ANT 3
Living Primates: Comparing Monkeys,
Apes, and Humans
CHAPTER 7
Our Close Relationship with Great Apes
• The Ebola virus episode of 2014 is a tangible reminder of the
close relationship between the great apes and our species
• 25,000 cases in Guinea, Sierra Leone, and Liberia; 10,000
confirmed deaths.
• Simultaneously, Ebola epidemic outbreak in chimps and gorillas
in Western and Central equatorial Africa. Since the 1990’s, ebola
has reduced the worlds gorilla and chimpanzee populations by
1/3.
• Biological anthropology encompasses the study of primates with a
goal of identifying what in human behavior is general to primates,
what is restricted to a few kinds of primates and humans, and what
is uniquely human.
“today, between 250 and 300 species live in mostly tropical and
subtropical regions of the Americas, Africa, and Asia”
Being Primate and Human
What can studying other living primates tell us about what it means
to be human? Embedded in this larger question are the following
problems:
• What does it mean to be a primate, and why does it matter to anthropology?
• What are the basic patterns of primate behavioral diversity, and under what
conditions did they develop?
• How do behavior patterns among monkeys and apes compare with humans?
• What can studying monkey and apes really illustrate about human distinctiveness?
There is a wide array of possibilities involved in being a primate and
no single primate provides a totally adequate model for human
evolution or behavior. After he published his book The Descent of Man in 1871, which explains human origins
in terms of natural selection, the satirical magazine The Hornet published this caricature
called “A Venerable Orang-outang.” Darwin’s evolutionary theory, and especially his book,
insisted that humans and apes had common ancestors, which provoked widespread social
outrage.
What does it mean to be a primate, and why does it
matter to anthropology?
• “Primate” derives from the Latin word for “of the first rank,” implying that these creatures are a higher order than other life forms.
• They share a common ancestry that split from other mammals some 65 million years ago.
• “social mammals with grasping hands, bony and enclosed eye sockets, and relatively large brains”.
• Humans are not monkeys, nor did we evolve from them. But, we are both primates.
Key Characteristics
• Manual dexterity: Primates are able to live in a wide variety of environments and make use of many different resources, which manual dexterity supports.
• Adept and skillful with hands, and in some cases, feet.
• Having 5 individually moving fingers involving an opposable thumb, as well as large toes, allows for fine movements.
• Visual acuity: Primates have excellent vision and are not as reliant on smell as other animals. Their eyes face forward and are close together, and each eye captures its own information, creating stereoscopic vision, or three-dimensional vision with depth perception.
Shared Characteristics
Other shared characteristics include:
• general intelligence, which is related to a larger brain size;
• locomotive flexibility and a collarbone which provide greater mobility;
• longer gestation times and childhoods which often involves training to live in
complex social groups.
Primate Suborders
Taxonomists identify two suborders in the order Primates:
1. Strepsirrhines, consisting of prosimians (lemurs, galagos, and lorises).
2. Haplorrhines, which includes all species of tarsiers, monkeys, apes, and
humans.
Primate Suborders: Strepsirrhini
• There are two groups of Strepsirrhini, or prosimians: lemurs and a group that includes the lorises and galagos.
• Strepsirrhines have smaller body sizes than other primates, a smaller brain- to-body- size ratio (still larger than most other mammals), and a keener sense of smell (olfaction) than other primates.
• Most Strepsirrhines are arboreal (living in the trees) and nocturnal (active at night)
Ringtailed lemurs (Photo: Paul Maguire/Shutterstock)
Shown are slender loris (A); indri with young (B); adult male crowned lemur (D);
ring-tailed lemurs (D).
A
B
C
D
Primate Suborders: Haplorrhini
• There are two infraorders of Haplorrhini:
• Tarsiiformes (tarsiers) and Simiiformes (include 3 superfamilies or anthropoids: Ceboidea, or monkeys of the Americas, Cercopithecoidea, or Asian and African monkeys, and Hominoidea, or apes and humans, or hominoids)
• Haplorrhines have larger bodies and larger brain-to-body-size ratios, lack a wet nose, and have more brain devoted to vision than olfaction. They show greater diversity in lifeways (tree-living,
ground living, and a mix of both), so their skeletons are more varied.
Philippine tarsier (Photo: Cgaa/WikiCommons/CC BY 3.0)
Tarsiers, Ceboidea, and Cercopithecoidea
• Tarsiers are found in Southeast Asia.
• Small-bodied, nocturnal, possess extreme leaping abilities, and live in small groups.
• Large eyes (whose combined weight is larger than their brain!) facilitate movement in dense forests at night.
• Ceboidea, or New World Monkeys, range from Southern Mexico to Southern Argentina.
• Most are arboreal, have a prehensile tail.
• Fleshy pad on tip of tail has its own “fingerprint”
• Cercopithecoidea, or Old World monkeys, are found in Asia and Africa.
• Baboons and macaques. Active in the daytime, arboreal and terrestrial (living on the ground).
Hominodiea
African apes (gorillas and chimpanzees), Asian apes
(orangutans and gibbons) and humans
• All except gibbons have large bodies and brains.
Apes and humans don’t have tails but have adaptations in
the upper body permitting full rotation of the arm and
greater hand movement, allowing them to hang and swing
among branches.
• The initial adaptation for swinging from limb to limb (so-
called brachiation) eventually led to bipedal walking,
unique to the human lineage.
Chimpanzee (Photo: Dean
Pennala/Shutterstock)
Primates and Anthropology
• Primate studies within anthropology began in the
1950s.
• Early thinking held that human social behavior evolved
from primates
• Biological anthropologists helped create primatology
as an interdisciplinary field.
• Anthropologically-specific approaches to primates are
often approached through study of living primates as a
window into the evolution of social behaviors among
humans.
What Are The Basic Patterns Of Primate Behavioral
Diversity, And Under What Conditions Did They
Develop?
In creating a comparative baseline for understanding humans, anthropologists look for three kinds of behavioral patterns in primates:
• primate-wide trends
• hominoid-wide trends
• unique human characteristics
**Understanding these might ultimately help us begin to
understand what it means to be human**
Common Behavioral Patterns
Primates share a number of common
behavioral patterns, all of which are connected
to the requirements of living in groups and
negotiating social relationships.
• Mother-Infant bond
• Affiliation and grooming
• Dominance hierarchies
• Dispersal
• Cooperation and conflict
Basic Primate Grouping Patterns: Many of the primate
behaviors observed are closely related to the demands
of living in groups.
All connected to the requirements of living in groups and
negotiating social relationships
Mother-Infant Bond
• The mother-infant bond is a long period of infant dependency.
• The infant relies totally on others for its nutrition, movement, regulation of body temperature, and protection from predators.
• Mothers and other relatives have a clear evolutionary interest in ensuring the offspring will reach maturity.
• Caregiving is a learned behavior, gained through individual experience and observations of how
other group members handle infants.
Grooming
• Primates create affiliations and avoid agonism through
grooming: touching another individual to remove dirt,
insects, and debris, usually as a way for individuals to
bond.
• When conflicts erupt, primates engage in grooming
behavior to reduce stress.
• Affiliation: a relationship between individuals who are
frequently in close association based on tolerance, even
friendliness.
• Agonistic relationship: exists where individuals are in
conflict with each other.
Dominance Hierarchy
Dominance hierarchy: the ranking of access to desired
resources by different individuals relative to one another.
Often the hierarchy is obvious, and an “alpha animal”
has priority over other members of the group.
• Sexual Dimorphism
Dominance is a social role, not an inborn trait, which an
individual occupies for a period in their life.
• Males are often dominant over females, but in some
circumstances females are dominant over males.
Dispersal
The life cycle of a primate involves several main
stages:
• growth and development;
• reproductive maturity;
• old age and death.
As they enter reproductive maturity, selected
members leave the group, referred to as dispersal: a
pattern of one sex leaving the group they were born
into about the time of reproductive maturity.
Cooperation and Conflict
• It is rare for primates to spend much time alone, and social relations are maintained
through cooperation.
• Because dominance hierarchies exist conflicts do occur.
• Reconciliation is the act of repairing relationships damaged through conflict by sharing,
embracing, or other acts of post conflict physical contact.
Primate Behavioral Diversity is thought to be the
result of sociological pressures:
• Nutrition - the pressure to obtain key dietary items affects how and
where a primate will find its food.
• Locomotion – primates are arboreal, terrestrial, or both but these is a
lot of variability between and within species in terms of locomotion.
• Predation - avoiding predators is one reason for group living. The
more individuals in a group, the lesser odds of being eaten. Predator
detection also increases.
• Competition – access to key resources results in differential
behaviors.
How Do Behavior Patterns Among Monkeys
Compare With Humans?
Commonalities
• The existence of mixed groups of males and females; social interactions around kin relations
• Widespread dispersal based on remarkable adaptability
• Similarities in dominance hierarchies, including how we establish and maintain them
• Both species are able to survive in diverse habitats
Differences
• Significantly different body morphologies
• How we mover around through locomotion
• The size of our brains
• The scale and complexity of social organization
• Significant differences between male and female life patterns, which most human societies do not have
How Do Behavior Patterns Among Apes Compare
With Humans?
Commonalities
• Living in community.
• Division into subgroups and types of relationships between individuals in
communities are similar
• Male-to-male bonding in aggression contexts, social use of sex, hunting
• Sexual aggression, mate guarding, and aggression between communities might
superficially seem like rape, marriage laws, and war in humans
Yet significant questions about social patterns yield different possibilities:
• Some patterns are analogous: similar in appearance or function, not the same.
• Some patterns are homologous: similar due to shared ancestry
• Some patterns are not even comparable because they are totally distinct behaviors.
What Does Studying Monkeys And Apes Really
Illustrate About Human Distinctiveness?
Claims of morphological, genetic, and behavioral terms have proliferated.
• Ex. Primatologist Frans de Waal observed, “just like us, monkeys and apes strive for power, enjoy sex, want security and affection, kill over territory, and value trust and cooperation”, “they can recognize themselves in mirrors, and use sign language”, and use sophisticated problem-solving skills”.
Different disciplines answer this question differently.
• It is more than just a descriptive problem, or listing behavioral characteristics, checking off similarities and differences. Rather, a holistic and comparative anthropological approach is needed.
Do Non-Human Primates have Culture?
• The idea that nonhuman primates have “culture” has become more popular.
• Some non-human species of primates exhibit patterns of behavioral variation across groups which are not reducible to genetic or to ecological factors.
• Use of the term “culture” to describe these behavior patterns is controversial.
• There is a tendency to reduce culture to socially- transmitted learning.
• Reducing culture to social transmission of behaviors and variation across groups vastly oversimplifies the
role of language and symbolic abstraction in culture.
Human Distinctiveness
• Most of human evolutionary history has involved humans living in small groups of mostly genetically-related individuals, cooperating together in foraging, defense, and raising the young.
• About 2 million years ago, these early humans began moving out of Africa and encountered new environmental challenges.
• To meet those challenges, those humans relied on tools and basic forms of social cooperation and alliances.
Anatomically-Modern Homo sapiens
Anatomically-modern Homo sapiens usher in radically different social behavior.
• Size of human social groups grow, becoming more sedentary.
• Divisions of labor create new social roles.
• Agriculture enables population growth and environment change
• Cultural differences between groups increases.
Although certain elements resemble primates, no single primate exhibits them all.
No primate species mediates these relationships and behaviors so thoroughly through culture.