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.