ANTH 1101 W2025 Chapter 5

Why Study (Non-Human) Primates

• Humans are classified as primates by Linnaeus (1735) and Darwin (1871).

• Modern studies utilize DNA, morphology, behavior, and fossils for insights.

• Shared characteristics of primates:

  • Grasping hands and developed vision.

  • Long juvenile periods and relatively large brains.

  • Comparable physiological and cognitive structures.

• Reasoning by homology: focuses on similarities in anatomy and behavior due to common ancestry.

Diversity of Primates

• Primates exhibit diversity in:

  • Body size

  • Habitat and diet

  • Social organization

  • Activity patterns

• Evolution influences behavior through reasoning by analogy, addressing adaptations and solutions to evolutionary challenges.

What Is a Primate?

• Common characteristics shared by all primates include:

  • Grasping hands and feet.

  • Nails instead of claws.

  • Hind-limb driven locomotion.

  • Reduced olfaction and enhanced vision.

  • Forward-facing eyes encased in bone.

Primate Characteristics

• Additional characteristics include:

  • Relatively large brains.

  • Long gestation periods.

  • Small litters (commonly one or two).

  • Extended juvenile periods.

  • Long lifespans.

  • Increased dependence on learning and behavioral flexibility.

Primate Dentition

• Primate dental formula comprises:

  • Incisors (I), Canines (C), Premolars (P), Molars (M).

  • Upper dental formula: 2:1:2:3

  • Lower dental formula: 2:1:2:3

  • This uniformity across all primates indicates evolutionary traits.

Primate Distribution

• Geographic distribution of primates:

  • Primarily tropical and forest-dwelling, arboreal animals.

• Modern ranges include:

  • Americas, Africa, Asia.

• Historically included regions such as North America and Europe.

• Homo sapiens are unique in their range, having reached Australia, Greenland, and Antarctica.

Primate Taxonomy

• Not all primates are equally related; the order diverges into two main suborders:

  • Strepsirrhini (strepsirrhines)

  • Haplorrhini (haplorrhines)

Suborder: Strepsirrhini

• Characteristics:

  • 'Twisted nose'—wet nose with rhinarium.

  • Presence of a tooth comb.

  • Tapetum lucidum present for night vision.

  • Dental formula: 2:1:3:3.

• Divided into two infraorders:

  1. Lemuriformes (lemurs)

  2. Lorisiformes (lorises and galagos)

Suborder: Haplorrhini

• Characteristics:

  • 'Simple nose'—dry nose without rhinarium.

  • Inability to produce Vitamin C.

  • Complete orbital plate with no tapetum but possess a fovea.

• Divided into two infraorders:

  1. Tarsiiformes (tarsiers)

  2. Simiiformes (new and old world monkeys and apes)

Infraorder: Tarsiiformes

• Primarily located in Asia.

• Characteristics:

  • Small, nocturnal insectivores.

  • Specialized for vertical clinging and leaping.

  • Lack tooth comb and tapetum.

Infraorder: Simiiformes

• Split into two parvorders:

  1. Platyrrhines (New World monkeys)

  2. Catarrhines (Old World monkeys and apes)

Parvorder: Platyrrhini

• Characteristics include:

  • Flat noses with outward-facing nostrils.

  • Many species have prehensile tails.

  • Found in tropical forests of South and Central America.

• Most Share a 2-1-3-3 dental formula.

Primate Families: Platyrrhini

• Five families within Platyrrhini:

  1. Callitrichidae (marmosets and tamarins)

     • Pair-bonders and cooperative breeders.

  2. Atelidae (howler, woolly, and spider monkeys)

     • Suspensory climbers with prehensile tails.

  3. Cebidae (capuchin and squirrel monkeys)

     • Highly social and omnivorous.

  4. Aotidae (night and owl monkeys)

     • Only nocturnal anthropoid.

  5. Pithecidae (titi, saki monkeys, and uakaris)

     • Diurnal, arboreal, and polygamous.

Parvorder: Catarrhini

• Characteristics:

  • Downward-facing nostrils.

  • Found in Africa and Eurasia.

  • Larger body sizes and diverse habitats compared to Platyrrhines.

  • Distinguishing dental formula: 2-1-2-3.

Superfamilies of Catarrhini

• Two superfamilies:

  1. Cercopithecoidea (Old World monkeys)

  2. Hominoidea (apes)

Superfamily: Cercopithecoidea

• Family: Cercopithecidae

  • Two subfamilies: Colobines and Cercopithecines.

  • Approximately 150 species, located in Africa and Asia.

  • Noteworthy traits include tails and ischial callosities.

Superfamily: Hominoidea

• Also known as Hominoids (apes).

• Characteristics:

  • Generally larger brains, taillessness, and suspensory, orthograde climbing abilities.

  • Dental structure: unspecialized Y-5 molars.

• Two families:

  1. Hylobatidae (lesser apes)

  2. Hominidae (great apes)

Family: Hylobatidae

• Features:

  • Includes gibbons (Hylobates) and siamangs (Symphalangus).

  • Habitat: Southeast Asia.

  • Characteristics include long arms for brachiation, pair bonding, and male parental care in siamangs.

Family: Hominidae (Great Apes)

• Three Genera:

  1. Gorilla (gorillas)

  2. Homo (humans)

  3. Pan (chimpanzees and bonobos)

• Two subfamilies:

  • Ponginae: Contains the genus Pongo (orangutans).

Genus: Pongo (Orangutan)

• Limited to Borneo and Sumatra.

• Characteristics:

  • Three species, largest arboreal animal, primarily frugivorous, and relatively solitary.

  • Notable for intense male-male competition for mating.

Genus: Gorilla (Gorilla)

• Two species: Western (Gorilla gorilla) and Eastern (Gorilla berengei).

• Characteristics:

  • Largest ape, lives in one-male/multifemale groups, diet includes mixed vegetation with fruits when available.

Genus: Pan

• Divided into two species:

  1. Pan paniscus (Bonobo)

     • Known for strong female social bonding, Congo region.

  2. Pan troglodytes (Common chimpanzee)

     • Equatorial Africa, strong male social bonding, different conflict resolution methods between species.

Genus: Homo (Humans)

• Single living species: Homo sapiens

• Characteristics:

  • Global distribution, diverse social and mating structures, primarily omnivorous diet, complex verbal communication, bipedalism, and advanced tool use.

Primate Ecology

• Examines how primates interact with their environments.

Primate Diets

• Nutritional needs are essential for survival, influenced by several factors:

  • Basal metabolic rate.

  • Active metabolism.

  • Growth rate.

  • Reproductive effort.

Primate Diet Requirements

1. Nutritional Needs:

   • Carbohydrates, amino acids (proteins), fats and oils, vitamins, minerals, and water.

2. Toxin Avoidance:

   • Awareness of bitter-tasting insects and leaves.

What Do Primates Eat?

• Diverse sources include:

  • Insects, animal prey, leaves, fruit, gum, seeds, and fats.

Primate Diets: Ways to Obtain Nutrients

• Examines strategies for nutrient acquisition.

Insectivores

• Characteristics:

  • Small body size, sharp cusps on teeth, high crest on molars, and simple digestive systems.

Folivores

• Characteristics:

  • Larger body size, small incisors, sharp shearing crests on molars, and complex digestive systems.

Frugivores

• Characteristics:

  • Medium body size, large broad incisors, low-cusped molars, and relatively large digestive systems.

Gummivores

• Characteristics:

  • Relatively small size, long robust incisors, potential presence of claws (in callitrichids), and unspecialized digestive systems.

Diet and Home Ranges

• Home Range: Geographical area utilized by primates for activities, not defended.

  • Connects movements with resource distribution necessary for survival.

Territories and Territoriality

• Territory: Actively defended area for breeding young, marked with displays, calls, and scents.

  • Typically smaller than home ranges, with territoriality varying among species.

Primate Territoriality

• Influenced by mates and resource availability.

• Balances costs (risks in defense) and benefits (control of limited resources).

Avoiding Predation

• Primates face predation pressures, adapting through:

  • Arboreal evolution or increased body/group size.

• Outcomes vary by geographic location and predator presence.

Defenses Against Predation

• Strategies include:

  • Fleeing, vocalization with specific calls, forming associations, increased group size for detection and deterrence, mobbing behavior, and dilution of risk.

Primate Sociality: Benefits and Costs

• Benefits:

  • Predator avoidance and resource defense.

• Costs:

  • Competition for food/mates and disease transmission.

Internal Competition

• Results in dominance hierarchies and resource access disparities.

Types of Social Groups

• Variations in social structure among primate species.

Primate Conservation

• Endangerment is due to:

  • Habitat loss, poaching, subsistence hunting, bushmeat trade, pet trade, and disease.