ANTHR1: Biological Anthropology
Second Exam – Primate Essays (75 total points)
A. You were to propose a model of the cultural behavior of the earliest hominids AND give the data on which you
based your modeling.
10 points
Answer: Tool making (chimps/bonobos: hunting spears, insect probes, leaves as sponges, stones and wooden
limbs as hammers to crack open nuts, hammer-and-anvil technique; capuchins: hammer-and-anvil, stones thrown
at predators; gorillas: stick to measure water depth); food-preparation prior to eating (macaques: washing sweet
potatoes, winnowing seeds from sand using water floatation; capuchins: sequential steps in getting, preparing palm
nuts); medicine (chimps/bonobos: use of leaves to expel worms, relieve pain resulting from injury); non-estrus
sexual activity (chimps/bonobos: social reasons including bonding, tension relief, political-economic-social gains,
entrance by females into new groups); multi-female/multi-male social groups with dominance hierarchies
(chimps/bonobos, nearly all monkey species); symbolic communication (chimps/bonobos: leaf-clipping/leafgrooming); grooming for non-hygienic purposes (chimps/bonobos: establishing social-political alliances,
perhaps gaining entrance into new groups); passing on of learned traits, most likely via mother to children
(seen in all of the above activities); cooperative hunting that changes with the environment (chimps/bonobos:
baseball vs. football vs individual spearing);
B. Why do anthropologists study non-human primates?
5 points
Answer: To learn about their behavior, especially chimps and bonobos. We want to know about the origins of our
behavior, but behavior doesn’t fossilize. But anthropologists believe that an understanding of primate behavior
today may help us understand the behavior of the earliest humans. That’s because any shared behaviors of
modern primates was in the last common ancestor and thus in the first humans.
C. List SIX physical traits that set primates apart from other mammals.
12 points
Answer: 3-D vision (cud say forward facing eyes with overlapping vision fields); grasping hands; five fingers and
five toes; retention of the clavicle; trunk verticality; fingerprints; tactile pads on the ends of the fingers; fingernails,
color vision, opposable thumbs, large brain-to-body-size ratio; raised ridges on the tips of the fingers (friction pads
on finger tips); eyes enclosed in a bony ring; skeleton that allows opportunistic bipedalism
D. Name 2 physical features of prosimians that easily distinguish them from anthropoids.
4 points
Answer: Prosimians have wet noses, tactile vibrissa (whiskers like a cat’s), long snouts, immobile faces, mobile
ears, many have specialized scent glands, lack post-orbital closure (no body plate behind their eyes).
E. Name one physical feature of American monkeys that easily distinguishes them from all other monkeys. 1 point
Answer: American monkeys have flat noses, with widely spaced nostrils that point to the sides of their face; many
have grasping tails; many have 36 teeth
F. Name one physical feature of all monkeys that easily distinguishes them from all apes.
Answer: All monkeys have tails – no apes have tails.
1 point
G. What is the term used to describe how the original lemur species evolved into more than 30 species?
Answer: Adaptive radiation.
1 point
H. What is the typical social grouping among chimpanzees and bonobos?
Answer: Both are multi-female / multi-male; chimps are male-dominated with an alpha male; bonobos are
egalitarian with an alpha female.
2 points
I. What is (are) the typical social grouping(s) among hanuman langurs?
2 points
Answer: 1 or 2 adult males with many genetically related adult females and their kids; bachelor (male) groups.
How do female bonobos gain entry into a new community? Be very specific in your answer.
4 points
Answer: They watch the new group looking for mid to high ranking females; select one (or more); attempt to have
sex with her (by rubbing her genitals against the other female’s); and if successful, the female will act as the new
comer’s sponsor and take her to the alpha female, with whom the new comer rubs genitals.
J.
K. Name three types of tools that chimpanzees/bonobos use and/or make.
6 points
Answer: spears for hunting bush babies; termite probes; ant wands; leaf sponges; rocks and tree limbs to crack
nuts; bone splinters to extract bone marrow; certain plants eaten only to expel intestinal parasites or lessen pain
due to trauma; roots as anvils (used in cracking nuts); stick wrapped with leaves to sop up water
1
L. What can you tell me about the “medical” behavior of chimpanzees?
Answer: They eat leaves to expel intestinal worms; eat different leaves to alleviate pain due to injuries.
2 points
M. In terms of anatomy, what makes a primate a hominid?
2 points
Answer: Almost anyone of the following skeletal features: foramen magnum directly under the braincase; S-shaped
spine; bowl-shaped pelvis; femurs angled inward (knock-kneed); all toes parallel to each other; no divergent big
toe; two fixed arches in the feet.
N. Briefly describe the inventive behavior of Japanese snow monkeys.
4 points
Answer: Washing sweet potatoes in fresh water (later some monkeys washed them for a second time in sea water);
separated rice grains from sand by water floatation.
O. How did the ancestors of modern day lemurs get to Madagascar?
Answer: Floating on rafts of vegetation
1 point
P. Briefly discuss at least two styles of hunting behavior among chimpanzees.
6 points
Answer: Two cooperative styles and one solo style. One cooperative style (the baseball analogy) is more like a
free-for-all in which the chimps work as a group, but each individual chimp is acting selfishly, hoping to capture a
monkey. Often the alpha male, even if he doesn’t participate in the hunt, will take the kill away from the chimp who
caught the monkey. The other style requires a pusher, blockers and netters, all working out of sight of each other
and each anticipating that the others are doing their jobs. Only those who participate get to share in the kill. The
solo hunting involves chimps sharpening a stick and then using it to “spear” bushbabies while they sleep.
Q. Bonobo females engage in sexual behavior outside of estrus. Briefly explain the reasons for such non-estrus
controlled sexual behavior.
4 points
Answer: By immigrating females in order to gain entrance/acceptance into a new group; establish alliances
(political, social, economic); reduce aggression when encountering scarce resources; friendship; because it “feels
good.”
R. Name at least two functions (other than hygiene) that grooming serves among the primates.
4 points
Answer: Social lubricant; social glue; establish alliances (political, social, economic); friendship; because it “feels
good.”
S. In terms of primate evolution, what two physical traits seem to have been the most important?
Answer: 3D vision; grasping hands.
4 points
EXTRA CREDIT: Describe the inventive behavior of capuchin monkeys.
1 – 4 points
Answer: Sequential Palm-nut acquisition (test for ripeness, remove fibrous outer husk, leave on ground for
several days to dry out, tap to test for ripeness, take nut to stone anvil that has shallow depression, bring round
hammerstone from river to anvil stone, hammer nut til it cracks open); sequential steps to get honey (select a
stone, make a “knife” by banging stones together; cut open top of honey container; insert probe); throwing rocks
at predators; sharing a tool in the hopes of sharing the proceeds of tool-use by another monkey.
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