appear to be more sexually dimorphic than terrestrial vervet monkeys ("C. aethiops"). It has been hypothesized that niche divergence between the sexes attributes to the evolution of size dimorphism in primates. Males and females are known to have different preferences for ecological habitat due to different reproductive activities, which could possibly lead to