Lecture on Primates

Introduction to Primates

• Primates include humans, apes, monkeys, tarsiers, and lemurs.
• They belong to the order Primates within the class Mammalia.
• All mammals are warm-blooded vertebrates with hair and mammary glands.

Characteristics of Primates

1. Brain Size and Intelligence

   • Large brains relative to body size.
   • Humans have the largest brain-to-body mass ratio.
   • Intelligence depends on:
     • Density of neurons in the cerebral cortex
     • Speed of nerve impulse transmission
   • Intelligence ranking: Humans > Apes > Whales/Elephants > Monkeys > Other animals

2. Vision

   • More brain power dedicated to vision.
   • Flattened face with forward-facing eyes for stereoscopic vision.
   • Lemurs are more primitive with longer snouts and better sense of smell.

3. Reproduction and Development

   • Long gestation and developmental periods.
   • Examples:
     • Human: 9 months gestation
     • Mountain Gorilla: 8.5 months
     • Orangutan: 8+ months
     • Black Bear: 7 months
     • Florida Panther: 3 months
   • Development after birth is slower in primates.
     • Humans: Walks after almost a year
     • Wildebeest: Stands within 7 minutes
   • Primate adolescence occurs in early teens.

4. Physical Features

   • Five digits on hands and feet with flattened nails.
   • Old World Monkeys & Apes: True opposable thumbs.
   • New World Monkeys: Grasping hands, less opposable thumbs.
   • Human Feet: Specialized for walking, no opposable digit.

5. Posture and Locomotion

   • Tendency toward upright torso and bipedalism in apes.
   • Humans: Fully developed bipedalism.
   • Apes often use knuckle walking.

6. Shoulder Mobility

   • Primates have mobile shoulder joints allowing rotation in all directions.
   • Most mammals have legs that move in one plane.

Advantages of Primate Features

• Mobility and dexterity help in escaping predators and survival.
• Large brains enhance learning and adaptation capabilities.