Non-human primates are a very diverse order of mammals that includes lemurs, tarsiers, new
world monkeys, old world monkeys, and apes. Primates are descended from tree-dwellers and
can be found in most parts of the world. Many of the adaptations and related traits of non-human
primates have evolved from or to dwelling in arboreal environments. Primates have an increased
reliance on vision and a decreased reliance on their senses of smell and hearing. There are
several physical adaptations that support this including forward facing eyes, binocular vision,
true depth perception, large eyes relative to body size including a large occipital lobe, more
complex eyes completely encircled by bone with a postorbital bar and/or postorbital closure, and
most see in color. Primates also have great manual dexterity and flexibility with prehensile
hands and feet. Prehensility provides the benefit of being able to have generalized locomotion,
and to manipulate things in their environment to assist in feeding, grooming, and defense. Their
