Chapter 6 Flashcards
One key unifying feature of all primates
Forward-facing eyes —> part of the generalized and arboreal adaptation
Primatologists
Scientists who study primates
One of the most impressive characteristics of primates
Ability to adapt to new or changing circumstances —> can live almost anywhere, intelligence, long lives, variable diets, complex social behaviors
Primate inhibit (…)
Every continent except Antarctica and Australia
New World primates live in
North and South America
Old World primates live in
Europe, Africa, and Asia
Practical implications for the study of primates
Advances in medicine (same diseases), clues about the origin of human, study of behavior provides insight into our own behavior
What is a primate
- Arboreal adaptation (adaptation to life in the trees): set of behaviors and anatomical characteristics that is unique among mammals
- Dietary plasticity: the ability of an organism to utilize a wide range of foods in meeting its nutritional requirements
- Parental investment: the I’ve and energy parents expend for their offspring’s benefit
Enormous diversity!
The Tai National Park, Ivor Coast, West Africa
Primate adaptation in microcosm
Generalized skeletal structure
Highly mobile articulations in the should, upper and lower limbs, hands and feet —> great flexibility when living in trees
Enhanced touch
Sensitivity: presence of dermal ridges (fingerprints and toe prints) on the inside surfaces of the hands and feet
The more derived the dermal ridges are, the better the gripping ability is
Enhanced vision
Increased depth perception and seeing in color.
Eyes’ convergence provides significant overlap in the visual fields —> greater sense of depth
Reduced smell
Smaller and less projecting snouts indicate their decreased reliance on smell
Dietary versatility
Teeth 2/1/2/3 dental formula
(Arboreal adaptation) Versatile skeletal structure
Wide range of motion involving the limbs and body trunk
Bones are articulated at highly mobile joints
Opposable thumbs
Thumb that can touch each of the four fingertips, enabling a grasping ability
Longest thumb —> Greatest opposability
Power grip
A fist like grip in which the fingers and thumb wrap around an object in opposite directions
Precision grip
A grip in which the fingers and thumb come together, enabling fine manipulation
Opposable big toes (the halluces)
Enable their feet to grasp things such as tree branches
Humans lack this feature due to their adaptation to life on ground
Body trunk of primates
Backbone has 5 functionally distinct types of vertebrae (cervical, thoracic, lumbar, sacral, cocygeneal): greater range of movements
Body trunk tends to be vertically oriented —> essential to pre adaptation to bipedalism
Pre adaptation
An organism’s use of an anatomical feature in a way unrelated to the feature’s original function
Dermal ridges
Increase the amount of friction, or resistance to slipping, when grasping n objects
Flat nails
Made of keratin
Protect the ends of the fingers and toes, aid in picking up small objects, provide broad support to the ends of the fingers and toes by spreading out the forces generated in the digits by gripping
Enhanced sense of vision - 2 evolutionary developments
- Eyes rotated forward from the sides of the head to the front of the head —> two fields of vision overlapped —> depth perception
- Color vision evolved: nocturnal to diurnal adaptation