![]() ![]() Larger areas associated with visual abilities, learning and intelligence Larger areas associated with body control and coordination Social Arboreal Living in trees One adaptation to life in trees is our grasping ability Although some contemporary primates do not live in trees, they retain features inherited from arboreal ancestors Grasping hands and feet Primates have kept the ancestral condition of having 5 digits on each hand/foot The hands and feet of most primates are prehensile (capable of grasping objects) some primates even have prehensile tails Grasping Reflex The Palmar Grasp Reflex appears at birth and persists until 5-6 months of age Nails instead of Claws Nails serve to protect the sensitive skin at the ends of the fingers and toes The nerve endings at the tips of our digits provide primates with an enhanced sense of touch that is useful in manipulating objects Forward Facing Eyes Depth perception is provided by overlapping fields of vision, with both sides of the brain receiving images from both eyes the Result is Binocular Stereoscopic vision In general we see a reduction in dependence on sense of smell and increasing visual abilities among the primates Enclosed eye sockets Haplorhine (Anthropoids + Tarsiers) - Post-orbital closure + Fully enclosed sockets to protect eyes + Diurnal and rely heavily on visual input Strepsirhine (Prosimians - Tarsiers) - Post-orbital bar + Bony bar that runs around the eye socket + mainly nocturnal primates with decreased reliance on visual input Primate brains - Larger than expected for body size Cladistic/Phylogenetic Approach Strepsirhine + Haplorhine S has wet noses and H has dry noses Strepsirhines Prosimians - Tarsiers retained more primitive characteristics Relatively long rostrum (nose) + Postorbital bar + no plate Haplorhines Anthropoids + Tarsiers Relatively short rostrum (nose) + plate separating orbits from temporal fossa Platyrrhines New World Monkeys Round, sideways facing nostrils Catarrhines Old world monkeys + Hominoids (Humans + apes) Narrow, downward facing nostrils Primate Characteristics 1.
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