Primate Studies
So what? The Comparative Approach
Anatomy
Evolutionary Trends
Taxonomy
Primate Studies
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
Apes & language behavior
Koko signing “help!”
Many of these insights are owed to
a number of primatologists.
Jane Goodall (chimpanzees)
Diane Fossey (mountain gorillas)
Birute Galdikas
(orangutans)
F. B. de Waal
( field and zoo
study of bonobos)
Susan
Savage-Rumbaugh
(chimpanzee
Language)
Where does primatology fit into anthropology?
A branch of physical (biological) anthropology…
…but important in psychology, social
psychology, zoology.
Studies of primates can help us:
•better understand the nature of the human body and
mind.
•to see what behavioral characteristics correlate with
intelligence.
The big question as far as
anthropology is concerned is …
…explaining what it is to be human, a
profoundly difficult task.
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 nonhuman primates.
prosimians
monkeys
apes
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.
• Retained traits that other mammal species have lost
over time.
• Some responded to particular selective pressures
and became specialized.
Example
• 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
Evolution of
Primate digits
vs.
Horse hooves
This diagram shows the evolution of horse hind
feet.
a. shows Hyracotherium, from 55 million years
ago.
b. shows Miohippus, from 35 million years ago
c. shows Merychippus, from 17 million years ago
d. shows Equus, the modern horse, with its
single hoof.
Except for some odd characters
Primates can't be easily defined by a few
traits.
• We can see evolutionary trends instead.
1. Limbs and locomotion
2. Dentition
3. Senses and the brain
4. Development
5. Origins from arboreal life
Trends
Limbs and locomotion
• A tendency toward erect posture (primarily upper body)-sitting,
standing, leaping, some bipedalism
• Flexible, generalized limb structure permitting most to use a number of
locomotion behaviors
• Retention of some bones (clavicle) and certain abilities (forearm
rotation) lost in specialized mammals
• Hip and shoulder morphology allowing wide range of movement such
as knuckle walking, brachiation, bipedialism
Locomotion forms
Brachiation
Bipedalism
Knuckle walking
Laetoli, Tanzania, c. 3.5 3.8 million years ago
Hands & Feet (& tail?)
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
Teeth
Lack of dietary specialization
Omnivorous
Carnivorous
Frugivorous
Diet and teeth—cutting, tearing, grinding
The dental formula is the
quantity of each type of tooth
(incisor, canine, premolar,
and molar) in each quadrant
of the mouth, counting from
the front.
The human dental formula is
2.1.2.3.
The Old World monkeys and
apes also share this dental
formula.
Primates have 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
•binocular vision-both eyes set toward
front of head
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!)
Development
• 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