1. Primate evolution

3. Characteristics of Primates • Unspecialised mammalian body (good for all habitats) • Unspecialised limb structure: allows greater diversity of use • Pentadactyl: five highly mobile digits • Opposability of the first digit (can touch all other digits) (degree varies) • Most primates have an opposable toe – humans being the exception • Allows for an arboreal lifestyle (in trees) • Precision and power grips

4. Characteristics of Primates • Digits: • Nails instead of claws: allows prehensile hands • Claws limit grasping • Friction ridges (finger prints) for better manipulation • Sense receptors at digits • Decreased importance of smell (olfaction) • Reduction in snout length

5. Dentition • Dental formula: • Primitive mammals – 3:1:4:3 • Lemurs/lorises/New world monkey’s – 2:1:3:3 • Tarsiers – 2:1:3:3 (upper jaw), 1:1:3:3 (lower jaw) • Old world monkey’s/apes/humans – 2:1:2:3 • Diastema: gap between upper incisor and upper canine (allows space for large lower canine) • Cusp molars: • Primitive mammals – 3 cusp • Old world monkeys – 4 cusp • Apes / humans – 5 cusp

6. Increased size of Cerebral Cortex (complex thought processes) • Due to larger brain and more convolutions • Vision, memory, reasoning, manipulative abilities • Allows development of tool making skills

7. Developed reproductive structures / behaviours • Single offspring at a time • Rhythmic sexual cycle (not a season) • Long period of parental care (dependency on parent) • More time to ‘learn’ from parents • Long period of growth and maturation • Longer period of gestation • Delay in development to sexual maturity • Each offspring is particularly valuable (a big investment)