Primate Studies 1

I. What fascinates us about non-human primates?

Their apparent similarity to us physically: little "people."
Their apparent similarity to us behaviorally.

Our studies of non-human primates have changed the ways we see ourselves, especially

tool using and tool making behavior
ape language behavior

Many of these insights are owed to a number of primatologists, especially those who did field studies
Some famous primatologists: Jane Goodall (chimpanzees), Diane Fossey (mountain gorillas), Birute Galdikas (orangutans), F. B. de Waal ( field and zoo study of bonobos), Susan Savage-Rumbaugh, Roger Fouts and Eugene Linden (ape language)

II. Where does primatology fit into anthropology?

Primatology is a branch of physical (biological) anthropology, but important in many other fields such as psychology, social psychology, zoology
Studies of primates can help us better understand the nature of the human body and mind. For example, before our ancestors became biped walkers we were brachiators like some apes. Before that, we were arboreal quadrupeds like some monkeys. Knowing something about how monkeys and apes move around can tell us something about what life was like for our ancestors.

In terms of mental phenomena the non-human primates offer us a spectrum from lemurs, which are about as intelligent as a dog, to chimpanzees, which are more intelligent than anything other than a human.

This allows us to see what behavioral characteristics correlate with intelligence and allows us to investigate the nature of learned behavior. At a minimum, we can assume that anything a non-human primate can do, a human can do better. But, this may be an anthropocentric view

What physical anthropology is actually faced with is explaining what it is to be human, a profoundly difficult task. There are many avenues to answers about our humanity, and our approach here will be biological, in one sense, but quite cultural in another.
We find ourselves at that special place where anthropology always finds itself-in questions of nature versus nurture.

II. The comparative approach

Primatology gives us one of the few ways to have a biological comparative perspective.
To gain an understanding of any organism, it is necessary to compare its anatomy and behavior with other closely related forms.

Helps us to describe and explain significance of physiological and behavioral systems as adaptive responses to various selective pressures as our species evolved.

For humans this comparative perspective works best with non-human primates.

There are approximately 190 sepcies of non-human primates

prosimians
monkeys
apes

III. Physical Characteristics of primates Prosimians evolved before anthropoids. Don't confuse this as some do with an idea that prosimians "progressed" into anthropoids. There is no implied "superiority" of one form over another. They simply adapted to have characteristics that allowed them to live in particular habitats. All the groups we'll talk about are physiologically and behaviorally successful in evolutionary terms. Nor should you think of any primate group as the final evolutionary stage of a primate lineage. They are continually evolving. The only "final stages" are those that are extinct!

All primates have remained quite generalized, retaining many mammalian traits that other mammal species have lost over time. Some responded to particular selective pressures and became specialized. --Horse and cattle hooves as reduction of the number of digits as an example whereas primates keep the five digit pattern allowing more types of locomotion and ability to manipulate objects

This means that primates can't be easily defined by a few traits--we can see evolutionary trends instead.

IV. Trends

Limbs and locomotion
- tendency toward erect posture (primarily upper body)-sitting, standing, leaping, some bipedalism
- Flexible, generalized limb structure permitting most to use a number of locomotion behavior--retention of some bones (clavicle) and certain abilities (forearm rotation) lost in specialized mammals, as well as hip and shoulder morphology allowing wide range of movement such as knuckle walking, brachiation, bipedialism
- Hands and feet are prehensile (grasping)
  - Five digits on hands an feet, but some show diminished thumb and second finger
  - Partially opposable thumb and most have fully divergent , partly opposable big toe
  - Nail instead of claws (except some New World monkeys)
  - Tactile pads with nerves at ends of fingers to enhance touch sense
Diet and teeth
- Lack of dietary specialization
- Generalized dentition
Senses and the brain
- Color vision -all diurnal have it, nocturnal don't
- Depth perception-stereoscopic vision allows to see in three dimensions comes from:
  - binocular vision-both eyes set toward front of head
  - visual information from each eye transmitted to visual centers in both hemispheres of brain-In most nonprimate mammals optic nerve fibers mostly cross to opposite side through structure at base of brain. In primates about 40% remain on each side.
  - visual information is organized into three-dimensional images by specialized brain structures-need input from both eyes to both hemispheres and from overlapping visual field
- Decreased reliance on sense of smell (olfaction) - reduction in sensory areas of brain and in snout
- Expansion and increasing complexity of brain-visual areas and areas having to do with hands (humans especially!)
Maturation, learning and behavior
- More efficient fetal nourishment, longer periods of gestation, smaller numbers of offspring (a single birth norm), delayed maturation, extension of whole life span
- Greater dependence on flexible, learned behavior-greater parental in offspring
- Tendency to live in social groups and permanent association of adult males with the group (most tend to associate at least with offspring), male association uncommon in all but primates
- Tendency for diurnal activity patterns

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