ANTH 1210: Living Primates

• The living primates are the subject of lectures 14 & L15 on February 10 and 12, 2025 for ANTH 1210 A01.

Shared Traits in Mammals

• Mammals give birth to live young.
• Mammals produce mother’s milk to feed their young.
• Mammals have a long period of dependence on their parents.
• Mammals learn through play.

Defining Primates: Shared Physical Traits

• Primates have a unique combination of physical traits.
• Primates are adapted to arboreal living.
• Primates have prehensile hands and feet.
• Primates have an opposable thumb.
• Primates have flexible arm movement.
• Primates have specific upper and lower limb bones.

Shared Physical Traits: Diet and Senses

• Primates have an omnivorous diet.
• Primates possess teeth adapted for a varied diet.
• Primates have forward-facing eyes.
• Primates have stereoscopic and color vision.
• Primates have a larger brain size in comparison to body mass.

Primate Reproduction

• Primates typically have one to few offspring per birth.
• Primate infants are born helpless and require extensive care.
• Primates take a longer time to reach sexual maturity.
• There is a potential trade-off between offspring quantity and development.

Dependency and Play

• Primates have a long period of dependency.
• A strong mother-infant bond is crucial for primate development.
• Play is important for developing physical and social skills in primates.
• Primates engage in learning behaviors.
• Primates use imitation as a means of learning.
• Primates show capacity for independent learning.
• Primates display deliberate teaching behaviors.

Social Features: Communication

• Primates use referential communication, where a sound is associated with an object or event.
• Primates communicate through semantic communication.
• Symbolic communication is shown by primates.
• Symbolic communication is where meaning is without a referent and arbitrary.
• Primate communication primarily operates through a closed system.

Primate Classification

• Primate classification considers clade approach
• Primate classification accounts for derived versus ancestral traits.

Primate Classification: Strepsirrhini

• Strepsirrhini are mammal-like primates.
• Strepsirrhini have longer snouts.
• Strepsirrhini have a rhinarium
• Strepsirrhini rely on olfaction.
• Strepsirrhini have mobile ears.
• Strepsirrhini have grasping hands, a primate trait.
• Strepsirrhini have stereoscopic vision, a primate trait.

Strepsirrhini: Lemurs, Lorises, Galagos

• Strepsirrhini includes lemurs, lorises, and galagos.
• In Strepsirrhine societies, females dominate social groups.
• Strepsirrhini are not sexually dimorphic.
• Strepsirrhini typically have a vegetarian diet, supplemented with insects.
• Strepsirrhini are quadrupedal in their locomotion.
• Strepsirrhini engage in vertical clinging and leaping.

Primate Classification: Haplorrhini

• Haplorrhini includes humans, apes, and monkeys.
• Haplorrhini have rounded braincases.
• Haplorrhini have better vision, and no rhinarium.
• Haplorrhini have reduced, non-mobile ears.
• Haplorrhini have relatively small, flat faces.
• Haplorrhini possess a more fully formed placenta.
• Haplorrhini have highly dexterous hands.

Tarsiers

• Tarsiers are nocturnal and arboreal.
• Tarsiers are insectivores.
• Tarsiers belong to the Haplorrhines.
• Tarsiers have eyes in bony orbits without a tapetum lucidum.
• Tarsiers are vertical clinger leapers similar to lemurs.

Platyrrhines: New World Monkeys

• Platyrrhines are New World Monkeys which have three premolars.
• Some Platyrrhines possess a prehensile tail
• Platyrrhines have an arboreal lifestyle.
• The dentition formula of Platyrrhines is 2.1.3.3/2.1.3.3.
• Marmosets and tamarins are a type of Platyrrhine.
• Cebids, such as capuchins, is a type of Platyrrhine.

Catarrhines: Cercopithecoids

• Catarrhines include arboreal - Colobine Monkeys and terrestrial - Baboons.
• The dental formula of Catarrhines is 2.1.2.3.
• Catarrhines’ group size is variable, male dominated, and they have few offspring.
• Baboons are Terrestrial.
• Baboons are sexually dimorphic and live in female troops.

Hominioids

• Hominoids includes apes (Hylobates, Pongids) and Humans (Hominins).
• Hominoids have larger brains.
• Hominoids have greater flexibility.
• Hominoids have longer limbs.
• Hominoids have a short, broad trunk, and no tail.

Hominoid Dentition

• Hominoids possess flat and rounded teeth with a Y-5 pattern
• Hominoids have Canine diastema.

Hominoids: Hylobates

• Hylobates are brachiators
• Hylobates have small body size and weight.
• Hylobates are frugivores.
• Hylobates live in small family units.
• Hylobates express little sexual dimorphism.

Pongids: Orangutans

• Orangutans are arboreal.
• Orangutans are frugivores.
• Orangutans are sexually dimorphic.
• Orangutans are Socially solitary.

Pongids: Gorillas

• Gorillas are quadrupeds, and knuckle-walkers.
• Gorillas eat and sleep in trees.
• Gorillas structured with a dominant male that serves as a protector.
• Gorillas have flexible membership.

Pongids: Bonobos and Chimpanzees

• Bonobos and Chimpanzees organized in stable, female centered groups.
• Bonobos and Chimpanzees are Quadrupedal and bipedal
• Bonobos and Chimpanzees have a diet of: Frugivore, with some meat
• Bonobos and Chimpanzees live in Highly social, large groups
• Chimpanzees live in fluid groups.

Primate Adaptations: Body Size and Ecology

• Small body size primates are typically nocturnal, arboreal, and frugivorous.
• Being fast moving in trees requires low body size and weight.
• Fruit sugars provide high energy.
• It’s easier to move around at night.
• Large body size primates are typically diurnal, terrestrial, and vegetarian.
• Slow moving terrestrial animals require large body size.
• Vegetarian diet means a poor quality with large guts to process vegetation.
• Being active during day, living in large groups provides protection.

Primate Adaptations

• Increase in brain size relative to body size is a primate adaptation.
• Frugivores tend to have larger brains.
• An ability to remember where and when fruit is produced is beneficial.
• Having a Group size variable is a primate adaptation.
• Safety in numbers is important.
• Smaller group number when feeding at night, larger number when feeding in the day

Hominins: Homo sapiens

• Hominins such as Homo sapiens are bipedal.
• Hominins possess a dish-shaped pelvis.
• Hominins have straight lower limbs.
• Hominins feet are not prehensile.
• Hominins possess hands that are dexterous.
• Hominins have no large teeth or claws

Hominins: Homo sapiens - Unique features

• Hominins have a large complex brain,
• Hominins have a large cerebral cortex.
• The cerebral cortex is responsible for thinking and spoken language.
• Humans have a lowered larynx, for speaking.
• Hominins dentition reflects an omnivorous diet
• Hominins incisors and canines have similar size and shape
• Hominins have no spaces between their teeth

Hominins: Homo sapiens - Learning & culture

• Learning through culture is key for Hominins
• Tool use by greater apes is considered culture.
• Chimpanzees termite sticks
• Chimpanzee engaging in ‘planning’ and tool use
• Chimpanzees cracking seeds open with two rocks

Models for Understanding Hominin Behavior

• Understand hominin through Homologous vs Analogous traits
• Use a trait from common ancestor vs trait independently derived in two primates to understand hominin.
• Understand hominin behavior through using Living primate behavior as model
• Understand hominin through Ethnographic analogy
• Non-Western traditional societies
• Limitations exist
• All cultural groups have own qualities
• It’s NOT always reflective of a universal pattern