INTRODUCTION TO PRIMATES AND PRIMATE TAXONOMY

Taxonomy Each taxon tells us more about that group’s adaptations Makes important biological statements about genetic & evolutionary relationships

Adaptive Radiation The evolution & spreading out of related species into new environmental niches Juramaia sinensis

The Primate Order Diverse and varied order

I. Characteristics of the Order Primates Features that define a distinct “primate way of life” Arboreal adaptations

A. Vision is predominant sense Binocular vision Forward facing eyes Overlapping field of vision Stereoscopic (3-D) vision Depth perception Essential for agility in trees Increased protection of the eyes Color vision Locating ripe fruit Spotting different individuals/predators Reliance on visual communication facial expressions/gestures

B. Reduced sense of smell Reflected by flat faces Progressive shortening of snout Tree shrew Monkey

C. Locomotion/Movement Upright posture Flexible limbs Prehensile (grasping) hands AND feet Five digits on hands and feet Opposable thumb Divergent & partially opposable big toe Enhanced sense of touch from tactile pads with sensitive nerve fibers Nails instead of claws

C. Locomotion, cont. Variety of loctomotive patterns Terrestrial & arboreal quadrupedalism – walking on all fours (primary mode)

C. Locomotion, continued Vertical leaping Jumping Sifaka locomotion Tarsier

Locomotive Patterns, cont. Brachiating – arm over arm swinging from beneath branches Gibbon

Locomotive patterns, cont. Knuckle-walking Occasional bipedalism Bipedal Knuckle-walker Arboreal quadruped

D. Diet & Teeth Generalized dentition – variety of non- specialized teeth Lack of dietary specialization Mostly omnivorous – variety of food (mostly plants/fruit) Dietary preferences, tooth structure varies by species

E. Reproduction Only occurs while female is in estrus = period of sexual receptivity Long gestational period Usually single infant births Distinct life stages Prolonged infant dependency Delayed sexual maturation

F. Behavior & Organization Highly social & intelligent 2. Tendency to live in social groups Mother-infant unit is foundation Greater dependence on learned behavior

G. Communication Use of vocalizations/call systems Alert to danger/threat Location of food source Can USE but not SPEAK language Lack the vocal apparatus necessary to form words Specific genes (Foxp2) involved in spoken language

H. Habitat Primarily arboreal (tree-dwelling) Tropical forests and woodlands Occupy different layers/levels of forest Some terrestrial species (baboons, gorillas)

Forest Layers/Levels

I. Threats to Primates Loss of habitat due to deforestation Hunting (for meat) Poaching Captured for sale Killed for body parts

Why study non-human primates? To decipher evolutionary trends Transition from quadrupedalism to bipedalism Transition from arboreal to terrestrial way of life To use as a basis of comparison Biological development (comparative anatomy) Social development (how our ancestors may have lived) Life in the Trees